Document
a ) .
I
NASA Tec h nical Memorandum 83564
. P e r fo rmanc e D e grad at ion of a n
Engine Commuter Type Aircraft in Measured
Natural Icing Conditions
lJ& S A -T _ -835 6_ ) PE R ¥ OR _&J C E D _ G R _ D A TIO _ G£ 1 i8 % -131 7 3
• 2X PIC A L T ff l _ EI I GI I _E CO a _UIEB 2 1 PE _ I R CII A FT
Z_ I aE& S UI I E D _ TU RA L _ Cl g_ CO _ D _ T IO I _ S (IIA S & )
31 p HC A0 3 / _ &Of CSCL O IC g nclas
G3 /0 5 g 27 97
R i c hard J . R a naud o, Kev in L . Mi kke l sen ,
and R obert C. McKnig h t
• Lewis Res earch Center
!_ Cl ev el and, Oh io
., !_ a nd
'i" I! Porte r J. Pe r ki ns, J r .
I "
t: An al ex Corp oration
:!: D ayton, Ohi o
_ ' _!_i i Pre pa red for the
, , , _ Twe nt y - s e c on d Aer o space S cie n ces Mee t i n g
' s po ns ore d by the Am e r ica n In s t i tu t e o f Ae r on a ut ,= , and A s tr o n au t ics .
!I' / R e no , Nev ada , Ja nu ar y 9-12 , 198 4
ti" [ -
i'i
C
i /
c_ ..... _ .
,j • i P ERFORMANCEDEGRADA T IONOF A TYPICAL T W I N ENGINE COMMUTERTYPE AIRCRAFT IN MEASURED NATURAL ICING CONDITIONS Ri c hard J. Ra n au d o,Kevin L. Mikkelsen,and Robert C. McKnight NationalAeronauticsand Space A d ministration Lewis ResearchCenter Cleveland,Ohio 44135 " and Porter J. Perkins,Jr.
Analex Corpo r ation 5335 Far Hi l ls Ave.; Suite 222 Dayton, Ohio 45429 Summar Z Glaze icing cause d the greatest aerodynamic performance l penalties in terms of increaseddrag This paper deals with the initial results of and re d uction in lift. Rime icing prov i ded the NASA Lewis Research Center'sfligl_t research proportionatelylower aero d ynamicperformance in quantifyingthe performanceof an aircraft in penalties.
various measured icing con d itions. Flight researchperforme d i n natural icing con d itions Data acquired through this flight test pro- supportsa numbcr of major program elements at gram will provide a basis to develop aircraftper- NASA. • One of tnese elements is to develop fo nn ance pre d ictioncodes for icing con d itions.
analyticalmethods (computercodes) that predict One such code is being developedunder a NASA aircraftp e rformancedegradation in a given icing Lewis ResearchCenter grant by the Ohio State c o n d ition. A maj o r problem in devel op ingt h e s e University. Th e ge o metry o f t h e icing re s earch co d es has been the lack of an experimentaldata aircraft,along with the measured icing environ- base where measuremen t sof the natural icing ment and correspondingaircraftperformance environmentwere associatedwith a corresponding degradationdata, will be used to provide a basis measurement o f aircraftperformancedegradation, for the developmentof this co d e.
Icing parameters such as liqui d water con- tent, temperature,cloud droplet sizes, and ice Intr oduction accretionswere measured with icing instruments mounte d on the research aircraft. Continuous The NASA Lewis Research Center is conducting on-line rea d ing of these instrumentsprovide d a an aircrafticing research pr o gram. Flight test- quantitative d isplay of the icing environment, ing is performedin natural icing con d itions to Thus, when icing was detected the extent of the supp o rt several major program elements. I Among icing could be monitoredand c o ntrolledby holding these elementsare f l ight experimentsthat provide within the icing area. ice accretionshape and attendant aerodynamic drag data for va l idatingc o mputercodes and the Lewis F o llowingeach measured icing encounter, Icing Research Tunnel ( IRT). Other elementsof level flight spee d / powerruns were made from maxi- the flight program involve _he evaluationof cur- mum obtainable level flight speed to a speed just rent icing in s trumentation, _ the collectionan d above sta11. When possible,repeat runs were ma d e d o cumentation o f icing cloud meteorologicaldata, after selectivelydeicing the wings and empen- and the measurementof aircraft performance nage. F light data were reduced to provi d e plots degradati o ndue to icing. This paper will address of the aircraftdrag polar for the measured"iced" the l atter element by presentingour initial • conditionand a lift curve (CL vs. _) as refer- experimenta l results in quantifyingthe perform- _I I n order to de t erminethe e f f e ct o f icing on aircraft in measurF_ natural icing conditions.
I ence d to th e unic ed o r cl e an airframebaseline, ance degradationof a twin engine commutertype !i engi n e-outperformancecapability,these data were Includedin these data are the mea s ured c o ntribu- al s o reduced t o provide plo t s of th rust horsepower t ion of the wing s dnd t ail group to the overall requiredvs. single engine power available, d rag of the ice d aircraft. These d ata will be used to verify compute r codes currentlyunder Aircraftperformancemeasuremen t sare refer- developmen t , t ha t pred i c t t he degradationof air- enced t o th o se characteristics of the icing con d i- craft performance in icing con d iti o ns. _ tion tha t crea t ed t he ice accreti on s. Performance degradation is primarily influencedby the amount A major problem in developing the s e codes has and s i _ape of t h e accumulatedice. The amount of been the lack of an experimentaldata base where L ice was measured but shape was no t quan t itatlve l y comprehensiveai r craftperformancemea s urements determined. In addit i on to presenting s pecific were ma d e along with c o rrespondingmea s urement s of : , values of the i cing variable s ,the icing encoun- the ic i ng environment. In thi s regard some ter s were c h aracteri z edin term s of t heir relation li mitedefforts were made in the pa s t4, 5 but the to frequencyof occurrence an d the FAA icing clou d resultingdata lacke d eitner complete documenta- criteria for ice protectionsy s tems, tion o f the icing c l oud variable s ,and / or compre- hen s ive measurementsof aerodynamicperformance penaltiesdue t_ ice accretions. In this flight Thi s p m_ rI _ d _ l m r e d u work ofth e U .S.
G o Y e rflm e nt und Ih e r e for e IqinIhepubli c domsln .
t est program, several icing ins t rumen t s were Angle of Attack: Specialties,Inc. i employed to measure icing cloud variables. Data (uni t s/deg) from these instrumentswere then used to charac- terize each icing encounterrelative to the Engine shaft horsep o wer (SHP) was calculated measure d icing c lo ud variables,an d t o Federa l Air ac co rdingto a simple equation in the aircraft Regulation (FAR) Par t 25 AppendixC certification f l ight manua l using torque pressure and pr o pel l er criteria. 6 After each measured icing encounter RPM. Thrust horsepowerwas obtained by mu l tipying rigorou s l eve l -f l ightspeed / powerperformance ca l culatedSHP by prope ll erefficiency. Aircraft f l igh t testing was accomp l ished wi t h the icing weigIlt was determined by adding the fuel relnaining research aircraft (fig. la) to determinethe at tes t condition t o the zero fuel weight of tl,_ increase in aircraf t drag coefficientand the aircraft.
reductionin aircraft l ift coefficientdue to ice. Additiona l speed / powerruns were then made after se l ectivelydeicing the wings and tai l group F 1iBht Test Procedures to furtherdetermine componentdrag contributions to overa ll aircraf t drag. Baseline performancein t erms of an aircraftdrag po l ar was obtained for the icing research aircraf t Eight out of e l even icing researchf l ights in c l ear air _ _p_gying l eve l f l ight performance provided reportabledata; however,to avoid test methods. _,_,_ a Numerous data points were unnecessaryrepeti t ion and to focus in on key obtained for the instrumen t ed aircraft. A lift ob s ervation s and resu l ts, three flight s ,each curve and drag po l ar were derived to estab l isha representingunique icing encountersare presented base l ine for l if t and drag coefficientcomparisons herein, between the iced vs. un-iced airp l ane. A l l instrumentsused to measure aircraftperformance were bench calibratedfor instrumenterrors. The In strumentation service airspeedand a l titudesys t em were f 1 _ght lq ca l ibrated for static s ource positi o nerror.
