Calculated and flight measured handling- qualities factors of three subsonic jet transports

N A S A TECHNICAL N O T E

CALCULATED AND FLIGHT-MEASURED

HANDLING-QUALITIES FACTORS OF

THREE SUBSONIC JET TRANSPORTS

?

by WaZtev E, McNeiZZ

Ames Research Center I Y C

Moffett Field, CaZzy

N A T I O N A L AERONAUTICS A N D SPACE A D M I N I S T R A T I O N W A S H I N G T O N , D. C . NOVEMBER 1 9 6 8 TECH LIBRARY KAFB, NM

I llllll lllll lllll 1 1 1 1 1 1 lllll I I l l 1 I l l 1

013Lb37 NASA T N D-4832 CALCULATED AND FLIGHT-MEASURED HANDLING-QUALITIES FACTORS OF THREE SUBSONIC J E T TRANSPORTS By Walter E . McNeill A m e s R e s e a r c h C e n t e r Moffett Field, Calif.

N A T I O N A L A E R O N A U T I C S AND SPACE ADMINISTRATION ~ F o r s o l e by the Clearinghouse for F e d e r a l Scientific and T e c h n i c a l Information

Springfield, V i r g i n i a 22151 - C F S T I p r i c e $3.00

CALCULATED AND FLIGHT-MEASPJD HANDLING-QUALITIES FACTORS O F THREE SUBSONIC JET TRANSPORTS By Walter E. McNeill Ames Research Center SUMMARY As p a r t o f anNASA i n t e r c e n t e r study of j e t t r a n s p o r t s t a b i l i t y and c o n t r o l problems i n severe turbulence, s e v e r a l calculated and flight-measured handling-qualities f a c t o r s of t h r e e current j e t t r a n s p o r t s have been reviewed, and compared with various handling-qualities c r i t e r i a .

The longitudinal and lateral handling-qualities parameters w e r e c a l c u l a t e d by means of a d i g i t a l computer program, f o r s e v e r a l t y p i c a l f l i g h t conditions within t h e normal operating envelopes, using aerodynamic and physi- c a l d a t a supplied by t h e manufacturers of t h e a i r c r a f t as t h e most r e l i a b l e information available. The c a l c u l a t i o n s did not t a k e account of e f f e c t s of yaw dampers and automatic p i t c h t r i m devices.

O n t h e b a s i s of t h e c u r r e n t m i l i t a r y s p e c i f i c a t i o n and o t h e r published c r i t e r i a , a l l t h r e e t r a n s p o r t s had s a t i s f a c t o r y or acceptable predicted o r f l i g h t -measured l o n g i t u d i n a l short-period frequency and damping c h a r a c t e r i s - t i c s i n t h e f l i g h t conditions of i n t e r e s t . Ekcept f o r some cases of speed i n s t a b i l i t y associated with disengagement of Mach trim compensation devices, acceptable longitudinal phugoid c h a r a c t e r i s t i c s a l s o were calculated f o r t h e s e t r a n s p o r t s . The l a t e r a l - d i r e c t i o n a l o s c i l l a t o r y (Dutch roll) character- i s t i c s varied from s a t i s f a c t o r y f o r normal operation t o unacceptable with dampers inoperative. According t o t h e current m i l i t a r y s p e c i f i c a t i o n , t h e predicted r o l l c o n t r o l c h a r a c t e r i s t i c s were generally acceptable f o r two of t h e t h r e e t r a n s p o r t s .

INTRODUCTION I n recent years, s e v e r a l l a r g e j e t t r a n s p o r t a i r c r a f t have suffered loss of c o n t r o l during scheduled operation. In some cases, recovery w a s not e f f e c t e d and d e s t r u c t i o n of t h e a i r p l a n e resulted. I n a d d i t i o n t o t h e c l a s s of a i r p l a n e , t h e s e incidents had two f a c t o r s i n cormnon: t h e a i r c r a f t were being operated under instrument conditions and i n severe storm turbulence.

I n December 1963, a cooperative N A S A study w a s i n i t i a t e d , involving research teams from t h e A m e s , Langley, and F l i g h t Research Centers, t o inves- t i g a t e a l l pertinent aspects of t h i s problem. Reference 1 summarizes t h e a o v e r a l l program and presents some of t h e key observations r e s u l t i n g from l i m i t e d analysis at t h e A m e s Research Center of t h e handling q u a l i t i e s of jet t r a n s p o r t s .

t h r e e current I n t h i s r e p o r t , t h e r e s u l t s of t h e handling-qualities a n a l y s i s a r e discussed i n g r e a t e r d e t a i l and i n terms of e x i s t i n g or recommended numerical c r i t e r i a . Comparisons of t h e calculated c h a r a c t e r i s t i c s with t h e s e c r i t e r i a a r e not used as bases for conclusions as t o t h e a c c e p t a b i l i t y of a given air- plane because of inconsistencies among some of t h e c r i t e r i a and a lack o f c l e a r l y established a p p l i c a b i l i t y of t h e c r i t e r i a t o t h e j e t upsets. Rather, t h e c r i t e r i a a r e included t o provide a s t r u c t u r e f o r presentation of represen- t a t i v e behavior and t o serve as i n d i c a t o r s of gross inadequacies. Some comparisons between computed c h a r a c t e r i s t i c s and f l i g h t measurements a r e a l s o included .

NOTATION - - wing span, f t C

dp ’ rad

2 P wing mean aerodynamic chord, C f t

‘sa

drag drag c o e f f i c i e n t ,

ac 2 1

- -

as, ’ rad

czgr

C

d(pb/2V) ’ rad

l P 2 1 - C

- acD

d(rb/2V) ’ rad

‘r aM pitching-moment c o e f f i c i e n t , l i f t

l i f t c o e f f i c i e n t , -

p i t c h i n g moment %S qmSF

ac, 1

&- ’ rad

a c L -

’ rad

C mse cmM rolling-moment c o e f f i c i e n t ,

acm 1

r o l l i n g moment

-,rad

%Sb pressure a l t i t u d e , f t yawing-moment c o e f f i c i e n t , yawing moment r o l l i n g , pitching, and yaw- %Sb ing moments of i n e r t i a , acn 1 respectively, about body

- -

reference axes, slug-ft"

ap ' rad

product of i n e r t i a about acn 1

- -

body reference axes,

as, ' rad

s l u g -f t2 acn 1

- -

constant r e l a t i n g damping

36, ' rad

c r i t e r i o n t o Mach number m a x i m u m permitted Mach side-force c o e f f i c i e n t , number f o r normal opera- side f o r c e t i o n , m i l i t a r y and c i v i l a i r c r a f t , r e s p e c t i v e l y

sas

acY 1

- - po s i -

normal acce lerat ion,

a p ' r a d

t i v e upward, g

acY 1

an, -

- - ,

as, ' rad

ha

acY 1

r o l l i n g angular velocity,

- -

as, ' rad

rad/sec m a x i m u m a t t a i n a b l e steady-

a c Y 1

( $ s , , , s t a t e wing -t i p h e l i x

a(pb/2V) ' rad

angle, rad

acY 1

&! , rad/sec2

d t

"rad

maximum a t t a i n a b l e r o l l i n g *,ax

a c c e l e r a t i o n , r ad/s ec2

cycles t o damp t o 1/10 amplitude Dutch roll o s c i l l a t i o n ' d period, sec t o 1/2 cycles t o damp amplitude l o n g i t u d i n a l phugoid ' P H o s c i l l a t i o n period, sec undamped n a t u r a l frequency

of l o n g i t u d i n a l s h o r t -

period mode, cps p i t c h i n g angular v e l o c i t y , Go trimmed angle of a t t a c k , q rad/ s ec dynamic p r e s sure, lb/f t2 P angle of s ide s l i p , 4 , radians yawing angular v e l o c i t y , r rad/sec Yo trimmed longitudinal f l i g h t - p a t h i n c l i n a t i o n , p o s i t i v e for climb, deg complex frequency S (Laplace operator) &a t o t a l a i l e r o n d e f l e c t i o n , p o s i t i v e f o r r i g h t a i l e r o n S down, radians wing reference area, ft2 Ee e l e v a t o r deflectton, posi- thrust, l b T tive t r a i l i n g edge down, radians a T v a r i a t i o n of t h r u s t with Mach number at trim aM 6 , rudder deflection, p o s i t i v e condition, l b t r a i l i n g edge l e f t , radians Dutch roll time t o T1/2, d damp t o half a m p l i - damping r a t i o o f t h e

’ (PH’ SP

tude, sec o s c i l l a t o r y Dutch roll, longitudinal phugoid, .

and longitudinal s h o r t - phugoid time t o damp ‘i/z ,PH period modes, t o half amplitude, r e s p e c t i v e l y sec s i n g l e -degree -of -freedom time, sec t T% roll time constant, sec V t r u e airspeed, f t / s e c T roll-subsidence mode time R3 constant, sec c a l i b r a t e d airspeed, VC TS s p i r a l mode time constant, knots sec cp bank angle, radians equivalent airspeed, Ve knots or f t / s e c r a t i o of bank amplitude t o

Id

-

s i d e s l i p amplitude i n t h e maximum permitted

I d o s c i l l a t o r y Dutch roll

c a l i b r a t e d airspeed mode f o r normal operation, knots angle of a t t a c k , radians a Wn7PH, undamped n a t u r a l frequency of t h e o s c i l l a t o r y Dutch roll,

'"n, SP I-

l o n g i t u d i n a l phugoid, and l o n g i t u d i n a l short -period modes,

re spec t ive l y , r ad/s e c

frequency of t h e o s c i l l a t o r y p a r t of t h e numerator of t h e cp

"CP t r a n s f e r function, rad/sec E a

METHOD Computation Computation of t h e s t a b i l i t y , control, and handling-qualities fact0r.s of i n t e r e s t w a s based on equations of motion t h a t included a l l six a i r p l a n e degrees of freedom. The equations were l i n e a r and perturbations i n v e l o c i t i e s and angles were assumed s m a l l . The c a l c u l a t i o n s were performed by d i g i t a l computer programs ( h e r e i n a f t e r r e f e r r e d t o as t h e "exact f a c t o r s " programs) ,l which t r e a t e d t h e l o n g i t u d i n a l and t h e l a t e r a l - d i r e c t i o n a l s e t s of equations separately. The programs were w r i t t e n i n Fortran N computer language.

