Proceedings: Sixth Annual Workshop on Meteorological and Environmental Inputs to Aviation Systems

landing. However, the Vertical Speed (VSI) i s 2000 r part of the primary flying instruments and a good location i f the W B I cannot be modified, T h i s i s ft/min where the Smiths Industries and SFENA displays are located.

The Smith Industries VS/ERI i s shown i n a nominal thunderstorm microburst (downdraught) situation

2000 L

i n Figure 10, I t has been tested on piloted sim- ulators ( R E F 15) and flown i n a BA T r i s t a r , a Britannia Airways B-737, the RAE BAE 1-11, which has advanced electronic displays, and on the RAE HS-125. In a l l simulated wind shear cases, the pilots found t h a t the VS/ERI gave t h e i r f i r s t indication of wind shear and this i s supported by a few encounters with moderate shears i n the f l i g h t t r i a l s . However, there i s some criticism of using the VSI for the display because many pilots do not usually include i t i n t h e i r pri- mary scan.

220 t-

VS/ERI INDICATIONS I N THUNDERSTORM W I N D SHEAR I I 35 40 45 50 55 Figure 11.

'JAWS' Microburst Response o f Smiths Industries' 2 Pointer VS/ERI H E A D W I N D VERTICAL SPEED t h r o t t l e had been used in response t o the s p l i t ENERGY RATE between the needles, then a decrease i n thrust 1000 FPM would not be demanded until the speed was about DOWNDRAUGHT INCREASING 15 k t above datum (Datum = 025 k t ) b u t an in- TAILWIND crease i s called f o r while s t i l l 3 k t ABOVE Figure 10.

Expected Response of the Smiths datum. This fortunate response i s largely due Industries' 2 Pointer VS/ERI in to the steeper gradient of velocity (dV/dt) near a Thunderstorm Microburst the centre of the microburst, where V is also greatest. Thus giving a much f a s t e r response in the midst of the microburst, A time history of the response of the Smiths 2.3.2 Groundspeed/Airspeed Displays Instrument i n the microburst of Figure 8 is This shows the Energy Rate shown i n Figure 11.

The principle of t h i s system i s t h a t the hazard needle responding directly t o the r a t e of change from w i n d shear i s reduced by maintaining the of airspeed. The VSI needle does n o t respond h i g h e s t airspeed compatible with a safe touch- t o the downdraught i n this case because the down groundspeed. This principle i s generally p i l o t increased pitch angle to compensate. All confirmed by the RAE studies of hazard levels.

these types of instruments have a lag in response Thus, instead of flying approaches on airspeed t o wind shear as they must calculate the r a t e of relative t o a target threshold speed, they can change of speed. In the Smiths VS/ERI, t h i s be flown to keep the lower of e i t h e r airspeed lag to shear i s about 1.6 sec. Note that: (1) or equivalent groundspeed above the target is only about 0.6 sec because the ac- The lag speed. In the more usual case w i t h a head wind cel erometer terms provide compensation f o r rates a t touchdown, this will lead t o higher than of change of velocity r e l a t i v e t o the earth, b u t usual airspeeds on the approach.

n o t for shears, which a f f e c t airspeed with l i t t l e e f f e c t on ground speed; (2) The lag is made by the increase in pitot- greater i n Figure 11 In the case of a microburst (Figure 81, the use s t a t i c system lag w i t h a l t i t u d e , as Denver is of this groundspeed/airspeed method would i n h i h i t over 5000 f e e t above sea level and hot. No the normal reaction to reduce thrust as airspeed scale i s shown on the difference between the two increases because the groundspeed hardly changes needles as the t e s t s in Figure 11 were flown a t and will be the lower speed, Thus, a higher is maintained to help cope w i t h the airspeed downdraught I t is interesting t o note t h a t the difference between the two needles i n the microburst i s If must greater when the speed loss occurs.

shown i n Figure 12. The weak return signal i s The main complications with this system a r i s e rapidly converted t o a Doppler Spectrum and suc- when high head winds p u s h the approach airspeed cessive spectra integrated to give very clearly u p to f l a p limiting speeds. If f l a p angle i s For low a l t i t u d e wind shear defined spectra.

reduced, then the speed safety margin f a l l s .

detection, a few hundred integrations are usually In most cases, it would seem best from a per- adequate and an output data r a t e of more than 100 formance point of view t o keep airspeed below samples a second can be obtained.

the flap, limiting speed even i f it means t h a t the groundspeed f a l l s below the target speed.

However, this could be a poor philosophy t o adopt i f the instrument is to have a clearly defined role as an indicator of m i n i m u m speeds.

The head wind variation i n the microburst (Figure 8) is a d i r e c t indication of the dif- ference that would be seen between the two needles of a 2-pointer ASI, Positive head w i n d would place the groundspeed lower than the airspeed pointer The information on any AS1 can be improved by u s i n g a laser system, such as the LATAS which looks ahead of the a i r c r a f t , as the airspeed source, b ) Illumination intensity

-

The airspeed/groundspeed display does n o t give Laser Beam any information on downdraughts , which will appear as a transient decrease in normal accel- eration and a subsequent increase i n descent rate, b u t i t has the advantage of being located a ) Beam geometry on the airspeed indicator which i s continuously monitored d u r i n g both take-off and landing.

Figure 12. Principles o f a CW Focussed Laser Anemometer 2.3.3 Laser Airspeed Systems Laser systems measure airspeed by Doppler an- One useful feature of C W laser signals i s infor- alysis of reflections from minute particles mation on the spread of airspeeds over a larger (aerosols) in the atmosphere, These particles range which is given by the minimum and maximum have an extremely rapid response t o airspeed W i t h t h i s data, i t i s possible t o velocities.

changes and can thus be used as a d i r e c t mea- distinguish real shear from turbulence. Figure sure of airspeed in a region remote from the 13 shows the RAE/RSRE LATAS airborne l a s e r sys- laser equipment, Two main types of laser are tem signals recorded i n the microburst of Figure avai lab1 e: 8, and the width of the peak of the velocity spectra clearly identifies the real shears. The Pulsed systems which use time gating t o a.

difference between the laser and the a i r c r a f t establish the range and short pulse true airspeed i s a d i r e c t measure of the shear duration (typically 1-2 microseconds) t o gradient over 250 m (about 4 seconds of f l i g h t obtain range resolution. These systems These shear time a t normal approach speeds).

can operate t o quite long range and the gradients have values of around 4 kt/sec ( 2 m/s/s) s i z e of the optical aperture r e l a t e s t o a t approach.

the amount of backscattered signal re- ceived. Range resolution is constant The RAE i n close collaboration with the Royal a t about 300 m.

Signals and Radar Establishment ( R S R E ) , who have been responsible f o r the development of the b. Conti nuom Wave (CW) focused systems where optics and signal processing equipment, have the beam i s focused t o a waist a t remote tested both ground based and airborne CW laser point to give a maximum level of illumina- systems. Both systems use eye-safe carbon tion and t h u s the greatest signal returns dioxide lasers from that point. The sharpness of t h i s focusing i s greatest a t short range and The main aims of the research programne have been w i t h a larger optical aperture. Range t o establish the character of l a s e r wind signals resolution can be very fine, b u t increases features required i n production and the essential rapidly a t long ranges, and optical aper- versions f o r regular use a t airports or i n a i r - ture i s determined by the resolution and craft.

maximum range required, 2.3.3.1 Ground Based System The choice between the two systems depends on whether 300 m range resolution is adequate, and the maximum range required. Research i n the UK A ground based system (Figure 14) was tested a t RAE, Bedford, and the results compared well w i t h has concentrated mainly on the CW focused sys- more conventional anemometer data Power Spectra tems. The general principles of the system are 3r7d Discrete G u s t Analysis of these data con- firmed that the laser system was a r e l i a b l e source o f w i n d information. The system used 30 c m dia- meter reflecting telescopes, was monostatic and had an output power of 5 watts. I t was used s a t i s f a c t o r i l y out t o ranges of about 1 km.

Figure 14.

Ground Based Laser Airspeed System a. The theoretical data is only supported by experimental results from bi-static systems 2601 with the beam only a few f e e t above an LATAS arid surface, and

AIRSPEED__ I

b. Other limitations on laser effectiveness have proved l e s s of a constraint than theoretical estimates woul d suggest.

However, until t e s t s can be made t o see whether such a l i m i t on effective aperture e x i s t s , i t will be d i f f i c u l t t o persuade commercial com- AIRSPEED panies t o invest in the development of an a i r - port system based on CI4 lasers. Pulsed lasers do n o t rely on focusing for range definition CAS and may be more suitable f o r a ground based system.

However, as yet there has not been a detailed evaluation of a pulsed system against 35 40 45 50 55 other wind measuring systems.

Time, sec, 2.3.3.2 Airborne System Figure 13. 'JAWS' Microburst Response o f RAE/RSRE 'LATAS' System An airborne system (LATAS), Figure 15, ( R E F 16), has been flying i n the RAE HS-125 f o r about two years and is proving very successful and reiiable Any ground based system f o r airport use would for measuring airspeeds a t remote points u p to need t o make w i n d measurements from about 0,5 km about 300 m ahead of the a i r c r a f t . A s Figure 13

to 6 - 10 km and preferably w i t h a f u l l 360 deg

shows, t h i s gives extra v i t a l seconds of warning azimuth scan. The measurements could then be o f wind shear. The system uses C W optics made used to give a i r t r a f f i c continuous wind infor- RSRE and a 3-watt waveguide carbon dioxide by mation f o r a l l landing and take-off points, and laser manufactured by Ferranti. Based on e a r l i e r also identify any wind shear development, Mea- experience, the c r i t i c a l areas f o r r e l i a b i l i t y suring both i t s magnitude and i t s track r e l a t i v e were expected t o be the laser, the optical t r a i n to landing and take-off paths.

and the germanium window used t o transmit the The main problem with operating a t such long infrared beam. In the event the lasers have ranges with a C W system i s the large s i z e of the been operating f o r periods of u p t o s i x months is about 1-2 m without any attention, the optics have not re- optical aperture required which diameter. T h i s could be expensive, although quired any adjustment a t a l l , except a f t e r laser changes, and the front surface of the germanium f u l l visible wavelength accuracy is not required, window, w i t h i t s special protective coating i s and, i n theory, there may be a l i m i t t o the ef- fective aperture size, despite the geometric unmarked a f t e r 2 years of f l i g h t t r i a l s , which i n s o f t hail. Figure 16 shows size, because of the e f f e c t s of small scale included f l i g h t There is not appropriate experimental the s t a t e of the surrounding paint, which was turbulence.

data t o confirm this limit on effective aperture, pitted down to the metal, a f t e r flying i n heavy rain and s o f t hail. The window surface i s un- b u t , i f the present estimates are correct, i t harmed. Reliability of this level from proto- may not be possible t o use apertures greater than about 1 m diameter. The author views this type experimental equipment argues very well for a re1 iable commercial development, theoretical l i m i t with some scepticism as: research programme i n the UK i s addressing pos- s i b l e features t h a t could produce savings i n operating costs. Such as: a , an e f f i c i e n t autothrottle sensor which is responsive t o significant shear w i t h negli- gible lag and y e t able t o ignore short period turbulence; b. a control system f o r tyre spin-up t h a t accurately measures both ground and tyre speed; a sensor for active ride smoothing and/or c.

g u s t load alleviation control systems which provides adequate lead.

For t h i s l a s t application the system has t o function a t a1 1 heights , and great advances have been made i n obtaining r e l i a b l e signals in very l o w backscattering conditions a t h i g h altitude. Figure 17 shows an example of the signal to noise r a t i o measured i n a climb to 43000 f t pressure altitude. To give some relationship between this data and v i s i b i l i t y , i t should be noted t h a t the quite high signal to noise r a t i o a t l o w a l t i t u d e corresponded t o Figure 15. Airborne Airspeed Laser System (LATAS) a v i s i b i l i t y of about 70 nm. The system is not yet able to obtain a usable signal i n a l l conditions a t h i g h a1 ti tudes, a1 though there The only real obstacle to commercial development are no problems near the ground.

i s finding a suitable incentive f o r a i r l i n e s t o purchase such a system.

This requires e i t h e r t h a t the u n i t earns i t s keep by saving a i r c r a f t XI o4 operating costs, or that airworthiness require- 4,507 ments call for such a system t o be f i t t e d , The 4 . , 00- Signal/Noi se (Power) 3.50-

.oo 1 ,OO 2.00

LOS S/N (PWR) , I -70 -60 -50 -40 -30 -20 -10 0 10 ST. TEMP ( D E G CENT) Figure 17.

Example of Variations in Backscatter and Air Temperature W i t h Height (RAE/RSRE LATAS) The system also has uses f o r special test pur- poses. The data of Figure 17 can be converted directly into backscatter coefficient, and these Figure 16. Effect of Hail on Germanium Window data are needed to a s s i s t i n the design and evaluation of proposed earth s a t e l l i t e laser d systems for global wind measurements. Another so f a s t t h a t the i n i t i a l pressure resonances following the bursting of the balloon a r e clearly application is for accurate determination of identified. A n example of one of the vortex s t a t i c pressure errors on airc:-aft. The true The defin- measurements is shown i n Figure 19.

s t a t i c pressure can be calculated by measuring i t i o n of the vortex structure w i t h data a t every total pressure, which is usually unaffected by 5 c m is quite remarkable.

the a i r c r a f t flowfield, and t o t a l temperature, as well as the true airspeed ahead of the a i r - Assessment of hazard levels needs three main c r a f t . T h i s can be compared w i t h the pressure i n p u t s : measured by the a i r c r a f t s t a t i c pressure system, The laser system could be mounted i n place of a. Information on Vortex structure; the a i r c r a f t a radar f o r these t e s t s and frees t o obtain pressure e r r o r data under any f l i g h t b. A means of relating this structure t o the conditions w i t h o u t ground based ranges, t r a i l i n g roll control capability of the encountering cones or calibration a i r c r a f t .

a i r c r a f t ; next stage of wind shear research w i t h the The C. Criteria f o r acceptable r o l l disturbance, L A T A S system is to develop and t e s t various laws and simple displays using a 2-pointer AS1 and/or 3,l Vortex Structure a Fast/Slow indicator on the ADI. These will be flown on the HS-125 and also assessed on When trying t o estimate the probable vortex larger a i r c r a f t i n the RAE, Bedford, piloted induced velocities f o r advice t o the accident f l i g h t simulator.

So f a r the LATAS signals have investigators on the two military a i r c r a f t been displayed only t o the p i l o t on rudimentary accidents, the author found two main d i f f i c u l t i e s .

meters mounted on the cockpit coaming.

F i r s t the two most generally used relationsihps between tangential velocity, vorticity and radius

3.0 VORTEX WAKES

were not very suitable and secondly there were d i f f i c u l t i e s in establishing the probable core Vortex wakes are another invisible hazard 3 a i r - radius, i.e., the radius t o the peak tangential c r a f t , mainly d u r i n g take-off and landing, al- velocity.

t h o u g h some encounters in cruise have also been found (REF 4).

T h e two most commonly used equations for vortex structure have been The RAE has been actively involved i n research i n t h i s f i e l d (REF 3,4,5 & 6 ) , although no new

-1.256 (r/R)2 }

experimental work has been dcce since 1977. That i s , until recently, when two military accidents, one t o a fighter and the other t o a j e t t r a i n e r , which was developed by Squires (REF 17 & 181, and highlighted the need f o r methods of assessing hazard levels f o r a wider range of a i r c r a f t than the civil transport group. To support these

C = & { 1 + I n (r/R)

studies, some further vortex wake measurements were made i n f l i g h t using an RAE designed very from Kuhn and Nielson ( R E F 19), f a s t response airflow sensor on the HS125. The sensor i s a f i v e hole conical yawmeter w i t h where V = tangential velocity surface mounted transducers and has a response time lag of about 1 millisecond. The response K = vorticity when enclosed i n a balloon, which was then burst, i s shown i n Figure 18. The response i s R = core radius r = radius Vc = maximum V (+.e.,, a t core radius) These two models are compared i n Figure 20 a t u n i t peak velocity. W h e n compared w i t h measured Pressure sensing head mounted vortices, the Squires model contains more of

Pressure 1

\ inside a balloon which was

the total v o r t i c i t y inside the core and this punctured, results i n a more rapid f a l l i n velocity out- side the core. However, the model does r e l a t e velocities t o the total vorticity. The Kuhn and Nielson model is quite a good f i t to experi- mental data around the core diameter and outside i t , b u t unfortunately i t i s not related t o total vorticity. Indeed a t large distances from the core the vorticity tends t o infinity.

0 10 20 30 T h i s is not problem when f i t t i n g experimental Time , m i 11 i sec.

data, b u t i t does make it very d i f f i c u l t t o use when estimating Vortices from an i n i t i a l Response of the RAE 5-Hole Airflow Figure 18.

Sensor To A Balloon Burst After this point, the experimental evidence ( R E F 22) suggests t h a t the radius remains con- Distance = 5cm / DATAPNT s t a n t and the v o r t i c i t y reduces 1inearly w i t h time. (Actually, the vorticity i s redistributed w 20 m I- h L L -20 v m 8 I-

-

5 6 v E 4 w n * 2

n

0 1 2 3 4 5 6 7 8 9 1 0 900 950 1000 1050 1100 Flight Measurement of Vortex Velocity RADIUS (UNITS) Figure 19.

Using the RAE Fast Response Air Data Figure 20.

Comparison of Vortex Models Sensor from the main vortices into small eddies.)

REF knowledge of total vorticity. The author has 22 indicates that the changeover occurs when therefore developed a model (Figure 20) which ( d L i f t Coefficient/(b Aspect Ratio)) is 9.6.

matches the experimental data as well as the I t may be coincidental that w i t h the author's Kuhn and Nielson model and i s related t o t o t a l vortex formulae, this occurs when the t o t a l v o r t i c i t y , viz induced velocity a t the point midway between the pair of vortices is equal t o the tangential

V = 20 { tan-' 1.392 (r/R))

velocity a t the core radius.

The separation r3 (r/R) between the vortex centres is then about 9 vortex r a d i i , Figure 21 shows t h e form of the three vortex models f o r t w i n vortices a t t h i s separa- Having defined a suitable formula, i t i s then tion.

necessary t o derive values of total vorticity, K, and core radius, R , so t h a t a velocity dis- For typical c i v i l transport a i r c r a f t on the tribution can be defined, Various methods a r e approach, the changeover occurs a t about 2-3 nm.

discussed i n R E F 20. Except i n r a r e cases, i t Thus, normal separation requirements (REF 23) , i s not worthwhile u s i n g the more sophisticated which are 3 nm or more, a l l r e l a t e to the region methods, and the author of t h i s paper normally where the vorticity i s decaying.

uses 3.2 Vortex Strength Vortex strength i s a relative feature i n the context of a i r c r a f t operations and i s defined where P = r a t i o of centreline l i f t per u n i t here as the r a t i o of vortex induced rolling span moment to the maximum r o l l control moment of the encountering a i r c r a f t .

Studies a t the RAE L = total l i f t p = a i r density

VORTEX STRENGTH = e ( K / D ) f { $ , Taper }

b = w i n g span PMAX- e V t = a i r c r a f t true airspeed where D = vortex diameter( = 2R) pMAX = maximum r o l l r a t e suffices P i s chosen as 4 / r (= 1.27) f o r cruise configu- rations ( e l l i p t i c l i f t d i s t r i b u t i o n ) , or 2 f o r landing configurations {triangular l i f t dis- g = generating a i r c r a f t tribution), e = encountering a i r c r a f t Estimation of radius i s l e s s well-defined a s the growth depends strongly on the level of turbu- The s i z e and shape function for the usual case lence i n and close t o the vortex. However, the of t w i n vortices (Figure 21) is found, Figure 23, worst case is the slowest growth and experimental t o be only weakly dependent on b /D f o r a i r c r a f t evidence ( R E F 21) suggests t h a t Owen's formula, of the same span as the generatitg a i r c r a f t which i s incorporated in Squires Vortex Formula (b/2R = 9) down to about 20% of t h a t span and predicts growth proportional t o the square (b/2R = 1.8) , and f o r most normal values of taper root of vortex age, i s reasonable u p t o the point r a t i o between 0.3 and l o o .

where the two main vortices s t a r t t o interact, xlo-2 T h u s 2.00 VORTEX STRENGTH a ( K / D ) g / ( pMAXb), Tkis can be evaluated using the vortex equations discussed in the previous section and the ap- proximate relationship f o r transport a i r c r a f t 1.60 (Figure 23) t h a t

1.40 c 1

he (metres) = { MTOW

or .- -1 0 . I t t i oecornez

MTOW - maximum takeoff weight

where 1 /3

W - weight

2/3 A = aspect r a t i o ' 1 CL = l i f t coefficient ;::I , , , , d = separation between a i r c r a f t (I 00 I f a general rule f o r categorizing a i r c r a f t i s 0 2 4 6 8 1 0 1 2 required, then p CL and pMAX a r e approximately SPAN/VTX ( V / 2 R ) the same f o r most transport a i r c r a f t , and many long-range a i r c r a f t tend t o have both a higher Figure 22, Vortex Strength: Size and Shape r a t i o of maximum take-off weight (MTOW) t o Function, f , a t 9 R Separation maximum landing weight ( M L W ) and higher aspect r a t i o , A. T h u s , the simplest relationship i s grouping for a i r c r a f t below about 7000 kg would VORTEX STRENGTH 0 ( M T O W ) ~ ' / ~ J ( M T o w ) ~ ~ / ~ be useful especially f o r separation from the Heavy group. Also i t looks as t h o u g h the top of the Heavy group may be somewhere around the xlo-l present maximum of about 380000 kg. The I C A O recommendations do n o t f i t the weight relation- ship so well. In particular there a r e insuffi- cient groups and the separation between the h Heavy and Light groups would seem to be too low, CT 2 "20 v -.20 w > K & N vorticity 1 - Transports -.60 2. Fighters CT W 3. Jet Trainers - 50 > -1 .oo 4 - Exec.

v) W 5, Commuter W L * -1.40C 6, L t , Prop.

W I I I , I I I E -20 -16 -12 -8 -4 0 4 8 12 16 = 2 0 - n DISTANCE (RADII) S x l u 1 0 - Figure 21. Twin U n i t Vortices (K=R=l) a t m 9~ Separation, S

b = M T 0 I . J '

.r X Pi tt Special 5 - The range of (MTOW)g/(MTOW)e are plotted against recommended separation distances in Figure 24 I t I A (a) f o r CAA and Figure 24 ( b ) f o r ICAO, The CAA recommendations a r e generally grouped i n a way which agrees w i t h the above weight relation- ship, Although i t would seem t h a t a weight d 3.4 Discussion 3.3 Vortex Strength Criteria The practical experience t h a t led t o the CAA The data of Figure 24 also gives indications of recommendations f o r separation distances r e l a t e a possible relationship between Vortex S t r e n g t h The CAA recommendations well t o the theoretical estimates and show t h a t and Separation Distance, the RAE estimation methods form a rational basis are based on practical experience of vortex wake for assessing suscepti bi 1 i t y t o vortex induced encounters reported a t London (Heathrow) over many years. REF 24 indicates the general philo- r o l l . In general , i t seems appropriate t o cate- MTOW as a t present, and then cpphy, which i s t o reduce severe incidents t o gorize a i r c r a f t by use more detailed calculations t o identify the about 15 in 100,000 landings, which is expected t o be equivalent to an accident r a t e of about 1 few exceptions t o the general groupings. An i n 107 landings. obvious example is Concorde, whose low aspect r a t i o would place i t i n a lower category than I t i s possible to work back from the relation- i t s weight would suggest. T h i s i s supported ship between separation distance and the weight by the results of e a r l i e r t e s t s by the RAE (REF factor t o find the approximate value o f Vortex 3 ) , which showed t h a t the Coticorde wake d i d i n - Strength (i*e,,, r a t i o o f induced rolling moment deed decay much more raFidly than other trans- t o r o l l control power) t h a t the relationship p o r t a i r c r a f t .

implies. This i s found to be about 0.7 f o r the CAA ( o r about 1.0 f o r I C A O ) recommendations. Another conclusion from the theoretical equations The CAA c r i t e r i a f o r a severe event i s more than i s t h a t military f i g h t e r and j e t t r a i n e r a i r - 30” of bank; thus, the equivalent f o r I C A O would c r a f t are no less susceptible t o vortex wakes be more t h a n 45” o f bank. than transport a i r c r a f t of the same weight. This CATEGORY W E I G H T (Kg.)

CATEGORY W E I G H T (Kg,) 380 ,OOO* 380 ,OOO* HEAVY HEAVY 1 36,000

--

M E D I U M 136,000 40,000

--

M E D I U M

----------

S M A L L 7,000 17,000 LIGHT LIGHT 3 , ooo** 3,000** *approx. current maximum *approx. current maximum **nominal minimum **nominal minimum MTOWg/MTOWe (tonnes) MTOW /MTOWe (tonnes) 380/3 380/3 40 - 9

-

I 380/3

380/7 380/7

-

0 / 0 /

~ i/ I , 10 2 4 6 8 0 2 4 6 8 10 Separation, n o m .