Icing Cloud Parameters Prope l lerefficiency for each performancedata point was ca l culated from a prope ll erefficiency Measurementswere made of c l oud liquidwater chart supplied to NASA by The Hartze l Divisionof content, cloud droplet size distribution,vo l ume TRW, Inc.
median diameter, air temperature,ice accreti o n ra t e, and durationof t he icing encounters. A ll airframe icing was accre t edat a nomina l Photographswere taken in f l ight of the ice accre- cruise f l ight condition, i.e., a cruise airspeed : ti ons o n the o utb o ard s ection o f the wi n g l eading o f appr ox imately12 5 KIAS ( 150 to 1 6 0 mph true edge and of other airframecomponentsvisible from airspeed). While in icing, the aircraftwas kept i_ the cockpit and cabin. "on condition" by adjustingpower to maintain a constantcruise airspeed throughoutthe icing i_ Instrumentationincluded: encounter. While the aircraftwas allowed to ice up, icing instrumentation continuallymeasured i_ For liquid water content: Johnson and liquid water content, icing rate, tota l ice accre- _i_ Williams (J-W) heated wire7 producedby t/on, temperature, and cloud water droplet sizes Cloud Technology (fig. 2(a)); and distribution. Cameras were used to photograph ice shapes as the aircraftprogressed through the • volume median diameter:rotatingmulti- performancemeasurementswere made. The pneumatic Ii For cloud droplet size distributionand icing encounterand while level flight aircraft cylinder 8 (fig.2(b)); wing and tail deicer boots were not activateddur- i!_" ing the icing encounter; however,propellerand Ii" For air temperature:platinum resistance engine inlet heaters were always kept on to insure _!I_ total temperatureprobe g produced by that full aircraftpower was always availableif _;_ Rosemount(fig. 2(c)); needed. After a sufficientamount of ice had been accretedon the airframe,the aircraftwou l d be _ - !ii_ For i ce accretion:Pre s sure-typeIcing Rate fl o wn t o e x it the icing area as quickly as p o ssi- .. and AccretionMeter (PIRAM) I0 developedby b l e. Generallythe quickestmeans was to c l imb ,:_ NACA (fig 2(d)). above the ic i ng c l oud.
If' _ AircraftPerformance Instrumentation At this point l eve l f l ight speed / powerrun s I. . o_ wer e flo wn (u s i n g the same proceduresas in the A 11 aircraftperformancemea s urement s were c l ear air base l ine tests) first with the aircraft made with ca l ibrate d servicesystem in s truments, a ll iced, exceptingthe prope l lersand engine i_ , The on l y in s trumentused that was not a part of in l ets. A second and third speed / powerseries !_ i the s hip' s service s ystem was the heated angle of were then successively flown with wings and tail i l . i : attack probe. These in s trumen t sin c luded : deiced respective l yto establish the drag contri- bution of each airframecomponent. Figure ib ._( Engine T orque: Edison Torque Pre s sure shows these portions of the airframe that are ' Gage(Ib l in L) protected by deicing systems. Residual ice remainingon t he wings and tail surfaces was not ' Pro p e ll erRPM : Ge n eral E l e c tr i c (per- photographically documented since all portions of : c ent ) these s ur f aceswere not visible from the cockpit i,i ......
o r cabin. E l evat o rs, ai l er o n s ,and rudder were _ Pre s sure Altitude: AerosonicEncoder (ft) tr i _ned for each data point. If the aircraft _'_ began shedding ice during the course of a speed / .... :" IndicatedAirspeed: Bendix Pioneer (knots) powe r series, the series would be abandoned.
:_ Speed / powerseries were not attemptedbetween i s ucce ss i v e i ci ng encou n t er s unl e ss t he airfram e s ig n ifican tl yaff e c t t h e a e rodynamicp e rformance, coul d be tota ll y deiced prior t o eac h new icing par t icu l arlyai r craf t l if t an d d rag. Unfortu- encounter. In addi t io n ,speed / p o werserie s were nate i y, empirica l relation s hipscorre l atingthe not attemptedun l e ss flight con dit ion s were aero d ynamicperformance d egradationof individua l s mo ot h. A l l le vel f l igh t performa n cemea s urements airframec_mpon e ntswit h ice ac c re t ion s from icing were made from maximum le v el fli g ht sp ee d t o sta ll encounter s 5 are presently not in existence.
buffet onse t with the flaps up. No performance Unti l va l id computer code s are avai l able,the mea s urement s were made with any degree of flaps de l eteriouseffects can on]y be determined by ' , down. At the s peeds and t emperaturesencountered flight te s t s of each type of aircraft in natural during the re l at i vely short period of time when conditionsas is reported herein for one cla ss of leve l f l igh t performancemea s urementswere made, airp l ane.
sublimationrates of ice were judged to be negli- gib l y smal l and had no appreciableeffe c t on the For this reason, aircraftperformancedata in data. this report is as s ociatedon l y with the avai l able icing en v ironmentob s er v ation s and measurements, which are pre s entedin Tab l e II under tw o care- Resul ts and Discussion gories; the basic icing cloud variablesand the proper t ie s of the ice accre t ions. Measured cloud variablesinc l ude liquidwater content,drop l et D ata p er t a i ningt o the resu l t s and d i s c us sionfor size d istributions, me d ian volume diameter,tem- each of the three s e l ected icing re s earchf l ight s perature,and the durationand extent of the are co n tained in Tab l e s I to Ill. Date, time, icing. Ice accretionproperties include icing air s peed,and a l titudefor each icin g e n counter rate, amount of ice accreted,and the shape of the are give n i n Tab l e I. Basic icing c l oud variab l e s ice formationas determined by observation.
and those propertie s of the ice accreti o n s that inf l ue n ceaircraftperf o rmancedegradati on are Frequency of Occurrence. - An approachto given in Tab l e If. Aircraft performancedegrada- categori z ingthe s everity of an icing encounteris tion in term s o f drag po l ar curve fit s are s umma- to relate that encou n terto the frequenc y of its ri z ed in Tab l e Ill. occurrence. A 11 the pertinenticing encounter parameter s that determine inten s ity( L WC, extent Figure 3 i s inc l udedto s how the variability of icing, droplet si z e distribution,median volume and peak va l ues o f l iquidwater content mea s ured diameter,and air temperature) s hou l d be treated du ring e ach o f the th r ee s e le c te d icing en c o u n ters, in combinationin as s es s ingthe probabilityof Co n tinuous pl ots fr o m rec o rded indi c ationsof t h e e x ceedingthe int_psityof a sp e c ific c o n dition.
I_ he ate d wire probe are sho wn in Fig. 3 for each of Lewis and Bergrun _ u analyzed s tati s ticallyall ' t h e t h r ee icing en c o u nte r s . Va l ues were recorded the availabledata obtained in icing flights up to i_ once per s econd in flight, but the arithmetic that time (1952) and presentedthese data in I_ ; " a v erage ov er a 10-secondperiod was u s ed to estab- probabilitycharts. In one approach,plots are !_ f i s h each p o int on the p l ot s , providedto determine the probabilityof equaling !_i or exceedingany specifiedva l ue of LWC under the Figures 4(a) to (c), disp l ay icing data f o r conditionthat the value is associatedsimultane- i_ ea c h f l ight re l ative to FAR 25 Appendix C certifi- ously with values of temperatureand drop diameter i_ c ation cr i te r ia,while the remainingFigs. 5 to 15 l ying within specifiedintervals. The plot s are i_ : s h o w l ift cur v e, d rag pol ar, and po wer- v e l ocity based on pre s e l ectedva l u es o f h o ri zon ta l e x tent.
of p l ot s aircraftperformance as compared Thus, a ll the icing encounterparameter s as s oci- _I _ with ice _. to the uniced ba s e l ine, ated with inten s ityare considered.