Input D a t a The aerodynamic s t a b i l i t y derivatives, mass and i n e r t i a parameters, and dimensional data f o r each a i r p l a n e and f l i g h t condition were based l a r g e l y on wind-tunnel measurements supplemented by f l i g h t t e s t s , and were represented by t h e a i r c r a f t manufacturers as t h e most r e l i a b l e d a t a a v a i l a b l e for use i n developing o p e r a t i o n a l f l i g h t simulators. Theoretical estimates were given f o r parameters t h a t did not lend themselves t o ready experimental measurement Corrections f o r t h e e f f e c t s of air- (e.g., most of t h e r o t a r y d e r i v a t i v e s ) .

frame f l e x i b i l i t y were included i n t h e data. Yaw dampers and automatic p i t c h t r i m devices were assumed inoperative.

The major dimensions of t h e j e t t r a n s p o r t s a r e given i n t a b l e I. The b a s i c f l i g h t conditions analyzed a r e tabulated below.

Condition Vc, knots M Altitude, f t

Climb 2 8 0 0.46 5,000

Climb 285 0.62 20,000

Cruise 2 1 6 - 250 0.72 - 0.82 40,000

C r u i s e - 295

264 0.78 - 0.86 35 , 000

22,400 - 23,500

Maxi" VN0 376 - 397 0.844 - 0.90

Holding 225 - 240 0.45 - 0.48 15,000

The a l t i t u d e s and c a l i b r a t e d airspeeds f o r t h e b a s i c f l i g h t conditions a r e compared with t h e operational f l i g h t envelopes i n f i g u r e 1. Because a l l t h e reported upsets occurred at higher speeds, t h e take-off and landing - lFurnished by- Systems Technology, Inc., Hawthorne, California, under Contract NM2-864.

.. .. -..- .----.. I.., ... I . . ..... .... ..---_._._____.-.___ ~

conditions w e r e not considered. The values f o r a l l input parameters corre- sponding t o six b a s i c f l i g h t conditions are presented i n t a b l e 1 1 . Four a d d i t i o n a l conditions, which c l o s e l y approximated conditions f o r which f l i g h t d a t a were a v a i l a b l e , were s e t up f o r computation. These conditions are described i n f i g u r e 2 and t a b l e 111.

Output D a t a The results obtained d i r e c t l y from t h e d i g i t a l programs were i n t h e form of (1) t h e r o o t s of t h e c h a r a c t e r i s t i c equation (where complex roots were obtained, they were expressed as n a t u r a l frequency and damping r a t i o ) , and ( 2 ) t h e numerator roots ( z e r o s ) and gains of s e l e c t e d a i r p l a n e t r a n s f e r func- t i o n s . One parameter of i n t e r e s t , t h e bank-to-sideslip r a t i o lCp]/lpl of t h e lateral o s c i l l a t o r y (Dutch roll) mode, w a s not computed e x p l i c i t l y i n t h e d i g i t a l program; r a t h e r , it w a s hand calculated by expressing as t h e Cp/p r a t i o of numerators of bank and s i d e s l i p t r a n s f e r functions ( e . g . , t h e 'p/6, and p/Sr t r a n s f e r f u n c t i o n s ) w r i t t e n as polynomials i n terms of t h e complex roots of t h e Dutch roll mode.

frequency s, and evaluated by s u b s t i t u t i n g t h e The r e s u l t i n g complex r a t i o w a s converted t o t h e amplitude r a t i o lCpl/lpl by t a k i n g t h e square r o o t of t h e sum of squares of t h e real and imaginary p a r t s .

A l l o t h e r output data were d i r e c t l y t r a n s l a t a b l e i n t o c u r r e n t l y applicable handling-qualities f a c t o r s .

RESULTS AND DISCUSSION The l o n g i t u d i n a l and l a t e r a l - d i r e c t i o n a l handling-qualities f a c t o r s computed f o r t h e basic conditions a r e shown i n t a b l e IV, and i n f i g u r e s 3 through 19. Where applicable, boundaries i n d i c a t i n g e x i s t i n g or proposed handling-qualities c r i t e r i a a r e included. These c r i t e r i a a r e indicated f o r comparison purposes only, s i n c e t h e builders of c i v i l t r a n s p o r t s i n t h e United S t a t e s a r e not required t o comply w i t ! any d e f i n i t e numerical standards regarding t h e handling-qualities parameters considered herein. They need s a t i s f y only P a r t 25 of t h e Federal A i r Regulations, t h e F A A c e r t i f i c a t i o n t e s t p i l o t , and t h e buyer of t h e airplane.

Although t h e t h r e e t r a n s p o r t s have accumulated many thousands of f l i g h t hours, no documented p i l o t comments were a v a i l a b l e f o r inclusion i n t h i s r e p o r t .

The handling-qualities f a c t o r s computed for t h e a d d i t i o n a l f l i g h t conditions ( f o r comparison with f l i g h t measurements) a r e presented i n t a b l e V.

Longitudinal Short-Period C h a r a c t e r i s t i c s Basic f l i g h t conditions.- The longitudinal short-period n a t u r a l frequencies and damping r a t i o s are shown i n f i g u r e 3. The c h a r a c t e r i s t i c s of a l l three airplanes are similar, with between 0.24 and 0.45 cps fn,Sp I and cSp between 0.33 and 0.65. The present m i l i t a r y s p e c i f i c a t i o n (ref. 2 ) is indicated by t h e rectangular-appearing boundaries a t t h e l e f t . This c r i t e r i o n would be s a t i s f i e d i n a11 cases.

Figure 3 a l s o shows pilot-opinion boundaries from v a r i a b l e - s t a b i l i t y f l i g h t t e s t s by Cornell Aeronautical Laboratory i n a B-26 a i r p l a n e ( r e f . 3 ) .

According t o t h i s c r i t e r i o n , t h e t h r e e t r a n s p o r t s as a group would cover t h e f u l l range from "best t e s t e d " t o More recent pilot-opinion d a t a from

Cornell (refs. 4 and 5) are not used f o r comparison because they were obtained

i n tests of a f i g h t e r - t y p e v a r i a b l e - s t a b i l i t y a i r p l a n e , an F-94AY with charac- t e r i s t i c s markedly d i f f e r e n t from those of a t r a n s p o r t . Another analysis of l o n g i t u d i n a l handling q u a l i t i e s r e s u l t e d i n a new set of boundaries i n terms of t h e same two v a r i a b l e s , short-period n a t u r a l frequency and damping r a t i o (ref. 6 ) . This set of boundaries, shown i n f i g u r e 4, more nearly represents c u r r e n t thinking among handling-qualities i n v e s t i g a t o r s .

The d i s s i m i l a r i t y i n t h e nature of t h e boundaries from references 2, 3, and 6 is of i n t e r e s t . The present m i l i t a r y s p e c i f i c a t i o n says t h a t as long as E t h e t h e period is less than 6 seconds, damping requirements m u s t be met.

period is 6 seconds or longer, no damping requirements need be s a t i s f i e d .

(The s p e c i f i c a t i o n states only t h a t r e s i d u a l o s c i l l a t i o n s s h a l l not be of ) O n t h e other hand, t h e boundaries of reference 3 objectionable magnitude.

i n d i c a t e t h a t , at a n a t u r a l frequency l e s s than 0.29 cps, poor c h a r a c t e r i s t i c s should be expected regardless of t h e damping r a t i o . Although t h e r e may be disagreement as t o t h e p r e c i s e shape of t h e boundaries, t h e proper v a r i a b l e t o use as t h e ordinate, and as t o whether (as indicated by t h e lower boundary of ref. 6 ) increased damping r a t i o can compensate f o r very low n a t u r a l frequen- c i e s , a l l recent work shows t h a t t h e low-frequency, low-damping corner should be avoided.

The results of t h e present study, shown i n r e l a t i o n t o t h e proposed boundaries of reference 6 i n f i g u r e 4, i n d i c a t e t h a t most of t h e b a s i c f l i g h t conditions would have marginally acceptable c h a r a c t e r i s t i c s f o r normal opera- t i o n . Exceptions would be t h e m a x i m u m speed case f o r a l l t h r e e t r a n s p o r t s (which c l e a r l y would be acceptable) and t h e 40,000-foot c r u i s e and holding B (acceptable f o r emergency).

conditions of t r a n s p o r t I n f i g u r e s 3 and 4, t h e shaded areas denote short-period dynamics estimated f o r two r e p r e s e n t a t i v e four-engine propeller-driven t r a n s p o r t s i n t h e 100,000 t o l30,OOO-lb weight c l a s s . These c h a r a c t e r i s t i c s are t y p i c a l of a c l a s s of a i r c r a f t not associated with upset i n c i d e n t s . With propeller- driven t r a n s p o r t s , t h e consequences of upset ( a l t i t u d e loss and overspeed) would u s u a l l y be l e s s s e r i o u s than with current j e t t r a n s p o r t s . Although t h e short-period damping r a t i o s a r e somewhat g r e a t e r f o r t h e s e earlier t r a n s p o r t s than f o r t h e current jets, t h e frequencies a r e at about t h e same l e v e l .

Additional f l i g h t conditions. - Values of t h e short-period frequency and

damping r a t i o computed and measured (unpublished r e s u l t s of N A S A f l i g h t t e s t s ) for t h e a d d i t i o n a l f l i g h t conditions are p l o t t e d i n f i g u r e 5 . The boundaries of references 2 and 3 are again presented f o r compwison. (No f l i g h t d a t a were a v a i l a b l e f o r t r a n s p o r t B; instead, manufacturer's estimates are shown.