Separation, nom, Figure 24 (a). U K C A A . Separation Recommendations Figure 24 ( b ) , I C A O Separation Recommendations (AIC 81/1981) (10 Aug. 1978) has surprised most military p i l o t s who f e l t t h a t tions will also be used as a guide t o levels of their extra manoeuverahility in r o l l would give acceptability, as i t would be undesirable t o them more protection. However, although the create any turbulence worse than the level a t maximum roll rates on the approach a r e about Heathrow e twice as high a s transport a i r c r a f t , the span of the military a i r c r a f t is about half.

T h u s , The data from these experiments will be available the c r i t i c a l term ( b pMAX) i s about the same.

i n 1983 and it should then be possible t o es- tablish test methods and c r i t e r i a f o r assessing proposals f o r large b u i l d i n g s a t , o r near,

4.0 BUILDING WAKES

airports, Building wakes are related to both wind shear and vortex wakes. The increasing pressure to

5.0 CONCLUDING REMARKS

build on airport land t o provide maintenance f a c i l i t i e s f o r large a i r c r a f t and new terminals T h i s review of research i n the U K on two of the has produced situations such as the large a i r - more significant invisible enemies of a i r c r a f t , l i n e engineering base alongside the f i n a l kilo- particularly during landing or take-off, has metre of the approach t o runway 28R a t London described the main features of the wind shear (Heathrow) Pilots landing on t h i s runway programme; the results from a recent vortex a r e warned 'Turbulence likely below 300 wake study, and the status of a study of airport bu i 1 d i n g wakes.

f t near threshold 28R i n strong S/SW w i n d s ' .

This applies generally i n winds of more than The wind shear programme is aimed a t providing 15 k t .

relevant advice on a i r c r a f t c e r t i f i c a t i o n i m - plications, and developing suitable systems t o The RAE are asked t o advise the CAA on the acceptabi 1i ty of proposed new 1arge buildings provide information to p i l o t s t o make it possible a t many UK airports, b u t have been unable t o f o r them t o penetrate wind shear w i t h safety.

give any positive guidance so f a r . There are The three main elements of the programme are: basically two problems : Worldwide measurements of wind shear from a.

a. a need f o r theoretical or model t e s t regular a i r l i n e f l i g h t s and special t r i a l s methods t o assess the character of the with the RAE HS-125 research a i r c r a f t ; building turbulence, and b. Assessment of potential hazard t o a i r c r a f t b. relating turbulence characteristics t o from wind shear; a i r c r a f t disturbances.

C. Development of systems t o give the o i l o t information on wind shear.

The second area i s being addressed by the work to establish hazard levels for w i n d shear.

These are expected t o reach a point d u r i n g 1983 when fundamental research will be sufficiently The f i r s t i s the subject of j o i n t research a c t i - complete t o provide the basis for c e r t i f i c a t i o n v i t i e s by Bristol University Aeronautical Engi- and design of automatic control systems, such as neering Department and the RAE. The f i r s t stage autopilot, autothrottle, and autoland, and also of the work showed t h a t building wake turbulence f o r the development and production of wind shear i n simulated natural turbulence can best be detection and display systems. A t t h i s point, described as discrete eddies shed i n a random most of the RAE research e f f o r t will be trans- fashion. The s i z e and probability of encoun- ferred to other basic research tasks. The tering eddies being a function of the building, Establishment will continue t o provide i t s wind strength and natural turbulence. As the usual consultancy service t o the CAA and U K wind velocities a r e varying i n space in a form I ndus t r y that i s related t o the building geometry, i t means that the frequently used Taylor's hypo- The study of vortex wakes following the acci- thesis cannot be applied. This hypothesis says dents to a military fighter and a j e t trainer that the distribution of velocities i s the same a i r c r a f t has led t o the development by the RAE i f the observer i s stationary and the wind of a rational method f o r assessing the potential brings the turbulence past h i m o r i f the observer hazard f o r a given encounter, and also f o r cate- moves t h r o u g h the turbulence (in an a i r c r a f t ) .

No gorizing a i r c r a f t into convenient groups, further work i s planned, although the recent I t was, therefore, decided t h a t meaningful t e s t s study was unexpected. T h e study does highlight could only be made by traversing the wake of the the benefits of flexible research f a c i l i t i e s such building along a typical a i r c r a f t path and a t as the HS125, which can respond rapidly t o such the same order of speed. A s e r i e s of such unexpected needs.

traverses would then allow the d i s t r i b u t i o n of turbulence and the probability of encountering i s also reaching a The building wake programme large distrubances t o be determined. The main point where i t may be possible to establish experiment i s on a model of the Heathrow s i t e i n c r i t e r i a f o r acceptability, and corresponding the Bristol University B u i l d i n g Research Wind t e s t procedures f o r assessing new building Tunnel. This i s being compared w i t h a more proposals.

limited s e t of data obtained from f l i g h t s by the RAE HS125 a t Heathrow. The Heathrow condi- Camp, Dennis W. , Walter Frost, "Proceedings: F i f t h Annual Workshop on Meteorological and Environmental I n p u t s t o Aviation Sys- Pinsker, W , J. G . , "The Assessment of the tems", March 31 - April 2, 1981, UTSI, Potential Hazard of a Yind Shear Field N A S A CP-2192 , pp91-95.

Containing Horizontal and Vertical RAE TR 78073 (July 1978).

Draughts", McCarthy, J., E. F. Blick, and R. R.

Bensch, "Jet Transport Performance i n Bisgood, P. L . , J. lil. Britton, H. Y Thunderstorm Wind Shear Conditions", Ratcl i f f e , "Wind Shear Encounters During Visual Approaches a t N i g h t . A Piloted Simulator Study", RAE TR 79126 (Sept. 1979).

Bisgood, P. L., "A Brief Investigation i n F l i g h t of the Vortex Wake Generated by Concorde, w i t h some Recommendations on Separation", RAE TR 78025 (Feb. 1978).

Pinsker, W . J. G., "The Hazards of Vortex Wake Encounters in the Cruise", RAE TR 79063 (June 1979).

Bullock, C. , "Turbulence Detection by

Laser", Interavia 1/1981 , pp82-83.

Bisgood, P. L o , "Some Observations of i n Condensation Trails", RAE Technical Memo- Squire, H . B o , "The Growth of a Vortex randum FS 330 ( A p r i l 1980). ARC 16666 (1954).

Turbulent Flow", Pinsker, 1 . J . J. G., "Further Observation on Owen, P o R., "The Decay of a Turbulent the Vortex Wake Hazard i n Cruise Flight Vortex", ARC 25-818 (1955).

w i t h Particular Reference t o the Effects of Crow Instability", RAE TR 81069 (May Kuhn, G. D., J. W. Nielsen, "Analytica 1981).

Studies of Aircraft Trailing Vortices", A I A A Paper No. 72-42 (1972).

Woodfield, A. A . , J , F. Woods, "Wind Shear from Head Wind Measurements on Donaldson, C. Du. P., A. J. Bilanin,

British Airways B-747-236 Aircraft -

"Vortex Wakes of Conventional Aircraft" , I n i t i a l Results", RAE Technical Memorandum AGARD-AG-204 (1975).

FS 409 (June 1981).

"Aircraft Wake Vortices: A State-of-the- Haynes , Ann , "Description of a Program Art Review of the United States R & D Developed f o r the Analysis of !Jind Shears Program" , FAA-RD-77-23 (1977).

Experienced During Aircraft Approach to Landing", RAE Technical Memorandum F S 321 Hallock, J. N . , "Vortex Advisory System (1980).

Safety Analysis", Volume 1 : Analytical Mode-1 , FAA-RD-78-68 , 1 (1 978).

Jones, J. G., "The Application of Worst- Case Analysis to Aircraft Gust Response CAA Air Information Circular 81/1981- Assessment, A S t a t i s t i c a l Discrete Gust Theory Progress Note", RAE Technical Memorandum FS 309 (1980).

Piggott, B. A. M., J. A. Pask, "Wake Vor- tex Incidents Reported i n the U K " , 1972-76, Haverdings, H . , "Statistical Analysis of CAA Paper 77012 (1977).

Wind Shear Obtained form AIDS - Data

Measured During Approach (Interim Report)" , NLR TR 79095 (1979).

Haverdings, H. , "AIDS-Derived Wind Shear

S t a t i s t i c s f o r Approach and Landing. In- fluence of Ground Wind, Day/Night Effects NLR and Search f o r Worst-case Airports", TR 81066 (1981).

John McCarthy National Center f o r Atmospheric Research The Joint Airport Weather Studies (JAWS) Project is a j o i n t program t h a t i s funded primarily by the National Science Foundation, which is the parent organization of the National Center f o r Atmospheric Research ( N C A R ) . I t i s j o i n t be- tween the University of Chicago and NCAR; and there are three s c i e n t i s t s t h a t a r e the scien- t i f i c investigators: Ted Fujita, Jim Wilson and myself; the l a t t e r two are from NCAR and Ted Fujita is from the University of Chicago.

NASA, NOAA, and FAA have also contributed heavily t o the project, The major objectives of the J A W S Project a r e a fundamental description of the phenomenon, a determination of the hazard potential and a definition of a protection and warning system, a l l of which are r e l a t i v e t o low-level wind Figure 2 .

shear. The focus o f the e n t i r e project has been a l l aspects that w e could address of the low- taken from one of our research a i r c r a f t . I t level wind shear phenomenon. The principal should be obvious, from t h i s picture, t h a t w e the microburst. The focus, however, has been were able to f l y very closely around Stapleton microburst (Figure 1 ) i s fundamentally a rather Airport i n many contexts, I would l i k e t o em- simple atmospheric flow. I t is a downdraft t h a t , phasize that the support w e obtained from a i r upon approaching the surface, spreads out hori- t r a f f i c control to conduct t h i s experiment was zontally, producing what i s called a diverging phenomenally good- i n a l l directions, T h u s , f o r any radial flow direction t h a t an a i r c r a f t f l i e s through the microburst, i t will f i r s t encounter increasing head winds; then the remnants of the downdraft; and then, increasing t a i l wind (Figure 21, Figure 3, Many observational tools were used in the ex- periment, but the principal observational tool was the Doppler radar. Doppler radar i s a Figure 1.

conventional weather radar w i t h additional hardware that allows us to measure the velocity T h e microburst feature, no doubt, has been around component of the atmosphere i n a radial direc- a long time. I t was not identified, however, tion to the radar. I t is the key t o our obser- until the l a s t few years. Probably about 1977, vational system.

w e had our f i r s t evidence of the existence of the microburst; b u t , because it is so small and The blue dots on Figure 4 represent surface short-lived, i t has been a d i f f i c u l t feature t o measurement systems which measured wind speed address s c i e n t i f i c a l l y and technologically. The and direction, temperature, humidity, pressure focus of the J A W S Project has been t o address and r a i n f a l l . Doppler radars were located a t that feature.

each point of the t r i a n g l e shown i n the figure.

Basically, the e n t i r e area seen i n the figure The location of our experiment was chosen t o be represents our research area, and i t covers the Stapleton International Airport i n Denver, the northeastern quadrant of Denver.

Colorado. Figure 3 is a picture of the a i r p o r t i The program had three components. Basic studies a r e ostensibly the National Science Foundation's concentration in the program. What is the micro- i t s four-dimensional wind struc- burst? What i s ture; the spatial and temporary dimensions?

Where d i d i t come from and what a r e the condi- tions that set u p the existence o f a microburst type featuse? H o w long do they l a s t ? W h y do they die? What i s the relationship between -nall-scale and large-scale? These a r e very Jndamental questions t h a t the program addresses.

1 ) 'ERATORS Figure 4.

The National Center f o r Atmospheric Research The University of Chicago Figure 5 is simply a summary of what I will cover i n this presentation of the J A W S Project: b ) the microburst, a summary of data collection EDERAL GOVERNMENT highlights; some impressions on low-level wind National Science Foundation shear detection and warning, which is the major Federal Aviation Administration focus of our program; some analyses p r i o r i t i e s National Aeronautics and Space Administration and some recommendations and directions.

0 Marshall Space Flight Center 0 Langley Air Research Center The J A W S Project has just ended i t s f i e l d phase.

0 Dryden Flight Research Facility W e have l o t s of data t h a t have not y e t been National Oceanic and Atmospheric Administratio analyzed so t h a t I a m presenting impressions, 0 Prototype Regional Observing and not definitive results. Much analysis i s needed Forecasting Service (PROFS) t o make those results concrete.

0 Wave Propagation Laboratory 0 Office of Weather Research and Modification 0 National Weather Service 1. What i s the Joint Airport Weather Studies 0 Research Flight Facility Project Transportation Systems Center (Dept. of Transportation) 2. The Microburst Next Generation Radar (Depts. of Commerce , Defense, and Transportation) A Summary of Data Collection Highlights 3 .

c ) 4. Preliminary Impressions on Low-level Wind NIVERSITIES Shear University of Chicago Massachusetts I n s t i t u t e of Technology 5. Analysis P r i o r i t i e s 0 Department of Meteorology 0 Lincoln Laboratory 6 . Some Recommendations and Directions University of Wyoming University of Tennessee Space I n s t i t u t e Discussion 7 .

d ) OREIGFJ Figure 5. Summary of Presentation Royal Signals and Radar Establishment, United Kingdom Royal Aircraft Establishment , Figure 6 shows the organizations t h a t partici- United Kingdom this project. These were NCAR, the pated in University of Chicago, and the Federal Govern- ment agencies shown i n Figure 6b. The Univer- Organizations Participating in J A W S Figure 6.

s i t i e s which participated are shown i n Figure 6c. W e had a rather broad participation from A second major component of the program is a i r - the university community.

c r a f t performance, How do a i r c r a f t perform i n Figure 6d shows a very important and, frankly, ( A l o t of work went the face of wind shear?

a surprise addition t o our program. This was into this t o c l a r i f y our t h i n k i n g before we the Royal Signals and Radar Establishment and began the project.) Much of the interface Royal Aircraft Establishment from the United between the atmosphere and a i r c r a f t performance Kingdom. Most of the airborne w i n d shear was s e t u p in discussions a t the workshop on detection warning concepts were flown on the meteorological i n p u t s to aviation systems held a i r c r a f t supplied by this group.

annually a t the University of Tennessee Space Institute.

a addresses many applications of Doppler radar i n I t was our intention when w e s e t up the program, an area-wide mode and i t also addresses wind to have a very careful examination o f f l i g h t data recorder from operational a i r c a r r i e r a i r - shear explicitly. Finally, a t the a i r p o r t center, w e had a N A S A Doppler Lidar (Lidar is a c r a f t operating i n the J A W S environment. How- l a s e r system as opposed t o a pulse microwave ever, w e could not obtain the necessary funds, T h u s , w e did not study operational a i r c a r r i e r radar system), which measures the longitudinal components of the wind .

a i r c r a f t performance in the k i n d of quantitative detail t h a t w e wanted.

The Doppler radars i n the J A W S Project are A third area of study was made by the Department located a s shown i n Figure 4. Figure 7 shows of Transportation, Transportation Systems Center, our main radar control center w i t h the front on a i r t r a f f i c movements i n the weather condi- i n the background. The i n - range of Colorado tions t h a t w e faced in the J A W S Project. T h i s t e r i o r of our control center is shown in Figure work was done f o r FAA; i t examined how the a i r 8, Our entire operation was r u n from this cen- carrier, a i r t r a f f i c flow was affected by not t e r , I t was a tremendous center. Some of you only wind shear, b u t the thunderstorm environ- visited it. I t was a very impressive control ment. Some very excellent data were obtained.

center where the a i r c r a f t and the complete operations were directed.

An extremely important part of J A W S is the de- tection and warning aspects, W e have three surface sounding-type systems t h a t we examined (or are i n the process of examining). The out- p u t from the Low-Level Wind Shear Alert System (LLWSAS), which i s currently a t Stapleton, was recorded. I t was t h r o u g h arrangements with FAA t h a t w e were able t o record the data which, you know, i s not normally recorded. The spacing of the LLWSAS between the center f i e l d station and the outlying station on the average a t Stapleton i s about s i x kilometers, a rather im- p o r t a n t number to remember; roughly 3.6 miles between the center f i e l d and the outlying station W e had our own PAM (Portable Automated Mesonet) systems located where the blue dots are shown in Figure 4. Spacing between these wind recording stations was about three kilometers. Therefore, Figure 7.

w e had a system t h a t was about twice as dense as the LLWSAS a t the Denver airport.

j u m p array system Finally, w e had a pressure devel oped by the NOAA Wave Propagation Labora- tory, which essentially looks a t rapid surface pressure fluctuations as a means o f identifying wind shear, All airborne systems flown were on the Hawker- Siddeley 125 from England; w e had a really ex- cellent platform from England. The a i r speed and ground speed procedure developed by FAA was flown on t h i s a i r c r a f t , The a i r c r a f t had a forward-looking Doppler l i d a r t h a t looked o u t the nose of the a i r c r a f t and measured the longi- tudinal component of wind ahead of the airplane Finally, i t with about s i x seconds lead time.

had a S m i t h ' s Industry's vertical velocity Figure 8.

energy r a t e system, which is fundamentally an accelerator concept t h a t allows the p i l o t t o Figure 9 i s a picture of our f i v e centimeter understand t h a t he i s i n a wind shear situation, Doppler radar located a t Stapleton Airport w i t h another example of one of several thunderstorms A number of Doppler radars were used a t the and e l e c t r i c storms t h a t occurred i n the vicinity center f i e l d of Stapleton Airport looking i n of the airport.

The terminal building i s in the a l l directions. Most of the time they were immediate background.

looking up the approach and departure corridors , measuring the head wind/tail wind component t o In terms of l i d a r s , w e also had the N A S A l i d a r or from the airport. W e also had what I con- a t CP-4 and a NOAA l i d a r a t CP-3. As I men- NEXRAD stands f o r sider the N E X R A D concept, tioned, w e also had an airborne l i d a r on the the Next Generation Radar program, I t i s a HS-125. Figure 10 shows the HS-125 with a wind j o i n t program between NOAA, FAA and the Depart- probe on the nose. The l i d a r looks out ahead ment of Defense t o Dopplerize the national of the a i r c r a f t a t a l l times and gives you about weather radar system in t h i s country. NEXRAD a four-second lead of what the winds are going d tation, including heavy precipitation. There- fore, I t h i n k in the wind shear context, i t is really a very viable system. If i t i s foggy or cloudy, i t is not viable; so t h a t is a limitation, The l i d a r , l i k e the radar, will work i n clear a i r because, i n f a c t , the a i r i s not clear.

There i s dust and there a r e a l l k i n d s of s c a t t e r s out there, particularly a t the low levels. I f you get u p i n the h i g h a l t i t u d e , i t doesn't work because the a i r is clean. However, i n the a i r - port environment, there is no problem seeing the wind with a laser.

The HS-125 also had a Smiths Industry system, which i s basically an accelerometer system. If Figure 9, you get an upward acceleration difference, i t implies a head wind increase, and there is a transition until you get a sudden downward ac- t o be when you get there. The forward-looking celeration, which implies a t a i l w i n d . I t i s an l i d a r , basically, gives you a few seconds of inferred system; i t i s not dissimilar in concept advanced notice as you go through a rapidly i n - with the Safe Flight type system and I will make creasing head w i n d , downdraft and t a i l wind. W e some comments on a l l of these systems a l i t t l e think i t i s an interesting system when i t i s b i t l a t e r on.

coupled with the a i r speed and ground speed con- cept because i t allows us t o address wind shear I have already mentioned the surface observation w i t h a s l i g h t lead time. Lead time on approach systems which are portable and automated. NCAR would represent about two-thirds of the spool- has 27 such stations. A PAM system, located up time required i f you were t o encounter a near Stapleton, i s shown i n Figure 11.

sudden w i n d shear. Therefore, i t i s an exciting sy s tem.

I n i t s current configuration, the system does n o t work on takeoffs. There i s no question t h a t i t certainly will operate, b u t I think i t s use- fulness is obviously less on takeoff mode than on landing mode. I t h i n k that the airborne systems are basically designed f o r approach rather than departure, However, there has been quite a b i t of discussion about trying t o de- velop a forward-looking Lidar t h a t has scanning capabilities and considerably greater range.

I t i s a concept t h a t w e ought t o pursue. If you extend the range and give i t some scanning capabilities, then i t would be a viable system on takeoff as well.

Figure 11.

In terms of a i r c r a f t , w e had the research King Air from the University of Wyoming; the NCAR Sabreliner; and the NASA B-57, which carried o u t a gust gradient experiment during JAbIS. W e also had the NOAA P-3 a i r c r a f t primarily t o t e s t an airborne Doppler radar. The King Air a i r - i n Figure lZ0 W e had very h i g h c r a f t i s shown resolution a i r motion sensing on i t as well as some excellent cloud physics instrumentation t o study precipitation; precipitation rates i n the downdraft, which a r e important i n the heavy rain kinds of studies as well as i n the evolution of the downdraft i n precipitation. T h i s i s a very important part of the project, Figure 10.

During the project, w e had l o t s of heavy rain.

W e had a number of cases where the r e f l e c t i v i t y Lasers are, of course, subject to attenuation, values were i n excess of 70 DB. Of course, t h a t particularly i f they are C02 lasers and operate is probably hail contaminated i n terms of the in the visible range. I t does not penetrate r e f l e c t i v i t y . W e had many cases of s t r o n g w i n d into cloud; b u t i t has a rather excellent abil- shear in heavy rain. An important part of that i t y t o penetrate some distance into precipi- i study with the King Air a i r c r a f t is t h a t by sketch done i n about 1650 i n England of some- measuring the precipitation spectrum in great t h i n g t h a t closely resembles a microburst. Thus, d e t a i l , we will be able t o determine the nega- people have seen t h i n g s l i k e microbursts f o r a t i v e buoyancy associated w i t h precipitation loading i n the precipitation shaft and t o under- stand why the downdraft occurs and why i t i s so strong.

The N A S A 8-57 was i n the project t o study gust gradients. I t had a gust probe on each wing t i p , and a g u s t probe on the nose. The g u s t gradient program is designed t o study turbulence and wind shear, not only i n the longitudinal sense, a s the a i r c r a f t f l i e s , b u t also i n the latitudinal cross-spanwise sense. T h i s i s a very important basic study.

the surface.

A s f a r as any relationship between the amount of rain t h a t i s measured a t the surface and the intensity of w i n d , w e t h i n k there i s no corre- lation. The reason I say t h a t is because i f w e have low-level wind shear i n a microburst context, i t appeared t o be just as likely to occur in a l i t t l e o r no-rain situation, as i t d i d i n a very heavy rain situation., T h i s sug- gests that r e f l e c t i v i t y measured by ground-based radars, as well as airborne radars, has no correlation between storm intensity and wind shear. This, w e believe, is exactly r i g h t in the microburst context. The larger and more severe the thunderstorm, the more l i k e l y i t will be t o produce a g u s t front, which is a large- scale system. However, in terms of the micro- Figure 12.

b u r s t , ioi?., the small-scale wind shear event, us, in a preliminary sense, t h a t i t appears t o i t is uncorrelated; a very significant r e s u l t The NOAA P-3 had an airborne Doppler radar t h a t i n our opinion.

got some outstanding results in microbursts.

W e were able to look down, r i g h t down through Again, referring t o Figure 2 , why w e think a the center of a microburst on the 29th of June microburst i s such an insidious wind shear event . and collect data on the vertical velocity right is t h a t i t is a downdraft and radial outflow.

down t o the surface.

I t i s very small and rather symmetric; l i k e a j e t of water from a hose directed towards the Without getting too f a r into the technical de- surface of the ground, i t spreads out in a l l t a i l s , I would l i k e t o say t h a t one of the directions t h i n g s w e are trying t o do in the J A W S Project is t o take Doppler radar from three ground I f you f l y through a microburst with an airplane, Dopplers. Remember now, t h a t a single Doppler you get the same t h i n g every time, i n a concep- radar gives you only the radial component. So, tual sense. Y o u get a rapidly-increasing head i f w e want to reconstruct the three-dimensional wind, which suddenly changes t o a rapidly- wind f i e l d , we have t o look a t i t from three increasing t a i l wind. idhen- you cross through different directions. W e have rarely had the the center, you encounter the remnant of the k s t r a i g h t up through a micro- downdraft.

a r e so small and don't l a s t efore, w e have t o infer through The problem w i t h the microburst, as w e see i t , the equation of continuity what the vertical based on some of the a i r c r a f t velocity structure will be. That is a viable w e have done, is t h a t thing to do. However, what w e have w i t h the ng head wind when you P-3 airborne Doppler is a measure of d i r e c t T h i s is good news, resulting i n microburst.

vertical incidence a l l the way through a micro- i ncreased 1 i f t , b u t decreased airspeed . However, burst. N o w w e are able t o understand the shape the head wind suddenly changes rapidly t o a t a i l function of how the vertical d r a f t converts t o wind, killing the aerodynamic l i f t .

a horizontal d r a f t from d i r e c t measurement. I t i s very important, s c i e n t i f i c a l l y and technique- I believe t h a t approximately 80 percent of the wise, t o analyze this data set.

problem w i t h wind shear is loss of l i f t due t o the decaying wind speed horizontal component.

I want t o now spend a few minutes on describing The downdraft and what is l e f t of i t i s certainly the microburst. The microburst is a downdraft.

not helping the a i r c r a f t , I t is acting in the W e have known about downdrafts f o r a long time.

wrong direction, downward.