_i_ _:: A ircratt Performance ate the s everityof the icing condition s reported i _:_C Chara cterization of Icinl Encounters as Related to These probabi l ity p lot s were used to a s soci- herein with the previou sl ydetermined icing sta- ' Air c raft p erf o rmancemea s urement s ta k e n f ol - ti s tics. Fo r ea c h i c i ng f l ight the mea s ured v a l ue , , Ii_ lo wing a n i c ing e n c o unterare referencedt o t hos e !i_ of average L WC occurring s imu l taneous l y with the IK ch ara ct eristic s of t h e i c ing cond ition th at o t h e r m e a s ure d icing p arametersare u s ed with the i i created th e ice ac c retion s . Pe r fo rmance de _rada- plo t s to determinew h at th e chances are in n o rmal t ion is primari l y influencedby (I) the amount of flight operationsof equaling or exceedingthat :_ ice acc u m u la ted a nd by (2 ) t h e s ha p e o f th e ice spe cific L WC va l ue. Fo r e_amp l e, the LWC mea s ured I_ tha t f o rmed, T h e qua n tity o f i c e coll e ct r j i s i n f l l gh t 8 3 -9 (0. 3 5 g m s / m _) wou l d be equa l ed o r _' _')_ main l y a fu n ction o f the c lo u d li q ui d _ ._erc on - exc ee ded i n only I out o f 250 icing enc o u n ter s ,!_ tent, th e e x te n t of th e ici n g clo ud, ; he dr o p le t when formed in combinationwith t h e ot h er measured )!_ s i z e d i st ribution,an d vol um e m ed l a r diameter, ici n g p arameter s (see table Ill. Thi s l o w p r o ba- Temperaturemay part l y determinethe amount co l - billty stems primarilyfrom the unusual duration _ _ . l e c te d if clos e t o fre ez ing. Th e sh a p e o f t h e ice o f the i c in g p r od uced by the p r oc edure o f h o lding _ _ formation i s i n f l u en c ed by t he ra t e o f free z ing, within t i lei c ing cl ou d s.
i_ , L o w t e mp era t uresan d water c o nc e n trationswith _ sma l l drop l ets p romote rapid free z ing producing { _i FAA Ice CertificationCriteria . F or many ,,_ rather sm oo t h a nd po inte d ic e a c cretion s (rime y e ars t h e e x tr em itie s of icin g c o ndition s w e re _i; ice). Temperature s near free z ing and higher gauged by the FAR Part 2 5 icing parameteren v e- i accretionrate s ( 1 1quldwater co n tent x air s peed) l ope s u s ed to de s ign and certify ice protection with l arger d rop l e t _i z e s resu l t i n de l ay s in s y s tems. T hu s, ic i ng characterist i cs o f a gi v en i fr e e z i n g, c reating irregulari ce f o r m a t i o nsw i t h icing enc o untercan be re l ated to t he s e en v e l ope s .
_. flat or concave surfaces (glaze ice) facing the Figure 4 from FAR Part 25 gives the maximum liquid ;" airstream. T he i c e s ha p e that f o rms i s o f e x treme water c ontent t o be f o u nd con tinu o u sl yin s trati- : _ : . imp o rtance s i nc e t h e c o ntour s _r , d l ocationof the form c lo uds as related to mean e f fective d rop _ , . i c e formations on the variou s aircraft co m po ne n t s diameter,air t e m p er a ture,and clo u d h ori z onta l
!i
i
ext e n t . T his FAR en v elop e of m aximum conditi o n s RPM at any altitude,and ( 2 ) propeller effi c ien c y is for a s tandarddi s tance of 20 miles (1 7 .4 charts to calcu l atethe prope l lerefficiencies NauticalMile s ). For icing enc o unterdistances which are used to obtain THP. It shou l d be noted liquidwater content may be increasedor decreased not exactly representthe sing l e engine case dependingon whether the encounterdistance is because trim drags caused by asymmetricthrust are shorter or longer than the standarddistance, not inc l uded.
Data have shown that the more localizeda cloud I other than the standarddistance, the maximum that the two engine power required curve s shown do ; formation,t h e higher wil l be its liquid wa ter Photographsof ice shapes that had accreted content. A variablefactor re l atingmaximum on various portion s of the aircraftat the time l iquidwater content with hori z ontaldi s tance has each performancemeasurementwa s made were been deve l opedfrom previousdata. The ma x imum obtained in flight with hand-heldcamera s . A l iquidwater content is modified by mu l tiplying group of photographs that inc l ude the wing leading values of l iquid water content for the standard edge and other representativeairframecomponents distanceby the appropriatefactor determined for visible from the cockpit or cabin are listed by the actual distance flown in icing. For example, researchflight number and contained in Figs. 6 to the actual horizontalextent of the icing 8. Table I] contains a descriptionof these ice encounterfor f l ight 8 3 -9 was 72 N.M. The l iquid types and s hapes.
water content factor for this distance would be 0.5 5 , and the maximum liquid water cont,nt would As mentionedpreviously,on l y three of the be decrea s edby that amount. As shown _n Fig_ eight icing re s earchflights are discu s sedin 4(a), the dotted line for maximum LWC at -_.4 C detai l . Re s earch f l ights 8 3 -9, 8 3 -10, and 8 3 -11 (interpolatedv a lue) is moved downwardas given by were se l ectedfor di s cussio n as each one presented the solid line in this figure. Thus the measured a unique icing situation: 8 3 -9 was flown in glaze liquidwater content of encounter8 3 - 9 becomes icing conditions that were 81 percent of ma x imum closer to the maximum (81 percent of max.) than if LWC (adjustedfor horizontal distance)in the FAR comparedto the s tandarddistance. Figures 4(b) 25 appendix C icing certificationenvelopeand (flight83-10) and 4(c) (f l ight8 3 -11), respec- thereforerepresenteda relativelysevere icing tive l y, were constructedby employingthe same encounter;8 3 -10 providedthe best complete set of pr oc edure. Re s ults from these figures are als o aerodynamicand measured environmentalparameters containedin Table If. for a gla z e ice encounter;83-11 provided the s ame quality of data as 83-10, but for a rime ice The variable fac t or relating LWC with dis- encounter. Also note that f l ight 8 3 -11 was f l own tance i s of primary interest in determiningthe in conditions that were ca l cu l ated to be 104 per- amount of ice which can accumulateon unprotected cent of the maximum LWC in the FAR 25 Appendix C surfacesduring an icing encounter (Reference criteria. This fact provided some interesting Tota l Accretion,tab l e If). However,for design comparisonsbetween glaze and rime i cing from an of ice protection s ystems,the maximum LWC for the aerodynamicperformancestandpoint.
_ standarddi s tance (1 7 .4 N.M.) is used, !!I Research Flight 8 3-9. - The CL vs. o plot i_ AircraftPerformanceDegradation for 83-9 (fig. g(a)), shows that ice affected the aircraft l ift curve considerab l y. At a = 6 " , for l_ Eight of eleven icing researchflights pro- example, the "all-iced"aircraft lift coefficient !i _ vided aircraft performancedegr a dationdata over a is 17 p_rcent lower than the united ba s eline.
_ range of icing conditions;however, the resu l ts of However,when the horizontal and vertical tail 6" , o nly three se l e ct edf l ights are d i s c u s s ed herein, p l anes were deiced, the lift coeffic i entat _ = !!i: " ;: Overall aircraft l ift coefficientdecreasesand is 10 percent lower than the uniced base l ine.
ill drag coefficient increaseswere documentedfor This indicatesthat with the tail surfacesdeiced f each measured natural icing encounter. Contribu- the CL vs. _ curve s hifts upward towardsthe i tion s of the iced wing and tail group to the baseline. A simi l arobservationwas made on f l ight te s t measured change s in aircraft l ift another re s earchf l ight (not shown in this report) I:_ c oeffi c i e n t (CL) an d drag c oef f icient(CD ) where the tai l surfaceswere deiced first and a l: _ were successfu ll yidentifiedby making l eve l correspondingset of aircraftperformancemeasure- _,. fligh t pe rf o rmancemeasurementsafter each of ments made. The upward shift in the lift curve ::_'_ t he s e c o mponen t sw e re s el e c tive l ydei c ed. I c ed may be attributed to the recovery of elevator I'_ aircraftperf o rmance d ata in terms of resu l ting effectivenessafter ice is removed from the l ead- ,I_ d rag p olars and lift curves were comparedto the ing edge of the horizontal tail plane. The impli- i_ unice d a i r c raftperformancebaseline to quantita- cation here is that ice on the leadingedge of the determinehow ice accretions affected horizontaltail re d uce s elevator effectiveness, aircraftdrag, aircraftllft coefficiett,and wing and for a given aircraftweight, center of gr_w !!i_ tlvely efficiencyfactor (e). The uniced aircraft per- ity, and configuration,increaseslevel flight ;, f o rmanceba sel ine i s shown in Figs. 5(a) and S(b). trim speed. Unfortunately,since elevatorposition -_ and aircraft c e nt e r of gravity were not preci s ely ! Power / ve loc it yplo ts were a l s o deve l ope d t o k n own at the time, there is insufficientinf o rma- Ii I approximatethe magnitude of icing effects on tion avai l ab l eto address thi s observationfurther.
enginE-outperfor m ance. These p l ots were con- Futu r e re s earch f l ight s wi ll incorporatete s t s to _ structedby c o mparingthe tw o engine flight examine this phenomen o nm o re c los e l y.
i d erivede q uivalent weight thrust horsepower (THPEw)required curves for the unlced vs. iced The CD vs. C_ drag polar for flight aircraftagainst a ca l cu l ationof one-englneTHP 83-g (fig. g(b)), shows relative drag increasefor ! a v ailable.This p lo t o f one engine THP a v ai l able both the "all-lced"and "tail-onlydeiced" condi- I TI_ was calculatedby using (I)max continuous power tlon. Additional componentdeicing of the wings settingcharts in the Pi l ot's Handboo k for 100 was r_otcomp l etedsince ice began to shed from the ,i_ " percentpropellerRPM at sea level and 9 6 percent airframe immed l atelyafter the tail-delcedspeed / :i i ,, ,J ,, ; i_ : IIII'_ _ ...... lli ...................
z , . ........................
