4•

b, USAAEFA PROJECT NO. 75-19-1

LOW AIRSPEED SENSOR LOCATION TESTSAH-1G HELICOPTER

FINAL REPORT

KENNETH R. FERRELLPROJECT OFFICER GARY E. HILL

CPT, CEBARCLAY H. BOIRUN US ARMYPROJECT ENGINEER PROJECT PILOT

DO

FEBRUARY 1977 S

Approved fo." public release; distribution unlimited.

C.2 UNITED STATES ARMY AVIATION ENGINEERING FLIGHT ACTIVITYEDWARDS AIR FORCE BASE, CALIFORNIA 93523

4I

i)MSCLAIMER NOTICE

Tlhe. findings of [his report af,. not to be construed as an official Department ofthe Army position unless so designated by other authorized documents.

DISPOSITION INSTRUCTIONS

=Destroy this report when it is no longer needed. Do not return it to the originator.

TRADIE NAMES

The use of trade namies in this report does not constitute an official endorsementor approva! of the use of the commercial hardware and software.

UNCLASSIFIED-~~~~~ ~~SECURITY CLASSIFICATION OF THIS PAGE (IWhon Doet. Entered __________________

REPORT DOCUMENTATION PAGE BFREA COMPRLETINFORM

-5.1 '~2 GOVT ACCESSION NO, S. RECIPIENT'S CATAOI NME/tUSAAEFAA-5l-4.TITLE (and Subtitle)-9

d.OW-.,A1RSPEED_,ENSOR LOCATION JESTDe 7-A r3 6.

_________USAAEFA PROJECT NO. 75-19-1'1. CONTRACT OR GRANT NUMBER(#)

V ~j 6p ý13 A RC LAY $.OIRUN~

NAME ND ADRESS10. PROGRAM ELEMENT. PROJECT. TASK*-4%eý ý NAM ANDADDESSAREA & WOSRK UNIT NUMBERS

US ARMY AVIATION ENGINEERING FLIGHT ACTIVIT9-17-UZ EDWARDS AIR FORCE BASE, CALIFORNIA 93523 EJ-6-NJ469OF6U

%_ff It. CONTROLLING OFFICE NAME AND ADDRESS

7M US ARMY AVIATION ENGINEERING FLIGHT ACTIVITY / B7EDWARDS AIR FORCE BASE, CALIFORNIA 93523

t I-r-~~4.MONITORING AGENCY NAME a ADDRESS(If different from Controtlling Office) IS. SECURTTY CLAS3.r ~f0aa&~

UNCLASSIFIED15a. DECL ASSI F1CATION/ DOWNGRADING

taSCHEDULE N

16. DISTRIBUTION STATEMENT (of this Report)

Approved for public release; distribution unlimited.

j - II7. DISTRIBUTION STATEMENT (of the abstract entered In Block 20. If different from Report)

18. SUPPLEMENTARY NOTES

M19. KEY WORDS (Continue or, reverse side if necessary and Identify by block number)

Elliott low airspeed systemAH-IG helicopter

- - .Airspeed signal

20. ABSTRACT (Continue on reverse aid& It necessary and Identify by block number) A

for an Elliott low airspeed system mounted on an AH-IG helicopter to improvethe accuracy of the actual aircraft airspeed signal to the fire control computer.The airspeed system was provided by Frankford Arsenal, and the necessarymounting hardware was constructed by the United States Army Aviation

(Contd)

DD I AN7 1473 EDITION OF I NOV 65 IS OBSOLETE UNCLASSIFIEDSECURITY CLASSIFICATION OF THIS PAGE (W7,en Data Entered)

77 r'R

UNCLASSIFIEDSECURITY CLASSIFICATION OF THIS PAE(I.an Data a•mred)

20. Abstract \ (rfIt'¢f

Engineering Flight Activity, Edwards Air Force Base; California$in catonsalong the fuselage from the engine mount to the forward canopy area were tested.

