Summary of v-g data obtained from turbine- powered transport airplanes from 1959 to 1963

SUMMARY OF V-G DATA OBTAINED

FROM TURBINE-POWERED

TRANSPORT AIRPLANES

FROM 1959 TO 1963

by Walter G, Walker

Ldngley Research Center

Langley S t d o n , Hampton, Va, N A T I O N A L A E R O N A U T I C S 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. A P R I L 1 9 6 5 i TECH LIBRARY KAFB, NM 0079709 ~ SUMMARY O F V-G DATA OBTAINED FROM TURBINE -POWERED TRANSPORT AIRPLANES FROM 1959 TO 1963 By Walter G. Walker Langley R e s e a r c h Center Langley Station, Hampton, Va.

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION For sale by the Office of Technical Services, Department of Commerce, Washington, D.C. 20230 -- Price $1.00 SUMMARY O F V-G DATA OBTAINED FROM TURBINE-POWERED TRANSPORT AIRPLANES By Walter G. Walker Langley Research Center S - Normal acceleration and airspeed data obtained with NASA V-G recorders i n s t a l l e d on two types of turboprop and three types of turbojet commercial transport airplanes have been analyzed t o determine the frequency of occurrence and the severity of t h e i n - f l i g h t accelerations experienced. The data cover approximately 176,000 hours of f l i g h t on eight d i f f e r e n t U.S. a i r l i n e s during

operations from 1959 t o 1963. The r e s u l t s indicate t h a t t h e frequencies per

f l i g h t mile of t h e occurrence of acceleration increments equaling or exceeding 5L.4g ranged from about 1.1 x 10-7 t o 3.0 x 10-6 f o r t h e four-engine turbine transports. For t h e operations of a two-engine turboprop transport, t h e f r e - quency of occurrence w a s about 7.0 x Such variations i n t h e acceleration experiences a r e not unusual. From overall considerations, the frequency of occurrence of large accelerations i n t h e turbine transports does not appear t o be appreciably d i f f e r e n t from t h a t observed previously i n piston-transport operations. However, t h e l a r g e s t accelerations f o r the turbine transports tend t o occur a t random throughout t h e design airspeed range; whereas f o r piston transports, t h e l a r g e s t accelerations were usually experienced a t l o w speeds r e l a t i v e t o the design airspeed range.

INTRODUCTION The National Aeronautics and Space Administration i s collecting normal- acceleration, airspeed, and a l t i t u d e data from d i f f e r e n t types of turbine- powered, commercial transports operated i n long-haul, short-haul, and feeder service. The present program i s a continuation of the long-standing NASA e f f o r t i n collecting operational d a t a on commercial transport airplanes and i s providing information on current operations similar t o t h e information sum- marized i n reference 1 f o r a number of piston-engine transports. The d a t a obtained not o n l y provide a b a s i s f o r comparing actual airplane operation with t h e design concepts, but a l s o point out unanticipated operational aspects and provide a background of information applicable t o t h e design of new airplanes.

"he data are being obtained with NASA V-G recorders (ref. 2) which provide envelope-type records of indicated airspeed p l o t t e d against acceleration and VGH recorders (ref. 3 ) which provide time-history records of indicated with airspeed, pressure a l t i t u d e , and normal acceleration. Some of t h e r e s u l t s t h a t have been obtained from turbine t r a n s p o r t s are given i n references 4 t o 7.

This paper summarizes t h e V-G data collected on turbine-powered trans- ports. The d a t a were obtained from a two-engine turboprop transport operated i n feeder service, a four-engine turboprop transport used i n short-haul service, and t h r e e types of four-engine t u r b o j e t t r a n s p o r t s used i n long-haul service.

The r e s u l t s are presented as composite envelopes of t h e acceleration increment p l o t t e d against airspeed and as cumulative frequency per f l i g h t m i l e of t h e m a x i m acceleration d i s t r i b u t i o n s . Comparisons a r e made between t h e accelera- t i o n experiences of turbine- and piston-engine t r a n s p o r t s .

SYMBOLS normal-acceleration increment, g u n i t s an m a x i m u m p o s i t i v e and negative normal-acceleration increment from "n, m a x each V-G record, g u n i t s C f cumulative frequency of occurrence acceleration due t o gravity, 32.2 f t / s e c 2 g f l i g h t distance, i n t e r n a t i o n a l n a u t i c a l miles V indicated airspeed, knots design cruising speed, knots VC

-

average t r u e airspeed, knots VT m a x i m value of never-exceed speed, knots 'NE, max m a x i m value of normal-operating l i m i t speed, knots vNO, m a x The airspeeds used i n t h i s paper are indicated airspeeds unless otherwise noted .