( 3
% pow e r series was finished. A ]east squares fit of for the steeper slope of the "all-iced"drag polar i ! : the "al l -iced"data for flight 83-9 shows a very in Fig. lO(b). For this case, the wing is only substantia l i_crease in tota l aircraftdrag. For 53 percent as efficientas the uniced wing. After example,at C_ - 0.25, aircraftdrag deicing the wing, "e" is still on l y 84 percent as increasedapproximate l y62 percent over base l ine, efficientas the uniced wing. Again this is prob- _ Whe n th e ho ri zon ta l a nd v ertical tails were ab l y due to the combinationof incomp l eteice d eice d , th e "al l -iced" d rag was reduced by 16 per- removal by the pneumaticboots, and ice remaining i cent. No te t h at t hes e p erce nt age va l u e s wi ll vary on tho s e portionsof the wing between t h e fuselage somewhatover the attainablerange of lift coeffi- and nace ll e. The nondeiceableportion of the _i cients. Also n o te that the four "all-iced"data wings is approximate l y20 percent of the tota l point s represen t the "compre s sed"range of attain- s pan excludingthe portion of the wing behind the ! a ble l ift coef ficientsbetw ee n m a x imum l eve l engi n e n ace lle an d fu s e l age. When the tail gr o up i: flight s peed and ons e t s tall buffet. Wh e n o nly is d e ic ed , it is interestingto note that wing i t h e tail gr oup is de ic ed , this envelope expands efficiency improves to 95 percent of the baseline I c on si d erab l y. T h e c h ange s in p ara s iticdrag value.
! : c o efficientand wing efficiency fac t or for this I flight are sumari z ed in Tab l e Ill. ResearchFli g h t 83-11. - This f l ight yie l ded _ the be s t rime ice data fr o m both the envir o nmenta l ' I Re search Flight 83-10. - This fligh t yiel d e d and aerodynamicstan d point. Referring to Fig. 8, "dl i -ice d "the CL vs. a plot (fig. 10(a)) enco u ntere d on f l ights 8 3 -9 and 83-10 (figs. 6 and and aero d ynamics t andp o in t . With t h e aircraft s hapes are in comparison to the gla z e ice shapes ._.il the be s t gla z e ice d ata both from an envlronmental no t e how m uch smootherthe accretedrlme ice again s hows the effec t s o f ice o n l if t c o efficien t 7). Also no t e t ha t In referringto the environ- I reduction. At a - 6 ", for example, there is a n me nt a l data for flights 83-10 and 83-11 (table deicing the wing s (excludingthe nondeiceab l epor- gm l m_, respective l y)were obtained;however, the a pp r ox imate1 6 p erc ent lo ss in CL. After Ill, nearly the same average LWC's (.31 and .29 tion between the fu s e l age an d engine nacel l e s a s icing encounterin 8 3 -11 wa s approximately40 per- C_ . l oss I s hown in fig. l(b)), t he is approxi- cent longer than that for 83-10. Yet the aero- ' m a tely 4 pe rc ent a t a - o . S ubseq u entd ei c ing dynamic affectsmeasured were entirely different.
o f t he ho r izo nta l an d vertical tail pl a nes do e s i no t appear to provide any appreciableimprove- On t he CL v s . _ plot for fligh t 83-11, men t . No t e that even wi t h both wing s and tai l F ig. 11a, the same characteristicdegradationin ' deic ed , t h e lift curve al w ays remain s below the lif t slope is observed as in flight 83-10. How- J ) ba se line. Th ere are two p oss iblee x planations: se v e re, ever, t i _e ma g nitude o f this degradationis less I i ) T he re sul tin gl ift c u r ve r e f le ct s th e los s in C_ d ue to ice remainingon the por t ion of A comparison of the resultingdrag polars wlngs between the fuselage and engine from f l ights 8 3 -10 (fig. 10(b)), and 83-11 (fig.
nace ll e s ,i.e., t h e n on -deiceab l e po rtion o f 11(b)), shows an in t erestingcontrast in results.
the "a 11 -iced"drag polar disp l ays an approximate I the wing s . On f l ight 8 3 -11, for examp l e, at a C_=0.25, 2) The s ma l l amoun t of residua l ice l eft a l ung 15 percent aircraftdrag increaseas opposed to a I th e wing after pneumaticboot activationmay 45 percent aircraftdrag increaseobtained on p rovide sufficient c o ntaminationt o d e g ra d e f l ight 83-10 at the same value C_. Even 1 l if t c o eff i cient, thoug h f l ight 83-11 wa s flown through ic i ng at near l y the same LWC as flight 83-10, and the time The comp l etereason for t hi s observedphe- of enc o unterwa s 7 7 percen t longer, the drag n o mena is probab l y due t o a c o mbinati o nof both increa s ewas only 1 1 3 as great. Indeed, the factor s . "a ll -iced"rime conditionencounteredon 83-11 provides less aircraf t drag than the "wings and T h e drag p ol ar s deri v e d f o r this f l igh t are tail deiced" case on 33-10. Referringto the • sh o wn in F ig. 10(b). Cho os ing a C_ o f 0.25, t abu l ateddrag po l ar equationsfor f l ights83-10 (CL = 0.5), the aircraftdrag coefficie n t is and 8 3 -11 in Table Ill. the parasiticdrag coeffi- approximate l y45 percen t higher t han base l ine at cient !CD o ) for the "a ll -iced"ca s e in f l ight tha t p o in t . When the wing s are de i ce d (except t he 8 3 -11 i s 17 percent a L ve the uniced baseline n o n-deiceab l eportion),the aircraf t drag c o effi- while the "wing and tail deiced" ca s e in 83-i0 is clen t i s reduced t o 3 3 percent above ba s e l ine. 25 percent above the uniced ba s e li ne. It is a l so When t he hori zo n t al and ver t ical tail p l ane s are difficu l tt o infer h o w wing efficiencyfactor "e" deiced, the d rag coefficien t i s 28 percent above changed with this icing condit i on s ince the magni- ba s e l ine. No t e t ha t appr o ximate l y60 percent of rude of the drag measurementsappeared to fal l t he increa s eddrag due t o ice stil l remain s after w ithin the range of s ca t ter norma ll y achieved.
deicing bo t h wings and t ail. This is d ue t o ice H o wever, the main conc l u s ion to draw from Flight accretion st hat canno t be remove d , i.e., ice tha t 8 3 -11 as o pp o se d to F l igh t s 8 3 -9 and 83-10 i s the accreteson non-protectedsurface s s uch a s strutsj much l ower l lft and d rag pe n a l tie s i ncurredin an t e n na e ,hi ng e brack ets ,etc. rime icing versus glaze icing.
The drag polar equa t ion s resu l ting from a En glne-OutCapability. - F igu r e 12 sho w s the l east s quare s curve fit of t he data are shown in base l ineunlced thrust horsepowerrequiredfor Table Ill. The wing efficiency factor "e" an d standardday, standard weight, and sea l eve l con- parasiticdrag coefficien t may be extracte d from ditions. F i gures 13(a), 14(a), and 15(a) were these equa t ionsto quantify aerodynamicaffec t s, p l otted to show approximateengine-outcapability _ _ '_ N o te th e v a l u e o f "e" f o r th e "a ll -lced"airp l ane for the i cing research aircraft for standard day, in compari s on to the uniced base l ineva l ue. The standardweight, and sea- l eve l conditions. F ig- decrea s e in wing efficiencyfactor Is responsib l e ures 13(b), 14(b), and 15(b) were p l otted to show !.
[
__ ®
d' qi i , I .
_ engine-out c apabi l ityfor standardweight, at te s t a s st ru t s, l anding gear, hinge bracke t s, antennae, altitudecond i tions. As previouslydiscussed, and otller small p r otuberance s as are found on the these plot s are somewhat ideal i zed. Extrapolation Lewis icing research a i rcraft,can retain 50 - w i th no deicing capabil i ty,the aircraftwould after deic i ng the wings and tai l group.