The optimum location tested was at fuselage station 128, water line 104, andbuttline -35. The Frankford system was then calibrated at the optimum location,and the electronic linearization circuits were added to the computer. This locationfor the linearized system provided accurate airspeed inforniation out of groundeffect from 15 knots calibrated airspeed (KCAS) rearward to 125 KCAS forward,and lateral airspeed from 28 KWAS left to 25 KCAS in right sideward flight.•

UNCLASSIFIED

SECURITY CLASSIFICATION OF THIS PAGE(U1lon Date thlered)

~+

TABLE OF CONTENTS

iNTRODUCTION

Background ............... ........................ 2Test Objectives ................ ...................... 2Description ............... ........................ 2Test Scope ............... ........................ 3Flight Test Methodology ............ .................. 3

RESULTS AND DISCUSSION

General .................. ......................... 6Sensor tocation Tests ............ ................. 6

Engine Mount Location ..... ............... .. 6Pylon Mount Location .......... ............... 8Canopy Mount Location .......... .............. 8

Airspeed System Calibration ..... ............... .. 11

CONCLUSIONS... . ........... ........................ .. 12

RECOMMENDATION ........... ..................... .. 13

APPENDIXES

A. References ......................... .............. 14B. Test Instrumentation ........... .................... 15C. System Description and Theory of Operation ............. .. 17D. Test Data ................ ........................ 21

DISTRIBUTION

175

- -- - - - -- -~ - -~ME

INTRODUCTION

BACKGROUND

1. The Frankford Arsenal, Philadelphia, Pennsylvania, was required to install anair data system on an AH-1G helicopter as part of a weapons fire control system(enhanced Cobra fire control system). They installed the Elliott Industrial AssociatesCorporation low airspeed sensing and indicating equipment (LASSIE) during thefiring tests, but the information obtained was not of sufficient accuracy. Previoustests of the airspeed system by the United States Army Aviation Engineering FlightActivity (USAAEFA) had shown the position error to be strongly influenced bythe sensor location (USAAEFA Project Nos. 71-30 and 75-17, refs 1 and 2,app A). The sensor location used by Frankford Arsenal was unsatisfactory, andanother location for the sensor was required to improve system parformance. TheUnited States Army Aviation Systems Command (AVSCOM) directed USAAEFAto conduct tests with the LASSIE installed on the AH-IG helicopter to determinea satisfactory location (ref 3).

TEST OBJECTIVES

2. The objectives of the low airspeed sensor location tests were to determinea satisfactory location for the sensor on the AH-IG helicopter and to calibratethe system at that location.

DESCRIPTION

3. The test helicopter, serial number 67-15844, was a production AH-IGmanufactured by Bell Helicopter Textron of Hurst, Texas. A detailed descriptionis contained in the operator's manual (ref 4, app A).

4. The LASSIE system consists of a finned swiveling pitot-static probe linkedto pressure sensors, an air data computer, and cockpit display of longitudinal and -Alateral airspeed and rate of climb. The probe was mounted to utilize the rotordownwash to maintain adequate dynamic pressure on a pitot-static probe. The probewas mounted on a swivel and thus aligned itself with the relative wind (vectorsum of aircraft velocity and rotor downwash). The angle of the probe was usedwith the differential pressure to obtain aircraft longitudinal and lateral airspeedor total velocity. The angles can also be used to calculate angles of attack andsideslip. The static pressure was differentiated with respect to time to obtain rateof climb. A further description of the LASSIE system and theory of operationis provided in appendix C. The required mounts for the different locations areshown by drawings and photographs presented in appendix C.

2

TEST SCOPE

5. The tests were conducted at Edwards Air Force Base, California in accordancewith the approved test plan (ref 5, app A). The evaluation was partially flownin conjunction with the AH-IG flow field test (USAAEFA Project No. 74-02,ref 6), and required 20 hours of productive testing. The location optimizationtesting was simplified by using a LASSIE II probe available at USAAEFA, sinceits design provided greater simplicity and flexibility in the mounting supportstructure than the LASSIE III system. The LASSIE III probe was specificallydesigned to mount in the pylon position, which limited the flexibility of supportingstructure. The aerodynamic characteristics of the swiveling probe were expectedto be very similar. The LASSIE III test system was then installed arid calibratedat the most satisfactory location tested.

6. Flights were conducted within limitations specified by the AVSCOMsafety-of-flight release (ref 5, app A) and the operator's manual. The tests wereconducted at an average gross weight of 8000 pounds, the-longitudinal center ofgravity (cg) was mid, and rotor speed varied from 314 to 328 rpm. The stabilityand control augmentation system (SCAS) was operational for all tests.

7. In-ground-effect (IGE) and out-of-ground-effect (OGE) low-speed tests wereconducted at a field elevation of 2302 feet, and the high-speed tests-were flownat approximately 6000 feet. Airspeed ranges investigated were from 30 knotsrearward to 125 knots forward, and 35 knots to the left and right.