As a matter of f a c t , when I was i n Washington l a s t week, an employee of N S F told m e about a a Now, l e t m e contrast the microburst flow from front was the k i l l e r i n aircraPt accidents. W e that of a gust front. I think t h i s i s very did a l o t of work i n t h a t area. A l o t of work g u s t important. Figure 13 i s a picture of a was done a t NSSL, and g u s t fronts were considered front. A g u s t front is produced by a downdraft t o be really a very serious situation. However, and outflow, b u t the outflow has become very i t is our opinion i n the J A W S Project t h a t the large-scale. I t may be a front, o r like a cold g u s t f r o n t is a larger-scale feature t h a t pro- front that stretches out ahead of a thunderstorm bably i s not the k i l l e r i n the generic sense.

f o r many, many kilometers. Figure 16 i s a So, w e are actually now concentrating on a much picture of a cross-section through a g u s t front.

smaller scale, t h a t w e t h i n k is important. I'm A g u s t front flows outward from a thunderstorm n o t saying, of course, t h a t g u s t fronts a r e not into quiescent a i r ; thus, cold a i r flows over an aviation hazard; b u t there is an evolution the ground while warm moist a i r flows up into i n our t h i n k i n g . W e are beginning t o believe the thunderstorm. The flow i s fundamentally t h a t the aviation hazard is more associated w i t h a converging phenomenon; t h a t i s , cold a i r i s a small-scale event than a g u s t front. I'm not impacting warm a i r .

I f you f l y through a g u s t recommending flying through g u s t fronts. There front a t low levels, as i l l u s t r a t e d i n Figure are some hazardous features i n g u s t fronts. They 14, you may have a l i t t l e l i f t loss i n the warm a r e t u r b u l e n t . M e t h i n k there have been several a i r accelerating over the cold a i r ; b u t , as soon accidents associated w i t h the turbulence i n g u s t as you penetrate the g u s t front, you get a l i f t fronts.

increase because you a r e entering a rapidly- increasing head wind.

Figure 15 is a composite picture of a dry micro- burst situation over Stapleton Airport. Fre- quently, a 50-, 60-, 70-knot differential a t the surface can occur w i t h this k i n d of feature.

T h i s is an important picture because it shows what a dry microburst can look like. They don't look too serious w i t h the eyeball, b u t i t i s a visual clue. D o n ' t f l y through virga shafts, i o e o , something l i k e t h a t i l l u s t r a t e d i n the picture a t Denver, when you are on immediate --c MOTION OF STORM --c MOTION OF STORM approach o r takeoff. On one day, w e had an 80-knot differential on the north-south runway in Stapleton f o r this k i n d of situation (Figure + W A R M AIR INFLOW + W A R M AIR INFLOW 1 5 ) ; dry, r e f l e c t i v i t y values from radar about Level 2. You f l y through this situation and get a few drops of rain on the windshield; b u t Figure 2.1 Typical thunderstorm cross section (schematic) [22].

you get tremendous w i n d shears.

Figure 13.

Figure 15.

Figure 16 is a good picture o f what a dry micro- burst looks l i k e from the a i r . In this picture, Figure 14.

a microburst has h i t the ground and i s spreading out horizontally, creating a r i n g of d u s t . The Penetrating a g u s t front, in m y opinion, is an r i n g goes a l l the way around the back side, energy builder f o r the a i r c r a f t , b u t a micro- although the picture does not show i t t e r r i b l y That is, i n a diver- burst is an energy loser.

well. If you see such a d u s t r i n g when you are g i n g outflow (microburst), you tend to lose l i f t s i t t i n g on the runway or on approach, we recom- as you penetrate it; but a g u s t f r o n t , i n a mend t h a t you do not f l y through it. I t may be general sense, is probably an energy gainer.

a visual clue t o a very severe w i n d shear condi- i t , b u t a tion. W e don't have a picture of T h i s is significant because f i v e years ago, w e p i l o t reported seeing the trees blowing out t h o u g h t the g u s t f r o n t was the name of the game.

radially when looking down on approach t o W e t h o u g h t i n the research community t h a t a g u s t d r a f t which has reached the surface and has Stapleton. This indicates the wind was blowing spread o u t i n a l l directions horizontally, b u t out in a l l directions.

remember, w e can only see the component towards or away from the radar.

The green biological tones represent a i r moving towards the radar and the browns represent a i r moving away from the radar. Every color change in the color coding represents 5 knots o f increase or decrease i n w i n d speed. NOW, con- sider the evolution of the microburst as a function of time.

- f are a sequence of pictures of

Figures 18 a the same microburst as i t evolves i n time. The time of the f i r s t picture, Figure 18a, is 1641 local time, on the 14th of July. A t t h i s time, the low-level velocities are benign.

Each color change represents 5 knots, so there is 15 knots of velocity represented; no s i g n i f i - Figure 16.

cant microburst features. Figure 18 b is two minutes l a t e r . W e now have the beginning of what w e call a diverging outflow, as seen by The important p o i n t from t h i s discussion is t h a t Doppler radar w i t h a i r moving away and a i r there are certain visual clues t h a t are associ- moving towards the radar, as indicated by the ated with the microburst, W e are recommending changing colors. A microburst has h i t the t o FAA t h a t they produce a revised information ground and has begun t o spread out.

There are film to address the visual clues of microbursts, now five (5) different color changes shown on the simulator aspects of microbursts, and f i - i s 25 t h i s diverging outflow; five times f i v e nally, the radar aspects of microbursts. These knots...not a particularly serious situation a r e some of the t h i n g s w e t h i n k can help; and yet. Note the total dimension from maximum one of the f i r s t things w e can do w i t h J A W S w i n d to maximum t a i l wind is s l i g h t l y l e s s head results i s to p u t out a revised information than 2 kilometers, Three minutes l a t e r (Figure film t h a t gets to the core of the issue and helps r a i s e visual consciousness of the pheno- menon.

NOW, I would like t o show you what a microburst observed d u r i n g the J A W S Project this summer l o o k s l i k e on Doppler radar. Figure 11 i s a The photograph of the Doppler radar scope.

radar i s located to the r i g h t a t the point where the horizontal lines converge. The circular lines are spaced a t 10 kilometers. The l i n e f a r t h e s t to the r i g h t i s 20 kilometers from the 17 is a t zero degrees elevation, radar. Figure such t h a t w e a r e looking just above the surface about 28 kilometers away from the radar. The colors represent the magnitude of the Doppler velocities according t o the color code given a t the bottom of the figure. Only the component of velocity towards or away from the radar i s displayed; that i s a l l you can measure w i t h a Figure 18a.

T h e figure shows a down- single Doppler radar.

Figure 18b.

Figure 17.

18c) there are eight color changes, i.e.,, 40-knot differential across roughly the same 2 kilometers, the a very small feature. The time a t the top of figure is now 1646, Five minutes previously there was nothing i n terms of wind shear.

Figure 18e, Figure 1 8 ~ .

Figure 1 8 d i s a t time 1648; w e are now 7 minutes from when there was nothing and w e have reached the maximum velocity differential Eleven d i f - ferent color codes; 55-knot differential. The Figure 18f.

s i t y . When they h i t the ground, they accelerate a n d then die. They are very small and they d o n ' t l a s t very long., W e d i d n ' t know about microbursts a few years W e began t o surmise t h e i r existence a f t e r ago.

Eastern 66, Continental 426 and a number of other a i r c r a f t accidents; b u t w e didn't have a handle on the short-time scale, the intensity and the small spatial dimension.

Figure 18d.

If you look a t the microburst i n the vertical feature is about 2-1/2 kilometers from peak t o direction a t i t s time of maximum intensity peak. Figure l e e , photographed another 2 minutes (48 past the hour), i t fades f a s t above 900 l a t e r , shows the microburst i s f a l l i n g apart f e e t , A t approximately 500 meters above the rapidly; i t i s spread out; the distance between ground, or a t an outer marker h e i g h t , there i s peak velocities i s about 5 to 6 kilometers. no sign of the microburst on the radar. T h i s Figure l e f , the l a s t picture, i s 52 past the hour i s what you would expect because i t is a sur- and shows the same k i n d of wind speed w e had in face feature, I t h i t s the ground and spreads the beginning (Figure 1Ba). The microburst i s out, I t is a downdraft t h a t converts into a gone. The e n t i r e evolution of the microburst horizontal flow close t o the ground. (Note: I t never got bigger than was about 6 minutes. downdrafts a r e not seen on a single Doppler about 2-1/2 or 3 kilometers in i t s most intense radar. ) form.

W e have just looked a t one record of a micro- A t Stapleton, the spacing between the LLWSAS b u r s t measured d u r i n g the JAWS Project. W e have an immense amount of other recordings and data f i e l d anemometer and the outlying s t a t i o n ane- mometer i s 6 kilometers. A L L W S A S i s not going as indicated i n Figure 19. The J A W S Project consisted of 91 possible operational days (from t o see such a small feature.

the 15th of M a y t o the 13th of August). Of t h a t t o t a l , w e had only 16 days where there was no ComlnonlY , microbursts a r e 1 to 3 kilometers in when a t their maximum inten- maximum dimension, convective weather.

d on these discussions is nowcasting applications of Doppler radar. W i t h Doppler r'audr, w e were Number of Events able t o see many features a t low levels t h a t Microbursts (<4 km) 62 allowed us t o make a nowcast as t o where thunder- Microbursts in Good Dual storms would form. This is a very exciting use Doppler Coverage 54 of Doppler radar i n the aviation context, and Downbursts (>4 km) 14 these data were sent t o the FAA's Center Weather Virga but NO Outflow Service U n i t i n real-time. The tremendous via- (null cases) 18 b i l i t y of Doppler radar i s t h u s demonstrated i n Gust Fronts 35 the aviation system context; not i n the wind Mesocyclones 20 shear sense, b u t i n using Doppler to identify Tornadoes 7 the formation of hazards for use i n changing Funnel Clouds 2 the airspace flow, etc.

Figure 20 lists detection and warning systems f o r which I will give you some impressions, and w e came u p Figure 19. J A W S Data Collection H i g h l i g h t s these are only impressions, on what w i t h this summer. The LLWSAS a t Stapleton had a spacing t h a t was too large t o capture the W e had expected, when w e began the project, t o microburst feature on a regular basis. The get maybe 25 microbursts this summer, W e got L L W S A S d i d see diverging outflows b u t only 62 microbursts, i .eo, diverging outflows less a f t e r they became large enough to reach the than 4 kilometers i n horizontal dimension. Ten scale f o r which the system was capable of re- or 12 of these microbursts were measured w i t h sponding. The NCAR system, which is on a den- dual Doppler radars, (Dual Doppler allows us s i t y twice as great as the LLWSAS, was corre- t o reconstruct the velocity structure in three spondingly more successful i n seeing the micro- dimensions.) W e got 54 downbursts i n dual burst because the spacing was 3 kilometers.

Doppler, which are distinguished from micro- bursts because the outflow is greater than 4 I 1 kilometers in extent.

@ Airborne Systems Airspeed and Groundspeed Procedure W e believe, from the a i r c r a f t performance work, Forward- 1 ooki ng LIDAR that i f the outflow region becomes larger than Vertical Veloci ty/Energy Rate about 4 kilometers, i t i s probably less likely t o be severe i n terms of a i r c r a f t performance.

0 Doppler Radar So, w e think that the microburst i s the feature Airport Approach and Deearture Corridors of most i n t e r e s t in an aviation context.

Area-wide NEXRAD Concept Doppler LIDAR a t Airport Center Virga i s the precipitation coming down towards the ground, b u t not reaching the ground. What @ Surface Sensors happens t o virga i s t h a t i t evaporates and, of Low-level Wind Shear Alert System course, i n the evaporation process, i t cools NCAR Portable Automated Mesonetwork and causes the downdraft t o accelerate. W e had Pressure Jump Array 18 cases where w e had downdraft a i r approaching the surface i n which i t seemed l i k e a micro- burst may have formed, b u t need not. Therefore, Figure 20. Detection and Warning virga d i d n ' t always cause a microburst.

O f the 62 microbursts, about 60 percent occurred in the non-thunderstorm situation; t h a t is, low- I t i s a preliminary, b u t , I think, logical, level r e f l e c t i v i t i e s , no lightning; not a t h u n - conclusion t h a t the LLWSAS system i n i t s current derstorm, by definition. The other 40 percent dimension i s really not addressing the scales of occurred imbedded i n thunderstorms where there motion which are of concern in the J A W S Project.

were rain, lightning, and a l l the properties of I t h i n k the low-level wind shear a l e r t system T h u s , both types of microbursts a thunderstorm, was p u t together a t a time when w e thought the were observed, g u s t f r o n t was the name o f the game i n terms of the severe hazard. Therefore, I t h i n k w e need Data were collected on 35 g u s t fronts, which i s to address making the system better, and you about 10 years of gust f r o n t data collected from can do t h a t by increasing the number of stations; the National Severe Storms Laboratory (NSSL) in or, possibly, a number of other things can be Oklahoma. There was a phenomenal amount of done.

weather this summer.

W e have n o t y e t addressed the pressure jump r a t e Twenty mesocyclones, which a r e the parent c i r - data. A t present, I have only the r e s u l t s of culations of tornadoes, and 7 tornadoes occurred verbal conversation w i t h the British HS-125 crew f o r which w e collected data. T h i s was not a relative to airborne systems. Their comments J A W S objective, b u t w e couldn't r e s i s t working are, "Very exciting data; the best data we have it. Nine hailstorms occurred t h a t dropped hail ever seen i n w i n d shear." The sound quantitative on the radar, which i s a pretty phenomenal sta- results, however, remain t o be seen, t i s t i c considering how close our radars were t o one another, Another factor which has a bearing Doppler radar proved t o be astoundingly success- doesn't l a s t very long, you have t o be i n the wrong place a t the wrong time in order t o be ful i n seeing the wind shear, both i n dry and wet cases. I t h i n k the NEXRAD system, i f the i n trouble. T h u s , even though they a r e f a i r l y radars are placed near the airport, will give common i n summer, the probabil i t y o f a micro- very exciting results. I t is preliminary, b u t burst being over the runway i n exact coincidence w i t h an a i r c r a f t landing or departure is a very i f you want to cover an a i r p o r t environment, the Doppler radar does a very f i n e job. A rare event, conventional radar, or a weather channel on the All of the detection and warning systems tested survei 1lance radars , w i 11 not measure wind shear. will be quantified as to t h e i r detection and warning capability, I have given you impressions Figure 21 lists the analysis p r i o r i t i e s . The which w e will analyze quantitatively. An up- wind shear profiles used i n simulation and dated information film is needed this year and manned-flight simulators are not adequate. They a newly updated film the year after. Pilots and controllers need t o view this film t o keep the do not address the scales of motion t h a t we a r e looking a t i n the J A W S Project. The current consciousness a l i v e as t o how serious a wind systems, therefore, do not address worse-case shear event is and how t o deal w i t h it.

i n the four-dimensional struc- conditions found ture of the microburst from the J A W S Project. H o w severe i s severe? W e have data t h a t w e will i n simulator studies, i n modeling studies i n These data need t o be provided t o the simulator use the analysis phase. The data from J A W S will be world, not only f o r proficiency and training, b u t i n testing of airborne systems. The analyzed used i n research simulators such as N A S A Ames,

, and el sewhere , t o measure "How

data should be added t o FAA Circular 120. N A S A Langley Analyses of the data is a high p r i o r i t y of the severe is severe?" I t h i n k t h a t a i r c r a f t a r e J A W S Project. going t o f l y i n w i n d shear f o r a long time. W e are not going t o keep airplanes out of wind shear.

Wind shear is a l l around us a l l the time. The question is one of accurate and timely detection Preparation of High Resolution 4-Dimensional of wind shear t h a t can cause accidents. W e have Microburst Profiles f o r Improved Manned-Flight the data to get t o the bottom of t h a t problem, Simu 1 a t i on which i s what w e plan t o do.

Establish Microburst Frequency Distribution Doppler radar s i t i n g as a function of range needs t o be resolved. I f the Doppler radar is s i t e d Quantitative Ordering of Detection and too far away, you cannot see the microburst Warning Critical Success Ratio because when i t ' s r i g h t on the surface, i t is l o s t i n the earth's curvature, T h u s , s i t i n g i s Training Film f o r Pilots Describing Microburst NEXRAD.

an important issue relative t o Hazard and Providing Visual Clues I t is our opinion that the research simuJators Quantification of Wind Shear Severity Using do a pretty good job o f simulating wind shear J A W S Data Set in the microburst scale, b u t we're not sure :his i s the case f o r training simulators. For Doppler Radar Siting t o Establish Suitable reasons which w e a r e not certain of yet, w e Detection Range as a Function of Hazard believe there is a lack of response t o the wind i n the training simulator.

shear profile They Research Versus Training Simulation Response either under-damp or over-damp the response t o to Microburst Wind Shear Profiles head wind, t a i l wind, or downdraft on the scale of a few seconds where microbursts wind shear Close Analysis Relationship w i t h United Kingdo i s c r i t i c a l .

Royal Aircraft Establishment Finally, w e are going t o work closely w i t h the Development of Prototype Airport Doppler United Kingdom Aircraft Wind Shear Program, and Concept f o r Wind Shear and Other Terminal w e may be addressing the issue w i t h FAA about Hazard Detection and Warning the next stage of a prototype system f o r Doppler radar.

Figure 21. Analysis P r i o r i t i e s A s the f i n a l part of this presentation, I a m going to give some impressions. Microbursts a r e cmmon i n Denver. W e didn't do a research W e d i d n ' t expect t o measure enough microbursts program elsewhere. W e d i d one i n Chicago in t o establish a microburst frequency distribution.

1978, and there were quite a few microbursts; However, w e have enough data from the J A W S Pro- b u t the program was not designed as i t was i n j e c t to do t h a t f o r Stapleton. What is the fre- Denver t o adequately address the scale.

I quency distribution? W e had l o t s of microbursts t h i n k microbursts a r e rather common. I t h i n k with velocities 50 knots or greater. W h y do i f you go e a s t and south from Denver, you are airplanes not crash a l l the time? The answer t o more likely t o find microbursts imbedded i n that, i n our opinion, is that the space time thunderstorms and less likely t o have the dry window f o r a microburst i s extremely small. You microbursts t h a t you have i n the west, Wind have t o encounter i t below 500 f e e t . Moreover, shear problems i n Tucson, E l Paso and Denver since i t i s very small i n spatial dimension and d have been more related to the dry case. I f you I a m a tremendous proponent of the airborne go east and south, t o N e w York and Philadelphia, systems. You cannot have a low-level wind you are more likely t o encounter the thunder- shear a l e r t system o r Doppler radar a t every storm-imbedded microburst.

airport because the money isn't available. An airborne system goes w i t h the airplane, so t h a t The question a r i s e s as t o whether you can apply i s an obvious advantage, The a i r speed and J A W S results in regions other than Denver. From ground speed system, I t h i n k , i s a good system the fundamental physics perspective, we always because ground-speed flying makes sense. There worry about that k i n d of problem. However, from i s , however, some disadvantages of the ground the warning and detection operations point of speed/air speed concept. Eventually, f o r example, view, I t h i n k the answer is yes. The micro- i t will encourage you t o f l y through a wind b u r s t flowfield which causes accidents will have shear and one of these days you will go into a the same kinematic form near the ground in wind shear t h a t exceeds the capability of the =lorida as i t does i n Denver.

a i r c r a f t . So, any system t h a t requires you t o enter the wind shear before you can detect i t W e have a l o t of data on microbursts. W e know has a problem in concept.

now t h a t they a r e small, short-lived and can be intensely lethal. T h u s , microburst detection The current airborne systems as they a r e now is very important i n aviation safety. construed are useful only on approach; and takeoff accidents a r e not covered. There is, The low-level wind shear a l e r t system i n i t s however, more research t h a t can be done t o help current form, w e f e e l , is inadequate. W e have improve this part of the situation.

no question t h a t i t was a proper decision t o i n s t a l l t h i s system. A t t h a t time, the g u s t The airport Doppler concept, I t h i n k , i s a great front was t h o u g h t t o be the c u l p r i t , and this idea. I t costs money. In a warning and detec- system i s a great g u s t front detector.

t i o n system, whether i t ' s the Doppler radar or any other system, time is c r i t i c a l , The wind Our technology and our awareness of the atrnos- shear signal will l i v e and d i e in a few minutes.

phere has concentrated a l o t of attention on This information must be related t o the cockpit the need f o r new systems and new approaches.

immediately. I t can be uplinked. The technology A l o t of work has been done by FAA. I t i s out- e x i s t s to u p l i n k the data. Uplink o f wind shear standing work. For some reason, results of information is an issue with which w e need t o be this work were not implemented. W e need t o dealing, Also, the issue of how w e decide to t h i n k about implementing airborne systems i n f l y or not t o f l y i n a certain situation, i s a W e need t o look a t Doppler a more riqorous way, big issue. T h u s , there are s t i l l many unresolved radar and w e may be able t o address the low- problems. The J A W S Project has provided a gold- level wind shear a l e r t system problem by in- mine of data t o address the issues. T h u s , w e creasing the number of anemometer stations.

believe that w e are a t the threshold of making a q u a n t u m step forward in resolving the wind shear pro bl e m d

ARY REPORT: Tra iai ng/Simula t ion Facilities Committee

Members : Ted Mallory, Chairman, Director, Flight Standards & Training, Republic Airlines Roland L. Bowles, Aerospace Technologist, NASA/Langley Research Center I r i s C. Critchell , Director of Aeronautics Program, Harvey Mudd College Keith A. H i l l , F l i g h t Simulation Applications, Boeing Computer Services Dale \.I. Istwan, Air Line Pilots Association John T. Klehr, Meteorologist/Systems Engineer, Singer Comnany John Prodan, President, AV-CON

~NTRODUCTION

portion of the meteorology section of the exam should be required to retake t h a t portion of The Training and Simulation Comittee i n t h i s the exam before being permitted to take his year's Workshop has been very active.

W e have f l i g h t check f o r a particular c e r t i f i c a t e . A had excellent discussion w i t h the floating review of weather should also be included on a committees as well as among ourselves. Our recurrent basis, such as i n the biennial f l i g h t expertise ranged from advanced civilian- review.

military training to general aviation-corporate training. We've had viewpoints from simulator Flight simulation f o r general aviation pilots and research experts as well as classroom has not progressed t o the s t a t e of the a r t t h a t academicians. I would l i k e to thank each i s possible w i t h today's technology. Simulators member of the committee f o r a job well done.

capable of demonstrating wind shears, turbulence,

low v i s i b i l i t y , icing ... would be of great value

t o the general aviation community; b u t , w e

CEHEUAl AVIATION

understand t h a t i t would be cost prohibitive.

The study of meteorology for general aviation students i s , i n our opinion, inadequate for Another important area i n the training of pilots today's environment. A 1 though ground and f l i g h t deals with the human factors. I t appears t h a t schools w i t h sufficient information i n the met- i t i s both practical and highly desirable t h a t eorology area a r e available, they are not cur- development of weather-related decision making rently required f o r p i l o t certification. Written should play a major part in the early training tests f o r pilots, as required by the FAA, does of p i l o t s . Although the VFR p i l o t can't be not place enough emphasis on basic knowledge trained f o r a l l weather conditions, early of weather phenomena and weather hazards. Pub- training can be planned t o develop the p i l o t lications available to the general aviation a t t i t u d e of a thorough respect f o r weather.

pilot on the subject of meteorology a r e not updated a t a pace to keep u p w i t h the increa- Previous workshops have d e a l t w i t h the human s i n g knowledge being obtained i n the area of factors area i n d e t a i l , and w e recommend the weather phenomena. Our committee strongly f e e l s implementation of t h e i r ideas, W e challenge the t h a t until requirements are mandated t o insure FAA t o explore regulatory changes; the aviation t h a t an adequate knowledge of meteorology and, education community to supply curriculum devel- in particular, weather hazards, a r e attained, opment; and the simulator manufacturers t o de- we can continue t o expect the general aviation velop a generic general aviation a i r c r a f t sim- p i l o t t o "learn by doing".

One suggestion t o ulator f o r in-fl.ight weather training.

insure t h a t each candidate f o r a p i l o t c e r t i f i - cate understands the basics of meteorology and severe weather i s the sectionalization of the FAA written exams. A p i l o t who then f a i l s any d 98

CORPORATE AVIATION

The incorporation of a line-oriented f l i g h t training program can best be utilized i n the A s w i t h the general aviation p i l o t , the re- training of weather hazards f o r the air1 ine quirements f o r a good working knowledge of pilot. The required six-months checks in con- weather is missing i n our present c e r t i f i c a t i o n junction with FAR 121 Appendix F do not provide process. Many corporations have well-established a good avenue f o r this training. The require- however, ground schools and recurrent programs; ments s e t forth i n Appendix F are a "jump- many do not. Corporate simulators a r e available through-the-hoop" type requirement, i .e. , per- which have f u l l motion and visual systems; how- form a particular maneuver and move t o the ever, training syllabi do not, necessarily, next one. W e feel t h a t significantkmeteor- Pri- include training i n severe weather flying.

ology training f o r a i r l i n e operation i s i m - mary emphasis i s based on a i r c r a f t systems, pro- portant and t h a t i t should be done i n a cedures and a i r c r a f t control. Simulators a r e training concept, not as a required check believed to be the best way t o teach crew co- f l i g h t .