I of the data for flight 83-9, Fig. 13a, shows that 60 percent of the total accumu l ateddrag even have to d escend i f an engine were to f ai l . How- ever, just by deicing the hor i zontal afm(I vertica l Rime icing which genera ll yoccur s at lower tail, a rather l imitedsing l e engine capability total a ir temperaturesbelow fr e ezi n g,re su lts i n ' exists at sea level on a standar d da_ at standard smoot h er,more pointed ice formations facing the gross we i ght. Referringnow to Fig. 13b, we see airstream. This type of icing generallycauses • how, at a pressure altitudeof 6000 feet, deicing much ]owe_ lift and drag penaltiesas comparedto capabilityof the tail group alone is not suffi- similar amounts of glaze ice. Thi s result is o cient to reduce drag to the point where level illustrate_by comparinga rime icing research flight coul d be maintained. Unfortunately,this flight (8_-11) to a glaze icing re s earchflight particulartest wa s abandone d bef o re the wings (83-10) w h ere approximatelythe same LWC's were cou l d be s electivelydeiced, so the extent of encoun t eredat the same airspeeds. Even th o ugh improvemen t can no t be determined. Based upon Flight 83-11 encountere d icing 77 percen t l o nger test results from other f l ight s , e.g. 83-10, it than Fl ight 83-10, the drag increa s efor F _ight appears that the amount of drag that is lost when 83-11 was only one-thirdas great a s that measured t he wings are d eiced is twice the amount lost when on Flight 83-10.
the tai l group on l y is deiced ( s ee fig. lOb).
T h is would lead one t o qua l ita t ivelyob s erve that at 6000 feet pressure altitudeon flight B 3 -9, Future Efforts fu l l deicing of t he wings and t ai l wou l d have recoveredengine-out capabilityf r om the fully T h is paper • presentsexperimenta l re s u l ts o n iced condition, aircraft performancein measurednaturai icing condi t ion s . Addi t ional aircraftperf o rmance Flights 8 3 -10 and 8 3 -11 occurringat 6000 re l ated experiment s wil l be emp l oyed in future feet and 6500 feet, respective l y,are inc l udedto research flights t o include: provide comparisonsbetween engine-out capability for gla z e and rime ice conditions (see figs. 14b I. T h e employmentof stereo pho t ographyto and 15b). It can be s een t h at a l arge amount of quanti t ative l ydocument ice shapes that form rime ice can accumulateon an aircraftbefore on the wing and _ther airframecomp o nents.
engine-out capability suffers. Conversely, it appears that only a sma l l amount of glaze ice wi l l 2. T_e use of a heated wake survey probe t o rapidly erode that capability. Nonetheless,these measure section drag across _he iced aircraft . , pl ots, though somewhat idealized, i ll ustratethe wing. C ombiningthis c a p abilitywith s tere o importanceof developing ai r craftperformancepre- photographyof t h e same section of aircraft dictionmethodo l ogiesthat can adequatelyaddress wing wil l estab!ishthe basis for computer both anti-ice / deicesystems requirementsfor both code s d evelopmentan d |RT c o rre l ative normal operations and in terms of failure modes experiment s .
analy s is. In addition,these methodo l ogiescould _( , ,, also be used to provide valuable flight manua l 3. Employmentof a pressure belt to measure formance limitations d uring icing encounters, data in conjunc t ionwith wake survey probe li inform a t i onto pilots in terms of aircraft per- un-iced wing sec t ion lift coefficient. These Ii _. results wi l l be used to establishaerodynamic conditi o nsfor wing section test s that wi ll ! Conclusions b e run in the NASA-LeRC IRT.
Icing can be characteri z edwith respect to 4. Measuremen t of icing research aircraf t eleva- those conditions that caused the ice accretions tot c o n t rol p o si t ion an d angle of attack with i ncluding(I) the b a sic icing cl oud variablessuch a capabili t y to vary center of gravity to a s liquidwater content, d roplet siz e distribu- determinehow ice accretionsaffect the basic tions, volume median diameter,temperature,and aircraftstatic longi t udinal stability ex t ent of the ic i ng cloud and (2) the properties coefficients.
Ii _ o f the ice ac c retionssuch as ice type, shape, icing rate, and reference total accretion. Air- I i_ craft perf o rmancecan then be associatedwith References _" these parametersor disp l ayedwith more fami l lar i_ criter i a such as FAR 2 5 ap p endixC icing certifi- i. Reinmann, .I.J., Shaw, R.J., and O l sen, W.A., , ii ,,_ _:!i ca t ion requirements. Jr., "NASA Lewi s Research Center's Program o n Ic i ng Re s earch," NASA TM-B30 3 1,1983.
h_ Glaze icing, w h ich generallyoccurs at total !_ a i r temperaturesjust below free z ing,results in 2. Ide, R. F., and Richter, G. P., "Eva l uation !!_ _'ough, irregularice formationswith flat or con- of Icing Cloud Instrumentation for 1982-83 , cave s urfaces facing the air s tream. Thls type of Icing Sea s on F l ight Program , " AIAA 84-0020, 1 i c i ng generallycauses the l argest a i rcraftper- Jan. 1984.
formance penaltiesin terms of loss in aircraft ' lift, and increase in aircraft drag. Depend i ngon 3. Gregorek,G.M., Bragg, M.D., and Shilling, icing rate s under these condi t ion s ,aircraftdrag J.B., "PerformanceAnalysis for A i rcraft in _ : can increasemeasurably in relatively short Icing Conditions," AIAA 84-0 1 B0, Jan. 1984.
_ p eriods of time ( l e ss than 3 0 min ) w i th attendant _ l osse s in climb rate and / or eng i ne out capability.
I._" Aircraftw i th many non-delceab l ecomponentssuch i
ii_ 6
IIL '
rb 4. Pre s t o n, G .M., an d Blac k man , C.C., "Effects APP ENDIXA of Ice F o rmationson Airp l anePerformance in EXPLA N ATIONOF TABLE II , Level CruisingF l ight", NACA TN-1598, 1948.
IC I N G CLOUD DATA AND ACC R ETIONPROPERT I ES 5. Leckman, P.R., "Qua l ificati o n of Light Air- craft for Flight in Icing C o nditi o n s ,"SAE ..... ; Paper 710394, Mar. 1 9 7 1. HeadinQ Explanation 6. "Ice P rotectiJn,"Airworthine ss Standard s : i. S tatic Static air temperature Tra n sportCa t egoryAirpla ne s, F.A.A. R e gula- T e mperature d er i ved from total air tions Part 25, Secti o n 25.1419, AppendixC, ('C) temperaturemeasurement s .
19 74. If variable, average value 7. Neel, C.8., Jr., and Steinmetz, C.P., "T h e i s s hown.
Calculated and Mea s uredPerformanceCharac- 2(a). Average LWC An arithmeticaverage o f Le ri s ticsof a H e ated-WireLiquid-Water- (gm s . / cum) indivi d ualreadings at C o ntent Meter for Mea s uring Icing Severity," equa l interval so f time NACA TN-2615, 1952.
8. Brun, R.J., Lewi s , W., Perkin s , P.J., an d 2 (b ) . Maxim u m LWC T h e peak LWC of the icing Serafini J.S., "Impingementof Cl o u d Drop- (gm s . / cum) encountermeasured over a , d i s tance o f ab o ut 2.6 let s o n a Cylinder and Proce d urefor Mea s ur- nauticalmiles. This i n g Li qu id-WaterC on te nt a n d Dr op l e t Si z e s in relates the encounter to SupercooledCloud s by RotatingMulticylinder the intermittentmaximum Method," NACA TR-121 5 ,19 55 . certificati o ncriteria of .... g. Lewi s , W., "A Flight Investigationof the F AR Part 25.
M et e o rclogicalC o n d itions C on duciv e t o the 3(a). Duration o f Time in m inutes fr o m _ F o rma t ionof I c e o n A ir pl ane s ," NACA Encounter start of icing to end of TN-1 3 9 3 ,1947. (min.) encounteras mea s ured by 10. P e rkins,P.J., McCullough, S., and Lewis, icing instruments.
R.D., "A Simplifie d Instrumentfor Recording 3 (b). Extent o f Duration of encounterx a n d Indicating F r eq uencyan d Intensity o f Enco u n ter true airspeed.