8. The sensor was mounted in the nine areas shown in figure A. Details of eachlocation are presented in the discussion of test results. Each sensor location wastested to determine the relative performance of the system.

FLIGHT TEST- METHODOLOGY

9. The low airspeed (zero to 40 knots) tests were conducted with a calbratedpace vehicle for ground speed reference. Wind speed and direction were recordedfrom a ground station anemometer. Reference airspeed was obtained by correctingground speed data for wind speed and direction. Airspeed data were also obtainedfrom a calibrated Pacer Systems Inc., low-range airspeed system (LORAS 1000)mounted on the rotor mast. Tests were conducted in winds less than 5 knots,and aircraft height above the ground was measured by a radar altimeter. The testswere conducted in stabilized level flight in the longitudinal and lateral directions.Dynamic maneuvers were not tested.

3

- -

I; g

.. a..

2I

I--

-- io

;- 4

10. The high-speed refedince was the calibrated swivei-head pitot-static probemounted on a nose boom -and the LORAS 1000 system mounted on the rotormast. Side~lip and angle of attack were measured by vanes-located on the boom.

11. The airspeed sensor and aircraft parainuters were recorded by an airbornemagnetic tape system. Test data ,'.-ro obtained by averaging the recorded dataover 10 to 20 seconds of steady fiig'"ý conditions. A list of the test instrumentationused is presented in appendix B.

5SZM

RESULTS AND DISCUSSION

GENERAL

12. The airspeed system output reflected the variation in airflow at the differentlocations, since each location produced a different position error. The mostsatisfactory location was determined with the LASSIE II system and then theLASSIE III system was calibrated at that location. With the electronic linearizationcircuits added, the system produced repeatable linear output when OGE forairspeeds from 15 knots calibrated airspeed (KCAS) rearward to 125 KCASforward and from 28 KCAS in left sideward flight to 25 KCAS in right sidewardflight. The electronic linearization of the LASSIE III system minimized the positionerror and removed the discontinuity that occurred when the probe transitionedfrom rotor downwash to free stream airflow.

Sensor Ldtation Tests

Engine Mount Location:

13. The sensor was mounted at the positions shown in figure B. The sensorperformance for these, two positions is presented" in figures 1 through 4,appendix D.

14. In position 1, the sensor was not-responsive in the area from hover to10 KCAS forward. At airspeeds above 10 KCAS, the system functioned andshowed distinctly different characteristics fOr the rang~s of 10 to 30 KCAS thanfor 30 to 110 'KCAS. The sensor apparently did not transition smoothly fromrotor wash to free stream flow. Lateral. airspeed was repeatable, but nonlinear,from 12 KCAS left to 26 KCAS right sideward flight. At left sideward airspeedsabove 12 KCAS, the readings were erratic and low.

15. Moving the sensor aft and inboard to position 2 considerably improved systemperformance in forward and rearward flight (fig. 3, app D). From 19 KCASrearward to 115 KCAS forward, the system output was linear, with the exceptionof the forward airspeed area from 15 to 40 KCAS. Above 105 KCAS anothermajor transition region occurred which caused nonlinear performance. In all cases,the data were repeatable. For sideward flight of 12 KCAS left to 25 KCAS right(fig. 4) system performance was much the same as for position 1. At left sidewardairspeeds above 12 KCAS, the flow conditions were improved; however, the systemoutput was still unusable.

-=6

TIM

00 MIN

4cc

4o

r- 000C-4 el

e100

N : 4).. .. .- .- C

Pylon Mount Location:

16. Figure C illustrates the two pylon locations tested. Test results for the pylonlocations are presented in figures 5 through 8, appendix D. The data between 5 and60 KCAS are missing on figure 5 due to an instrumentation malfunction, but theobserved performance in this region was similar to figure 6.

17. The overall forward airspeed system performance was essentially the same inboth locations. The airspeed indication was linear from 25 KCAS rearward to25 KCAS forward. However, there was a discontinuity as the probe transitionedfrom rotor downwash to free stream air between 25 and 30 KCAS. There wasless variation about the average in the outboard location.

18. In lateral flight system performance was similar in both locations. The averageindicated airspeed was repeatable and nonlinear from 27 KCAS left to 26 KCASright. However, the variation about the mean was less at the outboard location,as was the discontinuity between zero and 5 KCAS observed on the inboardlocation (fig. 6, app D).

Canopy Mount Location:

19. An adjustable bracket mounted on iop of the canopy was used to facilitateevaluation of five different locations. These locations are identified in figure D.