The two sets of computed c h a r a c t e r i s t i c s agree w e l l . ) Agreement between computed and f l i g h t -measured damping of t r a n s p o r t A w a s generally good. For t h e high-speed condition at each a l t i t u d e ( e s p e c i a l l y at 15,000 f t ) , t h e predicted frequency w a s less t h a n t h a t measured i n f l i g h t .

For transport C, t h e level of damping calculated w a s consistently g r e a t e r t h a n t h a t measured i n f l i g h t ; however, a l l damping values were within what would be considered t h e "good" range.

Figure 6 shows t h e above comparisons and t h e NADC boundaries ( r e f . 6 ) .

Previous comments concerning f i g u r e 5 apply here as w e l l .

Other frequency parameters.- I n f i g u r e 7 , t h e short-period dynamics of t h e three t r a n s p o r t s ( b a s i c conditions only) are indicated i n terms of damping r a t i o and two parameters, proposed i n reference 7, which relate l i f t or normal acceleration c h a r a c t e r i s t i c s and n a t u r a l frequency: &/an f o r nZa< 15 g/rad, and % /un f o r % > 1 5 g/rad. The boundaries separating s a t i s f a c t o r y , a a c c e p t a k e , and unacceptable areas are from reference 7 and were developed l a r g e l y from t h e f l i g h t - t e s t r e s u l t s of references 4, 5, and 8.

I n c o n t r a s t t o t h e marginal a c c e p t a b i l i t y of t h e s h o r t -period dynamics shown i n f i g u r e s 3 and 4, t h e dynamics i n terms of La/Un and nZa/un f i t , with only one exception, e n t i r e l y within t h e s a t i s f a c t o r y regions i n f i g u r e 7 .

The s h o r t -period c h a r a c t e r i s t i c s of t h e two reference p r o p e l l e r t r a n s p o r t s , shown as shaded areas, are a l s o within t h e s e s a t i s f a c t o r y regions.

Longitudinal Phugoid Characteristics Poorly damped or divergent phugoid c h m a c t e r i s t i c s could be excited by p i l o t c o n t r o l inputs i f t h e period of t h e phugoid mode i s s u f f i c i e n t l y s h o r t , or by a large-scale atmospheric di.sturbance which i s periodic and of a frequency near t h a t of t h e phugoid. For t h i s reason, t h e controls-fixed phugoid c h a r a c t e r i s t i c s of t h e three t r a n s p o r t s were examined.

Computed values of phugoid period and damping ( r e c i p r o c a l of t i m e t o h a l f or double amplitude) f o r t h e basic and a d d i t i o n a l f l i g h t conditions a r e p l o t t e d i n f i g u r e s 8 and 9, r e s p e c t i v e l y . The values of a / a M given i n t a b l e s I1 and I11 were used i n t h e computations.

Existing c r i t e r i a f o r t h e phugoid mode are very general, even f o r m i l i t a r y a i r c r a f t . I n general, i f t h e period i s 15 seconds or g r e a t e r , it i s required only t h a t t h e phugoid not pro-duce "objectionable" f l i g h t c h a r a c t e r i s - The only numerical requirement f o r damping, suggested i n references 6 t i c s .

and 10, is t h a t t h e t i m e f o r an unstable o s c i l l a t i o n t o double amplitude s h a l l be 55 seconds or g r e a t e r . Figures 8 and 9 a l s o show t h i s boundary.

A t a l l f l i g h t conditions where t h e phugoid mode w a s o s c i l l a t o r y , t h e above numerical c r i t e r i o n was s a t i s f i e d . Solution of t h e longitudinal equa- t i o n s of motion produced two r e a l r o o t s , one s t a b l e and one unstable, at f i v e f l i g h t conditions. For t h e s e cases, t h e r e c i p r o c a l of t h e times t o h a l f - amplitude and double amplitude of t h e aperiodic c h a r a c t e r i s t i c s are p l o t t e d i n f i g u r e s 8 and 9 at an i n f i n i t e phugoid period and are compared with t h e 55- ' second c r i t e r i o n even though t h e unstable modes are not o s c i l l a t o r y . The c r i - t e r i o n w a s not satisfied at two of t h e b a s i c f l i g h t conditions; t r a n s p o r t s A I M = 0.82 and B at maximum VNO, and two a d d i t i o n a l conditions; transport B at and hp = 32,160 f e e t , and t r a n s p o r t C at M = 0.835 and hp = 35,000 f e e t .

T, It should was 63 seconds f o r t r a n s p o r t C i n t h e 40,000 f o o t c r u i s e condition.

be noted t h a t t h e a p e r i o d i c a l l y divergent c h a r a c t e r i s t i c s presented i n f i g - where normally ures 8 and 9 occurred above M = 0 . 8 ( i n t h e "tuck" region), some type of automatic p i t c h t r i m device i s used, and would be expected only i n case of disengagement of such a device.

Lateral O s c i l l a t o r y (Dutch Roll) Characteristics

Basic f l i g h t conditions. - The calculated o s c i l l a t o r y damping and bank-to-

s i d e v e l o c i t y c h a r a c t e r i s t i c s without yaw damper are presented f o r t h e b a s i c f l i g h t conditions i n f i g u r e 10. The c a l c u l a t e d values of lCpI/lVe[ w e r e less than 0.4, a f i g u r e generally considered s m a l l and not i n d i c a t i v e of problems.

Included f o r comparison are t h e current m i l i t a r y s p e c i f i c a t i o n boundaries (ref. 2 ) f o r f l i g h t conditions o t h e r than t h e landing approach, and t h e esti- mated c h a r a c t e r i s t i c s of t h e two reference p r o p e l l e r t r a n s p o r t s (shaded a r e a s ) .

A l l t h e values of damping indicated f o r t r a n s p o r t A would m e e t t h e m i l i t a r y s p e c i f i c a t i o n f o r normal operation, even with t h e yaw damper inopera- t i v e . Although t r a n s p o r t s B and C were predicted t o be more l i g h t l y damped, a l l but one condition ( t h e high-altitude c r u i s e of t r a n s p o r t B ) were damped s u f f i c i e n t l y t o s a t i s f y t h e dampers-off requirement.

The above c a l c u l a t e d results are shown i n figure 1 1 i n terms of K / T , / .

and 191 /Ive I . The K f a c t o r as p a r t of t h e c r i t e r i o n w a s first introduced K = Pd f o r 0 < P d s 2.4 and K = 2.4 f o r Pa 1 2.4 sec.

i n reference 9: The conclusion t h e r e i n w a s , i n e f f e c t , t h a t when t h e Dutch roll period w a s rela- l/Tl,2 c o r r e l a t e d b e t t e r with p i l o t t i v e l y long, a parameter proportional t o opinion. The same c r i t e r i o n is presented as a design guide i n reference 10.

Because i n t h e present study a l l periods were g r e a t e r than 2.4 seconds, K = 2 . 4 is indicated i n f i g u r e s 1 1 and 15. For a l l t h e t r a n s p o r t s , including t h e K f a c t o r r e s u l t e d i n a less favorable comparison with t h e boundaries than e x i s t e d with respect t o t h e m i l i t a r y s p e c i f i c a t i o n .

In f i g u r e 12 t h e calculated Dutch roll c h a r a c t e r i s t i c s a r e compared with t h e proposed frequency-damping requirement of reference 6. Because a l l pre-

d i c t e d values of pI/Ivel w e r e less than 0.4, t h e only normal-operation

boundary shown is he one f o r I n t h e frequency region of 0 < ['pI/IVel s 0.4.

i n t e r e s t here, t h e s o l i d boundary corresponds approximately t o l/Tl,2 = 0 . 3 , or K/T,/, = 0.72 with K = 2.4.

I n figure 12, as i n figure 11, t h e only condition t o s a t i s f y t h e normal- O f t h e remaining condi- operation c r i t e r i o n w a s t r a n s p o r t A a t m a x i m u m VNo.

t i o n s , 7 f e l l between t h e normal-operation boundary and t h e boundary f o r acceptable c h a r a c t e r i s t i c s with s t a b i l i t y augmentation inoperative, and 10 were outside t h e l a t t e r boundary. A t least i n t h e frequency-damping region covered by t h e s u b j e c t t r a n s p o r t s , t h e boundaries i n f i g u r e 12 (from ref. 6 ) appear more conservative than those i n f i g u r e 1 1 (from ref. 9).

I

Additional f l i g h t conditions. - Calculated and f light-measured Dutch roll

periods a r e p l o t t e d versus- equivalent airspeed f o r t h e a d d i t i o n a l f l i g h t con- d i t i o n s i n figure 13 and t h e agreement i s considered s a t i s f a c t o r y . The f l i g h t values f o r t r a n s p o r t s A and B were underestimated by only 7 t o 2 1 percent.

a r e compared i n The calculated and f l i g h t -measured damping and

I cp 1 /I ve 1

f i g u r e s 14, 15, and 16 with t h e boundaries o f references 2, 9, and 6, respec-

Except for t r a n s p o r t A a t M = 0.77 and hp = 15,000 f t and a t t i v e l y .