The wind shear model concern was also ordination along w i t h normal and abnormal a i r - i t was in the cargo simulation expressed, as c r a f t operational procedures. The total p i l o t training area.

Heavy rain was also a concern learning concept is desirable...not just the because w e do not have exact models of t h i s teaching of how t o perform a certain maneuver.

weather phenomena and are n o t sure of the The thorough study of meteorology i n ground penalties encountered w i t h a i r c r a f t performance.

school classes cannot be overemphasized. Films, such as those being produced as a r e s u l t of the

MILITARY AVIATION

J A W S Program, along with qualified ground i n - structors are absolutely necessary t o teach, L i t t l e emphasis i s placed on adverse weather learn and/or review the basics of meteorology.

training i n the military. The future looks good f o r computer generated images of weather

CARGO AIRLINES

displays and, i n some cases, orders f o r such systems have already been placed by the military.

Cargo c a r r i e r s , which make use of simulators f o r Good academic training i s present i n the military training, a r e in d i r e need of accurate models environment. Classroom instruction i s of high Some data is simply for severe weather training.

quality and the emphasis on classroom instruction not available. Simulators are n o t necessarily i s commendable. An area of concern t o our com- programmed t o adequately demonstrate the wind mittee was the lack of information distributed shear models and the question arises as to to the civilian community pertaining to military whether or n o t simulators are implemented t o a i r c r a f t accidents and incidents. Many of the w i t h properly r e f l e c t wind shear. However, even accidents t h a t would help the c i v i l i a n community these questions, w e feel t h a t training should be as f a r as analyzing weather-related accidents is given i n w i n d shear recognition in order t o edu- simply n o t available t o the civilian aviator.

cate the pilot. Icing and heavy rain are i n the same category. Once data is available, i t In conclusion, simulation training in conjunc- should be validated before implementation i n tion w i t h professional ground training i n meteor- simulators. Older simulators i n the corporate ology is a must.

Weather models must be r e a l i s - market also. need to be updated i n order to begin t i c as soon as research data becomes available.

Advanced effective training in weather flying.

simulation training under FAR 121 Appendix H W e would l i k e t o thank the UTSI f o r the i n v i - may be an incentive f o r updating some of these tation t o come to this workshop and a special older simulators. W e endorse the JAMS data pro- thanks to the National Weather Service f o r the gram and any other program that would develop a wonderful weather t h a t they have provided while more real i s t i c , accurate , high-resol ution data w e were here. Again, a personal thanks t o each base for wind shear and the e f f e c t of heavy rain member on our committee f o r their efforts.

and icing for both crew training simulators and A t the same time, engineering simulators.

weather radar data and visual scene data should package be developed and coordinated as a total reprensentation of the cockpit world.

PASSENGER AIRLINES

P r i o r i t i e s of simulator updates f o r passenger a i r l i n e s a r e wind shear, heavy rain, clear a i r turbulence, lightning, icing, f r o s t , snow con- ditions, fog, low v i s i b i l i t y and ozone/acid rain.

SUMMARY REPORT : Communications Facilities Committee

Members: Frank E. Van Demark, Chairman, Engineerinq/Management Consultant James Banks, ATC & Airspace Consultant, Scott AFB & ATCA L t . Col. Ron Brown, Chief Staff Meteorologist, Wright Patterson AFB C. L. Chandler, Weather Manaqer, Delta Airlines Steven Cohen, Senior Staff Enqineer, Flartin Marietta Aerospace Steven Henderson, Meteorologist, CWSU Atlanta ARTCC Jack Hinkelman, PROFS Program Office, NOAA/ERL Fred Hochreiter, Chief, Data Acquisition Division, N W S Sidney Koslow, Associate Technical Director, Mitre Corporation L t . Col. C a m Tidwell, Deputy Proqram Director, NEXRAD/DOD Terrell Wilson, Planning Specialist, Air Traffic Service, FAA David Winer, Manager, Energy Division, Office of Environment and Energy, FAA

RECOMMENDAT~ON

INTRODUCTION

Seek means t o accelerate programs.

This summary report addresses specific issues which arose d u r i n g discussion w i t h each of the

ACTION

user committees. The issues a r e l i s t e d under user committee t i t l e s and a summary of the FAA discussion with recommended action and respon- s i b l e agencies is presented.

B. ISSUE

1. CORPORATION

Closing and Part-Timing o f FAA f a c i l i t i e s will cause loss of aviation weather observations.

A. ISSUE

DISCUSSION

Need d i r e c t access t o the FAA aviation weather data base used by FAA FSS personnel t o FAA i s committed t o continue aviation brief p i 1 ots .

weather observations where part-timing or clo- sure i s planned. Weather observations will be

DISCUSSION

contracted out, s a t i s f i e d by F A A ' s automatic weather observations system or assumed by N W S .

Reviewed FAA FSS Automation Program which includes Pilot Direct Access via computer termi-

ACTION

nal (privately owned from home or office o r owned by Fixed Based Operator and used by p i l o t s ) FAA, NWS, Airport Sponsor and by phone into the Voice Response System as i s now operational in Washington, DC, and

C. ISSUE

Reviewed other aviation weather Columbus, Ohio.

programs, e,g. , improved VOR broadcasts (State Aviation weather observations a r e not of Florida t e s t ) and aviation weather radar available f o r a l l airports having Instrument broadcast via VOR t o cockpit printer.

Approach Procedure.

i

cal.ly report icing and to structure F A A / N W S ols_eUSSlON

icing reports t o provide the information f o r FAA program f o r A W O S will cover a t o t a l p i l o t determinations of icing potential based N W S may cover some others.

of 900 airports.

on the type of a i r c r a f t flown.

User and Airport Sponsor can supplement F A A / N W S plans, i.e., Sponsor purchased AWOS a s done by

ACTION

the State of Virginia User/FAA/NWS technical interchange directed to Aviation Safety.

0. ISSUE

Professional quality of aviation weather briefgin by FSS s p e c i a l i s t s varies.

11. CARGO

A. ISSUE

FAA regions (Air Traffic) conduct pro- Similar to item I, Corporate Issues B fessional ism a c t i v i t i e s programs specifically and C. FAA personnel that previously read directed to the problem. Also FSS Automation, aviation weather observations f o r ATC Tower training of FSS Specialists on use of automation are no longer available; therefore, no aviation and new CRT displays will use standard formats weather observations f o r t h a t airport. Cargo f o r aviation weather briefings. Through auto- user has volunteered t o read tower instrumen- mation,software will be assisted i n calling tation b u t could not get FAA approval.

u p aviation weather and Aero. information related t o the p i l o t s stated need.

DISCUSSION

ACTION All users of an airport i n this situa-

tion should get w i t h airport sponsor to develop

FAA - Specialist Training

The sponsor can a user/sponsor requirement.

User - Constructive interaction w i t h

obtain permission from FAA. FAA cannot deal FAA f a c i l i t i e s directly w i t h individual users.

E. ISSUE

ACTION

Need aviation weather d u r i n g en route User/Sponsor develop requirements.

f l i g h t . Suggested use of s a t e l l i t e communica- Soonsor/FAA make aqreement.

tions.

6. ISSUE

DISCUSSIO~

Forecast is needed f o r a destination FAA programs include: a i r p o r t b u t user cannot get one.

1. EFAS voice (via radio briefings) DIS~USSION

2. Plan f o r weather radar digital data transmission via VOR voice channel.

Cargo a i r c r a f t f l i g h t times a r e into 3. Data Link up-linking of aviation airports a t hours when FAA/NWS aviation weather weather products. observations are not being taken. Lack of 4. Requestlreply by p i l o t s via data current aviation weather observations precludes link potential. N W S forecast.

5. S a t e l l i t e usage is not i n current

plan. ACTION

Users/FAA/NWS should review the A W O S

ACTION

program plans f o r long-term airport coverage.

User/FAA technical interchange is continu- In the short term, specific locations should a l l y needed.

be brought t o the attention of N W S t o review and possibly change weather observer schedules.

F . ISSUE Sponsor should cover locations n o t covered by

NWS/FAA plans .

Icing i n general i s a problem L e . , re- ports by pilots need standards and reporting

C . ISSUE

categories t o gain more use of collected data.

Icing problems predicted by FAA, N W S or others Sensing, forecasting and communications are too generalized, i.e., icing problem t o of severe weather a r e e r r a t i c , of questionable one a i r c r a f t i s not a problem to another a i r c r a f t accuracy and communications vary dependant on manual relay of information and/or low-speed DISCUSSION communication systems.

The total icing problem needs t o be

DISCUSSION

addressed by the Users/FAA/NWS t o define termi- nology standards f o r reporting icing conditions, There a r e many NWS/FAA programs directed to develop a i r c r a f t instrumentation f o r automati- t o the total area: Sensing - NEXRAD, A M O S , and i

Denver PROFS; Forecasts - PROFS, Centralized

Forecasting a t Kansas City and Automated Route Forecasting ( A R F ) ; Communications - NWS/AFOS, N W S / F A A / C W S U staffing f o r 24-hour FAA/NADIN, FSAS, VRS, CWP/CWSU, Improved TWEB periods and automation of CWSU (FAA FY 84 (Florida TWEB Test); D O D / A W E D S .

budget).

ACTION

111. PASSENGER

NWS/FAA/DOD proceed w i t h approved and funded programs.

A. ISSUE

FAA and user day-to-day flow planning

0. ISSUE

does conflict a t times due t o differences i n Wind Shear advisories a s generated by the exchange data base used f o r making decisions p i l o t reports or ground sensors are not con- regarding major hub weather conditions, structed w i t h standards f o r communicating assessed severity. T h i s causes varying com-

DISCUSSION

Drehension/reaction of p i l o t s , User weather offices project daily operations r e s t r i c t i o n s from early morning

DISCUSSION

inputs by personnel geographically distributed through t h e i r service area. FAA Central Flow The need f o r standards has been recog- nized, A j o i n t Government/user group developed Control Facility i s dependent on weather pro- standards. These have been recommended f o r jections from CWSU opeations the previous n i g h t o f FAA and NWS.

since C W S U s t a r t u p in the A.M. and aviation adoption weather observations i n the A.M. lag the i n i t i a l FAA/user daily flow control planning.

ACTION

NWS/FAA update opeartions handbooks and

ACTlON

AIM.

2 2 Users and FAA review C F /user coor- dination process and basis f o r agreement

E& ISSUE

regards predicting weather conditions a t major Wind shears d u r i n g en route f l i g h t are h u b s and resultant flow restrictions. FAA/NWS not sensed except a s p i l o t s experience and commu- review e a r l i e r s t a r t up of aviation weather nicate such events. T h i s information is spotty observations and forecasts f o r major hubs.

and not of great value except t o pilots in the FAA s t a r t u p C W S U operations e a r l i e r i n the immediate airspace.

day (as wigh2users) to provide more current i n p u t to,C F .

DISCUSSION

6. ISSUE

NEXRAD will provide a f a r more accurate picture of airspace severe weather Froblems. T h i s Wind shear experienced by and reported data when combined with other large-scale data by pilots on approach is not consistently ( s a t e l l i t e ) and processed as a t Denver PROFS, created w i t h the seriousness warranted ( p i l o t ' s will greatly improve the a b i l i t y t o sense/forecast view) nor communicated rapidly via the ATC sys- severe weather, including wind shear en route.

tem.

DISCUSSION

NWS/FAA/DOD proceed w i t h approved and There is no apparent ATC procedure t h a t funded programs.

i s enforced and/or routinely followed t o handle p i l o t reports of wind shear. ALPA provided the Congress (1e t t e r of 8/27/82) w i t h recommended

F . ISSUE

standard terminology t o report wind shear (W/S) Late n i g h t PIREPs are apparently l o s t i n five different levels of severity.

i n 'the system.

ACTION

DISCUSSION

Recommended actions were: FAA f a c i l i t y staffing of C W S U positions

i s from 6:OO A.M. or 7:OO A.M. t o 1O:OO P.M. FAA - ATC establish emergency pro-

1.

ATC personnel (except FSS) receiving PIREPs do cedure requiring ATC personnel to relay W / S not have the CWSU meteorologist to relay them report t o next pilot.

to. PIREPs f a c i l i t y operations vary as to personnel training and procedures for this

2, FAA/users - publish standard termi-

instance (no C W S U s t a f f t o receive PIREPs).

nology f o r reporting W/S.

3. FAA - establish NEXRAD-like systems

a t major, selected airports.

d NWS/FAA review and improve emergency 4 .

IV.

reporting procedures f o r timely area distribu- tion of severe weather reports,

A. ISSUE

Military p i l o t PIREPs given t o FAA ATC

C. ISSUE

do not get into reports system and exchanged Winds and temperature a l o f t are not w i t h Military reporting system.

timely or data is not accurate.

DISCUSSION

DISCUSSIO~

Military pilots, l i k e commercial p i l o t s N W S winds a l o f t f o r user use a t s t a r t (some a i r l i n e s ) , a r e f l i g h t followed; PIREPs are N W S believes its of day a r e not current. reported back t o t h e i r ground personnel and Limited Area Five Mesh (LFM) model t o be i n provided t o other pilots i n t h e i r system. The use 12/1/82 will help resolve this problem, weak link appears t o be the ATC/CWSU internal center communications. C W S U personnel can p u t PIREPs on Service A via Leased Service A auto-

ACTION

mation systems as can FSS EFAS and in-flight N W S implement LFM 12/1/82. Users moni- positions. PIREPs so handled do get into the t o r LFM results and advise NWS.

system.and exchanged w i t h the military.

D. ISSUE ACTION

"Preferred Routes" i n use by FAA due to

FAA - develop a system and procedures t o

controller s t r i k e and the need t o channel t r a f - f a c i l i t a t e ATC handling of PIREPs.

f i c into airspace t h a t current FAA s t a f f i n g can effectively manage causes uneconomical opera-

B. ISSUE

tions f o r the user, i.e., the most fuel-efficient rcutes are not used.

Military p i l o t s in peacetime f l i g h t and UHF miss PIREPs transmitted by other using airspace users who a r e on VHF.

DISCUSSION

FAA appreciates the problems and i s re-

DISCUSSION

structuring the ATC airspace sectorization f o r more effective use of personnel and t o reduce Military p i l o t s on U H F i n the same need to use "Preferred Routes". These e f f o r t s airspace sector and under control of the same receive user coordination through the NAR pro- ATC personnel miss VHF voice communications.

gram. p i l o t s hear communications on the ATC Civilian sector VHF radio.

ACTION

FAA - proceed w i t h airspace normalization

as rapidly as possible.

Military consider use of VHF i n the N A S d u r i n g peacetime.

E. ISSUE

C. ISSUE

Pilots are not, i n general , supporters of the PIREP program, i.e., they are not aware FAA/Military systems duplication, while of a systematic, conscientious FAA/NWS handling driven by wartime needs, of themselves foster of PIREPs. l e s s than satisfactory weather service t o a l l p i l o t groups (military and c i v i l i a n ) .

DISCUSSION

DISCUSSION

Pilot/ATC cooperation appears to vary -

Denver Center/PROFS I cooperation and management Ground resources, people and systems, attention t o the value of timely weather com- duplication cause dedication of a large mili- munications, whatever the source, has demon- tary resource t o military pilots. Integration strated t o p i l o t s t h a t a pilot/ATC cooperative of peacetime operations offer many avenues t o system works, Several other centers were improve the aviation weather system. Joint singled out for positive comments regarding the programs, e.g., NEXRAD and J A W S offer common handling of PIREPs. systems acquisition b u t are not directed to common systems operation.

ACTION

ACTION

FAA/user exchange operational experience a t the f a c i l i t y level t o forge a cooperative Mil itary/FAA/users a t national planning a t t i tude and appreciation.

conferences such as this Workshop should openly explore integration of aviation weather systems operations.

V. GENERAL AVIATION

B. ISSUE

A. ISSUE

EFAS i s not i n operation during daytime Access to aviation weather via FSS i s i n some Northwest areas.

not satisfactory - busy signal d u r i n g poor

weather conditions a t the local FSS.

DISCUSSION

DISCUSSION

The circumstances could not be f u l l y developed, i .e. , coverage problem, part-time To overcome current workload/staffing or staffing problem.

FAA has not planned problems that r e s u l t i n f a c i l i t y busy signals, EFAS service cut backs.

800 i n t r a s t a t e numbers have been p u t i n oper- ation by FAA to provide p i l o t s access t o a l t e r -

nate FSS's. AOPA has published a l i s t of these ACTION

FAA i s also considering the numbers by s t a t e .

FAA to investigate.

expansion of i t s VRS service as i n place in Washington and Columbus (ref. FAA's NAS Plan of

C. ISSUE

December 1982).

NIJS forecast i s not available f o r some

ACTION

'areas of the country.

(See response t o Cor- porate Issue B and C ; Cargo Issue A and B).

FAA highlight 800 number a v a i l a b i l i t y AOPA highlight 800 number i n t h e i r i n AIM.

FAA proceed w i t h weather dissemi- publication.

nation programs,

SUMMARY REPORT : operiWas/Airport Facilities Committee

Members: Thomas E. Greer, Chairman, Deputy Director of Airports, S a l t Lake City Airport Authority D. Neil Allen, Manager, Earth Station, Colorado State University John Blasic, N W S Representative t o FAA, NWS/FAA John H . Enders, President, F l i g h t Safety Foundation Arthur L. Hansen, Consulting Engineer, Enterprise Electronics Cathy J. Kessinger, Support Scientist, NCAR James C. McLean, Jr., Meteorologist, NTSB William Pickron, Manaqer, Sector Control, Federal Exoress Russell Peterman, Senior Engineer, Radian Corporation David A. Sankey, Manager, Meteorological Personnel , The Weather Channel Andy D. Yates, Pilot, United Airlines Andy Yates substituted f o r T o m Greer i n delivering the Summary Report f o r the Operations/Airport F a c i l i t i e s Committee.

The committee on Operations/Airport F a c i l i t i e s being generated a t the a i r p o r t , such as wind shear, turbulence, ozone, acid rain, etc., were was composed of representatives from many as- pects of the aviation community including the not pertinent to a i r p o r t operations. However, air1 ines, the National Transportation Safety the topics were expanded to include runway

conditions , braking action determinations and

Board, research and development firms and other governmental agencies, I t was the original the dissemination of such i nf ormati on.

intent t o form both fixed and floating commit- The fixed committees represented t h a t The topics which were discussed as they related tees.

aspect of the industry t h a t would generate data t o a i r p o r t operations were: and disseminate information to the users o f the aviation system. The floating committees would 1. Runway condition reporting d u r i n g inclement consist of representatives of the passenqer a i r - weather, ice, snow and heavy rains; lines, cargo a i r l i n e s , corporate aviation, 2. Slant visual range information a s i t is qeneral aviation and military aviation.

determined and disseminated t o the pilots I t was determined early on t h a t the term of the various a i r c r a f t ; "operations" and the information and data generated by operations a t a i r p o r t f a c i l i t i e s 3. De-icing applied to the technique and proce- would pertain s t r i c t l y t o t h a t information dures used t o de-ice a i r c r a f t prior to pertinent to airoort operations as opposed t o take-off; the operations of the various other segments of the industry. 4, Fog and fog dispersal techniques were dis- cussed, as well as what action and research I t was further determined t h a t many of the mete- is being done to deal w i t h fog.

orological topics which were to be discussed as d The remainder of the report will The military recommended t h a t con- be broken down discussed.

i n t o how these various topics were discussed t i n u i n g research be conducted by NASA i n w i t h each of the floating committees.

ice-phobics and other materials.

There was not much discussion regarding de-

RUNWAY CWDITMINS

icing i n the general aviation community o r corporate aviation. Cargo aviation and In discussing runway conditions w i t h the military passenger a i r l i n e s concurred pretty much w i t h floating committee, i t was determined t h a t there the military position.

were no standards w i t h regards t o how t o deter- mine "runway clutter", how t o measure it, and how t o disperse it, The military committee

W l S l ~ l l T Y SEEDUYG

reported t h a t there was a method i n existence The fog phenomenon was discussed w i t h each of which used a numbering system which is quite the user groups. The different types of fog extensive and i t related t o each individual were identified such as warm fog, cold fog, etc.

a i r c r a f t and a i r f i e l d . I t i s determined t h a t A l l of the groups f e l t t h a t while research each of the various military f i e l d s around the needed t o continue on dispersal methods f o r country had a different way of measuring and warm f o g , cold fog, convection fog, etc., disseminating runway conditions, Some opera- emphasis should be placed on improving the tors simply use a pickup truck and drive i t instrumentation i n the a i r c r a f t itself.

down the runway a t a predetermined speed, slam on the brakes and report the braking action as Experimental devices were discussed such as the good, f a i r , poor, n i l , etc. Unfortunately, "magic window" being tested by Federal Express.

these reports do not have very much relevance T h i s consists of an infrared camera located on to the various a i r c r a f t w h i c h would be landing board the a i r c r a f t which then projects through on the runway surface. The general aviation a computer enhancer a picture onto a heads-up group had very l i t t l e t o say regarding runway T h i s display screen i n front of the pilot.

conditions, other than the f a c t t h a t the general picture would, i n f a c t . sive a verv close aviation community was usually relegated t o a facsimile of the runwav which was not visible

secondary role when runway condi ti ons deteri -

bv a l l parties t o the naked eve. I t was f e l t orated d u r i n g snow and ice situations, The t h a t continuins an expedited research should passenger a i r l i n e s , as well as the cargo a i r - be conducted bv FAA. NASA and other groups i n lines, f e l t very strongly that a c r i t e r i a and the development of reliable landing aids which a method were needed t o determine accurately would then be available to a l l the users.

and relevantly exact existing runway condi- tions. They f e l t that work should continue Another situation, which was discussed exten- f o r a number value t h a t would be standard t o sively w i t h the military, corporate and passen- a l l airports and could be applied t o the vari- ger a i r l i n e s , was the use of s t r i a t e d paint ous operating characteristics of a i r c r a f t u s i n g markings f o r Category 2 runways w i t h a porous the airport. However, a l l operators f e l t t h a t f r i c t i o n coarse asphalt surface. I t was the best and most useful information t h a t can pointed out t h a t the large amount of paint be reported is t o get the exact conditions which i s required t o be used on a Category 2 which were existing on the runway surface as runway tends t o freeze f a s t e r than the surface often as possible d u r i n g inclement weather.

i t s e l f . The paint also tends t o clog the T h i s information would include the type of snow, draining feature of the porous f r i c t i o n surfacep whether i t is dry snow, wet snow, slush, water, t h u s reducing its effectiveness. The use of a etc,; the percent of the runway which i s covered, s t r i a t e d painting technique, where the paint preferably a t touch-down, mid-point and roll-out; markings a r e p u t down i n six-inch s t r i p e s w i t h and other conditions which m i g h t possibly a f f e c t six-inch voids between them, greatly reduces the slipperiness o r braking action of the runway, the amount of paint t h a t f i l l s the gaps and such as whether the runway had been plowed, also enhances the a b i l i t y of the runway t o broomed, sanded , treated w i t h chemicals , etc.

effectively drain water. The FAA has resisted the use of s t r i a t e d paint marking on Category 2

DE= ICIN6 runways because, i n t h e i r estimation, i t reduced

the visual acuity of the markings. I t was the The methodology, technique and standards used concensus of this committee t h a t the FAA should for de-icing varied widely among the different review and ammend i t s policy regarding the pro- user groups. The military had standards which hibition of s t r i a t e d markings on the Category 2 were established a t each a i r f i e l d depending on runways. I t was further pointed out t h a t the command a t the field. They f e l t t h a t the d u r i n g actual Category 2 weather conditions, standards needed t o be established regarding the the visual acuity of the painted surfaces is percent of glycol water mix, as well as the of minimal value t o the f l i g h t crew because of training for the ground crews i n the de-icing the reduced v i s i b i l i t y . The comni t t e e agree procedure. Another big question was: W h o bore of the f r i c t i o n coefficient t h a t the enhancement the f i n a l responsibility of determining whether on the runway was much more important than the or not the de-icing has been effective?

a b i l i t y of the p i l o t t o pick u p the painted markings on the runway. The user committee I t was generally agreed t h a t the pilot-in- members pointed out t h a t most of the reference cowand is always ultimately responsible.

checks used during these conditions was instru- mentation and runway l i g h t i n g , The use of ice-phobics (material which tended t o prevent ice b u i l d - u p on a surface) was also d The general aviation committee f e l t t h a t moving wind shears, i s s t i l l years away from implemen- the local f l i g h t service stations t o a computer- tation.