Icing Condition s Encounteredin F light," (Nautical NACA RM-E51E1 6, 1951. miles ) ss ,=. Lu s h, K.J., a n d M o akes, J.K., "Perf o rma n ce 4(a). Median Volume An averagevalue of i_ R ed ucti o nM etho d s f o r T urb o -Propeller Air- 'I craft," pp. 5 :1-20; D o mma s ch,D.O., "Data Droplet Dia. drople t si z e (m i crons)for f o r the enc o unter. A Reciprocating E ngine Aircraft," pp. 6 :1-26, e x p os ure is self a v erag- • 1 R ed uctiona nd Pe rf o rmanceTest Methods for rotatingmulticylinder AGARD F light Test Manual, V o I. I, edited by ing providinga repre- E.J. Durbln and C.D. Perkin s , 2nd revi s ed s entativevalue and o ed ., P ergam o n P r ess , O x f o rd, 1 96 2. because o f meth o d is "_ c alled M e an Effective 12. Smith, H.C., "Introductionto Aircraft Flight Droplet Dia.
Test Engineering,"PennsylvaniaState Unive=- sity, Univer s ityPark, PA, July, 1 9 74, pp. 4 ( b ) . D roplet Si z e Because rotatingmulti- 14-45.
Di s tributi o n cylinders are used, the 13. Small, S.M., and Prueher, J.W., "Fixed Wing Langmuirdistri b ution Perf o rmance:Theory and F light Test Tech- designation (A - J) is s h o wn.
niques,"USNTPS-FTM-I04,July, 1 9 7 7 , pp C VII-18 - VII-25.
14. F i sh er , 8.D. Ho l me s , B.J. anu St o ugh, H.P. Dia. (m i cr ons ) tributi on , t he dr o p l et iii 4( c). Maximum Dr op l e t I n the dro ple t si z ed i s - ' ' s i z e at which about }_ Ill , "A F light Eval u ationof a Trailing 5 p e rce n t of t h e t o tal Air s peed Systems on Re s earch Aircraft," NASA droplet s i z e s . (This TP-11 35, 1978. value is useful in deter- i Anem o meterf o r L o w S p eed Calibrationsof liquid water is in larger mining the are a of maxi- I_i 15. Gray, V . H . , " P rediction o f A er od ynamicP e na l - mum impingemen t on large ties Cau s ed by Ice F ormatio n s on Vari o u s s urface s - wing, and also it Airf o i l s," NASA TN D-21 66 , 1 96 4.
_ inf l uence s ic e sha p es ) .
1 6 . Lewis, W. and Bergrun, N.R., "A Probability , .! Analy s i s of the Mete o r o logical F act o r s C o n- 5 . C loud Type Either stratiformclou d s (c o ntinuous)or cumuli- ducive to Aircraft Icing in the United form cl o ud s (inter- States," NACA TN-2 / 38,1952. mitten,). This relates the enc o u n t e r t o the FAR Part 25 certificati o n , criteria.
_ : 7 I; i 6 . Type of Ice ler_ r ls comm o nly us ed to 10. Characterization describe ice accretions o f Icing Encoun t er such as Rime, Gla z e, Clea r , and Mixed. (a) . Fre q uency o f A m e ans of referencing Occurrence this icing encountert o a 7 . S ha pe o f Ice A s ingl e w ord de s cription previou s ly determi n ed obtainedfrom wing photo s , probabilitythat has e s tablished,f o r any ran- _ 8. Average Ice Obtainedfrom ice accre- dom icing encounter, the AccretionRate tion instrument(Avg. Ice pro b abilitythat the ( In. l hr. ) A c c. Rat e = Number o f m e a s ur ed LWC of this ter X .020 1 Totalaccumu- exceeded. A chart given toted time of each icing in NACA TN 2 738 is u sed 9. Reference To t al Thicknes s of ice f o rmed Ice Accretion on small sensing pr o be a t (b). Certif i cationT h is icing encoun t eris cycle), bilityt° determineva l ue, the proba- Mea s ured by ice accretion parameterenvelopesgiven ( i n c he s) e n d o f i ci ng enc o unt e r. Criteria re l ated t o the i c i ng i icing cycles for encoun- encounterwould be in s tr u ment ( Ref. Total in FAR P art 2 5 Appendix Ice Acc. = Avg. Ice Acc. C. Value shown is the Encounter). of the maximum value given in the FAR envel o pe correctedfor hori z ontal di s tance.
Rate X Duration of the mea s ured LWC as a percent r !I! .
ill:
_==_-_I T AB L E I. - ICI N G E N C OUN TE R FLIG HT DATA
F11g ht D a te B eg in Tr u e P r e ssure
number t ime, airspeed, al t itu d e,
EST mph ft
8 3 -9 3 / Il / 83 l0:4 6 A 138 4 7 00
_' 83- I 0 3 / 2 1 / 83 I O: 14 A 1 57 4 50 0
,,_ 83 -II 3 / 21 / 83 3: 07P 15 9 5500
....
,I . o l_b
! A
i; I
t_ ¢
TA BLE II. - I C ING CLO UD DA T A A ND AC CR E T I ON
PR O P E RT IESFO R I C IN G F LI GHT S
[ S e e a pp e nd i x A fo r d efin i tio ns.]
F1t gh t n u m ber 83 - g 8 3 - 10 83 -11
Ici ng cl oud d ata
la . To t al t empe rat ure (° C ) -3. 2 ° - 2 .3° -8.g°
lb. Static t em p er at u r e( °C ) -4.4 ° -4 ° - I0 . 6°
2a. Avera g e LWC (gm s / cum) 0. 3 5 0 . 3 1 0.2 g
)T
2b. Maxim u m LWC (gm s / cum) 0.80 0 .4 5 0 . 53
3a. Du r a t i on o f e n counte r (m t n . ) 36 2 6 46
3 b. Exten t o f en c oun ter (n a ut . m i l es) 72 5g 106
4a. M edi a n vo l ume drop l etdi am eter ( m i c rons) 13 13
i_! 4 b. Drop l et stze distribution E D
!_i " 4c Ma ximum d r op le t stze (mi c rons) ..... 35 29
!i 5. C l o u d t ype S t ra t o-Cu St ra t o-Cu S t rato-Cu
i
i_ I ce a ccr e tion properties
6. T y p e o f i ce ( s ee photo) Gl aze G laze Rtm e
Curved
D ouble Double
_i . _iti 7 . Sh a pe o f tce (see p hoto)
i! : !_ r t dged r t dged
w. 8 . Aver a ge a ccretion rate (tn . / hr) 2 . 68 3 . 32 3 . 80
ii_ g. Re f erence tota l accret i on ( i n.) 1.61 1 . 44 2.91
! : in
, I : _ 10 . Chara ct e r iz at ion of ic i ng
I : , ; ,i : a. F requen c yo f occurrence 1 I n 250 1 in 10 0 I I n 200
,: <- (number o f ic i ng enc ou n t er s t o excee d )
i'i! b. Cert ifica tio n cr lt er l a a 81 perce nt 70 percen t 1 04 pe r ce nt
:. a perce nt of ma x L W C .
i / ! - c , , j T ABLE Ill. - CURVE FI T S OF D R AG DA T A C0 e Clean Aircraft , St r ai g ht llne l e ast squares 0.04 5 + 0 . 0 414 C_ f lt o f range 0 < CF _ 1.0 0 . 763 5 Third order f tt o f complete 0 . 0 452 + 0 . 0 423 C L range -0. 0 1 C _ + 0 . 0 0 96 C _ F l igh t 83-9 A ll t ced 0.0747 + 0.0588 C L 0.5382 Tails de ic ed . 07 1 2 + . 05 1 2 CL .61 T5 Fligh t 83-10 All Iced 0.0 6 0 9 + 0.0 78 2 C[ 0.4045 Wings deice d .0 6 1 3 + .04 92 CL . 6 4 3 5 Wings a n d Ta il s de i ced . 0 5 9 7 + . 0 438 CL . 7 224 F l ight 83 -11 ,, ,, All lced 0.0525 + 0.0432 CL 0.7315 W ings deiced .0482 + .0494 CL .6399 ) : i 2 W ings a nd T a i l s d ei c ed . 0 4 65 + . 0555 CL . 5703 li '
• '
I '_ ( 2 0 . 6 7)
__L
75) (3 - - - iO ,i_ ( ROSEMOUNT -"_;_,_0_ _ . _ T E M P ERA T U_ ,_ _. ,. . dii_m 2 .59_ 8 . 5) , " I. . . P I R A M _ " -_ 3 . 81 L_--\ " iti ° : " (12.5) '- "" ' - J - W TE M PERATU R E !I ' , ; J- W _! RO S E N I OUN T j_ 5. -_ -66 i_ , _, .