M = 0.86 and h = 35,000 f t , and t r a n s p o r t B a t M = 0.82 and h = 32,160 ft,

t h e calculated $ amping l e v e l s agree well with those measured i n f f i g h t . The

f l i g h t lcpl/lvel values f o r t r a n s p o r t s A and C , though not e n t i r e l y i n close agreement with c a l c u l a t e d values, were i n t h e range between 0.1 and 0 . 4 t y p i - c a l of lcpl/lVel c a l c u l a t e d f o r both t h e b a s i c and a d d i t i o n a l f l i g h t condi- a l l t h r e e t r a n s p o r t s . For t r a n s p o r t B, however, the f l i g h t I cp 1 /I ve 1 t i o n s of w a s c o n s i s t e n t l y g r e a t e r than calculated, p a r t i c u l a r l y f o r hp = 32,160 f t and 41,650 f t . No apparent explan6tion f o r these l a r g e discrepancies e x i s t s , except perhaps i n t h e v a l i d i t y of t h e f l i g h t r e s u l t s (which had been supplied by t h e manufacturer) f o r t h e two high-altitude cases. For t h e t h r e e t r a n s - p o r t s taken as a group, half of t h e f l i g h t conditions considered (without yaw- damper augmentation) had l e v e l s of Dutch roll damping l e s s than t h a t c u r r e n t l y required of m i l i t a r y t r a n s p o r t s f o r normal operation. O n c e r t a i n occasions, any of these c i v i l t r a n s p o r t s may be dispatched f o r f l i g h t with t h e yaw damper out of service; or during climb, descent, o r turbulence penetration, t h e yaw damper may become inoperative when t h e a u t o p i l o t i s turned o f f . I n smooth air and good weather, t h e r e s u l t i n g low damping might not be highly objectionable t o most a i r l i n e p i l o t s ; i n turbulence and during f l i g h t on instruments, however, l a c k of s u f f i c i e n t Dutch roll damping may represent a s i g n i f i c a n t a d d i t i o n t o t h e already heavy p i l o t workload.

L a t e r a l Control C h a r a c t e r i s t i c s In addition t o t h e controls-fixed c h a r a c t e r i s t i c s of t h e t h r e e j e t t r a n s p o r t s , t h e lateral c o n t r o l response and closed-loop c h a r a c t e r i s t i c s are a l s o of i n t e r e s t from t h e standpoint of manuevering and recovery from l a t e r a l upsets due t o gusts.

Coupling with t h e ~ Dutch roll mode.- The range of calculated frequency is presented f o r t h e bazic f l i g h t conditions of each t r a n s p o r t r a t i o wq/Lc'd i n f i g u r e 17. Values of W q / W d f o r individual f l i g h t conditions a r e given i n t a b l e AT. Values of w(p/wd less than 1.0 are associated with adverse yaw during r o l l maneuvers and values g r e a t e r than 1.0 are associated with favor- able yaw. I n e i t h e r case, t h e Dutch roll mode can be unduly excited when t h e p i l o t is c o n t r o l l i n g i n roll. I f W q / W d is s d f i c i e n t l y less than 1.0, such e x c i t a t i o n can result i n o s c i l l a t o r y and severely decreased roll response; is s u f f i c i e n t l y g r e a t e r than 1.0, closed-loop i n s t a b i l i t y of t h e if mq/"d p i l o t - a i r p l a n e combination may occur (see ref. 11). A value of 1.0 often is considered optimum.

The shaded area i n figure 17 shows t h e spread of q u a l i t a t i v e p i l o t

opinion presented i n reference 12 f o r a v a r i e t y of f l i g h t and simulator t a s k s assuming vehicles with levels of Dutch roll damping comparable t o those of t h e t r a n s p o r t s . The range of uCp/ud represented by t h e s u b j e c t present j e t t r a n s p o r t s is only a small portion of t h e t o t a l range discussed i n refer- t h e expected v a r i a t i o n i n p i l o t opinion is correspondingly s m a l l .

ence 12 and Transports A and B are grouped within 50.10 of t h e u n i t y value of O n t h e b a s i s of reference 12, p i l o t opinions ranging from s a t i s f a c - uq/wd.

For t r a n s p o r t C, tory" t o "unsatisfactory b u t acceptable" would be expected.

varied from 1.15 t o 1.19 because of t h e favorable yaw due t o roll con- UT/Wd t r o l ( r e s u l t i n g from asymmetrical d e f l e c t i o n of highly e f f e c t i v e "full-time" s p o i l e r s i n addition t o inboard a i l e r o n s ) .

It should be noted t h a t , i n most cases, t h e l e v e l s of p i l o t opinion shown by t h e shaded band i n f i g u r e 17 applied e i t h e r t o c o n t r o l t a s k s involv- ing a high order of roll maneuvering or t o vehicles having l a r g e values of Dutch roll I Cp I / I P I . However, t h e maneuvering requirements of t h e c u r r e n t j e t t r a n s p o r t s general y are much less severe, e s p e c i a l l y outside t h e terminal area.

Steady r o l l i n g c h a r a c t e r i s t i c s . - The calculated s t e a d y - s t a t e wing-tip h e l i x angles, assuming maximum a t t a i n a b l e roll c o n t r o l surface deflection, a r e presented f o r t h e b a s i c f l i g h t conditions i n f i g u r e 18. The boundaries i n d i c a t e t h e minimum requirements of reference 2, assuming f l i g h t i n t h e clean configuration, f o r c l a s s I1 airplanes i n t h e performance range of i n t e r e s t .

f o r t h e holding and 40,000 f e e t c r u i s e conditions, f i g u r e 18 shows Except t h e r o l l i n g c a p a b i l i t y of t r a n s p o r t A (up t o 300 knots) t o be 30 t o 50 percent l e s s than t h a t required of m i l i t a r y t r a n s p o r t s . With f l a p s r e t r a c t e d , t h i s a i r p l a n e is controlled i n roll by means of inboard a i l e r o n s and s p o i l e r s .

In t h e same speed range, t r a n s p o r t s B and C e i t h e r exceed or come c l o s e t o meeting t h e m i l i t a r y s p e c i f i c a t i o n . A t t h e maximum operating Mach numbers j u s t under 400 k n o t s ) , a l l t h r e e j e t t r a n s p o r t s exceeded t h e s p e c i f i e d (Vc minimum pb/2V of 0.015, according to calculations.

Roll t r a n s i e n t response.- The r o l l i n g c a p a b i l i t i e s of airplanes have a l s o been assessed i n terms of t h e nature of t h e t r a n s i e n t response of roll r a t e t o a i l e r o n input, assuming single-degree-of-freedom r o l l i n g motion. The calcu- l a t e d roll-response parameters of t h e t h r e e j e t t r a n s p o r t s a r e presented i n f i g u r e 1 9 f o r t h e b a s i c f l i g h t conditions. The parameters shown are m a x i m u m r o l l i n g a c c e l e r a t i o n and single-degree-of-freedom roll time constant. The boundaries are from reference 13.

Although they w e r e derived f o r l a r g e t r a n s p o r t s i n t h e landing approach condition, t h e boundaries i n f i g u r e 1 9 a r e included on t h e premise t h a t satis- f a c t o r y roll response f o r t h e landing approach would be more than adequate f o r climb, c r u i s e , and o t h e r conditions which usually a r e considered less demand- ing. Figure 19 shows t h a t t h e roll parameters of a l l three s u b j e c t t r a n s p o r t s , i n t h e basic f l i g h t conditions, would f a l l within t h e s a t i s f a c t o r y region of reference 13.

Relatively l i t t l e is known about roll c o n t r o l requirements of airplanes

disturbed by lateral g u s t s . From theory, reference 14 i n d i c a t e s t h a t

a p p l i c a t i o n of c o r r e c t i v e a i l e r o n c o n t r o l proportional t o bank angle (which might represent t h e a c t i o n of a p i l o t a t moderate frequencies) can decrease, more e f f e c t i v e l y i n a l a r g e a i r p l a n e than i n a s m a l l a i r p l a n e , roll excursions i n continuous turbulence c o n s i s t i n g e n t i r e l y of s i d e gusts. A s a i r p l a n e s i z e and i n e r t i a l parameters are increased, t h e problem appears t o be whether t h e r o l l c o n t r o l power decreases more or less r a p i d l y than t h e amplitude of bank i n response t o t h e turbulence. Further study is needed on t h i s subject.

CONCLUSIONS Several calculated and flight-measured handling-qualities f a c t o r s of t h r e e subsonic j e t t r a n s p o r t s have been reviewed and compared with various handling-qualities c r i t e r i a . Because of inconsistencies i n some of t h e c r i t e r i a and questions regarding t h e i r relevance, no attempt was made t o c l a s s i f y a given t r a n s p o r t as s a t i s f a c t o r y o r u n s a t i s f a c t o r y f o r scheduled passenger operation. Within t h e s e l i m i t a t i o n s , t h i s study i n d i c a t e s t h e following : 1. O n t h e b a s i s of t h e current m i l i t a r y s p e c i f i c a t i o n and o t h e r published c r i t e r i a , a l l t h r e e t r a n s p o r t s had s a t i s f a c t o r y o r acceptable pre- d i c t e d o r f light-measured longitudinal short-period frequency and damping c h a r a c t e r i s t i c s i n t h e f l i g h t conditions of i n t e r e s t . Except f o r some cases of speed i n s t a b i l i t y associated with disengagement of Mach trim compensation devices , acceptable longitudinal phugoid c h a r a c t e r i s t i c s a l s o were calculated f o r t h e s e t r a n s p o r t s .

2. According t o several published c r i t e r i a , t h e s u b j e c t t r a n s p o r t s , without yaw dampers, exhibited l a t e r a l - d i r e c t i o n a l o s c i l l a t o r y c h a r a c t e r i s t i c s varying from s a t i s f a c t o r y f o r normal operation t o unacceptable f o r dampers inoperative. Unacceptably low damping, on t h e b a s i s of two o r more c r i t e r i a , usually occurred at high a l t i t u d e s o r at low speeds and moderate a l t i t u d e s .

3. In t h e climb, c r u i s e , and holding conditions, two of t h e t h r e e t r a n s p o r t s had predicted r o l l - c o n t r o l c h a r a c t e r i s t i c s t h a t s a t i s f i e d t h e current m i l i t a r y s p e c i f i c a t i o n s ( o r very n e a r l y s o ) f o r steady r o l l i n g , pb/2V. A t m a x i m u m speed, a l l t h r e e t r a n s p o r t s exceeded t h e s p e c i f i c a t i o n .