Also, the large cost of these radars ized, centralized point would have a detrimental will permit t h e i r use a t only the largest e f f e c t on their operations. They f e l t t h a t the iaci 1 i t i e s .

data needed t o be readily available a t most general aviation f a c i l i t i e s . They also f e l t T h u s , i t i s extremely important t o implement testing of several other technologies which t h a t they wanted AIP funds t o be used to pro- show promise f o r cost effective wind shear vide needed f a c i l i t i e s a t the various general detection, One such technology i s the Doppler aviation f i e l d s , They further f e l t t h a t the Acoustic Sounder. Although a large-scale FAA system should be standardized so t h a t a s they t e s t of the acoustic sounder as a wind shear traveled t o the various airports, they could detection system was carried out a t Dulles be assured of the a v a i l a b i l i t y of accurate Airport (see Beran , weather information.

the committee made the following observations: These systems are now available off-the-shelf In discussing lightning and other atmospheric from several U. S o manufacturers and the same conditions , the corporate aviation group iden- type equipment is installed currently i n a t t i f i e d a concern t h a t many of the fuel handlers were u s i n g nylon jackets, which have the ten- l e a s t 17 airports i n Europe. The Doppler Acoustic Sounder has evolved rapidly i n the dency to create a s t a t i c spark. The information l a s t few years as an accurate, low-cost remote should be readily available for dissemination wind sensing system which is capable of de- to fuel handlers and fixed base operators i n tecting w i n d shears a t altitudes u p t o 500 order t o eliminate the possibility of this type meters and temperature effects o f a downburst of clothing being used by ground handling per- event u p t o 2000 meters, T h u s , when installed sonnel.

near a glide slope, downburst events could be

WIND SHEAR

detected well before they reach the glide slope., Additionally, when installed on each end of an Although the wind shear phenomenon was dis- active runway, the Acoustic Sounder will pro- cussed, i t was f e l t t h a t the expertise avail- vide protection for both in-bound and out-bound able in the Operations/Airport F a c i l i t i e s t r a f f i c . The very low-cost of these systems Cornmittee was not s u f f i c i e n t t o address the ( = $50,000) necessitates another close look a t problem i n the detail necessary. However, the costlbenefit r a t i o between t h i s technology several of the members f e l t t h a t they would and other Doppler systems.

l i k e t o submit f o r the record an individual Specifically, the next two years will be spent recommendation which follows: analyzinq data from the J A W S s t u d y which, The 1981 committee reported the re-occurring unfortunately, did n o t include an acoustic theme t h a t current wind shear detection systems system, Therefore, the FAA should commit funds T h i s issue i s stressed i n the are n o t adequate, as soon as possible f o r a small-scale t e s t of 1981 summary which reminds us t h a t the wind a Doppler Acoustic Sounder System, This t e s t anemometer array has always been considered by should run for one calendar year and would best the committees as an interim solution a t best, be carried out a t Denver's Stapleton Airport The development of Doppler radar technology, since J A W S demonstrated a f a i r l y large number while extremely important t o the subject of of events a t t h i s location.

SUMMARY REPORT : Satellite Facilities Committee

Members: James F. W. Purdom, Chairman, NOAA/NESDIS/RAMM, Colorado S t a t e University A u g u s t H. Auer, Jr., Professor, Deoartment of Atmospheric Science, University of Wyoming John L. Keller, Research Meteorologist, University o f Dayton Research I n s t i t u t e Vincent Oliver, Chief Meteorologist, Environmental S a t e l l i t e Data, Inc.

John S. Theon, Acting Chief, Atmospheric Dynamics and Radiations Branch, NASA Headquarters William \.I. Vaughan, Chief, Atmospheric Science Division, NASA/MSFC Thomas H. VonderHaar, Professor and Head, Department of Atmospheric Science, Colorado State University Roger R . Weldon, Meteorologist, Applications Laboratory, NOAA/NESS/DOC When w e met i n our j o i n t committees, i t occurred to m e t h a t many people here have never seen a s a t e l l i t e picture. Figure 1 i s an Km resolution GOES example that uses two 1 visible images to show both what a picture looks l i k e and also t o i l l u s t r a t e a forecast capabilit.yo In the area "B", there a r e wave clouds; i n the area "A", there a r e cumulus clouds. This change i n cloud type locates a mesoscale boundary. Along the Texas/Oklahoma the pic- border, a t the very western edge of ture, a frontal boundary i s moving into the area. The question m i g h t be, "Where i n Oklahoma will the strongest convective weather develop? Precisely, rather than over a large area." A s i t turns out, the strongest con- vection develops where the boundary between the waves and the s t r e e t s and the frontal boundary interacted to trigger very strong thunderstorms t h a t produced tornadoes and downbursts--specifically, a t t h a t point-not a l l along the front o r a l l along the mesoscale boundary. The point i s , there i s a l o t of information available today u s i n g s a t e l l i t e data that can help i n aviation forecasting.

Our committee f e l t t h a t s a t e l l i t e data can be utilized for aviation applications a l o t better than i t i s today. W e found what appears t o be a huge gap in technology available versus the Figure 1. Example of Two 1 Km Resolution information t h a t ' s reaching the user community, GOES Visible Images as well as a gap in the user's knowledge of how d f r e e l y from one p l a c e t o another. Therefore, t o apply t h a t i n f o r m a t i o n i f i t g e t s t o him i n being a b l e t o f o r e c a s t where thunderstorms w i l l t h e f i r s t place.

develop, as w e l l as how they w i l l evolve over Furthermore, we found t h a t most of t h e a v i a t i o n t h e n e x t hour or two, i s extremely important.

weather problems t h a t we discussed were i n a L i g h t n i n g was a l s o f e l t t o be o f importance and nowcast time frame, i.e., i n v e r y l a r g e p a r t w i l l become i n c r e a s i n g l y i m p o r t a n t as a i r c r a f t

0 - 6 hours., What I w i l l do i s address what

evolve more toward composite m a t e r i a l s and we found i n t h e i n d i v i d u a l meetings w i t h t h e f l y - b y - w i r e systems. I n t h e area o f v i s i b i l i t y , d i f f e r e n t f l o a t i n g committees and then sum- en r o u t e weather problems a r e d u s t and volca- marize. Most weather-related problems can be noes ... t h i n g s o f t h a t n a t u r e which s a t e l l i t e s broken down i n t o two broad areas: weather en have been r o u t i n e l y d e t e c t i n g , and f o r which r o u t e and weather a t t h e t e r m i n a l . i n f o r m a t i o n i s usable r i g h t now i f it can g e t t o t h e user community. Severe c l e a r a i r turbu- l e n c e was n o t considered as i m p o r t a n t as t h e t o p i c s l i s t e d above,

CARGO AND PASSESEU AVIATION

1. Weather en r o u t e I n t h e area o f t e r m i n a l weather, t h e h o t and heavy t h i n g r i g h t now i s t h e m i c r o b u r s t w i t h

a. Winds and temperature - Minimum Energy

i t s wind shear and heavy r a i n . Programs such Routes using I n t e r a c t i v e Techniques as JAWS should have s i g n i f i c a n t impact here.

(MERIT), VAS, r e a l time r e l a y ; W e must g e t a b e t t e r understanding o f what causes t h e downburst and m i c r o b u r s t t o occur.

b. Thunderstorm development - Severe

Canbinations o f r a p i d scan i n t e r v a l s a t e l l i t e Weather Avoidance Program (SWAP) , d a t a and three-minute i n t e r v a l imagery, w i t h 1 i g h t n i n g ; Doppler r a d a r data should h e l p i n t h i s area.

V i s i b i l i t y - Dust, v o l c a n i c ash; NOAA, NASA and FAA a l l have r e s p o n s i b i l i t i e s i n c.

t h e above areas. MERIT and JAWS a r e a l r e a d y combined programs, w i t h NSF being a c t i v e i n t h e Severe CAT - Passenger/cargo comfort. d.

JAWS e f f o r t . The development o f a l i g h t n i n g 2. Weather a t t e r m i n a l sensor i s c l e a r l y a NASA r e s p o n s i b i l i t y w i t h NOAA involvement i f t h i s i s t o be done from a. Thunderstorm - M i c r o b u r s t (wind shear, spacecraft. Work a t NASA i n d i c a t e s t h a t a r e a l heavy r a i n ) ; t i m e h i g h r e s o l u t i o n 1 i g h t n i n g sensor c o u l d be added t o t h e GOES s p a c e c r a f t a t a nominal bo JAWS. c o s t - - t h i s c e r t a i n l y needs f u r t h e r i n v e s t i g a - t i o n . NOAA, NASA and NSF must g i v e h i g h p r i o - r i t y t o u t i l i z a t i o n o f GOES-VAS m u l t i s p e c t r a l For weather en r o u t e , t h e r e were s i m i l a r needs imagery and dwell sounding data f o r a v i a t i o n w i t h t h e cargo and passenger groups p r i m a r i l y a p p l i c a t i o n s .

f o r winds and temperature. This i n f o r m a t i o n was m a i n l y f o r f l i g h t planning. T h i s need f o r

MILITARY AVIATION

p r o v i d i n g b e t t e r wind and temperature i n f o r - mation i s one o f t h e major goals o f t h e MERIT program. To p r o v i d e b e t t e r i n f o r m a t i o n , t h e r e 1. A l l weather, anywhere a l l t h e t i m e i s a need f o r more research i n t h e area o f i n d i r e c t sensing o f winds and temperature using s a t e l l i t e data. a. Must have r e l i a b l e i n f o r m a t i o n Going along w i t h t h i s , t h e r e i s continued need f o r development o f our under- b, May n o t have ground-based observations standing o f l a r g e - s c a l e weather systems, espe- c i a l l y those over t h e oceans i n remote and data- Weather a t o b j e c t i v e most i m p o r t a n t 2.

scarce areas. T h i s , understandably, w i 1 l he1p us d e r i v e b e t t e r wind f i e l d i n f o r m a t i o n from

a. P o i n t s p e c i f i c (0 - 3 hours)

t h e f r e q u e n t i n t e r n a l temperature sounding data t h a t w i l l e v e n t u a l l y become a v a i l a b l e u s i n g

b. Varied m i s s i o n - t a c t i c a l t o s t r a t e g i c a l

GOES-VAS. Another area where wind i n f o r m a t i o n can be improved i s t o r e l a y winds from a i r c r a f t c. Nowcast i n t e n s i v e e f f o r t en r o u t e u s i n g s a t e l l i t e s ; from t h i s , you c o u l d have near-continuous updating o f t h e winds f o r

d. L i g h t n i n g - cannot detour

en r o u t e a i r c r a f t , I n t h e area o f en r o u t e thunderstorm development, 3, System design it was p o i n t e d o u t t h a t when SWAPS a r e implemen- a. Need f o r adequate data bases ted, they have s u b s t a n t i a l impacts on a i r t r a f f i c r o u t e s r e g a r d l e s s o f whether thunder- storms develop o r not. I f a SWAP goes i n t o b. Climatology o f s a t e l l i t e d a t a and appl i c a t i o n s e f f e c t , e v i d e n t l y a i r c r a f t cannot move as 4 . Soundings from satel 1 i t e s 2. Nowcast problems a. TIROS-N, VAS a. Thunderstorms b. Impact of soundings b. Icing c. VAS development c. IFR conditions 3. Access t o information The military requirements were, as you m i g h t expect, a l l weather anywhere, a l l the time.

a. Flight watch - EFAS

In-situ observations may not be r e l i a b l e , i.e., many times they are not available a t all..a so, b. A. M. Meather how do they get the information? In actuality, i t turns out that the weather a t the objective c. Continuous weather information is very important. The weather information needs to be point specific f o r a three-hour or less time frame, and the mission may vary from For general aviation, most f l i g h t s a r e of less paratroop drops t o s t r a t e g i c operations. T h i s than three hours. Two basic types of p i l o t s is certainly a complex nowcast area: various are: the VRF and the IFR pilot. Their main types of weather can e x i s t a t different seasons problem is lack of access t o meteorological of the year in different geographical areas.

information, w i t h t h e i r primary problems coming from thunderstorms, ice and a VFR p i l o t getting I t ' s not as simple as saying t h a t thunderstorms into IFR conditions, There a r e certain areas If you go t o northern are the most important.

where s a t e l l i t e data can help solve those pro- Europe a t a certain time of year, fog and s t r a t u s blems. For the thunderstorm and the icing become extremely important. Nowcast require- problems, there are ways through image analysis A s f a r as l i g h t n i n g i n ments vary greatly.

and interpretation t o get a nowcast of where point specific weather, the military will pro- ice clouds are, or where thunderstorms will bably design around t h a t problem. A t times, develop. For IFR conditions, u s i n g imagery, we they have no choice b u t t o f l y i n t o regions of can t e l l where i t ' s overcast and how i t ' s lightning a c t i v i t y , shamging i n time. M e can see the tops of the clouds and t e l l t h e i r height, although w e c a n ' t System design is one of the important military see t h e i r bases; however, t h a t information can uses of weather information. I t was pointed be surmised by combining other types of infor- out t h a t an inadequate climatology of s a t e l l i t e mation with s a t e l l i t e data using interactive data existed t o help t h a t area.

analysis systems.

Meteorology has moved into the era of the A tool t h a t should be utilized more is the re- TIROS-N pol ar-orbi t i n g satel 1 i te; and soundings mote data collection platform. Platforms can from those s a t e l l i t e s have had a positive impact on numerical weather prediction. There needs t o be designed t o transmit local weather informa- tion back through the s a t e l l i t e t o a terminal , be some type of updating of the s t a t u s o f atmos- thus providing users w i t h more surface weather pheric temperature sounding using s a t e l l i t e observations. The f l i g h t watch, EFAS, t h a t has data, W e now have the GOES-VAS s a t e l l i t e which been talked about is the primary interface with has the capability of taking sounding data from the general aviation p i l o t once he's airborne.

geosynchronous altitudes a t f a i r l y rapid inter- The EFAS personnel must have s a t e l l i t e imagery val s @ This capabil i t y holds tremendous promise i n animated form, along w i t h the tools t o use f o r the short-range forecasting of convection i t and the most up-to-date weather information and severe weather.

t h a t i s available. W e f e l t t h a t the EFAS people NEPERF and AFGL, along w i t h c i v i l i a n agencies, certainly need training t o interpret a l l the have responsibility i n assuring needs a r e met.

data types t h a t they have. W e feel t h a t , per- For improvement of nowcast a b i l i t y , the mili- be professional meteorologists , haps, they should tary should have personnel assigned t o the PROFS although many of these people, w e realize, do nrogram. The military should also support the have a broad background i n weather. T h i s is acquisition of a more complete s a t e l l i t e clearly an FAA responsibility, climatological data base along w i t h e f f o r t s already underway i n NOAA, NASA and NSF. Efforts Many pilots have a very hard time contacting a t AFGL and NEPERF should focus on investigating, the FSS and getting t h e i r pre-flight briefing and supporting investigations of , phenomena from AM Weather, T h i s program, w e f e l t , needs important on a nowcast time frame such as t o be expanded so t h a t i t is available on a thunderstorm produced arc cloud 1ines.

more frequent basis. T h i s could be done through some NOAA and FAA e f f o r t , Continuous weather

CEERAL AVIATION information! One of the items t h a t kept sur-

facing was the use of the AM Weather channel f o r pre-flight briefing o f a pilot, Perhaps, the TV channel t h a t exists now, perhaps a 1. Flight time frame channel t h a t would just carry s a t e l l i t e data-- zooming i n on different parts of the country-- a. Generally less than 3 hours radar data m i g h t be carried too. I t is clear d that some mechanism i s certainly needed f o r have their own forecast services--these people continuous weather updating for pilots.

need up-to-date weather information and the tools and training t o use t h a t information.

The pressing need i n general aviation i s , Accessibility t o the information as well a s obviously, access t o up-to-date information.

basic training development is a NOAA respon- This i s clearly an FAA and NOAA problem, The s i b i l i t y , while getting the information, d i s - information must be placed into the hands of playing the data and acquiring the training the EFAS person who has d i r e c t contact w i t h the private sector.

i s the responsibility of

en route f l i g h t s -- these people must have the

tools necessary t o interpret t h a t information

CQHCLUSIOHS

and the training required t o interpret such information as animated s a t e l l i t e imagery.

There a r e many areas where s a t e l l i t e data can T h i s is clearly an FAA responsibility, w i t h be better used today t o aid in aviation, and some of the training responsibility resting w e mean today, a t this very minute. Use of w i t h NOAA, The AM Weather program should be these data will require user access t o the expanded, and a commercial television weather s a t e l l i t e information and user training i n channel having up-to-date weather information the use of t h a t information. Many users of t h a t includes current animated satel l i t e meteorological information a r e adequately and radar data i s needed. This is a NOAA, FAA trained i n synoptic, large-scale meteorology-- and private sector responsibility.

weather of importance t o much of aviation is mesoscale or small-scale in nature, S a t e l l i t e data in combination w i t h radar and surface

CORP~RATE AVIATIQN

observations are our main tools f o r short-range forecasting of mesoscale phenomena--we must 1. Flights 1 to 2 hours, long distances have adequate interpretation tools in the f i e l d for analysis of these data s e t s , as well as 2. Lack of terminal weather meteorologists that are trained t o use them, a. Remote DCP W e found four major, broad areas t h a t need continued emphasis i n their development. All b. Nowcast are being addressed to some extent by NOAA, NASA and the FAA through MERIT, PROFS and CSIS 3, 3ptimum fuel consumption or other programs.

4. Pre-flight briefing very important The major areas f o r continued development are shown i n Table 1 and some of the technology a. AM bleather that may be brought to bear on certain of these problems is shown i n Table 2, While much of the

b. Accurate 0 - 3 hour forecast of en

responsibility f o r development and use of the route weather technology l i e s w i t h i n NOAA, NASA and FAA, there are certainly some major places where the mili- tary and NSF a1 so have responsi bil i ty--these Corporate aviation has many of the same one- t o m u s t be coordinated as much as is feasible.

two-hour problems as general aviation; b u t I t t h e i r f l i g h t s are over longer distances.

Once a person has used s a t e l l i t e data, he will was our understanding t h a t corporate p i l o t s are understand why i t is a must in local weather so busy once they get into the cockpit t h a t Local weather happens on scales forecasting.

they don't have time for many updates en route, between normal observations, except with Furthermore, there i s a serious lack of weather satel l i t e data. Routinely animated GOES information for many of the terminal areas into s a t e l l i t e imagery i s absolutely required f o r which they fly. T h i s points, again, t o the short-ranqe weather forecastinq, and t h a t need for remote data collection platforms and information must be a part of any traininq access to that information, as well a s accurate proqram. For f l i q h t watch and the f l i q h t nowcasting of ice, terminal ceiling and visi- service stations, there is a technoloqy Corporate aviation has b i l i t y and wind shear.

the optimum fuel problem t h a t the other a i r - lines have and most of t h e i r information on Table 1. Major Areas f o r Continued Development winds and temperature comes from briefings i n the pre-flight phase, Again, f o r them t o 1. Winds en route this means a good operate successfully, accurate nowcast of weather en route and a t

2. Nowcasting - Terminals and f l i g h t paths

the terminal 3. L i g h t n i n g detector on Geostationary The requirements and needs f o r corporate avia- Spacecraft tion have, i n large part, been covered in those of previous users--that is, winds en route, 4. Global s a t e l l i t e climatological data base.

nowcast and so forth--agencies w i t h those responsibilities have been pointed out. Ad- ditionally, many corporate aviation groups available--training, education and the techno- Table 2, Available Technology with Great logy are a l l needed. Finally, we should expand Promise AM Weather and the TV weather channel t o carry 3rp o f t h i s up-to-date information since this 1. Winds en route i s how so many p i l o t s i n general aviation and corporate aviation get their weather information.

a, VAS These, basically, are the findings of our com- b. Cloud Motion m i t t e e c. Image Analysis FESPOKSE: Jack H i nkelman, PROFS 2. Nowcasting I want t o second what Jim said about s a t e l l i t e i n p u t s . They a r e very important t o PROFS, and a , Image Analysis they are also very important because the CWSUs have GOES drops r i g h t now. I showed a viewgraph b. Rapid Scan Data Combinations before. W h e n w e were evaluating products t o i t was primarily based on some send t o the C W S U , c. VAS Technology 1981 information; and they had a problem w i t h That has been corrected.

the GOES navigation.

d . DCPs I t ' s a very important input.

There's no problem.

J

REPORT: Fuecastiq Facilities Committee

Members: Fred Ostby, Chairman, Director, NSSFC, N W S Herbert I. Brody, Assistant Federal Coordinator, FAA, NOAA Frederick H. Carr , Department of Meteorology, University of Oklahoma AES CMO Sepp J. Froeschl, Demos T. Kyrazis, Senior Research Specialist, R & D Associates Robert G. Hiller, Senior S c i e n t i s t , NWS, Techniques Development Lab.

Robert Serafin, Director, Atmospheric Technoloqy Division, NCAR Joseph F. Sowar, NEXRAD Denuty Program Manager, FAA Jan Tissot Van Patot, Meteorologist/Instructor, Atmospheric Environment Service Tommy W. Trimble, Regional Aviation Meteorologist, N W S Paul S. Trotter, Meteorologist-In-Charge, CWSU, FATCC military were interested in 12-hour forecasts.

INTRODUCTION

All committees expressed i n t e r e s t i n some k i n d of sliding forecast, where i t is periodically I j u s t wanted t o say t h a t our forecasting group, and consistently updated so t h a t you could then I think, really benefited from the interaction

march out another s i x ( 6 ) or 3 - 6 hours from a

w i t h the various user groups t o find out w e had new i n i t i a l point. Interests i n icing forecasts more about what they needed.

were n o t great among these groups, except per- haps the military, i n which one type of a i r c r a f t ,

DISCUSSION

the C-5, d i d not have the k i n d of anti-icing equipment t h a t others had. So, f o r the military, W e solicited the f i v e (5) different committees icing forecast was a problem.

t h a t came through and we've taken the l i b e r t y to lump some of these together; where there a r e Ceiling and v i s i b i l i t y was more a problem f o r the exceptions, they will be noted. In the Passen- military, again, f o r locations where forecasts ger, Cargo and Military areas, there were are not generally prepared. All expressed an several areas of common concern. One of the i n t e r e s t and concern about low-level w i n d shear.

concerns involved communications. W e found t h a t There was a concern about lack of observations, internally these systems had very excellent concerning mainly the military and the cargo communications: getting information within people. The cargo people, particularly, were their own systems; b u t , externally, w e had a Of course, while not speci- concerned as they had a l o t of operations l a t e number of problems.

f i c a l l y a forecasting problem, b u t a communica- a t night and observation stations were s h u t tions problem, i t has an impact on forecasting. down. L i g h t n i n g was a large concern for the the b u t to a lesser extent, f o r the other For example, the system response problem: military, terminal forecast goes bad; there is a time lag groups as well. The other groups recognized from the time forecasts a r e updated and back t h a t lightning may be more of a problem l a t e r on as they acquired more sophisticated on-board into the system. Also, there a r e problems in getting p i l o t reports shared through the system. electronic gear. Air turbulence was primarily The time frames of i n t e r e s t for most of these a problem f o r the military and a i r refueling operations , a1 though other groups acknowledged

groups were in the shorter range ... down around

3 - 6 hours; although f o r planning purposes, the that clear a i r turbulence, i f i t became severe, i s certainly a factor as f a r as passenger com- a great cost., One of the primary hopes in t h a t f o r t i s concerned, as well as safety. area of significant improvement was, f o r example, using the work t h a t Bob Miller described i n his Severe weather was an important problem f o r a l l impromptu session yesterday morning, the GEM o f these groups, particularly pertaining t o S t a t i s t i c a l approach, where a forecast f o r a terminal can be made a t a f a i r l y low cost and real-time information on severity of weather and location o f severe storms. can be updated frequently as information becomes avai lab1 e.

The next two groups were corporate aviation and Low-level wind shear, a h i g h priority; however, general aviation. They complained about the i t looks as i f i t ' s going t o be quite a while lack of communications, or poor communications, before that problem is solved or amenable t o They found i t d i f f i c u l t t o in the system.

solution. W e can see some of the shorter bene- secure weather information t h a t was updated in f i t s , such a s John McCarthy mentioned l a s t n i g h t .

a timely fashion. Also, there was a problem i n Particularly, i n the area of education and aware- accessing forecast information...in particular, ness. A s f a r as any k i n d of detailed forecasting being able to access FSS briefers i n any k i n d of a low-level wind shear, t h a t ' s going t o take of timely fashion. Time periods of i n t e r e s t quite a b i t of e f f o r t and i t ' s going t o be costly.

were primarily in the short range from 0 - 6

hours. For some planning purposes, there was Lack of observations is a h i g h p r i o r i t y f o r the i n t e r e s t i n a forecast i n excess of s i x (6) military as well as for some of the corporate hours. Icing was a problem f o r many of the and general aviation people. W e considered t h a t a i r c r a f t that had t o operate a t the f l i g h t a long-term e f f o r t a t h i g h cost would involve levels in which icing tended t o be prevalent.

the advent of automated surface observations as Ceiling and v i s i b i l i t y was a problem, particu- they become available, Lightning forecasting l a r l y for those stations that lacked observa- was mainly a secondary priority, b u t s t i l l tions. W e have heard about t h i s problem before, significant as f a r as the military i s concerned.