INSTRUMENTATION AND SCOPE OF DATA The data were collected with NASA oil-,damped V-G recorders (ref. 2) which provide envelope records of t h e l a r g e s t p o s i t i v e and negative acceleration increments from t h e +lg reference l i n e p l o t t e d against t h e corresponding w e r e i n s t a l l e d on f i v e types of turbine-powered trans- airspeeds. The recorders port airplanes. Some of t h e b a s i c c h a r a c t e r i s t i c s of t h e airplanes are given i n t a b l e I. The airplanes included t h r e e types of four-engine turbojets, one and one type of two-engine turboprop. The d i f - type of four-engine turboprop, f e r e n t types of airplanes are designated by t h e Roman numerals I t o V, and d i f - f e r e n t s e r i e s of a given type a r e designated by t h e l e t t e r s a t o c. A s shown i n t h e table, airplane Ia d i f f e r e d from airplane IC i n m a x i m u m gross weight, wing area, and w i n g span, and airplanes IIa, IIb, and I I c d i f f e r e d from each other i n m a x i m u m gross weight. Airplane IVb d i f f e r e d from airplane I V a p r i - were modified and strengthened.

marily because t h e w i n g and nacelle s t r u c t u r e s The V-G recorder w a s i n s t a l l e d i n t h e two-engine turboprop airplane on t h e a s e a t i n t h e passenger cabin within 1 foot of t h e center of grav- f l o o r under .b I n t h e four-engine airplanes, t h e recorders were i n s t a l l e d i n t h e main i t y .

w e l l within 3 feet of t h e center of gravity. The pressure landing-gear-wheel and s t a t i c airspeed l i n e s of t h e recorder were connected t o t h e c o p i l o t ' s air- speed system, with t h e exception t h a t i n t h e four-engine turboprop t h e recorder w a s connected t o an equivalent a l t e r n a t e system having balanced s t a t i c ports.

V-G d a t a samples i s summarized i n t a b l e I1 according t o The scope of t h e a i r l i n e , airplane type, and airplane s e r i e s . A s shown i n t h e table, t h e data consist of 18 samples of V-G records obtained during operations of t h e f i v e types of airplanes by eight a i r l i n e s (designated by t h e c a p i t a l l e t t e r s A t o H ) .

These data samples were collected between 1959 and 1963 and range i n s i z e from 1,300 f l i g h t hours t o approximately 23,000 f l i g h t hours.

A s an o v e r a l l description of t h e operations, t h e estimated average f l i g h t time, average pressure a l t i t u d e , and average t r u e airspeed a r e shown i n t a b l e I1 f o r each d a t a sample. These values were based on VGH time-history when such VGH d a t a data collected from t h e same operation as t h e V-G d a t a or, were not available, were based on VGH d a t a taken on t h e p a r t i c u l a r type of air- For t h e t h r e e types of t u r b o j e t s ( t h e long- plane flown i n a s i m i l a r operation.

haul operations), t h e average f l i g h t time ranged from 1.54 t o 3.75 hours, t h e average pressure a l t i t u d e from approximately 24,000 t o 30,000 f e e t , and t h e average t r u e airspeed from about 425 t o 450 knots. For t h e four-engine turbo- prop airplanes ( t h e short-haul operations), t h e average f l i g h t t i m e ranged from 0.88 t o 1.85 hours, t h e average a l t i t u d e from about 11,000 t o 15,000 f e e t , and t h e average t r u e airspeed from about 250 t o 315 knots. The two-engine turbo- props (feeder operations) had an average flight t i m e of 0.42 hour, an average a l t i t u d e of 5,000 f e e t , and an average t r u e airspeed of 180 knots.

For convenience, p a r t i c u l a r operations a r e subsequently i d e n t i f i e d by a combination of t h e c a p i t a l - l e t t e r designation of t h e a i r l i n e , t h e Roman-numeral designation of t h e airplane type, and t h e lower-case-letter designation of t h e airplane series. A I a denotes t h e operation by a i r l i n e A of air- For example, plane type I, s e r i e s a. (See t a b l e 11.)

The present samples of d a t a w e r e taken under conditions which are con- sidered t o be t y p i c a l of normal a i r l i n e operations, with t h e exceptions noted for operations AIVa and B I V a . (See t a b l e 11.) A s indicated i n t h e table, t h e m a x i m u m permissible placard speeds VN0," and V ~ ~ , m a x f o r t h e type I V Birplanes were r e s t r i c t e d from March 1960 t o February 1961 f o r a i r l i n e A and from March 1960 t o May 1961 f o r a i r l i n e B. I n order t o distinguish t h e samples N airplanes during speed-restricted operations, such of data taken on t h e type samples a r e designated as A I V a r and BNar.