_,_ o _ I (18. 58) (14.7 , _ ) _i "- ' , 15. 7 7 L51 , 75) ,_ F i g ur e l a . - N A SA L e wi s Resea rc h Cente r i c ingresear ch aircraftandicin g instru m ent l ocat i ons. A ll dim e ns i o ns '" are i n m ( fl ).
! i r_ '
i o _Iv:_ i j!,L _, ::: _._, OF PO O R QUALIT Y , /-- P NE U M ATI C
" ROO T DE IC ER S '_'-" - ' . / _" 7 "
PROPELLER " / . .
AIX! D EN GI NE _ " INLET ELECTRO- THERMAL ANTI - ICERS . I Fig u re l b . - I c i ng resear ch air c ra f t s h owi n g ar e asprote c te d by anti-icing / dei c in g e q uipment.
: i r.
, I W I W E . ; M t ' T [ . R _.
!, (a) Johnson Wi l liams h eat e d wire f or 2 .. Figure 2 . - Icing cloud in s trument a tion.
measuring LWC .
/ ! .
!!t '_ "
I O F PO 0_ L k .. , . _ ,; - t ' " ; i / / / // / / /
!
/ / • ¢ t \ \ (b)Rotating multi-cylinder for measuring waterdro p let siz e distribution.
ii;. Figu r e2 . - C o nti n u e d .
ii
_4 i I .
, " R O S E M O UN'I " O A I Pl _ O g_ 1 , (c ) Ro s emount tota l air te mp er a ture p robe for _. m e a suring a i r tem p erature.
_" F i gure2 . - C on t inued.
,e , ?
.l ( ,. , !_._ (d)P I RAM fo r measur i ng refe r ence iceaccret i on ratesandtota l accretion.
Figure 2. - C oncluded.
!,Ly 1.2 -- AVERAGE(0. : _) 7 F L T 83 - 9 !!! .8 -- / i_ - -
i ; f g o 5 l o 1s 2 0 25 3 0 35 40
i_ _ . 8 F AVERA GE (0 . 31)- 7 . I F LT8 3- 10 _ -- 0 5 10 15 20 25 3 0
i_ - _ 1.2-
" _ F LT 83 " 1 1 i=!. AVERA G E 10 . 2 9) " 7
I
• 0 10 2 0 3 0 40 50 I _ ' TI NE , mJn !, i_: Figure 3 . - V a ri a tiono f liquidw a ter content, ( L W C ) with time _ foreac h i c ingrese a r ch flight.
i . I )
• FLIGHT 83 - 9
--. - --.. F A R ENVELOPES O F MAXIMUM LIQUID W A TER
CONTENT FOR STANDARD HORIZONTAL ,, EXTENT OF17.4 NAUTICAL MILES (20S.M.)
......... MAXIMUM LIQUID WATER CONTENT AT- 4 .40C
-------- MAXIMUM LI Q UID WATER C O NTENT AT-4. 4 0C
FO R HORIZONTAL EX TE NT OF 72N. M .
--'-- LI Q UID WATE R CON TE NT FACTOR VERSUS
HORIZON T AL EXTE N T 1 .0 [--,_ U _, !.
i_ _ ._I .
: N . 6 \N N
o : 8 4 0 \
• _ . 4 3 \ _ .
" I T e ... --. "-._
- I I = 30 ' _,_ "_ _. _ _"'_
I I "--.- . _ _-._..... _- ' _
0 ' --'' _ _"-' _
1 0 1 5 20 2 5 3 0 3 5 40
MEAN EFFECTIVE DROPLET diam,pm
I . 4 m I . 34
\.
° _ 1 .O m
L ° \ , Q¢ ,
= \
_ Q
• -J _ 3 10
p
, t,l,l, I I , I ,J I, l I , 1 m,_,J,I
: 0 I 0 (72 1100 I000
CLOUD HORIZONTAL EXTENT, NAUTICAL MILES
: Fi gure 4 a . - F ligh t 83 - 9s u peri mp osed o n FA R appe n di x C o f part25
c o n t inu o u s m ax im u m (stratiform c louds) .
_° .,, c_ a" _ _ O lYl G }I'_ / _ . L . F , :,_._.°" _ , _ . _ ., 4 _ . ,_ ! O F POOR Q U ALITY i • FL I GHT 83 - 10 m_-- FAR ENVELOPE S OF M AXI M U M LIQUID WATER CONTENT F O RSTANDARD HORI Z ONTAL EX T EN T OF17. 4 NAU T ICAL M ILE S ( ; t O S . M .)
........ MA XI M U M L I Q UI D W A T E R CONTENT A T=5 o C ------- M AXI M U M LIQUID WATER CONTENT AT-50 C FOR H O RIZONTAL EXTENT O F59N. M .
'-.- o -'- LIQUID WATER CONTENT FACTOR VERSUS H ORIZON T AL EXT EN T 1.0 -- TEMPERATURE, _ o C i! g . 7 3 .. :5", _ ) _ . ".. "--.
-30 _ ' _ , _ _
_ I I I I--- I --==1
t o is 2 o 2s 3 0 35 4 0
;_ ME A N EF F E C T I VE D ROPLET d i a m, p m _ii ,.,- _._, 1 .2 - .
I \.
_ . _ \
!i \
u . 6
_ •
I , i . g . 4 - .
_ \
• I l ll,l,I I i I i Ilt l I I jl, l Jl I- O 10 (5 9 ) 100 1000 il C LO UD H O RIZ O NTAL EX T EN T , N AUTICAL MIL ES : ' _ " F igur e 4b . - F ligh t 83 -10s u peri m pos e d o n FAR ap p e n dix Co f p a r t :.: 25 co nt i nu o u s m axi m u m( s t r at i f or m c l ouds ) .
i'i I • F L IGHT 83 -1 1 - ----- - F A R ENVE L OPES OFMAXIMUM L IQUID WATER CONTENT FOR STANDARD HORIZON T AL , .
EXTENT OF17.4 NAUTICAL MI L ES (20S.M.)
" - - ---- - MAXIMUM L IQUID WA T ER CONTENT AT - 1 1 o C .......... MAXI M U M L IQUID WATER CON TENT A T-11° C FOR HORIZONTAL EXTENT OF 10 6N•M.
1.0 -- HORIZONTAL EXTENT TEMPERATURE, o C " --' " -- L IQUID WATE R CO N TE N T FACTO R VERSUS
) g . 63 ; _ _ x
o 8= -,,,
$
I I I I "i ---,I
$ 0 10 1 5 2 0 25 30 3 5 40 g m MEAN EFFECTIVE DROPLET diam,
i
_." 1.4--
i: --\_ . 34
!: \
i! - .. _ 1. 0 ;_ _ •
_: _ .8- \
_ , , .. . ,_ . 6 -
__ _ 3 1 0 i 2-- "_ I I tl l lc L _ I I I I (,l il", 1 , I I I I Itl 0 tO tO0_ -( 1 ( _ ) 1000 CLOUD H OR IZ O NTA L EXTENT, NAUTICAL M I LE S Figure 4 c. - Flight83 - 11superi m posed on FA R appendix Co f pa r t continuous maximum (st ra ti f or m clouds)• _ ¢ • r . , F' ?
OF poOR QU AL ITY . !
.! . 'j
1 . 7--
/ ._.,1 .4 -
I.- u.,
rr. 1.0--
"-I I I I I
: . 2 . 4 0 4 8 12 16
: _ A N G LE OFA TT A C K (R E F ERE NCED T OA IR CRA FT
'i FL O OR LINE) , d e 9
t. ( a) L ift cu rv e of un- i c ed icing r e s ea rch a i rc raf t
_,!_ . i o -
I'. _ 6F =O° •
',_ =_ .o 8 -- • .
i = ."
;' ,_ 0 .2 . 4 . 6 . 8 1 .0 1.2 1 . 4
i ' : )°_ L I FT C O E FF I C I EN T S Q UARED, CL 2
i,_. ( b )D r a g pol a r for un - i c ed i c ingresear ch a ir c r a f t
!_ Fi gu r e 5 . - Un -i c e d i c ing res ea r ch a ircr af t per f orm a nce.
_ ( Ba selin e . )
( ii , _'.
r _ I.
?
,?
3.
I,j ' L
O F P O O k_ Q UAL_T_ r "
( a)Wing l eading ed g e ic e format i on takenattimeofa i rcra f t p e r formance mea s urement s .
:7
tli / _
_ (b) Ic e f orm a tion onwingstruttakenat t i meofaircraft (c) Ic efor m at i ononrado m e takenafter l anding , _ p en ' or m ance measurements.