Low-level wind shear was acknowledged a s a Here again, I t h i n k there is a need f o r new serious problem; and, as I mentioned before, technology, better observation and detection, particularly the lack of observations.

and ways f o r getting the information into the system and disseminated. Similarly, clear a i r Lightning was not of much concern a t this point.

turbulence (CAT) i s another phenomenon t h a t one However, as future systems develop, there will cannot easily forecast because of i t s transitory be more concern in the future. Clear a i r tur- nature and realtively small scale. T h u s , fore- bulence was not expressed as a significant casting CAT is not going t o be a near-term, problem compared to other problems unless i t high-payoff propositi on.

became severe. Severe weather was indicated as important. All f i v e (5) groups had l i t t l e or Severe weather i s a major concern f o r a l l areas.

no concern about the problems associated w i t h There a r e improvements t h a t are available i n the ozone or acid rain, N o one expressed a parti- short term, W e have new technology, resulting cular concern in these areas.

as an off-shoot of the MCIDAS development, t h a t w e are now working with i n Kansas City. W e have W e t r i e d to p u t together a quick and d i r t y matrix our own stand-alone system called CSIS, which of some of these forecast parameters and some of stands f o r Centralized Storm Information System.

the perceptions from the different groups a s to I t h i n k w e are going t o see improvements through what was important. W e t r i e d t o make some these developments and technology, a t moderate assessment as to whether improvements were cost.

achievable i n some of these areas; and, i f so, how long i t would take t o make them. W e also In conclusion, many of the t h i n g s which a r e t r i e d t o make some statement about resources.

needed f o r aviation forecasting are t h i n g s that Relative to forecasting winds a l o f t , the cor- deal w i t h scales both i n time and space t h a t a r e groups had it as a porate and general aviation quite a b i t smaller than what we work w i t h a t very high priority. Passenger and cargo groups the present time. There i s a strong need f o r l i s t e d i t as a lesser priority. W e f e l t that greater temporal and spacial resolution, both i n

improvements i n winds a l o f t forecasting were

forecast models and in observations. !de t h i n k achievable i n the near term. W e know t h a t NMC t h a t NOAA should develop these through i t s will be making model improvement and enhancement research laboratories and that FAA, assisted by W i t h the advent of the w i t h i n the next year, NASA, should establish observational data.

next generation of computers , more frequent winds a l o f t forecasts and updates should be One of the common threads among our groups i s attainable. Icing was a very h i g h p r i o r i t y item the need f o r better education of the aviation f o r the corporate and general aviation groups.

community as f a r as meteorological problems a r e W e f e l t t h a t this represented probably a long- concerned. Developing and fostering a better term proposition as f a r as really being able t o understanding of meteorology, as well as better solve the icing problem from a forecast stand- i n the area of meteorology, training f o r p i l o t s point. There i s more research t h a t i s needed, i s needed. T h i s probably f a l l s into the arena There is a and more sensors t o be developed.

FAA. For many of the t h i n g s t h a t need of the lack of observations of icing a t the present t o be done, technology is available; however, time.

there i s a monetary need i n order t o develop them and get them on-line and operational.

The 1ow-cloud and cei 1 i ng probl e m was bel i eved t o be one t h a t could be tackled now and not a t a 114

MARY REPORT: General Aviation Committee

Members: Russell S. Lawton, Chairman, AOPA Don Cornwall, P i l o t , Delta Air Lines, ALPA Norman L. Crabill, Aerospace Technoloqist, NASAILanqley Research Center Kenneth M. Glover, Chief, Ground Based Remote Sensing Branch, Air Force Geophysics Laboratory Jean T. Lee, Program Coordinator, N S S L JoAnn Painter, President, Jolnlen Aviation Robert J. Shaw, Aerospace Engineer, NASAILewis Research Center Robert K. Sleeper, Aerospace Technologist, NASAILangley Research Center

INTRODUCTION

The general aviation p i 1 o t usual l y interfaces I'd l i k e t o give a quick overview of what the with the FAA Flight Service Station (FSS) when General Aviation Committee believes i s important Our group does to the general aviation community without going obtaining weather information.

not have a high degree of confidence t h a t the into too much detail of what some of the other committee chairmen will cover. Reinforcement in a b i l i t y of the p i l o t t o contact an FSS will a few areas couldn't h u r t , though. increase with the planned automation and con- solidation of FSS's around the country. The The other day i n our briefings, we heard t h a t state-of-the-art allows better methods of weather-related accidents i n general aviation obtaining weather information, and p i l o t s should account for four ( 4 ) out of every ten (10) f a t a l not rely solely on the FSS for obtaining t h i s accidents and two ( 2 ) out of every ten (10) non- information.

f a t a l accidents. When you hear those numbers, you know t h a t weather plays a significant factor, b u t keep i n mind t h a t weather is cited as a factor whether i t ' s a primary or secondary cause.

PREFLIGHT PLANNING

Unfortunately, there i s no area t h a t you can single out and say i f we could eradicate t h i s O u r group recommends t h a t FAA make the weather problem, the problem of general aviation acci- products available so the user can tap the data dents would be solved. The diversity of the base. T h i s could be accomplished through the beast i s such that i t simply is not possible.

use of home computers, which are growing i n The number one priority of the General Aviation numbers every day. Many people use them, and Committee is getting better weather information would not have t o j u s t i f y the purchase of one t o the pilot. I t seems whenever w e come t o solely on the basis of obtaining weather infor- Tu1 lahoma or other industry workshops, this mation.

W e hope i f w e recommendation always pops up.

continue to say i t frequently enough and loudly Several other types of self-briefing systems enough, improvements will continue. were tested by MITRE Corporation f o r FAA. The d voice response system (VRS) provides the p i l o t will make the r i g h t decision on the ground. lrle w i t h a go/no go decision; or to, a t l e a s t , would l i k e the individual to make this decision obtain more data. Another system tested was the on the ground, since t h i s is a significant fac- vu-set, which i s a small CRT and keyboard t h a t tor in weather-related accidents.

can be rented from the phone company. There was a lengthy discussion about presenting weather The forecast people indicate more real-time data on television as i s presently on AM Weather infomation would help them, especially to- and the Weather Channel Our group believes a l l hards improvl'ng the amended forecast.

of these programs are useful i n the planning stage, and a decision can be made t o obtain more

INCREASED WEATHER OBSERVATIONS

data, i f necessary. A l o t of weather informa- tion i s available, b u t there seems to be a There i s a fundamental division of p i l o t s problem with government groups cooperating w i t h operating in the system; instrument-rated each other. Private industry will have t o pick pilots and noninstrument-rated pilots. Both up the ball in order t o make the weather pro- these groups have t h e i r share of accidents i n ducts more accessible., proportion t o their respective share of the p i l o t population. A member of the AOPA s t a f f conducted a study of weather-related accidents

OBTAINING BETTER WEATHER INFORMATION

and found that the noninstrument-rated p i l o t i s most likely t o have a n accident d u r i n g the

IN-FLIGHT

en route phase of f l i g h t .

The weather briefing process takes two forms: the pre-flight stage, and the in-flight stage.

In those accidents reviewed, the accident The most important information d u r i n g the in- occurred furthest from a weather observation f l i g h t stage i s the p i l o t report (PIREP). The s i t e , which was not the destination airport.

P I R E P is highly perishable information. I t i s To restate the problem, these accidents occur useless i f not disseminated quickly. There closer to the destination t h a n the observation should be a simple machanism f o r accepting and point.

this information. One method disseminating This is suggested i s the VOR voice channel.

Our recommendation i s t o i n s t a l l automated done during the summer months in the N e w York i n those areas weather observation equipment area when severe weather avoidance plans (SWAP) which lack real-time weather. I t was mentioned are in effect. A broadcast i s made over the t h a t there are 900 automated observation s i t e s Phillipsburg and Coyle VORTAC's announcing the planned f o r the near future. Our understanding use of SWAP and the type of delays which should of t h i s program i s that the actual number of be expected. This device should be explored f o r weather observations won't increase. These disseminating p i l o t reports for a specific area.

automated s i t e s will only replace human obser- vers presently in existence. So i t does not M e are encouraged t o hear t h a t lease service A appear as i f there will be an increase i n the will be installed in a i r route t r a f f i c control number of observations when the automated ones centers so that the center weather service unit are i n place.

There i s (CWSU) can input PIREPS t o the system.

s t i l l the problem of getting the p i l o t reports, There are approximately 2500 airports in the and getting t h a t information passed from the United States w i t h approved instrument approach controller to the CWSU.

procedures, and less than 1000 of these airports have weather observations. W e had always hoped A problem with en route f l i g h t advisory service the money for these much needed observations (EFAS) was also discussed. Signal coverage f o r would be available from the trust fund, b u t i t t h i s service is not adequate in a l l areas, appears as i f these monies will once again be especially in remote locations where real-time impounded i n t o the general fund. W e hope t h i s weather information i s a necessity.

does not happen. Some of the money p u t into the coffers by the users should be returned f o r these

FORECASTING

type of aids.

There is a lack of c r e d i b i l i t y i n the forecast, and our group believes t h i s is a factor i n avi- ation accidents. Many p i l o t s do not have a high The areas our group believes are most important degree of confidence and simply do not believe wri tten materi a1 s the forecast. I t was acknowledged by the fore- i n t r a i n i ng/s imul a t i on are : and in-flight exposure t o weather hazards.

casting people that t h i s area could be improved.

The two c r i t i c a l areas f o r planning are the long- P r i n t e d material provided by the FAA f o r p i l o t s range forecast (24 hours) and the 12-hour fore- i s woefully inadequate in certain areas. Icing cast. The 0-6 hour forecast i s also important i s a good example, The o f f i c i a l publication to a s s i s t in-flight decision making.

FAA t o t e s t pilots on icing contains used by only three ( 3 ) pages of copy on the subject.

Another area of concern i s the amended forecast.

Certainly you will agree this area needs improve- When i t i s necessary t o amend a forecast, how ment, bad i s the weather going to be so I can make the r i g h t decisions? If the c r e d i b i l i t y of the forera$+ P G l ! l d be improved, hopefully, the p i l o t There needs t o be better training w i t h respect exams so t h a t i t ' s no longer possible t o pass w i t h o u t s u f f i c i e n t weather t o weather hazards. The inexperienced p i l o t one of these exams knowledge. An individual should be required should have the exposure to icing and thunder- to pass the section o f the exam on meteorology storms as part of a judgment training program.

before continuing the c e r t i f i c a t i o n process.

The general aviation p i l o t i s the first step i n the training process f o r proper judgment t r a i n - ing. Adequate training will prevent many pro- Finally, better training i s needed f o r special Industry should make avail- blems further down the road as t h i s p i l o t be- types of equipment.

able formal training programs on the use of comes a corporate or a i r l i n e pilot.

devices such as weather radar, de-icing/anti- With respect to meteorological knowledge, w e icing equipment which a p i l o t does not ordin- should return t o sectionalizing p i l o t written a r i l y receive d u r i n g basic training.

Y REPORT: Cargo Airlines Committee

Members: Robert L. Giordano, Chairman, Federal Express Corporation Keith W. Balcom, Staff Engineer, Air Line Pilots Association John H. Bliss, Captain, Flying Tiger Line, Retired Richard E. Cale, President, Environmental Research Applications, Inc.

Frenando Caracena, Physici s t , NOAA/ERL/Ob!RM Mark A. Dietenberger, Research Physicist, University of Dayton Research I n s t i t u t e George H. Fichtl , Chief, Fluid Dynamics, NASA/MSFC Ossi Korhonen, Research Meteorologist, Finnish Meteorological I n s t i t u t e Byron B. Phillips, Manager, Research Aviation Facility, NCAR

The following topics represent issues addressed F0R i s

and summarize the discussion r e l a t i v e t o those issues.

N W S i s not responsive t o user's tailored re- quirements. W e should not pay f o r a product

FORECASTING FACILITIES

t h a t requires modification to s a t i s f y o u r needs.

The basic domestic forecast requirement f o r I t i s wasteful f o r MWS t o generate a finished aviation purposes i s the 6-hour forecast.

product and f o r a user or separate contractor t o do the same work to s a t f s f y user needs.

There i s a need f o r an examination of the para- meters f o r timely update and revision of the An alternative is f o r NWS t o accumulate the raw original forecast.

data to be made more readily available t o the private sector , a1 lowing the users t o contract Update or validate the original forecast a t f o r their desired services whether synopsis, l e a s t every two hours, preferably each hour.

wind forecasting, etc. Meanwhile, N W S can make t o a " r u n n i n g " Consideration should be given their current products avail ab1 e t o government forecast t h a t i s continuously good f o r a 6-hour agencies and a s s i s t them in preparing t h e i r period b u t renewed every two (2) hours or l e s s , not just revised based on significant chanqes. unique products, i.e. , FAA requirements f o r aviation weather: Deoartment of Agriculture/ Tiqhten the parameters f o r revisinq a forecast Interior requirements f o r t h e i r weather pro- based on the l a t e s t information, e.g., hourly ducts, etc.

or special observation, etc. Provide f o r a more Due t o the reduction i n weather observation d i r e c t and current feedback or interface between users and personnel producing the forecast. capabi 1 i ty resul t i n g from recent tower clo- sures and tower reduced operating hours and Modify the use of terms such as "occasionally" the reduction i n Flight Service Stations, i n - and "intermittently" in the body of the fore- novative methods a r e required t o provide infor- cast. That is useful information, however, i t mation f o r destination airports where meteorolo- should be clearly identified a s advisory i n gical data i s not sufficient t o s a t i s f y current nature so as not t o be used t o determine the terminal forecast needs. There is a need f o r a legality for f i l i n g to that location as a "vicinity" forecast which is more detailed than destination or a1 ternate. Advisory information current area forecasts and designed t o provide could be appended to the forecast message as better information than available from an a separate advisory, not a "remark".

observation several hours old.

d 118 FAA take the lead and assure timely and adequate

CO~~UNICATIONS FACILITIES

Research and Development results on low-level Establish a n effective, "no-hassle" method of wind shear be made available f o r f l i g h t simula- handling PIREPs; assuring dissemination of t o r application. The data would be used by the PIREPs to those agencies requiring them, t o c a r r i e r , as coordinated w i t h , and acceptable to, include a prescribed level of d e t a i l . FAA Flight Standards, t o enhance simulator pro- grams.

The shortcomings created by closed or reduced hours FAA/MWS f a c i l i t i e s must be overcome.

O P E R A ~ I O N S / A I R ~ R T FACILITIES

N1dS and FAA should iointlv a c t as a focal aoint Vigorously continue research and development on f o r determination o f user needs a t a given fog dispersal systems. Assure t h a t such systems airport i n order t o develop methods of are fundable through the Trust Fund.

acquisition/dissemination of weather data f o r that airport. N M S provide training and c e r t i - NASA vigorously pursue the establishment of fication f o r a supplemental observation station. standards f o r runway f r i c t i o n measurement and operational reporting of that data. Standards Immediately begin uti1 ization of closed/reduced should be established f o r measurement, method hours FAA tower f a c i l i t i e s f o r acquisition/ of dissemination and computations of a i r c r a f t dissemination of weather observations.

performance.

NASA/FAA should provide operational advisory Assure the a v a i l a b i l i t y of weather observations

information on the use of distance-to-go runway

a t a l l public airports as a condition f o r markers f o r performance checks/reference.

provision of approach control service or f o r certification of instrument approach.

NASA/FAA develop procedures and equipment f o r the integration of ground speed indications A W O S Provide f o r the dissemination of complete and/or other airborne and ground based low-level data. Criteria used by FAA and N W S should w i n d shear detection devices.

consider user needs, in addition t o t h e i r own respective needs. N o important observational Airport Management should bring together local data should be withheld, such as not reporting interests (carriers, corporate aviation, FBOs, a l l cloud levels above a given altitude.

pol i t i c a l ) t o determine the extent t o which closed or reduced-hours tower faci 1 i t i e s could Develop a communications system, possibly a Data be utilized f o r weather data acquisition/dissem- Link, t o take advantage of real-time weather ination, and possibly airport advisories; seek and wind information constantly available from FAA authorization for the use of those f a c i l i - en route a i r c r a f t (see S a t e l l i t e section).

t i e s and equipment where reduced hours o f operation are in e f f e c t .

TRAINING/ SIMUL A T ~ N FACI L l TI ES

NOAA provide users with Flight Management- oriented material on the parameters f o r updating Weather s a t e l l i t e interests should s o l i c i t the terminal forecasts; the A I M or an Advisory Cir- attention of the aviation professional groups cular could be used.

(ATA, IATA, ATCA, ALPA, NBAA, AOPA, e t c . ) i n order t o encourage t h e i r constituents t o pro- FAA must assure t h a t adequate training i s pro- vide accurate and detailed PIREPs t o be used i n vided a l l users prior to implementation of the correlation of s a t e l l i t e data; explain fu- Automated Flight Service Stations.

ture benefits t o be derived from such correla- tion t o provide s a t e l l i t e capability t o detect Recommend development of ground based and a i r - and/or forecast CAT and other aviation-related borne wind shear detection systems for detection phenomena. Coordinate the use of communications and avoidance of hazardous low-level wind shear.

s a t e l l i t e s for the d i r e c t relay of weather Develop training procedures for: satel 1 i t e products t o en route (.especial l y oceanic) a i r c r a f t . Provide f o r communication 0 The use of ground speed, i f available, s a t e l l i t e relay of synoptic weather data and on approaches as one possible means t o cope observations to en route a i r c r a f t , especially w i t h low-level wind shear; oceanic. Encourage NASA and FAA t o develop an automatic a i r s a t e l l i t e ground communication 0 Optimizing performance of a i r c r a f t not link to relay both weather information and a i r - equipped w i t h ground speed o r other wind shear c r a f t position, a l t i t u d e , and path f o r trans- detection devices; oceanic f l i g h t . T h i s development should rely on navigation data from GPS (Global Positioning 0 Use of new wind shear detection devices System) to ensure accuracy necessary f o r i m - proved a i r t r a f f i c control over oceani'c areas.

as they a r e devel oped Publish instructional data on low-level wind shear for pilots not using sophisticated f l i g h t si mu 1 a tors.

SUMMARY REPORT : Corporate Aviation Go

Members: Leo Boyd, Chairman, Tennessee Eastman Company Robert S. Bonner, Physicist, Army Atmospheric Sciences Laboratory Warren CamDbell , Aerospace Engineer, NASA/MSFC Vernon W . Keller, Cloud Physicist, NASA/MSFC Porter J. Perkins, Aerospace Engineer, ANALEX Corporation Wayne Sand, Professor/Flight Facility Manager, Navy/University of Wyomina Sheri S. Sankey, Consultant, Aero WX Alan A. Woodfield, Head of General Aerodynamics Sect., Royal Aircraft E s t a b 1 i s hment

INTRODUCTION

In considering general aviation versus business/ corporate aviation s t a t i s t i c s , w e d o n ' t have a F i r s t , l e t m e thank UTSI for inviting m e here t o way of breaking out w h a t i s pleasure and what i s represent business (corporate) aviation. I t ' s business flying. All agriculture, business/ been an enlightening experience f o r m e to see corporate and general aviation a i r c r a f t together how f a r this distinguished international g r o u p consume approximately 10 percent of the total has gotten into some atmospheric science re- aviation fuel plus transport approximately one- search in areas that really concern p i l o t s in third (1/3) of a l l inter-city passengers. Com- being able t o maintain the highest level of mercial a i r l i n e s transport most of the passengers safety in business/corporate aviation operations.

on longer distance f l i g h t s . Business a i r c r a f t operator companies contribute with t h e i r goods There i s a purpose i n corporations having b u s i - and services and associated business a f f i l i a - These a i r c r a f t provide a trans- ness a i r c r a f t .

tions (example: auto maufacturers and t h e i r portation system to help gain more time f o r dealers) better than 50 percent of the Gross management, Business a i r c r a f t a r e among the few National Product.

unique tools available which can gain real chunks of time f o r management versus those using Corporate p r i o r i t i e s in i t s f l i g h t operations mass transportation. In the business a i r c r a f t are: safety is f i r s t , second, third and fore- engine a i r c r a f t f l e e t , there a r e many single most. Safety has to come f i r s t , or the r e s t of plus more than 12,000 piston twins, about 7,000 i t s services and conveniences a r e f u t i l e . Re- turbine-powered a i r c r a f t , and approximately l i a b l e transportation i s next. I t ' s better when 6,000 roto-craft, w i t h most of the roto-craft you can expect t o make your appointments. That's being in the energy f i e l d (numbers rounded o f f ) .

the reason management i s providing aviation de- O f the airports that business a i r c r a f t operate partments w i t h better a i r c r a f t including better into, 6,700 a r e public-use airports; 5,600 of instrumentation i n the cockpit. Many companies them a r e paved; 4,600 of them a r e lighted and a r e now using contract training centers f o r better than 2,000 have instrument approaches t h e i r f l i g h t crews f o r s i x months proficiency There a r e approximately (numbers rounded o f f ) training and currency checks just like the a i r - 430 control towers. Some of these a r e o u t of l i n e pilots get.

service temporarily and many o f the remaining active towers close a f t e r 1O:OO or 11:OO P.M., Economics i s also a concern of business manage- and open between 6:OO o r 7:OO A.M. everv day.

ment in a l l of the afore-mentioned corporate Approximately 900 airports have weather obser- a i r c r a f t operations. In any free-enterprise vations; some of these are by certificated system, managers show the same concerns as observers using unicom radios f o r transmitting managers i n government agencies. There is j u s t weather information t o pilots.

not enough money t o go around for everything Businesses operate a i r c r a f t from small twins u p for everyone; l i k e you, w e must p r i o r i t i z e our to some 30 companies, who a r e operating two, objectives.

three and four-engine Boeing-air1 ines-type a i r - craft. Most f l y domestically and quite a few High on our l i s t is passenger convenience, f l y internationally. Business a i r c r a f t vary i n f l e x i b i l i t y and comfort and minimization of operations from unpressurized i n the lower travel frustration factors; b u t these factors levels u p t o 51,000 feet. More corporate a i r - do not override the other factors whenever c r a f t are being Certificated above 45,000 f e e t safety may be compromised. For safety, business to be able t o f l y westbound above the stronger aviation needs easier access t o b e t t e r weather From the business a i r c r a f t j e t stream sinds.

The FAA re-emphasized t o the busi- information.

operator's standpoint, particularly f o r the ness aviation committee d u r i n g these meetings heavier a i r c r a f t w i t h the l a t e s t color radar t h a t until conversion to the new super f l i g h t equipment installed, the crews are getting pretty service stations is complete, we a r e t o be good information on severe storms. W e normally assured equal or better service a s policy; b u t use a l l the severe weather data available p l u s folks, i t ' s getting worse in r e a l i t y . W e need any other good weather information you providers r e l i e f now in easily acquiring real-time weather have available, provided the information is and notams information if safety i s t o be main- timely and readily accessible. M e must work tained and i f w e a r e to rely on the FAA/NWS's responsibly w i t h a l l available knowledge and common system. In many airport weather stations, information i f w e a r e t o maintain safety, com- NkIS personnel refuse to provide p i l o t s w i t h hard f o r t and efficiency .

copy. W e require more terminals with weather observations , automated or otherwise, and easy Judgment training is one t h i n g t h a t i s i n the access to these.

early development stage (such as the P i l o t Judgment Study contracted to Embry-Riddle Uni- Many of o u r f l i g h t s are to remote areas which versity by FAA for research and development).

A s f a r have poor t o no weather information.

When developed, i t i s hoped t h i s training can back as President Nixon's time, there was a get more people to use common sense and know- policy instituted to encourage building new ledge i n a predictable, logical and rational industrial plants i n remote areas a s one means manner, This type training, when available, can of dispersing the nation's industrial base and be extremely beneficial t o aviation. W e also population f o r national defense. This i s a need t o i n s t i t u t e state-of-the-art training t o unique national public benefit. Major disper- reduce the amount of a p i l o t ' s time needed for sions of industry can help reduce the chance effective recurrency training. ( A sage once of enemy nuclear blackmail. I t ' s also another said i f you t h i n k training is expensive, t r y means to help keep young people in rural areas ignorance.) I'm convinced, i t i s more impor- by providing jobs there. However, i f w e can't tant t h a n ever from listening t o t h i s group get specific weather information, i t i s d i f f - report on new developments i n weather research c u l t to reliably dispatch a i r c r a f t into these and forecasting techniques, t h a t formal class- I t i s relatively easy t o travel between places.

room instruction must be reinstituted f o r basic the metropolitan centers because they normally updating of subject materials.. .not only for have excellent weather and navigation f a c i l i - business a i r c r a f t crews and general aviation t i e s .

p i l o t s , b u t f o r a i r l i n e p i l o t s , also. Class- room instruction i n review of basic and new W e need better short-term forecasts f o r icing, developments in aviation knowledge is essential particularly f o r the a i r c r a f t t h a t ' s making an and primary prior t o making best use of advanced approach. If an a i r c r a f t i c e s up on approach and f l i g h t simulation f o r cost/operational effec- must make a go-around b u t cannot climb back u p tiveness. W e p i l o t s as a group a r e permitting through the icing, folks, i t then becomes a bad ourselves t o d r i f t . In the early days of con- situation.

t r a c t school p i l o t recurrency training, basic Accuracy of terminal ceiling and v i s i b i l i t y subjects review was the f i r s t priority. From b i g question. W e find measurement i s s t i l l a what you're t e l l i n g us and from the t h i n g s you RVR is good; b u t , t o date, do not believe i t s have shown us, once you're a p i l o t , you don't overall accuracy i s good enough f o r go/no go necessarily remain a well-trained pilot. W e can decisions, W e do make look-see approaches. become forgetful in some areas i f w e do not re- B u t , a s a confidence factor, i t helps us i n ceive refresher training in appropriate general our efficiency, economics and planning i f w e subjects a s cockpit management, FARs, ATC, find out early t h a t the ceiling and v i s i b i l i t y meteorology, medical emergencies, etc. , as well are too low f o r non-precision approaches and as advanced specific a i r c r a f t systems and w e cannot land; then why not divert a t t h a t f l i g h t simulation. A s you know, among your time t o an alternate a i r p o r t , thereby saving own people and ours, motivation is not the same

time and money? f o r each person; b u t w e must do our best --

and w e are a l l flying w i t h i n the same system.

establish p r i o r i t i e s The committee was asked t o I believe w e must work together within the winds a l o f t accuracy, for icing, wind shear, the national system f o r improvement i f i t is to factors are a l l i m - severe storms, etc. These remain one of the world's best, Education w i t h this information when portant and w e need a l l of good guidelines f o r acceptable performance stan- efficiency .

appropriate for safety and is, I believe, preferable to mandatory dards regulations. Mandatory regulations i n h i b i t innovation.