EVALUATION O F DATA AND RESULTS The evaluation of t h e V-G records consisted of reading from each record t h e m a x i m u m positive and m a x i m u m negative in-flight acceleration increments, i anyma, regardless of t h e airspeeds at which they occurred. I n addition, t h e individual records were combined t o develop a composite envelope of accelera- #..

t i o n s and corresponding airspeeds f o r t h e period covered by each data sample.

Accelerations which occurred at low speeds (below 120 t o 180 knots, depending upon t h e airplane type) were omitted i n order t o exclude accelerations caused by landing impact.

The composite envelopes of t h e accelerations and corresponding airspeeds a r e given i n figure 1 f o r each operation. The values of acceleration increment i n g u n i t s (an) a r e plotted against indicated airspeed i n knots. Several unusual accelerations which involved considerable changes i n airspeeds were recorded i n t h e AIVa, mar, AIVb, E I I b , and GVa operations and these prominent occurrences a r e shown as dashed l i n e s on t h e composites i n figure 1. Also shown on each composite are t h e maximum values of t h e normal-operating l i m i t speed and of the never-exceed speed and VNE, respectively based VNOYmax

)

(

on data supplied by t h e Federal Aviation Agency o r the airplane manufacturer.

The amounts of data used i n preparing t h e composite p l o t s a r e l i s t e d i n f i g u r e 1.

I n order t o compare t h e turbine-transport composites i n figure 1 with similar piston-engine composites, figure 1 1 ( b ) of reference 5 , which represents t h e V-G records from piston-engine transports, i s presented as f i g u r e 2. The l e t t e r designations used t o indicate t h e types of airplanes i n figure 2 a r e the same as those used i n reference 1.

Table III lists, f o r each operation, t h e frequency d i s t r i b u t i o n s of the values Of read from t h e V-G records. I n each sample t h e distribu- t i o n s of positive and of negative were found t o be e s s e n t i a l l y sym- metrical and, therefore, were combined. The t o t a l f l i g h t hours and t o t a l nautical f l i g h t miles f o r each sample a r e a l s o l i s t e d i n t a b l e 111.

The f l i g h t miles given represent the overall climb, cruise, and descent segments and were derived by multiplying the t o t a l f l i g h t hours of t h e sample by t h e average value of t r u e airspeed f o r t h e p a r t i c u l a r operation ( t a b l e 11).

The acceleration d i s t r i b u t i o n s of t a b l e I11 a r e plotted i n figure 3 i n terms of t h e cumulative frequency pes f l i g h t mile with which given values of were equaled o r exceeded. The ordinate values were obtained by pro- &n,max gressively summing each d i s t r i b u t i o n of t a b l e I11 (by s t a r t i n g with t h e frequency f o r t h e l a r g e s t acceleration and then dividing each sum by t h e number of f l i g h t m i l e s represented). The cumulative frequency d i s t r i b u t i o n s were f i t t e d with extreme value d i s t r i b u t i o n curves (ref. 8) i n order t o obtain a mathematical representation of t h e data.

It may be noted t h a t below accelera- t i o n values of about 0.8g, t h e slopes of t h e d i s t r i b u t i o n s i n f i g u r e 3 decrease.

This decrease i n slope r e s u l t s from t h e envelope nature of t h e V-G record and t h e attendant method of evaluating only t h e m a x i m u m values of positive and negative normal-acceleration increments from each record. Consequently, t h e d i s t r i b u t i o n s tend t o underestimate t h e frequency of occurrence of all but t h e l a r g e s t acceleration - t h e underestimation being progressively l a r g e r as t h e 3 acceleration l e v e l i s decreased. I n practice, however, t h e d i s t r i b u t i o n s have been found t o be an adequate representation of t h e complete frequency count f o r accelerations l a r g e r than about 1.Og.