20. The system's longitudinal airspeed performance is shown in figures 9, 11, 13,15, and 17, appendix D. The characteristics of the longitudinal airspeed indicationswere the same for all five locations. Between 20 and 30 KCAS, there was adiscontinuity as the probe transitioned from the rotor wake to free stream. Thesystem was generally operable to 30 KCAS rearward, and the indication was linear.The position error varied for each location, but in all cases, the indicated airspeedwas less than the- actual airspeed. After the probe transitioned to free stream, theuncorrected system output was linear, with airspeed error becoming higher ascalibrated airspeed increased.

21. The system's lateral airspeed performance is shown in figures 10, 12, 14, 16,and 18, appendix D. In all five locations, system performance characteristics duringlateral flight were essentially the same. During left sideward flight, the systemprovided airspeed information to the test limit of 35 knots. For right sidewardflight, the system was usable to 15 to 20 KCAS, depending on location. Beyond20 KCAS, there was an apparent airflow disturbance, and the system was notusable. As the sensor was progressively moved from position 5 to position 9, theairspeed indications became less erratic and more linear. The influence of groundeffect also diminished. The final data obtained with the LASSIE II sensor inlocation 9 are shown in figures 17 and 18.

S

IN

i i

Sensor Fuselage Water Buttlineposition station line

3 177 in. 106 in. 48 in.

4 177 in. 106 in. 60 in.

Figure C. Pylon Mount Locations.

9

_ _ _ -- - -FM

m

-0 0 0

tn~~ \0 w0

1 0

Akrsed System Calibration

22. The LASSIE III sensor was mounted at fuselage station 128, water line 104,and buttline -35 (location 9), which was judged the best on the basis of thelocation survey. Tests were conducted to define the characteristics of the probeand confirm that the two sensor models had similar performance. Results of thesetests are shown in figures 19 and 20, appendix D.

23. These data were supplied to the contractor, who adjusted the electronics tocorrect the position error and linearize the indicated airspeed signal (electroniclinearization). Flight tests were then conducted to calibrate the final configurationin the optimum location. The effects of the linearization are best seen by comparingfigures 19 and 20 with figures 21 and 22, appendix D. The linearizationminimized the position error and removed the discontinuity that occurs when theprobe transitions from rotor downwash to free stream airflow.

24. Figure 21, appendix D, shows that the system-has a negligible position errorfrom hover to 125 KCAS (the highest airspeed tested). In rearward flight, thesystem was not uasble at airspeeds greater than 10 KCAS, which indicated degradedperformance from •the LASSIE I1 system. The pbsiti6n error was changed-in IGEflight between zero and 30 KCAS, and the LASSIE III System was not usable

at rearward airspeeds greater than 5 KCAS.

25. In lateral flight system performance was the same both IGE and-OGE.Figure 22, appendix D; shows no error at hover. The system output was linearfrom 28 KCAS left to 25 KCAS right. However, the slope was less than one,Which caused the syntem to read increasingly 1ow as airspeed was increased from

hover. Output was 4uestionable for left airspeeds greater than 28 KCAS and notusable for airspeeds beyond 25 KCAS to the right.

-°j

!11

- - - -

F7 -v CONCLU-SIONSI

26. .ECh-sensor location produced' a different positionm error.-

27. The most satisfactory sensor location found during these tests was on theleft side of the canopy, at fuselage station 128, water line 104, and buttline -35(position 9) (para 22).

28. The electronic linearization of the LASSIE III system minimized the positionerror and removed the discontinuity that occUrred when the probe transitionedfrom rotor downwash to free stream airflow (para 23).

29. The LASSIE II and III systems have the same operating characteristics andsimilar accuracy, except at rearward aippeeds greater than 10 KCAS (para 24).

30. For the most satisfactory location, the LASSIE III system with electroniclinearization provided accurate airspeed information from 10 KCAS rearward to125 KCAS forward, and lateral airspeed froth 28 KCAS left sideward to 25 KCASright sideward flight (paras 24 and 25).

12

Nj

NI

7 777F~-~

]RECOMMENDATIONS

3 1, For best system perforMance the LASSIE XIII systm -should be -locited atfuselage station 128, water line 1014, buttline -35 (position 9) on the AH-IG

helicoptU

13

APPENDIX.-A. REFERENCES

1. Final Report I, US Ariny-Aviation -Systems Test Activity, Project-No. 71-30,Flight Evaluation, Elliott Low Airspeed System, September 1972.