I , personally, would l i k e f o r the runway con- operators), you have t o know a person well i n inches; dition information t o continue t o be before you can take his/her advice on whether o r and f o r other conditions stated as breaking not t o go. W e do need hard copies of weather action i s n i l , poor, f a i r and good. Pilots data and a means to get it. A 1 remote airports this language. I t will certainly be talk w i t h lighted, paved runways w i t h IFR approaches better when a new accurate d i g i t a l system i s need automated weather-reporting equipment w i t h developed; b u t w e must a l l use the current airborne p i l o t access t o this information.

system until a better system is developed. When everyone agrees to this new system and are W e have a concern f o r g e t t i n g more p i l o t reports trained i n its use, then i t can be widely imple- into the system and disseminating these. P i l o t m e n ted.

reports into the ARTC - when the system i s busy -

seldom get spread around. People a r e only human.

Are the runways clear? B y this, I mean a t n i g h t and/or during low v i s i b i l i t y conditions when

CONCLUSIO W

many towers are closed; and what about the 1,500 airports without towers which have instrument In review: These points covered a r e essentially approaches to runways f o r day and n i g h t instru- our p r i o r i t i e s w i t h special emphasis on being

ment conditions? Question f o r p i l o t s - is there

able t o get more information from remote broad- a car parked out there a t n i g h t on the runway casting a t the IFR airports where it is not you intend t o use; f o r example, unknown t o you, staffed by FSS or N W S personnel. For most ef- i s i t also being used as a lover's lane? Has a fective operations, w e do need hard copies of damaged a i r c r a f t been l e f t on the runway? I weather/NOTAM information. W e need recurrent have also seen a i r c r a f t j u s t l e f t parked on a training in a l l the subjects you're talking secondary runway, Have you? This i s dangerous; about here i n this UTSI, NASA, FAA, NOAA Work- and i t can be just as bad a s an a i r c r a f t flying shop i f w e are t o continue t o be well-trained into a downburst a t low a l t i t u d e , o r most any- professional pilots. Thank you, t h i n g else. We;re concerned about t h i s , W e don't know the answer. Federal Express' research Questions from the Floor on a fog-penetrating-type infrared heads-up display system may hold out hope.

W h y do you need weatherINOTAM hard QUESTION: copy? Wouldn't television copy be just as W e also have a real concern f o r lack of a system good?

which provides p i l o t s easy d i r e c t access t o aviation weather. Ladies and gentlemen, w e need RESPONSE: W e operators need i t t o assure hard copies of specific and professional quality effective f l i g h t planning and safe operations.

aviation weather and NOTAM information. lrle need For safety, the FAA requires hard copy of t h i s t o be able to review data and evaluate i t weather f o r a l l scheduled a i r c a r r i e r crews in an ongoing basis while en route, and not just i s prior t o take-off from each airport. There use a briefer's advice as to whether w e should no reasonable way t o commit so much data t o be able t o f l y or not. When you get i n t o heavy memory f o r long f l i g h t s .

a1 1-weather operations (and business a i r c r a f t do operate Category 1 down t o Category 3 A by some a

MARY REPORT(: Military Aviitiir Committee

Members: L t . Col. John D. Fox, Chairman, Director of Operations, U S A F A i r l i f t Center E. Buss, Staff Meteorologist, Flight Dynamics Lab., U S A F AFWAL/WEF Capt. Norman Harry W. Chambers, Acting Chief , Technical Integration Division, Directorate for Development and Oualification, U. S. Army Aviation Research and Development Command Col. Farid Cezar Chede, Brazilian Air Force, Retired Hugh J. Christian, Space Scientist, NASA/MSFC Maj. Gary A. DuBro, Chief, Atmospheric Electricity Hazards Group, AFWAL/FIESL

Maj. Edwin W . Jenkins, Assistant Chief, USAF - Air Weather Service/DNTS

Weneth Painter, B-57B Project Manager, NASA/Dryden F 1 ight Research Facility August M. Stasio, Pilot, United Airlines F i r s t , I would l i k e t o thank Dr. Frost, UTSI a t established airports w i t h i n t h i s system. When and the sponsoring groups f o r inviting the military a i r c r a f t operate from one a i r f i e l d to another within the system, then our requirements military t o participate i n this workshop. I , as one of the military representatives, a m i n f o r aviation weather a r e much the same as civi- lian requirements. However, most military mis-

the s t r i c t e s t sense an operations type -- no

technical background in the weather area -- sions do not operate i n t h i s manner.

s t r i c t l y a consumer of weather information.

Military missions most often depart home sta- This workshop has been a very enlightening tion w i t h the primary destination o r objective experience a s I've observed the interaction being something other than an established a i r - of the various groups and have become better f i e l d . ..enemy targets t o be bombed, a i r - informed concerning the major programs of par- refueling tracks f o r fighters and bombers, drop ticipating organizations. I would also l i k e zones where w e parachute i n troops and equip- t o thank each of the distinguished members of ment, or d i r t landing s t r i p s where w e offload our committee f o r his excellent work throughout men and supplies. Of course, d u r i n g peacetime, the workshop.

these objectives a r e practice bombing and gunnery ranges, air-refueling training routes,

INTRODUCTION

and training d r o p zones and landinq strips, When the mission is complete, the a i r c r a f t f l y This workshop has focused i t s e f f o r t s primarily to a designated recovery base or back t o home the needs of the users of aviation weather, on station both civilian and military, For t h a t reason, i t i s important a t the outset t o understand t h a t During peacetime, the military constantly military and c i v i l i a n aviation operations d i f f e r t r a i n s f o r i t s wartime mission; however, i t s consdierably even t h o u g h there are some aspects wartime needs a r e vastly different from peace- t h a t are similar.

time. Our military i s committed t o help defend The most common aspects a r e that both the civi- countries located i n a l l parts of the world lians and military operate w i t h i n the same a i r - and, consequently, during time of international the same route structures and under space, along c r i s e s , military objectives a r e often remote the same "system" w i t h i n the U. S., a s well as and distant points on the globe, The large a i r l i n e s , many international areas.

commuter a i r l i n e s , and most corporate and general Military exercises a r e routinely conducted t o aviation a i r c r a f t generally depart from and land t e s t our capabi1it.y t o accomplish our mission.

Exercise BRIGHT STAR 82 provides an excellent

RECOMMENDATION

example of the remote objective problem faced by our mi1itar.y today. T h i s exercise involved That Air Force and Navy research f a c i l i t i e s in o f airborne the movement of a larqe number cooperation w i t h other governmental agencies troops and t h e i r equipment nonstop from east continue t o develop and improve forecasting coast bases t o t h e i r objectives i n the deserts techniques and methodologies. Our requirements of Eqypt. The a i r c r a f t i n t h i s operation were range from very short l'go/no-goll forecasts i n f l i g h t refueled twice en route t o the a i r - ( l e s s than 6 hours) t o long-range planning and drop northwest of Cairo. Some of the a i r c r a f t

decision assistance forecasts, normally 1 2 - 72

recovered in Europe while others returned hours.

directly t o the U. S , In a more recent exer- cise, a i r c r a f t flew nonstop from east coast The committee found during interaction w i t h the bases to Europe f o r an airdrop and returned.

fixed committees several other areas of concern.

These a r e discussed below i n descending order These exercises i l l u s t r a t e i n a real way the of priority.

military's need f o r a capability to accurately observe the weather and produce valid forecasts

ATMOSPHERIC ELECTRICITY

on a worldwide basis. Each of these exercises required forecasts f o r multiple i n f l i g h t re- Lightning s t r i k e s have caused the loss of a fueling tracks over the Atlantic Ocean as well number of military a i r c r a f t over the l a s t few as the objective area and recovery bases. years. In just the l a s t two years, two C-130 a i r c r a f t were l o s t when fuel tanks exploded as a r e s u l t of lightning strikes. T h i s weather hazard i s of even greater concern as composite Our mil i tary commitments may, i n some cases , materials become more common in the manufacture require short notice deployment of forces i n t o of a i r c r a f t components and as digital f l i g h t areas of the world which have limited weather control (fly-by-wire) systems become the norm data available. These short-notice moves also in new a i r c r a f t .

limit our capability t o move sophisticated mo- b i l e weather s u p p o r t systems into the area.

RECOMMENDATIONS

Consequently the military needs improved capa- That the Air Force Flight Dynamics Laboratory, b i l i t y t o observe the weather i n the areas of the world t h a t are hostile toward the U, S . as i n conjunction w i t h N A S A and FAA, i n i t i a t e a well as those remote areas where w e have limi- program to: ted or no observation capability. Civilian weather s a t e l l i t e systems offer potential cover- develop electromagnetic data f o r cloud-to- ( a ) age of many o f these areas. ground lightning from an airborne observation point; and The committee concluded that there are two prime needs f o r military aviation and made recommen- ( b ) develop design guidelines and t e s t proce- dations f o r each.

dures for fuel tank and electronic systems lightning protection.

Priority #1 Need i s f o r a more complete and accurate worldwide data base f o r aviation

FLIGHT SlMULATlOK

meteorological parameters such as ceilings , visibil i t y , winds and temperatures. The committee concluded that military p i l o t s probably have less experience flying i n severe weather t h a n do a i r l i n e or major corporate

RECOMMENDATION

pilots. This i s due a t l e a s t i n part t o the The Air Force Geophysical Laboratory and Air f a c t t h a t the military e i t h e r c u r t a i l s or Force Global Weather Central should continue suspends operations when severe weather is i n development of weather s a t e l l i t e applications the area, while the a i r l i n e s t r y t o maintain i n conjunction w i t h NOAA agencies. T h i s should t h e i r schedules. For t h i s reason, w e believe include improved wind and temperature sensing i t v i t a l l y important t h a t the military have and the pursuit of the total use of c i v i l i a n current state-of-the-art f l i g h t simulators s a t e l l i t e data worldwide. They should also which include weather effects t o a i r c r a f t . The support development of remote automated surface l a t e s t generation Air Foree simulators are great observing systems such as the one currently t h a t some have improvements over the old in under develooment by the U . S. Army.

computer generated visual systems and provide f o r excellent weather effects such as t u r b u - Priority #2 Need is f o r improved objective 1 ence, cei 1 i ngs and v i s i b i 1 i ty. However , even area forecasts i n the data sparse and data void these new systems are lacking in some areas such areas. The objective areas include tactical as wind shear.

and s t r a t e g i c targets, i n f l i g h t refueling tracks, drop zones, etc,, and the elements needed are clouds, ceiling, v i s i b i l i t y , winds and severe weather.

RECOMMENDATION

That the FAA and U S A F Air Weather Service That the Air Force System Command, Aeronautical investigate ways of reducing the time required System Division continue t o develop state-of- t o process and disseminate PIREP weather infor- the-art simulators f o r military use, These m a t i on pro- systems should include visual systems and visions f o r r e a l i s t i c models f o r weather effects Not a l l military a i r c r a f t a r e equipped w i t h VHF such as wind shear, cross wind, turbulence, radios; b u t f o r those t h a t are, increased use of icing and heavy rain.

VHF frequencies when talking w i t h ARTCC could provide better weather cross-tal k w i t h c i v i l aviation which uses VHF exclusively. I f the military p i l o t prefers t o not use VHF as the T w o areas the committee t h o u g h t needed additional primary radio, then monitoring the Center VHF emphasis were the processing of p i l o t reports frequency could provide essentially the same (PIREPs) and the need f o r increased use of very i nf ormati on.

high frequency (VHF) communications when i n con- t a c t w i t h an a i r route t r a f f i c control center

RECOMMEN~ATION

( ARTCC) That the Department of Defense and the FAA The committee believed t h a t PIREPs were rarely encourage the military to increase i t s use of processed i n a manner which makes the weather VHF when operating within the a i r route t r a f f i c information available to other p i l o t s in a sys tem.

timely manner. Although there seems to be a number of reasons for this, w e believe t h i s information i s of such importance t h a t e f f o r t s t o improve the system should be undertaken.

S U W A R Y REPORT: Passenger AirliRes Committee

Members: James F. Sullivan, Chairman, +leather Watch Kanaqer, US Air David C. Burnham, Physicist, Transportation Systems Center, DOT Thomas H. Genz, Northwest Airlines, Inc.

Kao-Huah h a n g , Research Engineer, FI.16 Associates, Inc.

James K. Luers, Senior Research Scientist, University of Dayton Research I n s t i t u t e John McCarthy, Staff Scientist, NCAR William W. Melvin, Chairman, Airworthiness and Performance Committee, ALPA H. Geoffrey Molloy, Manager, Flight Safety, Qantas Airways Ltd.

Peter J. Super, Senior Engineer, Flight Controls, Beoing Aircraft Company T o m Genz substituted f o r Jim Sullivan i n delivering the Passenger Airlines Committee Summary Report.

After meeting w i t h the Forecasting Committee,

INTRODUCTION

i t is our recommendation t h a t the identifica- The Committee on Passenger Airlines identified tion of meteorological conditions conducive t o many areas of concern and addressed specific microbursts be pursued; and, when appropriate, i n each fixed committee d i s - an advisory or a watch issued. T h i s is not t o items, identified cussion, i n the following areas: wind shear, be considered a forecast or a warning and should turbulence, fog and v i s i b i l i t y , lightning, ice, be designed to raise the consciousness of the W e attempted t o p r i o r i t i z e p i l o t and the controller. I t is further recom- f r o s t and rain.

these items f o r our committee, b u t found t h a t mended t h a t the hourly forecast be changed to a each time the discussions started, the problems 3/6/12/24-hour forecast with 3-hour updates.

related to wind shear and winds emerged as the Also, a cost-effective means of s o l i c i t i n g en most significant problem for our committee and route p i l o t reports should be effected t o dominated each committee session. 1 will t r y improve forecasting e Research and devel opment to summarize i n point order what w e concluded should continue towards the understanding of i n discussion w i t h each of the fixed committees l i g h t n i n g f i e l d s t o insure t h a t this information i s available by the time the new generation a i r - In the S a t e l l i t e Committee, i t i s our committee's c r a f t (composite and fly-by-wire) are p u t into opinion t h a t more research i n measuring winds service. There should be continued improvement a l o f t and temperatures is necessary. Sate1 1 i t e of wind and temperatures a l o f t forecasting t o interpretation of lightning sensors now and i n improve f l i g h t planning a b i l i t i e s . This infor- the future is necessary due t o the needs of the mation should be available by 0300 local time, new generation airplanes w i t h composite and particularly f o r the a i r l i n e s i n t h e i r f l i g h t fly-by-wire concepts. The continued development planning f o r the day.

i n s a t e l l i t e analysis of large-scale weather is needed; the interpretation techniques systems The information t h a t i s available i s l a t e should be available i n a training program t o enough t o cause some conflicts and i t should allow the aviation community t o understand these be moved to an e a r l i e r time.

large-scale weather systems.

Communications Committee: I t is recommended CONCLUSION: t h a t the establishment of a program t o increase the awareness of wind shear hazards be imple- The committee is concerned t h a t the capability mented. The program should establish responsi- of the NEXRAD Doppler technology t o detect wind b i l i t y , priority and authority to immediately shear caused by downbursts , microbursts and transmit the hazardous condition t o a l l con- g u s t front phenomena may not be f u l l y utilized cerned by tower and/or ATC personnel. Second because of s i t i n g requirements necessary, point: the air1 i ne meteorological weather to s a t i s f y a l l requirements of the multiple uses analysis should be included i n flow control of NEXRAD. The u n i t cost of NEXRAD units will determinations and a general improvement i n probably be too h i g h t o get appropriations f o r functional communications in this area would dedicated radars t o monitor appro be most desirable.

: sry major afrport. While the committee en- dorses the implementation o f NEXRAD f o r en route Training and Simulation: Wind shear character- and terminal meteorological information, w e i s t i c s should be incorporated into training believe t h a t dedicated Doppler radar should be programs i n general and should include two (2) acquired as soon as possible t o provide limited items. First, the recognition of a severe volume coverage, rapid information update and situation; secondly, the understanding of a i r - the dissemination of w i n d and intense rain c r a f t performance i n t h a t condition. Second hazard information to both tower and cockpits point: the industry should be aware t h a t the i n a simple, clear and concise format.

capability of current simulations to reproduce r e a l i s t i c w i n d shear situations may be very questions from the Floor limited. The wind shear data base used in many present simulator programs is seriously inade- OUESTION: Alan Woodfield, Royal Aircraft quate and potentially very misleading t o crews Establishment, Bedford, England.

being trained on those simulators. As a corol- lary t o t h a t , the results from the J A W S and Just a s o r t of personal requirement, really, b u t similar programs should make data s e t s of wind i t would be very helpful t o m e t o get a l i t t l e and microbursts available i n one year.

b i t of a feel for how w e might help a p i l o t in the cockpit to warn h i m e a r l i e r t h a t he i s The l a s t committee w e met with was Airports and getting into d i f f i c u l t i e s in wind shear.

There's The f i r s t point is the importance Operations.

i n any of the been no specific mention of t h a t of continued work on warm fog dispersal tech- wordings come across so far. How would you see niques. The second recommendation i s t h a t work work i n that area?

should also continue toward improved instrument landing capabilities; including both the a i r -

ANSWER: D o I understand your question ... t h a t

c r a f t and the f i e l d . Third point: the National you're asking i f there has been a determination Weather Service Storm Detection (SD) Thunder- of the most effective way to communicate wind storm Reporting System should be retained i n shear?

i t s present format, including Azmuth and Range ( A Z R A N ) , t o insure maximum utilization. Van- A 1 an Woodf i e l d RESPONSE : dalism of N A V A I D S and other v i t a l equipment relating t o f l i g h t operations should be ad- No. I'm asking whether, in f a c t , there is s t i l l dressed. I t was noted that one of the low-level a strong need t o have wind shear information i n w i n d shear a l e r t systems a t N e w Orleans had been the cockpit as opposed to the information you're repeatedly p u t out of service prior t o July as stressing from the ground a t the moment!

a r e s u l t of vandalism. Another point i s t h a t it was f e l t by some members of the committee t h a t a ANSWER: Yes. I don't t h i n k I have t o elaborate consortium operated car wash de-ice f a c i l i t y on t h a t , other than t o say, yes. T h a t i s cor- could have many advantages f o r the industry and rect. I t i s very definite, very positive.

should be examined. Finally, there a r e two points pertaining to operations. Research should be continued towards the resolution of the effects of heavy rain on the performance of a i r c r a f t ; and, secondly, the exclusion of ozone from the i n t e r i o r of a i r c r a f t and the forecas- t i n g of ozone locations should receive continu- i n g development by the effected a i r l i n e s .

W e are debating, now, whether we will continue

CLOSING REMARKS on an annual basis, o r whether we'll go t o an

18-month schedule basis. Dennis, who funds the Dennis Camp, NASA/MSFC: program i n the main, will have to make some de- cisions along those lines and w e will welcome I appreciate your attendance and participation your i n p u t s i n making t h a t decision.

i n this, o u r Sixth Annual Workshop; and want you to be assured t h a t were i t not f o r each of Again, we've come t o a close. I really appre- you, the workshop would not be as successful as c i a t e your attendance. I t is pretty much agreed i t has proven t o be. I want t o encourage you upon by our s t a f f and personnel throughout the to d i r e c t any negative comments you may have t o Space I n s t i t u t e t h a t this group i s one of the m e o r to any member of our Organization Commit- very best i n terms of personality and working tee, so t h a t w e may be able to take any a f f i r - cooperation. They always enjoy you people; w e mative action necessary t o enhance the workshop's enjoy you. !de know you're busy; and the f a c t value t o the aviation community. However, i f t h a t you take time t o come here and give us your you have positive comments, w e ask t h a t they be expertise and t o help us p u t together a program expressed to the members of your peer group, a s l i k e this i s greatly appreciated. I really well as t o any others who may benefit from such enjoy working with you. Thank you.

comments. Thank you.

Peggy Evanich, NASA Headquarters: Since Dick Tobiason i s not here, I t h o u g h t some- body needed to come u p and say a few words f o r NASA. I want t o thank Dennis f o r organizing this. I t h i n k you did a l o t of hard work; and I want to thank a l l of you for being here and making i t as successful, as i t was, Like Dennis said, please pass the word on to any other i n - terested people you t h i n k might be contributors workshop in the future, I ' d also l i k e to the t o t h a n k l:alt Frost for what I t h i n k i s imparting his own particular personality t o the workshop, and making i t such a success, Walter Frost, UTSI: Thank you, Peggy; t h a t ' s kind of you. A con- cluding comment I ' d l i k e t o make i s that w e need t o get the information from this workshop d i s - tributed in a summarized form. W e need to get i t into the right places., If you have sugges- tions as how t o best do t h a t , please j o t them down and send them to me, I know Frank Van DeMark has some good ideas and some good contacts i n FAA and he's written some of these down here f o r me.

What I ' d l i k e is to receive some suggestions from you on how t o summarize the right information from the workshop f o r the r i g h t upper-level managers; and then, recommendations on how t o get the summaries t o them, So, i f you have ideas along that l i n e , I would appreciate t h a n , As Dennis said, i f you t h i n k the workshop i s doing the right t h i n g , and many of you have already expressed t o m e t h a t you do, in terms of getting a collective view of the users' requirements of the system, you m i g h t inform the proper upper-level management.

I t would certainly help us i n the future i n getting some of the right expertise. W e sometimes have problems getting this a t the workshop, because some groups of upper-level management do not understand exactly what i t i s that we're trying t o do a t the workshop. They think t h a t i t ' s s t r i c t l y a meteorological workshop. In t r u t h , i t i s ; b u t w e want much more than just the meteorology. There i s the user and the weather information and how i t ' s a l l handled. So, com- ments along those lines will be very helpful t o us in keeping the program viable and effective.