To f a c i l i t a t e comparisons of t h e acceleration experiences f o r t h e various operations, t h e values of t h e cumulative frequency p e r m i l e corresponding t o an acceleration increment of 3 . 4 g were obtained from figure 3 and are p l o t t e d i n f i g u r e 4. The value of a . 4 g w a s selected as a l e v e l f o r comparison because it i s s u f f i c i e n t l y l a r g e t o be of i n t e r e s t f o r s t r u c t u r a l considerations, y e t i s not beyond t h e limits of t h e m a x i m u m acceleration recorded i n most of t h e d a t a samples. Also shown i n f i g u r e 4 a r e t h e 95-percent confidence bands which are discussed subsequently. I n addition, t h e cumulative frequency d i s t r i b u - t i o n s from figure 3 are grouped according t o airplane type i n f i g u r e 5. For comparison, t h e upper and lower l i m i t s of corresponding r e s u l t s taken from ref- erence 1 f o r operations of piston t r a n s p o r t s are a l s o shown i n figure 5 . These l i m i t curves were derived on t h e b a s i s of t h e combined V-G and VGH acceleration d a t a of reference 1 and are not subject t o t h e underestimation noted previously i n t h e frequency d i s t r i b u t i o n s of V-G d a t a at low values of acceleration.

RELIABILITY O F RESULTS The e r r o r s i n t h e V-G recorder are discussed i n d e t a i l i n reference 2.

Based on past laboratory calibrations, t h e m a x i m instrument e r r o r s a r e e s t i - mated t o be l e s s than -+O.lg i n acceleration and less than 9 knots i n airspeed.

The record-reading e r r o r s a r e considered t o be random and s m a l l enough t o be negligible i n t h e o v e r a l l r e s u l t s . The V-G recorder w a s i n s t a l l e d s u f f i c i e n t l y close t o t h e center of g r a v i t y of t h e airplane s o t h a t e r r o r s due t o angular motions were negligible.

Past experience w i t h V-G data has shown t h a t samples of d a t a consisting of about 50 records representing approximately 10,000 or more flight hours from i an operation supplying homogeneous d a t a f o r at least one year w i l l y i e l d r e s u l t s having s a t i s f a c t o r y r e l i a b i l i t y . Inspection of t a b l e I1 shows t h a t 10 of t h e 18 samples are of adequate sample s i z e . I n order t o provide a yard- present s t i c k f o r measuring the r e l i a b i l i t y of t h e estimated m a x i m u m values of accel- l e r a t i o n and i n order t o judge whether differences between samples are r e a l , and not due t o sampling v a r i a b i l i t y , t h e 95-percent confidence bands were cal- culated from t h e d i s t r i b u t i o n s of t a b l e I11 by t h e procedures of reference 9.

These bands indicate t h e range within which t h e t r u e value (value for extended operations) may be expected with a probability of 95 percent. The resulting confidence bands shown i n figure 4 f o r t h e value of an," of 3 . 4 g indicate t h a t t h e data for each of t h e 10 samples i n the group representing 10,000 o r more f l i g h t hours l i e within frequency limits of about 5 t o 1 and, thus, t h e s t a t i s t i c a l r e l i a b i l i t y is considered t o be s a t i s f a c t o r y . For t h e 4,000- t o 10,000-hour group, 5 samples l i e within l i m i t s of about t h e d a t a f o r each of the one order of magnitude (a f a c t o r of 10 t o 1) o r l e s s , and t h e r e l i a b i l i t y of i s considered t o be acceptable. The remaining 3 samples have poor these samples r e l i a b i l i t y as a r e s u l t of t h e s m a l l number of records and t o t a l f l i g h t hours represented.

i The e f f e c t of dynamic s t r u c t u r a l response on the accelerations measured at t h e centers of gravity of t h e airplanes used i n t h e present investigation i s unknown and i s not accounted f o r i n the r e s u l t s presented. This e f f e c t should have no bearing on comparisons between data samples from t h e same type of air- plane. With respect t o t h e overall results, however, dynamic response e f f e c t may be important since d i f f e r e n t types of airplanes are represented i n the study.

DISCUSSION Composite V-G Envelopes Examination of t h e composite V-G envelopes i n figure 1 shows t h a t the general l e v e l of the m a x i m u m acceleration increments tends t o be roughly t h e same throughout most of t h e airspeed range f o r each operation.

The l e v e l of acceleration increments f o r the d i f f e r e n t airplane types ranges from roughly +0.75g (airplane type 11) t o about fL.25g (airplane types I11 and V ) . The l a r g e s t acceleration increments occurred randomly throughout most of the speed range with peaks a s high a s 12.0g evident on some of t h e composites. The com- posites indicate t h a t substantial accelerations were e q e r i e n c e d a t speeds i n excess of the maximum normal-operating l i m i t speed In some oper- VNoYmax.

ations, large accelerations occurred even a t speeds i n excess of the maximum never-exceed speed VN~,max.