2. Test Plan, USAAEFA, Project No. 75-17, Flight Evaluation of TWo LowAAfrspeed Sensor Systems, June 1975.0

3. Letter, AVSCOM, AMSAV-EýQI, 3 July 1975, subject: Low Airspeed- SensorLocation Tests, AH1G, USAAEFA Project No. 75-19i

4. Technical Manual, TM 55-152-221-10, Operator's Manual, Armyv ModelAH-1 G Helicopter, 19 June 1971, with Changes 1 through 14.

5.- Test Plan, USAAEFA, Project No. 715-19, Low Akispeed location tests,AH4IG Helicopter. September 1975.

6. Test Plan, USAAEFA, Prjet No.74-2, Rotor Flow Sturyy.Prbgram,,AH-1GCobra Helicopteri March 1975, to be published.

14

_ -iE

APPENDIX B. INSTRUMENTATION

1. The test instrumentation included the following:

Pilot Panel

Airspeed (boom)Airspeed (LORAS forward)Airspeed (LORAS lateral)Airspeed (Elliott forward)Airspeed (Elliott lateral)Altitude (boom)Rate of climb (boom)Rotor speedAngle of sideslip (boom)Radar altimeter

Engineer Panel

Airspued (boom)Altitude (boom)Outside air temperatureFuel counterData system controls

2. Data parameters recorded on the digital (PCM) system were as follows:

Time of dayEngineer event

Run number counterRotor blipFuel counterRotor speed (analog)Rotor speed (digital)Altimeter (radar)Pressure altitude (boom)Angle of attack (boom)Angle of sideslip (boom)Airspeed low range (boom)Airspeed high range (boom)Airspeed (LORAS longitudinal)Airspeed (LORAS lateral)Airspeed (Elliott total)Airspeed (Elliott longitudinal)Airspeed (Elliott Lateral)

is

rAigle of attack •(ElliottyAngle of sideslip- (Elliott) -

Pitch attitude . -

Roll attitudeLateral swashplate angleLongitudinal Swashplate angleAmbient air temperature

A4

ii

M57

I

16

APPENDIX C. SYSTEM. DESCRIPTION ANDTHEORY OF OPERATION

1. The system consists of an airspeed probe, a rate transducer, a vertical speedindicator, longitudinal and lateral airspeed indicators, and a computer.

2. The swiveling dual-axis pitot-static probe (type 05-006-01) is a standardpitot-static sensing head with four peripheral static parts. The circular vane, withspace wedges at 120 degrees, is slightly unbalanced to permit pendulous action.Two synchro resolvers are mounted within the assembly to measure the probeangular position. The total and static air pressures are piped to the airspeedcomputer along with the probe angle signals from the synchro resolvers.

3. The rate transducer (type 60-SK-3437) is an electromechanical design and hasa gearbox to drive synchros and potentiometer outputs. Also contained in the unitis an electrical force balance transducer whiich is used as a pressure altitude sensor.This unit produces the pressure altitude and rate of climb, which are displayedon the cockpit indicators. These signals may also be recorded by an instrumentationsystem.

4. The vertical speed indicator (VSI) (type 71-012-01) contains a servo amplifier,motor, and position feedback potentiometer. Input signals supplied from the ratetransducer are fed into the instrument servo amplifier which in turn drives themotor. Position feedback from the potentiometer within the instrument is fed backto the rate transducer VSI control amplifier.

5. The longitudinal airspeed indicator (type 71-011-01) consists of a steppermotor and a feedback potentiometer. This provides an indicator rate signal andposition signal which is fed back to the airspeed computer. The signals are summedwith the computer longitudinal airspeed and are checked by the servo monitor.Detected failures are indicated by a warning flag on the indicator.

6. The lateral airspeed indicator (type 71;.010-01) is similar to the longitudinalindicator and operates in the same manner. Pressure altitude is indicated on anAAU-19 servo altimeter.

7. If the pitot-static probe is mounted below the rotor, and is arranged to rotatesuch that it is always pointing into the resultant flow, then the sensed impactpressure will be proportional to the vectorial sum of the induced and transitionalcomponents of air velocity. The fundamental relationships involved are illustratedin figure 1.