4. Values of m a x i m u m r o l l c o n t r o l power and r o l l time constant calculated f o r a l l t h r e e t r a n s p o r t s were i n a region of s a t i s f a c t o r y response proposed by one i n v e s t i g a t o r f o r l a r g e airplanes i n t h e landing approach.

Such c h a r a c t e r i s t i c s probably would a l s o be s a t i s f a c t o r y f o r t h e f l i g h t conditions considered i n t h i s study.

Ames Research Center National Aeronautics and Space Administration

Moffett F i e l d , C a l i f . , 94035, J u l y 16, 1968

720-06-00-04-00-21

1. Sadoff, Melvin; Bray, Richard S.; and Andrews, W i l l i a m H.: Summary of N A S A Research on Jet Transport Control Problems i n Severe Turbulence.

A I M Paper 65-330, 1965.

2. Anon.: Military S p e c i f i c a t i o n - Flying Q u a l i t i e s of P i l o t e d Airplanes.

MIL-F-8785(ASG) , Sept. 1 , 1954, Amendment 1, O c t . 1954; Amendment 2 , Oct. 1955.

3 . Newell, Fred; and Campbell, Graham: F l i g h t Evaluations of Variable Short Period and Phugoid C h a r a c t e r i s t i c s i n a B-26. WADC TR 54-594, Cornell Aero. Lab., Inc . , 1954.

4. H a r p e r , Robert P., Jr.: F l i g h t Evaluations of Various Longitudinal

Handling Q u a l i t i e s i n a Variable-Stability Jet Fighter. WADC TR 55-299,

1955 -

5. Chalk, Charles R. : Additional F l i g h t Evaluations of Various Longitudinal Handling Q u a l i t i e s i n a Variable-Stability J e t Fighter. WADC TR 57-719, P a r t s I and I1 , Jan. -July 1958.

6. Mazza, C . J.; Cohen, Marshall; and Spector, Alvin: Proposal f o r a '%'lying Q u a l i t i e s of P i l o t e d Airplanes" Revised M i l i t a r y Specification, (MIL-F-8785(ASG) ), with Substantiating Text. U . S . Naval A i r Development Center Rep. NADC-ED-6282, Jan. 1963.

7. Shomber, H . A . ; and Gertsen, W . M . : Longitudinal Handling Q u a l i t i e s A M Paper 65-780, 1965.

C r i t e r i a : An Evaluation.

8 . K i d d , E . A . ; and Bull, G . : Handling Q u a l i t i e s Requirements as Influenced by P i l o t Evaluation Time and Sample S i z e . Rep. TB-1444-F-1, Cornell Aero. Lab., I n c . , Feb. 1963.

9. Crone, R . M. ; and A'Harrah, R . C . : Development of Lateral-Directional Flying Q u a l i t i e s C r i t e r i a f o r Supersonic Vehicles Based on a Stationary F l i g h t Simulatory Study. IAS Paper 60-18, 1960.

10. Anon.: Design Objectives f o r Flying Q u a l i t i e s of C i v i l Transport A i r c r a f t . ARP 842, Society of Automotive Engineers, Inc., Aug. 1964.

11. Ashkenas , Irving L. ; and McRuer, Duane T. : The Determination of Lateral

Handling Q u a l i t y Requirements from Air€rame - Human P i l o t System

Studies. WADC TR 59-1-35 , June 1959.

12. Ashkenas, I. L. : A Study of Conventional Airplane Handling Q u a l i t i e s Requirements, P a r t II., Lateral-Directional O s c i l l a t o r y Handling Q u a l i t i e s . F i n a l Report , Jan. 1 9 6 3 - ~ a y 1965. AFFDL-TR-65-138 , P a r t 11 , Nov. 1965.

13. Bisgood, P. L.: A Review of Recent Handling Q u a l i t i e s Research, and Its Application t o t h e Handling Problems of Large A i r c r a f t ; P a r t 1.- Observations on Handling Problems and Their Study; Part 11.- Lateral- Directional Handling. RAE Rep.-Aero 2688, June 1964.

1 4 . Zbrozek, J. K . : Theoretical Study of t h e Rolling Response of A i r c r a f t t o

Turbulent A i r . RAE TN-Aero 2753 ( B r i t i s h ) , April 1961.

I I I I1 I 1111 TABLE I.- MAJOR DIMEXISIONS O F THE SUBJECT JET TWSPORTS Transport Dimens ion A B C Wing area, sq ft o

2433 2000

Wing span, f t

130.8 142.4 118.0

Wing mean aerodynamic

chord, f t 20.16

22.17 18.94

Mean distance of engine t h r u s t axis below fuselage reference l i n e , f t

6.5 6.5 3.6

Inc idenc e of engine t h r u s t axis, deg 1.50 3.15 3.00 Distance of p i l o t ' s s t a t i o n ahead of c e n t e r of gravity, f t

56.2 69.0

50. o

T A B L E 11. - P H Y S I C A L AND AERODYNAMIC C H A R A C T E R I S T I C S - B A S I C F L I G H T C O N D I T I O N S .

5,000-ft C l i m b 20,000-ft Climb I 40,000-ft Cruise I 35,000-ft Cruise Wimm VNO Holding

- - B A C A B C A B C B A - - Altitude, ft >,OOO 35,000 23,500 22,400 23,000 15,000 0,000 5,000 15,000 15,000 5,000 vc, knots 280 295 397 376 395 240 225 240 280 250 251 276 176 160 174 219 224 279 279 -_ 279 234 6 8 836 920 865 912 503 472 503 797 506 506 Mach number 0.86 0.90 0.844 0.89 0.48 0.45 0.48 0 . 4 6 0.78 0.46 0.82 A i r demity, slugs/ft3 0.00205 .00074 0.00074 0.00112 0.00117 0.00ll4 0.00150 0.00150 0.00150 1. 00205 . 00205 O.OOl27 0.00127 O . O O l 2 i .00058 I.O& 0 00058 0.00074

Dynamic pressure, l b / f t 2 260 212 260 260 260 260 184 142 I '184 1 257

257 475 435 474 l g l 167 i g i 226,240 Weight, lb 20,000 150,000 180,000 250,000 150,000 150,030 185,000 130,000 !65,000 222,100 260,000 170,OoC 70,000 75,000 6838 4660 5 3 0 7770 4660 4660 5750 4040 8236 6900 8081 5280 Mass, slugs 7030 5440 5280 0 0 0 0 0 0 0 0 2.8 1.5 1.5 0 yo, deg 3.0 4.7 2.47

3.39 1.86 1.08 0.57 0.12 0.16 2.n 2.85 3.04 2.65 3.80 1 2.;0 1.jO

~ 6 , deg

-

. - 4.07 1.98 2.28 2.11 3.43 5.33 Body axes, IX million slug-ft2 I~ 4.08 3.41 3.59 3.98 1.97 3.44 8.18 7. 02 9.05 7.73 3.85 5.69 5.47 -__ --- 0.094 --- 0.30 0.29 1x2 ~~ --- -

0.380 0.288 0.380 0.323 ' 0.402 ' 0.340

0.358 0.370 0.536 0.337 0.351 0.363 0.327 0.023 0.020 0.024 0.020 0.020 0.022 0.023 0.037 0.020 0.020 0.020 0.024 0.020 4.326 4.584 5.266 5.415 5.358 4.133 4.555 4.853 4.274 5.701 4.567 4.733 4.295

--- _ _ _ _ _ _ 1.29 _ _ _ --- --- --- 1.64 _ _ _ _ _ _ _ _ _ 1.24 _ _ _

1.16 1.53 --- 1.59 0.203 0.212 0.260 0.223 0.203 0.21?14 0.232 0.254 0.186 0.201 0.227 0.230 0.138 0.144 0.177 0.210 0.247 0.238 -0.050 -0.108 0.313 .0.167 -0.013 0.026 0 0.099 -0.097 0.077 0.368 -0.116 -0.155 -0.198 -0.634 -0.037 -0.014 -0.157 0.205 0.191 0.238 0.150 0.221 0.354 0.263 0.240 0.181 0.105 0.215 0.523 0.152 0.315 0.178 0.168 0.241 0.158 S t a b i l i t y

--- -__ -0.016 --- -0.029 --- --- --- -__ -0.017 _ _ _ _ _ _

-0.017 _ _ _ -0.023 --- --- -0.011

axes 0 0 0 0 0.010 0 0.035 0.010 0.217 0.580 0.113 0.257 0 0 0 -0.814 -0.756 -0.649 -0.854 -0.774 -0.655 -1.255 -0.986 -0,796 -1.209 -0.986 -0.814 -1.037 -0.945 -0.606 -0.905 -0.860 -O.n6 -4.27 -8.98 -4.88 -4.77 -9.22 -6.19 -5.35 -10.09 -6.40 -5.80 -9.98 -6.01 -6.38 -9.36 -4.74 -4.27 -9.27 -4.62 -11.17 -10.76 -11.02 -11.53 -11.17 -11.27 -13.58 -12.62 -12.'(l -13.37 -12.49 -12.44 -11.48 -11.23 -11.40 -11.64 -11.41 -11.43 -0.66 -0.65 -0.66 -0.66 -0.65 -0.69 -0.69 -0.80 -0.76 -0.63 -0.69 -0.68 -0.43 -0.44 -0.53 -0.69 -0.76 -0.n 0.0175 -0.016 0.120 0.0010 -0.023 0.139 0 -0.041 -0.154 -0.0525 -0.113 -0.059 -0.1400 -0.395 0.379 0.0052 0.015 0.053 9450 9000 --- 6650 9200 --- 8950 9444 --- 19,900 16,690 --- 6203 3648 --- & b M , 3750 3100 --- , ----------- -0.705 -0.668 -0.790 -0.722 -0.696 '.-0.880 '3 -0.741 '-0.826 -0.796 -0.748 -0.849 "-0.814'--0.733 ' -0.841 "-0.705 '~-0.679-'-0.794 ' Cyp "I, -0.191 -0.023 --- -0.188 -0.046 --- -0.239 +0.034 --- -0.244 -0.076 --- -0.236 -0.182 --- -0.201 -0.007 --- cyr 0.361 0.258 --- 0.378 0.270 --- 0.421 0.300 --- 0.363 0.268 --- 0.449 0.278 --- 0.435 0.297 ---