A q u a l i t a t i v e comparison of the composite V-G envelopes from the turbine-

airplane operations ( f i g . 1) with t h e envelopes f o r piston-airplane operations

( f i g . 2) shows t h a t , i n general, the c h a r a c t e r i s t i c shapes of t h e envelopes f o r t h e two types of transports are different. Whereas t h e envelopes f o r the piston airplanes show a marked decrease i n acceleration l e v e l s at t h e higher speeds, t h e drop-off i n acceleration f o r t h e turbine airplanes i s much l e s s pronounced with the r e s u l t t h a t t h e envelopes tend t o be more o r l e s s rectangular. Such differences between t h e r e s u l t s f o r t h e turbine- and piston-engine transporks were noted previously i n reference 5, which indicated t h a t the turbine trans- ports were operated at a higher percent of t h e normal-operating l i m i t speed and a l s o t h a t a l a r g e r percent of flight t i m e w a s spent by the turbine transports at speeds i n excess of t h e normal-operating l i m i t speed. A s noted i n refer- ence 5, t h e increased accelerations experienced a t high speeds f o r t h e turbine t r a n s p o r t s a r e apparently a consequence of t h e l a r g e r amounts of f l i g h t t i m e spent at high speed.

V-G Acceleration Distributions Comparison of t h e acceleration d i s t r i b u t i o n s f o r t h e various operations i n f i g u r e 3 shows t h a t appreciable differences e x i s t between t h e frequency of

A s summarized i n f i g u r e 4, t h e f r e -

occurrence of t h e l a r g e values of anyma.

quency p e r f l i g h t m i l e with which a value of anyma of +1.4g w a s equaled or

exceeded, ranged from about 1.1 x 10-7 t o 3.0 x 10-6 f o r t h e four-engine turbine

transports. For t h e operations of t h e two-engine turboprop airplane t h e fre- quency of occurrence w a s about 7.0 x 10-6. Such differences between t h e accel- e r a t i o n experiences of various airplane types are not considered t o be unusual and have been observed previously i n r e s u l t s obtained from p i s t o n transports (ref. 1). The variations noted i n t h e acceleration h i s t o r i e s i n f i g u r e 3 are due primarily t o differences i n t h e airplane wing loading and l i f t - c u r v e slope, and, t o a l e s s e r extent, t o differences i n t h e s e v e r i t y of t h e gusts experi- enced, t h e operating airspeeds i n rough air, and t h e maneuvers performed during airplane and p i l o t check f l i g h t s .

The frequencies of occurrence of t h e l a r g e s t accelerations f o r a l l t h e four-engine turbine transports l i e within t h e upper and lower l i m i t s which define t h e past acceleration experiences of four-engine piston-powered trans- ports. (See f i g . 5 . ) Similarly, t h e frequency f o r t h e two-engine turboprop operation l i e s within t h e l i m i t s f o r t h e two-engine piston transports. Thus, t h e i n - f l i g h t accelerations experienced i n t h e turbine-transport operations generally appear t o be about t h e same i n order of magnitude and frequency as t h e accelerations experienced i n t h e past operations of piston-engine transports .

CONCLUDING REMARKS An analysis of 18 samples of V-G records taken on two types of turboprop t r a n s p o r t s and t h r e e types of t u r b o j e t transports during operations by eight a i r l i n e s has provided information on t h e l a r g e i n - f l i g h t normal accelerations experienced. The r e s u l t s indicate t h a t , f o r values of maximum normal- acceleration increments equaling o r exceeding 5 . 4 g , t h e frequencies p e r f l i g h t

mile ranged from about 1.1 x 10-7 t o 3.0 x 10-6 f o r t h e four-engine turbine

3 transports. For t h e operations of a two-engine turboprop transport, t h e fre- Such v a r i a t i o n s i n t h e acceleration quency of occurrence w a s about 7.0 x 10-6.

experiences are not unusual and have been observed i n past operations of piston transports. From o v e r a l l considerations, t h e frequency of occurrence of l a r g e accelerations f o r turbine t r a n s p o r t s does not appear t o be appreciably d i f f e r - ent from t h a t f o r piston t r a n s p o r t s . However, t h e l a r g e s t accelerations f o r t h e turbine t r a n s p o r t s tend t o occur at random throughout t h e design airspeed range; whereas f o r p i s t o n transports, t h e l a r g e s t accelerations were usually experienced at low speeds r e l a t i v e t o t h e design airspeed range.

Langley Research Center, National Aeronautics and Space Administration, Langley Station, Hampton, Va., January 6, 1965.

REFERENCES 1. Walker, Walter G.; and Copp, Martin R.: Summary of VGH and V-G D a t a Obtained From Piston-Engine Transport Airplanes From 1947 t o 1958. NASA TN D-29, 1959.