APPENDICES

APPENDIX A

ACRONYMS

ACAR ARINC COMMUNICATIONS ADDRESSING BA BRITISH AIRWAYS AND REPORTING SYSTEM B FG B. F. GOODRICH AD I ATTITUDE DISPLAY BSM BACK-SCATTER METER ADP ADVANCED DEVELOPMENT PROGRAM CAT CLEAR ATR TURBULENCE ADAP AIRPORT DEVELOPMENT AID PROGRAM CDC CONTROL DATA CORPORATION AEH ATMOSPHERIC ELECTRICITY HAZARDS CG ATIS COMPUTER GENERATED AUTOMATIC AEHP ATMOSPHERIC ELECTRICITY HAZARDS TERMINAL INFORMATION SERVICE PROTECTION CG I COMPUTER GENERATED IMAGERY AFFDL AIR FORCE FLIGHT DYNAMICS LABORATORY CHI CLOUD HEIGHT INDICATOR AFGL AIR FORCE GEOPHYSICAL LABORATORY CNRC CANADIAN NATIONAL RESEARCH COUNCIL AFOS AUTOMATION OF FIELD OPERATIONS AND SERVICES CONUS CONTINENTAL UNITED STATES AFWAL AIR FORCE WRIGHT PATTERSON COSPAR COMMITTEE ON SPACE RESEARCH AERONAUTICAL LABORATORIES CRREL COLD REGIONS AND ENGINEERING AIM AIRMEN'S INFORMATION MANUAL LABORATORY AIRMET AIRMAN'S METEOROLOGICAL INFORMATION CRT CATHODE RAY TUBE ALPA AIR LINE PILOTS ASSOCIATION CSIS CENTRALIZED STORM INFORMATION SYSTEM ALWOS AUTOMATIC LOW-COST WEATHER OBSERVING SYSTEM

csu COLORADO STATE UNIVERSITY

AMDAR AIRCRAFT METEOROLOGICAL DATA RELAY

cw CONTINUOUS WAVE

AOPA AIRCRAFT OWNERS AND PILOTS CWA CENTER WEATHER ADVISORY ASSOCIATION C ! d P CENTER WEATHER PROCESSOR APU AUXILIARY POWER UNIT

cwsu CENTER WEATHER SERVICE UNIT

ARF AVIATION ROUTE FORECAST DABS DISCRETE ADDRESS BEACON SYSTEM ARINC AERONAUTICAL RADIO INCORPORATED COMMUNICATIONS SYSTEM DABS DL DISCRETE ADDRESS BEACON SYSTEM DATA LINK ARTCC AIR ROUTE TRAFFIC CONTROL CENTER DBV DIAGONAL BREAKING VEHICLE AS D AERONAUTICAL SYSTEMS DIVISION DIRECT CURRENT DC ASDAR AIRCRAFT/SATELLITE DATA RELAY DMSP DEFENSE k4ETEORrZLOGICAL SATELLITE AS I AIRSPEED INDICATOR PROGRAM ATC AIR TRAFFIC CONTROL DNA DEFENSE NUCLEAR AGENCY ATIS AUTOMATIC TERMINAL INFORMATION DOC DEPARTMENT OF COMMERCE SERVICE DOD DEPARTMENT OF DEFENSE AVRADCOM ARMY AVIATION R & D COMMAND DOE DEPARTMENT OF ENERGY AWOS AUTOMATED MEATHER OBSERVATION SYSTEM DOT DEPARTMENT OF TRANSPORTATION AVIATION WEATHER PROCESSOR AWP DSD DROP SIZE DISTRIBUTION AZRAN AZMUTH AND RANGE DUAT DIRECT USER ACCESS TERMINAL DFAS EN ROUTE FLIGHT ADVISORY SERVICE JAMOS JOINT AVIATION WEATHER OBSERVATION SYSTEM EDF EXPLORATORY DEVELOPMENT FACILITY JAWS JOINT AIRPORT WEATHER STUDIES EPA ENVIRONMENTAL PROTECTION AGENCY JDOP JOINT DOPPLER OPERATIONAL PROJECT ENVIRONMENTAL RESEARCH LABORATORY ERL JFK JOHN F . KENNEDY AIRPORT ETABS ELECTRONIC TABULATOR DISPLAY SYSTEM JPL JET PROPULSION LABORATORY EWEDS EN ROUTE WEATHER DISPLAY SYSTEM JOINT SYSTEMS PROGRAM OFFICE JSPO FA AREA FORECAST LaRC LANGLEY RESEARCH CENTER FAA FEDERAL AVIATION ADMINISTRATION LATAS LASER TRUE AIRSPEED SYSTEM FAR FEDERAL AVIATION REGULATION LIFT-TO-DRAG L/D FBO FIXED BASE OPERATION LDV LASER-DOPPLER VELOCIMETER FL FLIGHT LEVEL LFM LIMITED FINE MESH FSDPS FLIGHT SERVICE DATA PROCESSING SYSTEMS LLWS LOW-LEVEL WIND SHEAR FSF FLIGHT SAFETY FOUNDATION LLWSAS LOW-LEVEL WIND SHEAR ALERT SYSTEM FSM FORWARD-SCATTER METER LPATS LIGHTNING POSITION AND TRACKING SYSTEM FLIGHT SERVICE STATION FSS LSA LEASED SERVICE A FT TERMINAL FORECAST LWC LIQUID WATER CONTENT GAMA GENERAL AVIATION MANUFACTURER ASSOCIATI ON MC IDAS MAN-COMPUTER INTERACTIVE DATA GASP GLOBAL AIR SAMPLING PROGRAM MDA MINIMUM DECISION ALTITUDE GE GENERAL ELECTRIC MERIT MINIMUM ENERGY ROUTES USING INTERACTIVE TECHNIQUES GEM GENERALIZED EXPONENTIAL MARKOV MAXIMUM LANDING WEIGHT MLW GOES GEOSTATIONARY OPERATIONAL ENVIRONENTAL SATELLITE MSFC MARSHALL SPACE FLIGHT CENTER GPS GLOBAL POSITIONING SYSTEM MEAN SEA LEVEL MS L GWD GLOBAL WEATHER DYNAMICS MTOW MAXIMUM TAKE-OFF UEIGHT HIFT HELICOPTER ICING FLIGHT TEST MVD MEAN VOLUME DIAMETERS HISS HELICOPTER ICING SPRAY SYSTEM NACA NATIONAL ADVISORY COMMITTEE ON AERONAUTICS HIWAS HAZARDOUS IN-FLIGHT ADVISORY SERVICE NADIN NATIONAL AIRSPACE DATA INTERCHANGE HEADS-UP-DISPLAY HUD NEWORK IAS INDICATED AIR SPEED NATIONAL AIRSPACE SYSTEM NAS ICAO INTERNATIONAL CIVIL AVIATION NAVAL AIR STATION NAS ORGANIZATION NASA NATIONAL AERONAUTICS AND SPACE INSTRUMENT FLIGHT RULES IFR ADMINISTRATION INSTRUMENT LANDING SYSTEM ILS NAVAI DS NAVIGATIONAL AIDS INS INERTIAL NAVIGATION SYSTEM NANOBARS NB IRT ICING RESEARCH WIND TUNNEL NATIONAL CENTER FOR ATMOSPHERIC NCAR RESEARCH IVRS INTERIM VOICE RESPONSE SYSTEM 7 32 NEXRAO NEXT GENERATION WEATHER RADAR S E R I SOLAR ENERGY RESEARCH I N S T I T U T E NHC NATIONAL HURRICANE CENTER SIGMET S I G N I F I C A N T METEOROLOGICAL ADVISORY NATIONAL METEOROLOGICAL CENTER NMC SST SUPERSONIC TRANSPORT SVR SLANT V I S U A L RANGE NOAA NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION SWAP SEVERE WEATHER AVOIDANCE PLANS NOTAM NOTICE TO AIRMEN TAS TRUE A I R SPEED NPRM NOTICE OF PROPOSED RULE-MAKING TCV TERMINAL CONFIGURED VEHICLE NRL NAVAL RESEARCH LABORATORY T I D S TERMINAL INFORMATION DISPLAY SYSTEM NSF NATIONAL SCIENCE FOUNDATION TOMS TOTAL OZONE MAPPING SPECTROMETER NSSFC NATIONAL SEVERE STORMS FORECAST CENTER TRACON TERMINAL RADAR APPROACH CONTROL F A C I L ITY NSSL NATIONAL SEVERE STORMS LABORATORY TS C TRANSPORTATION SYSTEMS CENTER NTSB NATIONAL TRANSPORTATION SAFETY BOAR0 TWEB TRANSCRIBED WEATHER BROADCAST NWS NATIONAL WEATHER SERVICE UDRI U N I V E R S I T Y OF DAYTON RESEARCH I N S T I T U T E OAT OUTSIDE A I R TEMPERATURE UHF ULTRAHIGH FREQUENCY OWRM OFFICE OF WEATHER RESEARCH AND M O O I F I C A T I O N UK UNITED KINGDOM PATWAS P I L O T AUTOMATiC TELEPHONE WEATHER USAF UNITED STATES A I R FORCE ANSWERING SERVICE UTS I U N I V E R S I T Y OF TENNESSEE SPACE PDP PROGRAM DEVELOPMENT PLAN I N S T I T U T E P I R E P P I L O T REPORT uws U N I T E D WEATHER SERVICE P I R M PRESSURE I C E RATE METER VAS V I S S R ATMOSPHERIC SOUNDER PMS PARTICLE MEASURING SYSTEMS VFR V I S U A L F L I G H T RULES PROFS PROTOTYPE REGIONAL OBSERVATION AND VHF VERY H I G H FREQUENCY FORECAST SYSTEM V I S S R V I S I B L E AND INFRARED S P I N SCAN PSBT P I L O T SELF-BRTEFING TERMINAL RADIOMETER PVD PLAN VIEW D I S P L A Y V I S U A L METEOROLOGICAL CONDITIONS VMC RAE ROYAL A I RCRAFT ESTABL X SHMENT VOR VHF OMNIDIRECTIONAL RADIO RANGE R&D RESEARCH AND DEVELOPMENT VRS VOICE RESPONSE SYSTEM VERTICAL SPEED/ENERGY RATE INDICATOR RE&D RESEARCHy ENGINEERING & DEVELOPMENT VS/ERI R&T RESEARCH AND TECHNOLOGY vsr VERTICAL SPEED INDICATOR RRWDS RADAR REMOTE WEATHER DISPLAY V S / E R I VERTICAL SPETD/ENERCY R,?Tf. INDICATOR SYSTEM WIND, ALTIMETER, AND VOICE EQUIPMENT WAVE RSRE ROYAL SIGNALS & RADAR ESTARLISHMENT WBRR WEATHER BUREAU REMOTE RADAR RVR RUNWAY V I S U A L RANGE WALLOPS F L I G H T CENTER WFC SAR SYNTHETIC APERTURE RADAR W M O WORLD METEOROLOGICAL ORGANIZATION STORM DETECTION SD a WPAFB WRIGHT PATTERSON A I R FORCE BASE

wso WEATHER S E R V I C E O F F I C E

WPL WAVE PROPAGATION LABORATORY

ws I WEATHER S E R V I C E INTERNATIONAL

WSFO WEATHER S E R V I C E FORECAST O F F I C E a

ROSTER OF WORKSHOP PARTICIPANT

Name Address Phone Number D. Neil Allen Manager, Earth Station (303)491-8233 Colorado S t a t e University Department of Atmospheric Science Fort Collins, CO 80525 August H . Auer, Jr.

Professor, Department of Atmospheric Science (307)766-3245 University of Wyoming P. 0. Box 3038, University Station Laramie , MY 82071 Keith W. Balcom Staff Engineer (202)797-4000 Air Line P i l o t s Association 1625 Massachusetts Ave., N. W.

Washington , DC 20036 James R. Banks ATC & Airspace Consultant (6181256-31 74 HQ AFCC, Scott AFB & ATCA 881 Vassar Drive Edwardsvi 11e, IL 62025 John Blasic N W S Rep t o FAA (202)287-0022 National Weather Service FAA Headquarters 800 Independence Ave., S. W.

Washington, DC 20591 John H . Bliss Capt., FTL Retired (213)831-1813 Flying Tigers 2740 Graysby Avenue San Pedro, CA 90732 Robert S. Bonner Phvsi ci s t (505)678-1801

U.5. Army Atmospheric Sciences Lab

ATTN: DELAS-AS-I White Sands Missile Range, NM 88002 Roland L. Bowles Aerospace Technologist (804)827-3914 NASA/Langley Research Center Hampton, VA 23185 Leo C. Boyd Chief P i l o t (615)229-3423 Tennessee Eastman Company Box 511 TN 37662 Kingsport, Herbert I. Brody Assistant Federal Coordinator (301 )443-8704 M e teoro 1ogy/FAA A c ti v i ti es NOAA 11426 Rockville Pike Suite 300 Rockville, MD 20814 Ronald R. Brown Chief Staff Meteorologist (51 3) 785-2207 Aeronautical Systems Division U S A F A S D / W E Wright Patterson AFB, OH 45433 a Name Address Phone Number Physicist (617)494-2432 David C. Burnham U.S. Department of Transportation Transportation Sys tems Center Kendall Square Cambridge, MA 02142 Staff Meteorologist (51 3)255-5496 Norman E. Buss Flight Dynamics Lab USAF AFWAL/WEF Wright Patterson AFB, OH 45433 President (213)926-6149 Richard E. Cale Environmental Research Applications, Inc.

P. 0. Box 366 Cerritos, CA 90701 (205) 453-2087 Aerospace Engineer Dennis W. Camp ES-82 NASA/Marshall Space Flight Center Huntsville, AL 35812 Aerospace Engineer (205)453-1886 Warren Campbell ES-82, Building 4481 NASA/Marshall Space Flight Center Huntsville, AL 35812 P hys i c i s t (303)497-6269 Fernando Caracena NOAA/ ERL/OWRM R X 8 Boulder, CO 80303 (405)325-6561 Frederick H . Carr Assistant Professor of Meteorology Department of Meteorology University of Oklahoma 200 Felgar S t r e e t Norman, OK 73019 Harry W. Chambers Acting Chief , Technical Integration Division (314)263-1708 Directorate f o r Development & Qualification U.S. Army Aviation Research & Development Command 4300 Goodfel low Boulevard S t . Louis, MO 63120 (404) 765-6478 Manager, Weather C. L. Chandler Delta A i rl i nes Operations Center-Atlanta A i r p o r t Atlanta, GA 30320 Farid Cezar Chede Brazilian Air Force Rua Santa Luzia 651-9-audar Rio de Janeiro, Brazil (205)453-2463 Space Scientist Hugh J. Christian ES-83 NASA/Marshall Space F 1 ight Center Huntsville, AL 35812 (303)977-7483 Steven H. Cohen Senior Staff Engineer Martin Marietta Aerospace P. 0. Box 179 Denver, CO 80201 FAA Retired (301 )843-0172 Frank Coons Consultant 64 Lantern Lane Waldorf, MD 20601 Name Address Phone Number (713)367-4024 Don S. Cornwall Pilot, Delta Air Lines ALPA 6 Goldthread Court Woodlands, TX 77301 (804)865-3274 Norman L. Crabill Aerospace Technologist MS-247 NASA/Langley Research Center Hampton, VA 23605 I r i s C. Critchell Lecturer i n Aeronautics (714)621-8128 Director, Aeronautics Program Harvey Mudd Col 1ege Claremont, CA 91711 Mark A. Dietenberger P hys i c i s t Research (513)229-3921 University of Dayton Research I n s t i t u t e 300 College Park Avenue Kettering Labs 465 Dayton, OH 45469 Gary A. DuBro Chief, Atmospheric Electricity Hazards Group (513)257-7718 Air Force Wright Aeronautical Lab ATV 787-7718 AFWAL/FIESL Wright Patterson AFB, OH 45433 John H. Enders President (703)820-2777 Flight Safety Foundation 5510 Columbia Pike Arlington, VA 22204 Peggy L. Evanich Aerospace Engineer (216)433-4000 x6836 NASA/Lewis Research Center 21000 Brookpark Road M S 500-127 Cleveland, OH 44135 James Evans MIT Lincoln Lab (617)863-5500 Room V-125 x7475 P. 0. Box 73 Lexington, MA 02173 George H. Fichtl Chief, Fluid Dynamics Branch (205)453-0875 ES-82 NASA/Marshall Space Flight Center Huntsville, AL 35812 John D. Fox Director of Operations (919)394-2443 U S A F A i r l i f t Center Pope AFB, NC 28304 Sepp J. Froeschl AES CMQ (514)333-3070 100 Alexis Nihon Boulevard Ville S t . Laurent Quebec, Canada H9P 1x5 Walter Frost Director, Atmospheric Science Division (61 5)455-0631 University of Tennessee Space I n s t i t u t e x217 TN 37388 Tullahoma, Thomas H. Genz Northwest Airlines, Inc. (715)772-4460 Spring Valley, W I 54767 Robert L. Giordano Manager o f F 1 i g h t Safety (901 )369-3273 Federal Express Corporation Box 727, Department 100 Memphis , TN 38196-01 31 a Name Address Phone Number Kenneth M. Glover Chief, Ground Based Remote Sensing Branch (617)897-8924 Air Force Geophysics Lab Hudson Road Sudbury, MA 01776 Thomas E. Greer Deputy Director of Airports (801 )539-2425 S a l t Lake City Airport Authority AMF Box 22084 S a l t Lake City, UT 84722 Arthur L. Hansen Consulting Engineer (703)821-3516 Enterprise Electronics 726 Lawton S t r e e t McLean, VA 22101 Steve Henderson Meteorol og i s t (404)525-5900 Atlanta Air Route Traffic Control x293 NationaJ Weather Service 299 Woolsey Road Hampton, GA 30228 Keith A. Hill Supervision Flight Simulation Applications (206)237-9636 Boeing Computer Services M S 66-22 P. 0. Box 24346 Seattle, WA 98124 John W. Hinkelman, J r . PROFS Program Office (303)497-6819 NOAA/ERL 325 S. Broadway Boulder, CO 80301 Fred C. Hochreiter Chief, DATA Acquisition Division (81 7)334-2655 Nationa? Weather Service Southern Region 809 Taylor Street F o r t Worth, TX 76102 David W. Holmes Chief, Data Systems Division (301 1427-7722 National Weather Service 8060 13th Street Silver Spring, M D 20910 Kao-Huah Huang Research Engineer (615)455-1982 F W G Associates, Inc.

UTSI Research Park Tullahoma, TN 37388 Dale W. Istwan Air Line Pilots Association (3141741-9259 11534 CorJyn Drive St. Louis, MO 63138 Edwin W. Jenkins Assistant Chief (618)256-4741 Forecasting Services Division USAF-Air Weather Service/DNTS Scott AFB, IL 62225 John L. Keller Research Meteorologist (513)229-3921 University o f Dayton Research I n s t i t u t e KL-465 Dayton, OH 45469 Vernon W. Kel 1e r Cloud Physicist (205)453-0941 Atmopsheric Science Division ES-83 NASA/Marshall Space Flight Center Huntsvi 11e , AL 3581 2 Name Address Phone Number Cathy J. Kessinger Support S c i e n t i s t (303)497-0736 National Center for Atmospheric Research P. 0. Box 3000 CO 80307 Boulder, (607) 772-4282 Meteorol ogis t/Sys tems Engineer John T. Klehr L i n k Flight Simulation Division Singer Company Binghamton, N Y 13902 Research Meteorologist Ossi Korhonen Finnish Meteorological Ins ti t u te Aeronautical Department PL 503 00101 Helsinki 10 Helsinki , Finland 657515 (203)827-6412 Assoc. Technical Director Sidney Koslow Transportation Systems Division Mitre Corporation 1820 Dol 1ey Madison Boul evard McLean, VA 22102 (505)345-8236 Demos T. Kyrazis Senior Research Specialist R & D Associates 2720-B Broadbent Parkway, N. E.

A 1 buquerque, NM 87107 (301 )951-3972 Assistant Vice-Presi dent Russell Lawton AOPA Air Safety Foundation 7315 Wisconsin Avenue Bethesda, MD 20814 (405)360-3620 Program Coordi na t o r Jean T. Lee N S S L 1330 Halley Circle Norman, OK 73069 Senior Research Scientist (5131229-3921 James K. Luers University of Dayton Research I n s t i t u t e College Park Avenue Dayton, OH 45469 Regional Director 800-241 -6101 / Ted Mal lory (404)762-41 71 FLT Standards and Training Republic Airlines At1 anta International Airport Atlanta, GA 30320 Staff Scientist (303)497-0651 John McCarthy National Center f o r Atmospheric Research P. 0. Box 3000 Boulder, CO 80307 Meteorologist (202)382-6679 James 6. McLean, J r .

National Transportation Safety Board 800 Independence Ave., S. W.

Washington, DC 20594 William W. Melvin Chairman, Airworthiness & Performance Committee (214)463-1246 Air Line Pilots Association 1101 W. Morton Denison, TX 75020 (301 1427-7768 Robert G. Miller Senior S c i e n t i s t National Weather Service Techniques Development Lab 8060 13th Street Silver Spring, MD 20910 Name Address Phone Number H. Geoffrey Molloy Manager, Flight Safety Qantas Airways Ltd.

M A - 1 1 Kingsford Smith Airport Mascot, N.S.W.

Austral i a Keith F. Mordoff Engineering Editor (21 2)997-2313 Aviation Week 81 Space Technology 122’1 Avenue o f the Americas N e w York, N Y 10020 Vincent Oliver Chief Meteorologist (301)423-2113 Environmental Sate1 1 i te Data, Inc.

5200 A u t h Road Suitland, MD 20746 Frederick P. Ostby Director (816)374-5922 National Severe Storms Forecast Center National Weather Service 601 E. 12th S t r e e t Kansas City, MO 64106 JoAnn Painter President (805) 948-8969 JoWen Aviation 424 E. Avenue 5-7 Lancaster, CA 93535 Weneth Painter B-57B Project Manaqer (805)258-3311 NASAIDryden F1 ight-Research Faci 1 i t y x238 Box 273 Edwards, CA 93523 Porter J. Perkins Aerospace Engineer (21 6)433-4000 ANALEX Corporation x614Q 21 000 Brookpark Road Cleveland, OH 44135 Russel 1 Peterman Senior Engineer, Electronics (512)454-4797 Radian Corporation P. 0. Box 9948 A u s t i n , TX 78766 Byron B. P h i l l i p s Manager (303)494-4141 Research Aviation F a c i l i t y x7850 National Center f o r Atmospheric Research P. 0. Box 3000 Boulder, CO 80307 W i 11 i am P i ckron Manager, Sector Control (901 )369-3402 Federal Express P. 0. BOX 727 (102-180) Memphis, TN 38194 John Prodan President (605) 348-9329 AV-CON 1100 Kings Road, R t . 11 Rapid City, SD 57701 James F. W. Purdorn NOAA/NESS, Chief NESS RAMM Branch (3031491 -8446

U. S . Government

Department of Atmospheric Science Colorado S t a t e Unjversity CO 80523 Fort Collins, Name Address Phone Number Wayne Sand Professor/Flight F a c i l i t y Manager (301 )267-3561 U.S. NavylUniversity of Wyoming (307)766-3245 Department of Oceanography U.S. Naval Academy Annapolis, MD 21402 David A. Sankey Manager of Meteorological Peronnel (404)433-5100 The Weather Channel 2840 M t . Wilkinson Parkway S u i t e 200 Atlanta, GA 30339 Sheri Schneider Sankey Consultant (404)971-7050 Aero WX 5197 Riverhill Road Marietta, GA 30067 Robert Serafin Director, Atmospheric Technology Division (303 497-0744 National Center f o r Atmopsheric Research P. 0. Box 3000 CO 80307 Boulder, Robert J. Shaw Aerospace Engi neer/lcing Research (216 433-4000 NASA/Lewis Research Center x36 7 21000 Brookpark Road Cleveland, OH 44135 Robert K. Sleeper Aerospace Technologist (804 827-2273 NASA/Langley Research Center MS-243 Hampton, VA 23665 Joseph F. Sowar NEXRAD Deputy Program Manager (301 427-7370 Federal Aviation Admini s t r a t i on NEXRAD JSPO 14x7 8060 13th S t r e e t S i l v e r Spring, MD 20910 Charles H. Sprinkle Chief, Aviation Services Branch (301 )427-7726 National Weather Service, OA/W113 8060 13th S t r e e t , Room 1306 Silver Spring, MD 20910 August M. S t a s i o P i l o t , United A i r l i n e s (408)245-7044 Air Line P i l o t s Association 929 Olympus Court Sunnyvale, CA 94087 James F. Sullivan Weather Watch Manager (41 2)777-7172 U.S. Air Greater P i t t s b u r g h International Airport

P i ttsburgh , PA 15213

Peter J. Super Senior Engineer, F l i g h t Controls (206)237-4017 Boeing Commercial A i r c r a f t Company P. 0. Box 3707 S e a t t l e , WA 98124

John S. Theon Acting Chief , Atmospheric Dynamics and

(202) 755-8596 Radiations Branch N A S A Headquarters EE-8 Washington, DC 20546 Name Address Phone Number (301 )427-7370 Deputy Program Director C a m J. Tidwell NEXRAD/DOD 8060 13th Street Silver Spring, MD 20910 (416)667-4644 Meteorol ogi st/Instructor Jan Tissot van Patot Atmospheric Environment Service 4805 Dufferin Street Toronto, Ontario, Canada M 3 H 5T4 (81 7)334-2652 Regional Aviation Meteorologist Tommy W. Trimble Southern Region National Weather Service 819 Taylor Street, Room 10A29 F t . Worth, TX 76102 (901 )794-0049 Meteorologi st-In-Charge Paul S. Trotter Center Weather Service U n i t Federal Air Traffic Control Center ZME C W S U 3229 Democrat Road Memphis, TN 38118 Director (202) 695-9604 Paul D. Try Office of Environmental and Life Sciences Department of Defense U S A F Pentagon 3D129 Washington, DC 20301 (205)453-4175 ES-84 Robert E. Turner NASA/Marshall Space Flight Center Huntsville, AL 35812 (703) 768-81 02 President Frank E. Van Demark Frank E. van de Mark, Inc.

7863 Midday Lane Alexandria, VA 22306 (205)453-3100 Chief , Atmospheric Sciences Division William W. Vaughan ES-81 NASA/Marshall Space F 1 i g h t Center Huntsville, AL 35812 (3031491-8566 Professor and Head Thomas H , VonderHaar Department of Atmospheric Science Colorado State University F o r t Collins, CO 80521 (202)426-8333 Director Robert W. Wedan Systems Research & Development Service Federal Aviation Admini s t r a t i on ARD- 1 800 Independence Ave., S. W.

Washington, DC 20546 (301 )763-8282 Meteorologist Roger B. Weldon Applications Lab NOAA/NESS/DOC World Weather B u i 1 d i n g 5200 A u t h Road Camp Springs, MD Name Address Phone Number Terrell E . Wilson Planning Specialist (202) 426-8488 Air Traffic Service Federal Aviation Administration 800 Independence Ave., S. W.

Washington, DC 20591 Roger Winbl ade Manager, Subsonic Aircraft (202) 755-3000 NASA Headquarters Code RJT Washington, DC 20546 David E . Winer Manager, Energy Division (202)755-9717 Office of Environment & Energy AEE-200 Federal Aviation Administration 800 Independence Ave., S . W.

Washington, DC 20591 Alan A . Woodfield Head of General Aerodynamics Sect.

F1 ight Research Division Royal Aircraft Establishment Bedford, England Bedford (0234) 55241 Andy 0 . Yates, Jr. Pilot, United Airlines (703)765-7423 7413 Park Terrace Drive A1 exandria, VA 22307 a