--- --- 0.027 --- --- 0.026 --_ --- 0.021 -__ --_ 0.020 _ _ _ _ _ _ 0.018 --- --- 0.027

' S a Cys, 0.234 0.199 0.191 0.245 0.196 0.190 0.273 0.210 0.194 0.282 0.197 0.175 0.31 0.ln 0.139 0.236 0.213 0.202 CZB -0.176 -0.164 -0.154 -0.186 -0.159 -0.163 -0.215 -0.211 -0.192 -0.203 -0.189 -0.181 -0.169 -0.135 -0.132 -0.177 -0.168 -0.158 Body Czp -0.325 -0.356 -0.333 -0.340 -0.372 -0.342 -0.426 -0.431 -0.430 -0.389 -0.425 -0.394 -0.311 -0.395 -0.301 -0.354 -0.381 -0.360 Axes Cz, 0.123 0.115 0.168 0.123 0.119 8.177 0.133 0.165 0.215 0 . 1 2 1 0.138 0.215 0.101 0.120 0.141 0.114 0.120 0.ln -0.018 -0.042 -0.047 -0.019 -0.038 -0.050 -0.023 -0.044 -0.062 -0.017 -0.038 C l g a -0.058 -0.010 -0.025 -0.047 -0.020 -0.050 -0.051 0.036 0.020 0.023 0.037 0.019 0.023 0.040 0.021 0.025 0.039 0.020 0.024 0.044 0.017 0.021 0.036 0.021 Gig, 0.025 0.108 0.126 0.130 0.117 0.128 0.153 0.126 0.135 0.163 0.132 0.140 0.174 0.142 GB 0.122 0.140 0.126 0.112 0.128 -0.042 -0.047 -0.008 -0.039 -0.045 -0.W -0.067 -0.052 0.013 -0.051 -0.037 0.041 -0.012 -0.018 -0.001 CnP -0.012 -0.047 -0.048 -0.160 -0.154 -0.160 -0.162 -0.173 -0.168 -0.180 Cnr -0.147 -0.156 -0.171 -0.172 -0.170 -0.189 -0.161 -0.169 -0.149 -0.163 -0.162 -0.0041 0.0005 -0.0230 -0.0039 0.0010 -0.0231 -0.0034 0.0004 -0.0223 -0.0026 0.0014 -0.0218 -0.0015 0.0020 -0.0209 -0.0339 0.000 -0.0231 Gs- -0.095 -0.089 -0.083 -0.03 -0.087 -0.083 -0.llO -0.094 -0.077 -0.115 -0.088 -0.067 -0.119 -0.077 -0.051 -0.Og5 -0.Og4 -0.087 T A B U 111. - PHYSICAL AND AERODYNAMIC CHARACTERISTICS.

ADDI-TIONAL FLIGHT CONDI-TIONS .