2. Taback, I s r a e l : The NACA Oil-Damped V-G Recorder. NACA TN 2194, 1950.

3 . Richardson, Norman R.: NACA VGH Recorder. NACA TN 2265, 1951.

4. Copp, Martin R.; and Fetner, Mary W.: Analysis of Acceleration, Airspeed, and Gust-Velocity D a t a From a Four-Engine Turboprop Transport Operating NASA TN D-36, 1959.

Over t h e Eastern United States.

5 . Coleman, Thomas L.; Copp, Martin R.; and Walker, Walter G.: Airspeed Operating Practices of Turbine-Powered Commercial Transport Airplanes.

TN D-744, 1961.

N A S A 6. Staff of Langley Airworthiness Branch: Operational Experiences of Turbine- Powered Commercial Transport Airplanes. NASA TN D-1392, 1962.

7. Hunter, Paul A.; and Walker, Waiter G.: An Analysis of VG and VGH Opera-

NASA t i o n a l Data From a Twin-Engine Turboprop Transport Airplane.

TN D-1925, 1963.

8. Press, H a r r y : The Application of t h e S t a t i s t i c a l Theory of Extreme Values (Supersedes NACA TN 1926.)

t o Gust-Load Problems. NACA Rep. 991, 1950.

9. Kimball, Bradford F.: An Approximation t o t h e Sampling Variance of an Estimated M a x i m Value of Given Frequency Based on F i t of Doubly Exponential Distribution of M a x i m Values. Ann. Math. S t a t i s t . , vol. XX, r no. 1, Mar. 1949, pp. 110-113.

I t TABLE I . - AIRPLANE CHARACTERISTICS . . . - . . . I M a x i m u m Airplane W i n g W i n g Number W i n g gross loading, of Propuls i 0: area, span, w e i g h t , f t l b / s q f t engines sq f t Series Type l b . - .__-___ . .

130.8 100.7 a 4 Turbo j e t 245,000 2,433 I 142.4 C 4 Turbo j e t 3ll, 000 107.5 2,892 . ______I . .

142.4 a 4 Turbojet

98.4 273,000 2,771

142.4 b 4 Turbo j e t 276, ooo

99.5 I1 2,773- 142.4 l l l . 7

C 4 Turbo j e t 310, ooo

2,771 . . . _ . .

120.0 94.8 I11 a 4 Turbo j e t 2,000 189,500 . . . . . . . . . . . . .- 86.9 a 4 Turb opro: 113,000 1,300 99.0 I V 86.9

*b 4 Turb opro: 113, ooo

99.0 1,300 _ _ . - . . . . . .

. - _ _ . - - - . . - - . . - - . - . ..

47.4 V a 2 Turbopro.

95.2 754 33,700 . . . . . . . . --____ . . . _ _ -. ..

- ...... - . _ _ . .

*

I n airplane type I V , series b d i f f e r s from s e r i e s a primarily because t h e wing and nacelle s t r u c t u r e s were modified and strengthened.

TABLE 11.- SCOPE O F V-G D A T A F R O M TURBINE-TRANSPORT OPEBATIONS Average overall f l i g h t t

Airplane Number of - conditions

(*I Dates of operation - Flight Pressure Flight VT, Airplanes Records time, altitude, hours knot E h r f t Aug. 1959 t o Apr. 1963 4 2.44 26,000 4 28 75 23,496 ~~ Oct. 1959 t o Apr. 1960 4 1.67 14 , 621 9 1,996 315 1.46 tMar. 1960 t o Feb. 1961 1 8 4,019 3 15 , 103 263 Mar. 1961 t o Apr. 1963 4 .88 55 17,056 I I J 598 287 Mar. 1960 t o June 1962 41 2.00 3 9,125 25,310 431 .~ ~ ~~ Dec. 1959 t o Apr. 1960 1,602 1.85 3 7 1319% 307 IMar. 1960 t o May 1961 4 41 1.23 12,702 8,865 M a y 1961to Feb. 1962 4 20 4,600 1 . 2 0 13, ooo Jan. 1959 t o June 1961 2 26,564 54 n, 623 3-35 Jan. 1960 t o Mar. 1963 2 13,440 47 3 . 3 6 28,036 445 _ - June 1960 t o Feb. 1963 4 26,000 54 13,750 2 . 7 5 Nov. 1959 t o Mar. 1963 2 10,145 2.31 24,419 Mar. 1960 t o Feb. 1963 1 29 5,890 3.75 30,453 449

I I i

Dec. 1959 t o Mar. 1963 2 4 6 13,571 1.91 26,000 Jan. 1960 t o Mar. 1963 2 3.11 26,000 54 15,353 ~ Oct. 1960 t o Mar. 1963 4 46 io, 103 1.54 441 24,657 Feb. 1959 t o Nov. 1961 io, 368 0.42 2 47 0 % 180 5, - - Jan. 1961to May 1962 1 6 2.44 1,300 27,597 433 *Based on VGH data from same operation except for operations AIa, B m , CIIc, E I I a , and EIIb.