/i, F i gure 6. - Fli ght83- 9 , g l aze ic ingp h otogra ph s.
, ¢ i'i . !.
i l )
o i : _ , _ (a)Wi ngleadi ngedge iceformation taken at time ofaircra f tperfor mance measu rements.
(b)Iceformation onc o ckpit entry _ tep taken (c)Iceformation onaileron hinge bracket taken :!_ . aft e rl a ndin g , a f terlandin g .
i_ : Figure 7. - Flight 83 - 1 0 ,glaze icingphotographs.
,I
.... ,............ , _ . _ _ __. _ _ • - :. .... . _..... - _ ._. ..... ., ...............
I O R I G I N, _ L p_ ., . i ; i -_ . _ 1
' O F P OO R QUALITY
_ (a)Wing leading edge iceformation taken attimeo f aircra f t performance measurements.
l'i r,.
!l:"
it !:_'^ ' i " ' (b) Iceformation onco ckpit entrystep taken a f terlanding.(c) Ice f ormarion onaileron hinge bracket taken a f terlan- • I_i ; ding.
Figure 8. - Flight 8 3- 11,rimeicing photographs.
:1
.3
, _- ....... " • .... _" ..... - - .- _ - _ _" i " ' '" . ..... _ -
1 . 2 --
1 . 0
' _ _ . 8 --
' _
.4
I I I I I
• 2 0 2 4 6 8 10
, AN G L E OF A T TACK (REFE RE NC E D TO
AIRCRAF T F L O OR LINE), deg
(a)Variation ofaircraft CLversus a .
I
!i: ._2 F -
_l : ==. o 8
1-
/" -- - 0- -- ALL ICED
° , 0 4 - " '- 0 "-" EMPENNAGE DEICED
.... " --'-'- - BA S ELI N E
_ " .oz I I I I J
!_ " 0 2 4 .6 .8 1.0
_ , . , . LIFT COEFFICIENT SQUARED , CL2
ii (b)Shiftin aircra ft drag polar.
_ , Figure 9. - Flight 83 - 9,effect ofh e avy glaze
I ;' , . icing onaircra ft liftcurve and drag p olar
i'_,_ a scompared totheun - ic ed baseline .
i 6 F" o° _
i'
, ( , )
v
OF P OOR QU, _ l. ir Y
1.2 _
1. 0_
g .B
8 .6
o
I I I I I
"20 2 4 6 8 10
ANGLE OF A'I'I 'ACK (REFERENCED TO
AIRCRAFT FLOOR LINE), de9
(a)Variation ofaircraft CLversus o .
• 14 m
i: ,, c, /
!t' ; i .o,
il ; " e A LL ICED
t WINGS DEICED
1!" .. WINGS AND
"> EMPE NNA GE DEIC E D
_ - . 04
:_ BASELIN E
I I I
_:_!_ I I I
_ "02 0 . 2 4 .6 8 1 . O
1/' • •
'>i " LI F T C OE FFICIENT SQ U A R E D , CL2
i , ' (b)Sh i ft in a i rcraft drag polar. j -.
_}, Figure 10.- Fl i ght 83-10,effect ofglaze icing
onaircraft liftcurve and drag polar ascom-
' pared tot h eun- l ced basel i ne. 8 F- 0 °
i, L' i , . _ " • 1 7 -
i
it { I I O F F_:_:_C_ " U' ' _ 'i' _ / ' 1 1.2-- ( 1. 0m / • i z .8 -- t_ • _,.
; _ . 6_
L I I I ) I s
• 2 -2 0 2 4 6 8 10 . _: l ANGLE O FA T rACK ( R EFE R ENCED T O AI R C R AFT FL OOR LINE), deg lil ' .
!!I+ (el Var i ation o f a i rcr af tCLversus a.
_s
, _ iliii _g . 08__ j : _ : y _ . e_ . /
i t,,t,J • _ .06 ! , li!] _ C E D , _ . 04 _ EMP ENN AGE DEICED _, -- BA S E L IN E !i _ WINGS A N D
_, .0 2 I I I I I I
0 . 2 .4 . 6 . 8 I .O 1 . 2 LIFT C O EFFICIENT SQUA R ED , C2 o (b) Shif t in a i rc r a f tdragpolar. , Figure11. - Flight83-11,e ff ecto f rimeicingonair - cra f tli ft curveanddrag p olarascompared tothe un - ic ed baseline. 5F • 0 °.
L i.
I q ,y
1000 -
00 m . . c
- _ 800--
700--
.... := 6 00--
3011--
•1, • I I [ I [
20 0 61 80 " I00 12 0 140 1 60 1 8 0
EQ UIVALENT W EI G HT TRUE A I R S PEE D , KNOTS
Fig u re 12 , - Thrust horsepower r e qu ired asa fu nctio n o f
velocity fort h e u n -i ced a i rcraft , Fl i ght t e s tdata corr e ct e d
tostandard d a y, s e _ lev e l, andstandard weight conditio n s:
8F . 0° ( B aseline . )
®
( , o
(3
I
' 7 00
:i 60 0 / _t
. o4'
_ "" - ONE E N G I N E
. . _
• 4 00 / - < > ,, POW E R A V A IL A B LE
3 00
L_ ; LLI _ . ( a) Fli ght test d ata corr e cted tostandard da y , w sealevel, andstandard weight conditions .
.,t - w 000 _ i oe i
. , , // i
I 700 -- o I
i / I P O W E R A VAI LA B L E
500 -- l
4 00 . _ * " " / ""_
" / - - 0 - " - AL L I C E D
T H P REQ UI RE D
3 00 m - -K > - - E MP EN NA G E DEIC E D
-----'- B A SEL I NE
I I I i I I
20060 80 1 00 120 1 4 0 160 180
! TR U E AIR SP EE D , KNOTS
(b) Test c onditions at 6000 ft. F li ght test data
correct ed to _ tandard weight only.
Figur e 1 3 . - Flight 83 -9 , e ffe c t ofh ea v y gl a ze icing
;_ o n t h r us t h orse pow er re qu ir ed r e lative t o calcu -
!! l at ed o n e - e ng ine t h r us t h ors e p o wer a v ailabl e .
•1 8 F • o °
J L , i 8 O0 ? OO 6 00
/
"-- ONE EN G INE 4 00 PO WE R AV A ILABLE 3 OO - 200 ( a)Fl ightte s tdat a corrected to s tandard d ay, 1DO0 s e alevel , andstandard weight conditions .
' ° - , ( i;"
6 OO h -- .L_.j'I @ '._._ --0-- ALLIC E D WI N G S A ND / ,. / "-- _ - WI N G S DEIC ED 3 0 0 -- E M PENN A G E DEICED -- -- ---- BASELINE
1 I I I I I
20 0 6 1 180 1 00 1 20 1 40 1 60 _ TRUE A IRSPE E D, KNOTS (b) Te s tco n d i t i o n s at 6 0 00ft . Flight testdat a corrected to standard weight only .
Figure14. - Flight 8 3- 10,effec t ofglaz e icingon thrust horsepower required relative to c alculat ed one - engine thrusthorsep ow er available .6 F • 0° .
®
\ ,, i / " 1¸ ¢ , .... _ ,1 _ " _ . • i ' 1 / !
9 0 0-- 00 m 7 00-- 600-- 5 00-- 4 00 ' - ONE ENGINE POWER AVAILABLE
I I I I
l a .i (a )Flightte s td a tacorrected to s t a nd a rd d a y, =. s e a level,and s tand a rd weightconditions.
l a d i o 1000--
!_ 800 -
'i-
ii_ 7 00 - _l
!l i
i:. _ ,: t
_' ] _ F ONE EN G I N E !!_i_ 5 00 -- ._=. ..-. L ' / '' #" // _.. PO W ER AVAI LAB LE __ •. _"" THPREQUIRED _ 400 -- _ . .' /_ " -- ' 0--- AL LI CED !; . _ / .. "_ " , _ " ' E]-- " WIN G S DEI C ED _i_i= 300-- " "_ -- WIN G S AND i; EMPENNAGE DEICED !'. BASE L I N E .
,, I I I I 1 I
: 80 100 120 140 160 180 " ; TRUE AIRSPEED, K N O T S r _; ' (b)Testconditions at 6.500 ft . Flight testdata _" c orre cted to s ta nd a rd weightonly.
} ' h _ ' : " F i gure 1 .5 .- F l ight83 - 11,effect of r i me I cingon thrust h or s ep o wer required rela t ive to calcul a t ed ;ii one-engine thru s t hor s ep ow er available.8F - 0° :i,t