T r m p o f i A B C ~~ ~~ Altitude, ft 15,000 15,000 35,000 35,000 99300 21,000 32,160 41,650 15,000 15,000 35,000 35,000 Vc, knots 175 395 213 296 182 165 298 216 250 320 250 287 ve, knots 174 383 211 277 180 162 280 203 247 313 239 270 Y, f t / s e c 370 815 023 837 350 381 805 721 525 666 723 817 Mach nmber 0.35 0.77 0.64 0.86 0.32 0.37 0.82 0.74 0.50 0.63 0.75 0.835 A i r density, s l ~ s / f t ” 0.00150 O.OOl50 O.OCO74 0.00074 0.00180 0.00123 0.00082 0.00054 0.00150 0.00150 0.00074 0.00074 Dynamic pressure, lb/ft2 l o ; ! L 9 O 143 257 110 8 9 280 140 208 329 195 242 Weight, l b 180,000 180,000 175,000 175,000 212,500 173,400 208,100 180,400 151,700 147,200 130,000 126,000 Mass, slugs 5,590 5,590 5,440 5,440 6,600 5,385 6,465 5,595 4 , n 5 4,575 4,040 3;915 Tor deg 0 0 0 0 0 0 0 0 0 0 0 0 6.77 0.08 3.58 0.88 6.77 6.60 0.70 3.08 3.41 1.58 2.40 1 . 4 1 r + , , deg 1 , 2.28 2.28 2.18 2,18 4.18 2.B 3.99 3.03 2.15 2.08 1.84 1.79 Body axes, I Y 3.44 3.44 3.45 3.45 3.99 3.86 3.97 3.88 2.05 2.01 1.91 1.88 million s1ug-ft2 I~ 5.69 5.69 5.61 5.61 7.85 6.42 7.64 6.57 4.10 4.00 3.65 3.57 1x2 --- _ _ - _ _ _ --- 0.29 0.27 0.29 0.28 0.095 0.095 0 . 6 4 6 . 6 4 0.151 0.503 0.280 0.702 0.270 0.467 0.224 0.705 0.365 0.333 0.260 0.010 0.027 0.020 0.046 0. ob6 0.021 0.032 0 . m 0.017 0.020 0.019 4.269 5.180 4.72 4.796 4.79 5.41 4.261 4.809 5.114 5.79 4.173 --- _ _ _ _-_ 1.26 1.28 1.63 --- --- --- --- 1.62 0.166 0.214 0.182 0.268 0.191 0.262 0.277 0.237 0.219 0.258 0.237 -0.10 -0.02 -0. 097 0 0 -0.150 0 0.050 0 0.365 0.356 0 0 . 2 5 0.178 0.688 0.685 0.311 0.430 0.168 0.073 0.172 0.161 S t a b i l i t y --_ _ _ _ --- _ _ _ --_ --- --- --- --- --- --- axes 0 0.025 0 0.070 0 0 0.05 0 0 0.W 0 0.066 -0.565 -0.878 -1.053 -0.911 -0.992 -0.708 -0. n 4 c . , -0.858 -0.957 -0.997 -0.563 -0.735 -5.21 -6.39 -5.05 -4.07 -4.19 -6.16 -9.08 c . , -4.80 -5.52 -9.23 -9.79 -9.92 -10.80 -12.58 -13.37 -11.54 -11.81 -11.53 -12.75 -11.36 -11.04 -12.22 -12.41 $ -12.16 -0.54 -0. n -0.63 -0.73 -0.820 -0.848 -0.585 -0.802 -0.706 -0.652 -0.769 -0.707 CmSe 0 0 -0.05 -0.050 -0.055 -0.180 -0.081 t0.014 to. 022 0 -0.227 %4 0 __- --- --- --- ar/aM --- --- --- --- --- --- --- --- Cy, -0.699 -0.762 -0.728 -0.797 ’ -0.673 -0.679 -0.749 -0.747 -0.799 -0.794 -0.817 -0.822 P --- -0.210 -0.230 -0.248 0.188 -0.220 0.1% -0.147 -0.013 cyP --- 0.467 0.422 0.522 0.269 0.274 0.294 oi, 0.391 0.303 --- _ _ _ --_ _ _ _ --- _-- -_- --- 0.027 %Sa 0.250 0.245 0.282 0.215 0.218 0.186 0.209 0.235 0.199 %ST CIB -0.224 -0.154 -0.214 -0.203 -0.227 -0.218 -0.144 -0.205 -0.163 C l p -0.385 -0.281 -0.296 , -0.394 -0.405 -0.424 -0.436 -0.393 -0.359 Body 0.211 0.108 0.174 0.142 0.160 0.163 0.158 0.178 0.139 axes C1T C -0.021 -0.019 -0.017 -0.058 -0.058 -0.034 -0.047 -0.050 ”a -0.020 0.018 0.019 0.018 , 0.021 0.021 0.018 0.021 0.024 0.019 “6, 0.130 0.134 0.139 0.154 0.130 0.0% 0.140 0.130 0.130 -0.029 -0.047 ~ -0.035 -0.075 -0.131 -0.100 -0.022 -0.057 -0.051 -0.166 -0.169 -0.163 -0.140 -0.167 -0.152 -0.165 -0,169 -0.174 -0.163 -0.0228 -0.0228 -0.0231 -0. ow26 -0.0041 -0.0036 -0.0018 -0.0006 -0.0233 -0.077 -0.082 -0.072 -0. log -0.101 -0.084 -0. og4 -0.086 -0.097 I-' CD TABLE IT.- COMPUTED HANDLING-QUALITIES FACTORS. BA.SIC FLIGHT CONDITIONS.

~~~ I 20,000-ft Climb I 40,000-ft Cruise I I 5,000 -ft Climb I

Transport A € 3 C A B C A B C I Altitude, f t 5,000 5,000 5,000 .' 20,000 20,000 20,000 40,000 ' 40,000 40,000 Vc, knots 280 280 280 285 285 285 250

242 I 250

Mach number 0.46 0.46 0.46 0.62 0.62 0.62 0.82 0.72 0.82 Longitudinal.

0.296 0.303 0.244 0.282

'h f n , SP J CPS 0.300 0.306 0.303 0.297 0.299

0.508 0.544 0.647 0.423 0.467 0.546 0.336 0.354 0.432 period 0.63 0.57 0.43 0.79 0.70 0.56 1.03 0.97 0 - 77 c l l 10

I Wn,pH, rad/sec 0.075 0.066 ~, 0.090 0.062 11 0.057 0.087 I 0.056 0.062 I ---

0.016 , 0.023 ' 0.010 0.016 I 0.027 0.021 0.046 0.036 ---

5PH

Phugoid PpE, sec 84.0 94.7 70.2 101.2 I 110.1 ' 72.5 112.6 102.2 ---

U T l , 2 ,m, sec 0.00169 0.00221 0.00128 0.00143 0.00220 0.00266 0.00375 0.00317 0.0303

--- --- --- --- --- ---

l/Tz.pH~ see --- --- 0.0159

Later al-D ir ec t i o n a l Ma, r&/sec 1.33 1.20 1.42 1.42 1.36 1.05 1.22 1.30 1.39 0.117 0.080 0.094 0.096 0.061 0.072 0.078 0.014 0.031

k t

w d Jm rad/sec 1.32 1.20

1.41 1.42 1.38 1.36 1.05 1.22 1.30 4.76 5.24 4.45 4.44 Pa, see 4.54 4.63 4.82 Dutch 5- 1.7 5.99 roll 1/T1,2,d, 0.224 0.138 0.191 0.146 0.156 0.021 0.058 0.331 0.458 0.048 2 * 4 / ~ ~ / 2 , a, l / s e c 0.538 0 - 350 0.374 0.139 0.65 0.71 0.12 0.28 1.80 2.62 2.22 2.12 0.220 0.380 0.366 0.308 S p i r a l I/T~, l / s e c 0.0079 0.0106 -0.0037 0.0084 0.0074 0.0004 -0.0007 0.0073 0.0060 & roll l/TR_ 2 l/sec 1.058 1.128 1.116 0.902 0.948 0.940 0.988 0.755 0.845 ~~

bma, r d / s e c 2 0.352 0.536 0.546 0.411 0.483 0.568 0.652 0.411 0.684

TR, J sec 0.977 1.032 1.018 1.138 1.238 1.238 1.026 1.659 1.423 R o l l c o n t r o l (pb/2VV)max, r d 0.044 0.078 0.065 0.048 0.066 0.065 0.055 0.070 0.072 w'P/wa 1.053 0.925 1.150 1.049 0.942 1.168 1.019 0.909 1.163

T A B U N.- COMPUTED HANDLING-QUALITIES FACTORS. BASIC FLIGHT CONDITIONS - Concluded

, 35,000-ft Cruise bhXhiUm VNO Holding A B C A C B A B C Altitude, f t 35,000 23,000 15,000 15,000 ’-5,0°0 35,000 35,000 23,500 22,400

ve, knots 295

304 295 Mach number 0.86 0.78 0.86 0.90 397 0.844 376 0.89 395 0.48 2 40 0.45 225 0.48 2 40 0.427 0.403 0.276 0.299 0.332 0.448 0.267 0.291 0.516 0.418 0.469 0.572 0.396 0.453 0.528 0.621 0.85 0.69 0.53 0.61 0.72 0.80 0.59 0.46 0.045

--- 0.121 0.022 0 . 6 8 4 --EZn--

0.077

--- 0.275 0.014 0.644

0.155 0.027 0.029 0 035

185.4 --- 54.0

81.2 139.2 368.5 76.1 75.0 0.00769 0.160 0.0481 o.00090 0.0208 0.0299 0.0347 0.0420

---

--- --- --- ---

0.136 ---

J

Lat eral-D i r e c t ional 1.60 wd, rad/sec 1.21 1.49 2.16 1.66 1.97 1-33 1.16 1.36 0.100 0.032 0.046 0.147 0.082 0.089 0.076 0.086

0 - 137

(d 1.21 1.49 1.59 2.14 1.66 1.96 1.32 1.16 1.36 w d d a rad/sec P,, see 3.94 5.20 4.23 2.94 3.79 3.20 5.44 4.63 Dutch 4.77 r o l l 0.226 0.198 0.253

0 - 057 0 099 0.254 0.127 0.170

0.459 0.542 0.137 0.238 1.102 0.475 0.607 0.634 0.305 0.408 0.89 0.30 0.42 0.81 1.26 1-35 0.69 0.79 2.44 2.00 2.07 2.12 1.68 2.35 0.300 : : : ; 6 ~ 0.242 0.272 0.256 0.192 0.334 0.0085 0.0070 -0.0003 0.0096 0.0119 0.0132 0.0009

0.898 1.357 ~ 1.164 I

1.075 0 943 1.362 1.555 0.491 0.469 0.384 0.706 0.662 0.695 0.776 1.256 0.682 0.638 0.836 0.974 0.915 1.354 0.060 0.019 0.064 0.089 0.075 0.035 0.062

1.047 1.041 1 0.914 1.147

1.184 1.070 0.939 Iu TABm V. - COMPUTED HArJDLnVG-QUALTIIIES FACTORS. ADDITIONAL FLIGHT CONDITIONS.

~~

I Transport

I

A B C A l t i t u d e , f t 15,000 15,000 35,000 32,160 41,650 15,000 35,000 9,300 21,000 15,000 35,000 35,000 v,, k n o t s 1.75 395 213 296 182 Mach number 0.37 165 0.82 298 0.74 2 16 0.50 250 0.63 320 0.75 250 0.835 287 0.77 0.64 0.86 0.32 0.35 0.196 0.342 0.359 0.224 0.329 0.221 0.203 0.247 0.287 0.335 0.281 0.327 0.560 0.383 0.384 0.530 0.487 0.424 0.368 0.590 0.643 0.494 0.505 0.499 0.54 0.89 0.88 0.59 0.66 0.79 0.93 0.50 0.44 0.64 0.63 Cl/ 10

0.099 0.058 ---

0.106 0.035 0.065 0.031 0.107 --_ 0.054 0.074 0.065

0.0088 0,036 ---

0.014 0.193 0.029 0.203 0.0094 --- 0.053 0.038 k 0.051

109.6 ---

59.2 183.0 96.3 207.6 58.9 63.6 --- 115.7 85.0 97.1

wd, r a d / s e c 1.13 2.20 1.25 1.68 0.95 0.96 1.40 1.13 1.35 1.66 1.37 1.55 0.024 0.062 0.0007 0.008 0.032 0.032 0.065 0.019 0.078 0.093 0.049 0.056

w d Jx r a d / s e c 1.13 2.20 1.25 1.a 0.95 0.96 1.40 1.13 1.35 1.66 1.37 1.55

2.86 5.54 5.03 3.74 6.59 6.54 4.50 5.56 4.65 3.80 4.60 4.06 Dutch 0.040 0.198 0.001 0.021 0.043 0.044 0.131 0.031 0.153 0.224 0.096 0.125 0.003 0.051 0.095 0.475 0.104 0.107 0.314 0.075 0.367 0.538 0.231 0.300 0.22 0.57 0.007 0.08 0.285 0.291 0.590 0.174 0.71 0.85 0.44 0.51 I 4 / l a l 1.95 1.86 2.36 2.42 1.95 2.07 1.57 2.35 1.56 1.70 2.01 2.04 l q [ / l v e l , d e g / f t / s e c 0.381 0.165 0.379 0.297 0.368 0.434 0.191 0.393 0.215 0 . B 4 0.285 0.256 .

50,000 50,000 0 5,000 f t climb 20,000 f t climb M - 40,000 40,000 40,000 f t cruise CI .35 A 35,000 f t cruise 30,000 0 .77 30,000 A Maximum VNo 0 .64 Ll Holding 20,000 h .86 20,000 I0,OOO 10,000 Transpot - t A Transport A 0 0 50,000 50,000 I - - 7- M - 40,000 40,000 0 .32 1c + L 0 .37 w - 30,000

- 30,000

a , 0 .82 -0 U h .74 20,000 .E - 20,000 Q a 10,000 I0,OOO Transpor ,t B Transport B 50,000 50,000 M - 40,000 40,000 CI .50 0 .63 30,000 30,000 0 .7 5 n .835 20,000 20,000 10,000 I0,OOO Transpor Transpor t C .t c 0 1 0 0 200 300 400 500 100 200 300 400 500 Vc, knots Vc, knots

Figure 2. - Additional f l i g h t conditions compared

Figure 1.- Basic f l i g h t conditions compared with with operating speed limitations.

operating speed limitations.

Iu P (Acceptable to right of boundary) 0 5 , 0 0 0 f t climb Unarmed, or stability augmentation 0 20.000 f t climb

} Ref. 2

inoperative ( h > 30,000 f t ) 0 40,000 f t cruise

/ ,Normal

A 35,000 f t cruise 0 5 , 0 0 0 f t climb A Maximum VNo a Holding Acceptable (7 20,000 f t climb emergency 0 40,000 f t cruise ln Q A 35,000 f t cruise