For these f i v e operations, values were estimated from VGH data f o r t h e same type of airplane i n a s i m i l a r operation.

+*eed-restricted p e r i d .

TABLE 111.- FREQUXNCY DISTRIBLFPIONS O F IN-FLIGBC MAXIMUM ACCEZERATIONS F R O M V-G RECORDS Mexhum Frequency d i s t r i b u t i o n f o r operation - acceleration J - - - - - - - - -

increment, ----

%,maXJ AIa CIa CIc DIa DIc B I B CIIc EIIa E I I b EIIc F I I I a AIVa mar Alvb BIVa BIVar BIVb GVa K u n i t s I*) (*I 0 . 3 t o 0 . 4 6 1 --- 2 --- -_- 1 1 1 - - - - - - - - - - - - - - - - - - 2 - - - - - - 1 --- --- --- 1 --- 5 --- --- 0.4 t o 0 . 5 9 1 2 7 5 1 5 7 5 18 11 1 4 0 2 1 7 3 - - - 8 - - _ - - - 0 . 5 t o 0 . 6 16 12 13 a ~1 2 2 3 25 19 7 19 20 21 3 3 3 8 12 1 lo 8 --- 0 . 6 t o 0 . 7 19 1 4 0 . 7 t o 0 . 8 26 30 1 6 22 7 1 5 1 25 12 2 6 4 5 1 7 2 4 0 19 5 1 0.8 t o 0 . 9 2.1. 1 3 u 4 4 io 17 18 18 0 12 3 6 2 . 1 . 2 13 6 4 0.9 t o 1.0 14 14 1 3 10 6 12 9 10 8 1 18 5 2 14 1 10 8 18 13 8 6 8 5 8 9 2 1 3 3 4 16 5 12 5 2 3 1.0 t o 1.1 4 16 1.1 t o 1 . 2 5 2 4 1 1 9 9 4 2 1 13 0 o l l 3 1 4 16 1 10 1 1 1.2 t o 1 . 3 8 1 4 3 0 3 0 3 7 2 1 3 1 . 3 t o 1.4 6 1 1 0 1 0 9 0 , 4 0 0 1 8 O I 0 1 0 4 0 1 1 . 4 t o 1 . 5 0 2 1 0 1 1 4 0 0 0 6 1 . 5 t o 1 . 6 2 0 0 ~1

1 . 6 to 1 . 7 0 0 2 :~

, l l

1 . 7 t o 1 . 8 0 1 1 1 1 1 . 8 t o 1 . 9 ' 0 1 . 8 t o 1 . 9 ' 0 0 0 0 1 . 9 t o 2.0 0 1 . 9 t o 2.0 0 1 0 0 I 2 . 0 t o 2 . 1 ~0 ' 2 . 0 t o 2 . 1 0 0 0 1 1 2.1 t o 2 . 2 0 2.1 t o 2 . 2 0 : 1 0 2 . 2 t o 2 . 3 1 2 . 2 t o 2 . 3 1 r Total 150 108 94 94 58 82 108 92 108 12 92 1 8 5 ll0 1 4 82 40 94 F l i g h t hours . . . 2 3 , 4 9 6 I4623 13,440 10,145 5,890 9,125 13,750 13,571 1 5 , 3 5 3 1,300 10,103 1,996 4,019 17,056 1,602 8,865 4,600 10,368 6 . 6 . 6 . 6 F l i g h t miles . . . l.OxlO7 5.WLO6 6.OxlO6 4 . j x 1 0 6 2 . 7 x 1 0 6 3.9~l.0~ 6.0xl06 5 . 9 x I . 0 6 6.7x106 5.7xl05 4.5x106 6.3x1d 1 . 1 x 1 0 6 4.9xlO 4 9x13 2.2xlO 13x10 1 9xlO *Operation during speed-restricted period.

Number o f - _ _ _ _ ~ Records Flighl houri

23.496 i

54 ' 11.623 47 l3.440 47 10.145 c I I C 5 4 U.750 E l l a ' 2 46 ! U571 , I C l a c II L 2 1

t I

I t J I I I I L I I I I I I I I 1 1 , I l I I - I "'NE.

4 -2 'NO. max L E II b t u ,.--.

'NE. max D I C F - ' N C , I L I 1 , I max ~ 1 - L I . I , 1 I U I I 160 200 240 280 320 360 4W 440 160 200 240 280 320 M I 4W 440 Indicated airspeed. V. knots ( a ) Airplane types I and 11.

Figure 1.- Composite envelopes from turbine-transport V-G records.

_._ __ Number of - Operation - F 111 a 10,103 A I V a 1,996 A l V a r 4.019 A l V b 4 1 55 17,056 B I V a 1,602 B l V a r 8,865 B I V b 4. Mx) G V a 10.368 __ F 111 a G V a -1 -2 I I B l V a A I V a L B I V a i A l V a r A l V b B I V b

- 1 -5 jnmax ' N O . max I # I , I I ~ ~ 'NO. max I , I

120 160 2W 240 280 320 3W 4W 440 120 160 2W 240 280 320 360 4W Indicated airspeed, V. knots (b) Airplane types 111, I V Y and V.

Figure 1 . - Concluded.

i Airplane 6 I Number Total : Airplane airlines -:- A 7 1937 to 1955 368 136,780 I 6 1 1948to 1950 388 38,578 C 2 1950to 1954 46 11,299 i I D 1 1955 to 1958 76 U.327 1 1947 to 1950 244 49.987 5 1947 to 1953 387 102,366 i H 3 1949 to 1953 226 49,655 K 1 1951 to 1953 231 22,233 _ _ ~ .._____-.

Airplane E

Airplane C Airplane D t

t

I - - I VC I I I I I I I I . ! I I Airplane H

t Airplane K

Airplane G

t

I -1 'NE, max V.

1 L I I I I I I I I l l , L I W 140 180 220 26Ll 3W 340 1W 140 180 220 260 303 340 Indicated airspeed, V, knots Figure 2.- Composite envelopes from piston-transport V-G records.

(From ref. 5 . ) Number of - C l a C I C D l a F 111 a 10,103 10- C l t c - - 10‘ 10-

\ I

10- D l c D l a f . 4 i.8 i l . 2 i1.6 t.4 i.8 i1.2 i1.6 i2.0 i 2 . 4 i2.0 *2.4 Maximum acceleration increment, an, max, g units (a) Airplane types I and 111.

3 . - Frequency p e r f l i g h t mile with which given values of maximum a c c e l e r a t i o n i n c r e - ment were equaled o r exceeded.

Number of - Airplanes I Records I Flight hours l3.750 13,571 E l l b 54 15,353 H l l c 1.300 G V a 47 10,368 - E l l a B l l b

\ 1

J

c I I c E II b

' I

H II t

I

\

i 0 f.4 f.8 f1.2 f 1 . 6 t2.0 f2.4 increment. an, max, 4 units Maximum acceleration ( b ) Airplane types I1 and V.

Figure 3.- Continued.

1 6

Number of - Operation Airplanes - A l V a 4 A l V a r 3 A I V b 4 B l V a B l V a r 4 B I V b 4 A I V a ‘a, A W a r B l V a r ~ I . .

t . 4 *.E * 1 2 t1.6 *2.0 t2.4 t . 4 i . 8 t1.2 i1.6 t2.0 *2.4 Maximum acceleration increment, an, max, g units ( c ) Airplane t y p e IV.

F i g u r e 3.- Concluded.

Number Flight of Operation h o u r s r e c o r d s A l a 75 23,496 A I V b 55 17,056 E II b 54 15,353

c II c 54 13,750

C l a 54 11,623 47 13,440 C l c G V a 47 10,368 D l a 47 10,145 E II a 46 13,571 F I l l a 46 10,103 B II b 41 9,125 B l V a r 41 8,865 29 5,890 D l c B l V b 20 4,600 18 4,019 A l V a r A I V a 9 1,996 B IVa 7 1,602 H II c 1,300 Cumulative f r e q u e n c y per nautical mile, tf/Z of f1.4g w a s equaled o r exceeded and t h e F i g u r e 4.- Frequency w i t h which a value of &n,- 95-percent coni‘idence bands.

\ \ \ \ \ \ \ \ \ - _ _ Turbine-transport distributions _ _ _ _ Limits of piston-transport distributions (ref. 1) \ w \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ Type I V \ \ \ 14-engine) \ \ \ \ \ \ \ \

\

I 52.4

\ k.8 f l . 2 f 6 f, f.4 Maximum acceleration increment, an, max, g units Figure 5.- Comparison of the acceleration distribution curves for two-engine and four-engine turbine-powered and piston-powered transports.

NASA-Langley, 1965 L4267

I Ill I 1 l 1 l 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 l I I l l

ill

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