” ‘2 .I

- - \ Unacceptable

A Transport ln A Maximum VN0 D Holding Transport A Shaded areas indicate propeller g .5 driven transports u (I a l B & .4 XI - ? ? Shaded areas indicate propeller .o .2 ’c driven transDorts.

a , a u .3 0 - ._ L . I L L Transport B 8 .2 5 0 - A = Best tested U Pilot opinion B = Good .5 Accept able (Ref. 3 ) C = Fair U D = Poor

J

Acceptable emergency Unacceptable Transport C TransDort C .I L I I I I I 0 .2 .4 .6 .8 1.0 0 .2 .4 .6 .8 1.0

Damping ratio, c S p

Damping ratio, 5 sp

Figure 3. - Lingitudinal short -period n a t u r a l

Figure 4 . - Longitudinal short-period n a t u r a l

frequency and damping r a t i o compared with frequency and damping r a t i o compared with boundaries of references 2 and 3. Basic suggested boundaries of reference 6.

f l i g h t conditions.

Basic f l i g h t conditions (Acceptable to right of boundary) Transport A Unarmed, or stability augmentation } Ref.

inoperative ( h > 30,000 f t ) - M h p , f t .

1 Normal - M f l P , f t

n .35 15,000 0 .77 15,000 n .35 15,000 0 .77 15,000 0 .64 35,000 0 .64 35,000 0 .86 35,000 n . 8 6 35,000 Filled symbols indicate flight results Filled symbols indicate flight results v) Transport A Transport 6 A = Best tested Acceptable

% L I I I I I B Good

normal ".I C = Fair - M h p , f t c 'c D Poor - M hp, ft n .32 9,300 c.5

-

u C 0 .37 21,000 n .32 9,300 Ref. 3 a ,

v a b l e .6fb emergency

g . 4 0 .37 21,000 0 .82 32, I60 ? ?

0 .82 32,160 'c n .74 41,650 n .74 41,650 -0 e3 0 unacceptable Flagged symbols indicate characteristics ._ est imated by manu f ac t urer Flagged symbols indicate characteristics $.2 Transport 8 estimated by manufacturer V Transport C Acceptable -0 M h p , f t - M hp, f t -

-

n .50 15,000 0 .50 15,000 0 .63 15,000 0 .63 15,000 0 .75 35,000 Acceptable 0 .75 35,000 emergency n .835 35,000 n .835 35,000 Filled symbols indicate flight results Filled symbols indicate flight results TransDort c .I L I I I I I

o .2 .4 .6 .8 1 . 0

0 .2 .4 .6 .8 1 . 0 Damping ratio, [ s p Damping ratio, 5 s p Figure 6.- Longitudinal short-period frequency

Figure 5. - Longitudinal short-period natural

and damping r a t i o compared with proposed frequency and damping r a t i o compared with boundaries of reference 6. Additional p i l o t opinion boundaries of references 2 and 3. Additional f l i g h t conditions. f l i g h t conditions.

Iu c 0 5,000 f t climb A 35,000 f t cruise Shaded a rea s indicate prope Ile r-d r ive n transports 0 20,000 f t climb A Maximum V N o nzz, < 1 5 g / r a d nZn > I5 g/rad ..

0 40,000 f t cruise 0 Holding I .o 20 .8 16 a a v) v)

- . 6 , = - I2

$ \ \ a 8 u a 4 N _I c .2 Transport A Transport A I .o .8 a v) ; . 6 \ w *4 -I .2 4 I - H+-- Transport B

0 1000

Q v) I

p 12

a"

\ a 8 U N c

-2 100

a" Transport C 2 1 0 1 .0004 .OOl .01 .I .4 .2 .4 . 6 .8 I 2 .2 .4 .6 .8 I 2 I / T z , P H , I/sec

Damping ratio, c S p I/Ti/z, PH , I /set

Damping ratio, 5 sp

Figure 7. - Longitudinal shprt-period

Figure 8.- Phugoid period and damping. Basic c h a r a c t e r i s t i c s compared with f l i g h t conditions.

boundaries of reference 7 . Basic f l i g h t conditions.

to cruise condition. Damping value / must occur on or above boundary to / I .2 meet the specification.

' /

&Normal @ / operation Shaded areas indicate propeller

.8=---- d

driven transports.

Y

- .4 - ,Emergency (dampers inop) W -0 I Transport A I I I I I

z o

Q

5 1.6

- 1

0 5 , 0 0 0 f t climb // Transport A + A 3 5 , 0 0 0 f t cruise 1 operation . 8 = 4 - & d Maximum VNo

E

-0 El D Holding 0 . 3 7 2 1 , 0 0 0 2 . 4 - ,Emergency A v) - W o1 I Transport 6 I I I $ 0

Transport B ~ 1.6 1 (I/C1/2 2.3)

- "2-1 / - / A - . 4 0 ,Emergency I Transport C Transport C I I I I I Figure 9.- Phugoid period and damping. Figure 10. - Lateral o s c i l l a t o r y (Dutch roll) Additional f l i g h t conditions. c h a r a c t e r i s t i c s compared with current m i l i t a r y specification (ref. 2 ) . Basic f l i g h t conditions.

K = 2.4 Boundories shown opply to cruise condition. Damping value must occur on or above boundary to meet / 1.2 the criterion.

/ driven transports.

Normal operation (dampers inop) -2-

1.6 r K = 2.4

Shaded oreas indicate / 0 5 , 0 0 0 f t climb I I I I I Transport A propeller driven / 0 20,000 f t climb

Z L I .2

U P transports.

/ 0 40,000 f t cruise A 35,000 f t cruise d Maximum VNo 0 40,000 f t cruise c l Holding A 35,000 f t cruise

-

CL .4 afq ,Emergency .- - d Maximum VN0 i noperat ive P E

Transport B O a, c l > & L S t a b i l i t y L- z -- augmenter D Holding

I 0 1 I I I

x 0 -

d tu 0 1 I I I I 1 Transport B I .2 / Acceptable characteristics to right of boundary 'Normal

a b o p e r a t i o n

- 5 0.4, Normal operation .8 --J

.4 i - 08 ,Emergency

I I I I Transport C 0 .2 .4 .6 .8 1 . 0 0 .I .2 . 3 .4 .5 Damping ratio, C d

Figure 11. - L a t e r a l o s c i l l a t o r y (Dutch roll)

Figure 12. - Lateral o s c i l l a t o r y (Dutch roll)

c h a r a c t e r i s t i c s compared with c r i t e r i o n c h a r a c t e r i s t i c s compared with c r i t e r i o n of reference 9. Basic f l i g h t conditions.

Basic f l i g h t conditions, of reference 6.

1.6 - / Specification boundaries shown apply to cruise condition. Damping value / must occur on or above boundary to / 1.2 meet the specification. - Normal operatio& Transport A / Filled symbols indicate .8 L - - --/ flight results - M h,, ft - Filled symbols indicate flight results a .35 15,000 \

P

- Transport A .4 - ,Emergency (dampers inop.) *77 1 5 1 0 0 0 A W u 0 .64 35,000 M h p , f t -0 - 1 , B I I I I n .86 35,000 .2 0 V - 0 .35 15,000 0 .77 15,000 0 .64 35,000 - M h,, f t 0 .86 35,000 2 1.2 Normal o p e r o t i o W n .32 9,300

- t c

/ a , 0 .37 21,000 -- Transport B 0 .82 32, 160 7 3 Emergency n .74 4 1 , 6 5 0 P .4 (dampers inop.)

- M h,, f t v) B n .32 9,300 0 .37 21,000 0 .82 32,160 n .74 41,650 Transport C M h,, f t d - n .50 15,000 8 -- v- Transport C 0 .63 15.000 - M h , , f t 0 .75 35,000 ,Emergency 35,000 .4 (dampers inop.) 0 .835 0 .50 15,000 0 .63 15,000 0 .75 35,000 : D .835 35,000 0 .2 .4 .6 .8 1.0 1.2 160 200 240 280 320 360 400 V e t knots Figure 1.3.- Variation of Dutch roll o s c i l l a t i o n Figure 14. - Lateral o s c i l l a t o r y c h a r a c t e r i s t i c s period with equivalent airspeed. Additional cf the additional f l i g h t conditions compared 2 ) .

f l i g h t conditions. with current m i l i t a r y specification ( r e f .

Boundaries shown apply to cruise condition. Damping volue must occur

K = 2.4 - "I-Ial operation } Acceptable characteristics to

on or above boundary to meet --__ right of boundary Dampers inap.

/ the criterion.

Normal --/

. operation Transport A

/ Filled symbols indicate - M h,, f t Transport A 0 .35 15,000 0 M h,, f t - 0 .77 15,000 ,Emergency (dampers inop.)

0 .35 15,000

*4 1 1

0 .64 35,000 I I I I lPf3 $I 0 .77 15,000 0 .86 35,000 0 , 0 .64 35,000

e 1 . 6

- 0 .86 35,000 Transport B k K 2.4 // . .

/ - M h p , f t Filled symbols indicate flight results r N / or ma 1 0 .32 9,300 L operat ion 0 .37 21,000 ._ + a , . 8 - - - - / Transport B L 0 .82 32, 160 u - M hp, f t n .74 4 1 . 6 5 0 ._ .4 - 0 ,Emergency 0 .32 9,300 0 .37 21,000 E o 0 .82 32, 160 n .74 4 1 , 6 5 0 / K = 2.4 1 4 1 Transport C -Values shown at data points

/

lvel M h p , f t / - Normal Transport C 0 .50 15,000 A o p e r a t ion M h,, f t . 8 = - - - / 0 .63 15,000 - 0 .75 35,000 0 .50 15,000 n .835 35,000 0 .63 15,000 ,Emergency 0 .75 35,000 I I I I I I I .835 35,000 0 .2 .4 .6 .8 1.0 1.2 I - 0 .I .2 .3 .4 .5 Damping ratio, [ d Figure 1.5.- Lateral o s c i l l a t o r y c h a r a c t e r i s t i c s

Figure 16.- Lateral o s c i l l a t o r y c h a r a c t e r i s t i c s

of the additional f l i g h t conditions compared of the additional f l i g h t conditions compared with the c r i t e r i o n of reference 9.

with the proposed requirements of reference 6.

.02 ' A proximate spread /oPpilot opinions from 0 >

- DIN .02

m 7 .I 0 .08 .O 6 .04 x b + v I I L v) .02

7-

._

7 'Transport C LO31 094 1

m 7 v)

'Transport A 1.078 5 c d 5 ,147)

Transport C n ~~ " I I I I I I20 160 200 240 280 320 360 400 440 .4 . 6 .8 I .o I .2 I .4 I .6 V , , knots wd'wd Figure 17.- Ranges of r a t i o of w q t o w d f o r Figure 18. - M a x i m u m steady-state wing-tip the subject j e t transports. Basic f l i g h t helix angle, (pb/2V)ss,ma, compared conditions. with current m i l i t a r y specifications, reference 2. Basic f l i g h t conditions.

w hp, f t Condition 1.2 0 5,000 climb 2 0,000 climb .8 .6 0 cruise 40,000 .4 A 35,000 cruise A MOX. VNO N .2 V a Holding a , m \ . I Trai isport A i n C .06 1.2 I .8 .6 .4 .I Transport C .06 - - - L L / L .I .2 . 4 .6.8 I 2 4 6 810 Single -degree-of-freedom rol I time constant, T ~ , , sec

Figure 1 9 . - Maximum roll acceleration and single-degree-of -freedom r o l l t i m e

N constant compared with c r i t e r i o n of reference 13. Basic f l i g h t

>

I conditions.

Iu Iu c n Vl