17

'Pat

Futre . Rsoltio o Feslow anerth Arfotow

lB 1IA

S••:• .• • • - ••.. . 5: -~ = '- •" - L . -'..' ' • ,•... , • .. . - -= • • . . .• • •

'Where:

V = Resultant airflow I

V = Forward speed

v = Induced flow

i= Rotor incidence angle

a = Probe angle relative to fuselage

8. Since at low airspeed i is small and at high airspeed v is small, the equationcan be simplified and horizontal airspeed can be obtained from:

V - V cos a

This arrangement has several fundamental advantages:

a. The sensor will never be required to measure impact pressure less thanabout 1.0 millibar (0.29 inch_.of mercury), since in every known operationalhelicopter the resultant flow (V) exceeds 25 knots in hover. M

b. Reversal of flight direction produces a reversal of sign in the output,thus indicating direction of motion of airframe relative to heading.

c. The static source will be aligned with the local airstream, thus minimizingthe effects of flight attitude, motion, and aircraft configuration (ie, doors open/shut,external weapon loads, etc).

9. The vector geometry of the dual-axis system is illustrated in figure 2, fromwhich it may be seen that:

Fore/aft airspeed (VF) = V cos q cos(3

Sideward airspeed (VL) = V sin (3

Where:

V Resultant airflow

N a = Probe angle relative to fuselage

(3 = Probe angle relative to aircraft datum in roll/yaw plane

It is also apparent from figure 2 that while the probe is within the downwashit is possible to compute the vertical component of velocity relative to the airframefrom the available data. In addition, an indication of the magnitude and directionof the thrust vector is available.

19

Z

[ I

SensedLateral

Airspeedt in a

Sensed Sensedhrut Forward Airspeed

Vacos ft cos a

YR IVC.vcot 8 -

/.. ..............

AirVertt #e rt

Fore-Aft II ~'I------------_J

A7cicr 7ai Lt-Lte-ralProb-

Solid lines - Resultant airstream vector (V)Cand components in aircraft axes.

Dashed lines = Aircraft reference axes.

(Dotted lines - Construction only)

Figure 2. Two-Axie Resolution of Flow Under Rotor.

20A

APPENDIX D. TEST DATA

INDEX

Fiaure Figure Number

LASSIE II Performance at Position I in Longitudinal I and 2and Lateral Flightat Position 2 in Longitudinal and Lateral Flight 3 and 4at Position 3 in Longitudinal and Lateral Flight 5 and 6at Position 4 in Longitudinal and Lateral Flight 7 and 8at Position 5 in Longitudinal and Lateral Flight 9 and 10at Position 6 in Longitudinal and Lateral Flight 11 and 12

at Position 7 in Longitudinal and Lateral Flight 13 and 14at Position 8 .in Longitudinal and lateral Flight 15 and 16at Position 9 in Longitudinal and Lateral Flight 17 and 18

LASSIE III Performance at P6gitibn 9 in Longitudinal 19 and 20and Lateral Flight

Linearized LASSIE III Performance at Position 9 in 21 and 22Longitudina! and Lateral Flight

21 JM

FIGURE 1

py.-.o Lz••• T3WN ,4 -- r7li

[ IlOa3 N E ARK. n LL G_.3 I

6?e) IMT e lý Ai of 7IiLT4240~. : .e'f1 _ C--- .---

1 Ij 74- 7-~ ~ *-

S! . II I /tI .L

NOTES'.I111 Fllt robe~on oUtb;)rdel~gi,•e deck I j • .,a : A m , -t110- _ _ L -4-

*. ' • I- • , + : . . - - . . .' . ..• .• - --•. . . . .; . ...... 4 --.....j;o~~nN~ ) 1. > ! J rI~2ROj- .- .. .. .o i ý _ý4 ... .. .. . .. - - -90 2 ' d -

roi .... .b - . .rs. ..d s- t

U. goF

- '70." - . ' ... I I,: I :-4

U3 601. . ..... i ,I , I ; - . . . .

'I 'II " 'II+ t

S. . ., - - . . .... .. ..J.. . . ." -I . . . . . . . . . - f : - I . . .' --I- - • . . . P - . . . . . . ..t.z'"I! ,I , , , , p . I I +' ,

-' I . i' ' I .!

IC I , , I ' -

10 - j .. I-4 -

20•

, I ...... - I -.711H-L" -1 - '-- .... . . .

"D -1 - 2 o, 1. , _0 a-A0 1. 0-• 1.l a11-40

6`0 FR L 8kT •IG3EE2.,' A .I -Si o5 41%4.-1 oi oo.

i , i~1+'i

43.

7 ' A -1 I 's 0 ,'

IF

__ IE-40 --- ---

.- 30-o - I _

5 0 a l ..,i a . 0 -ý j

-. FI / -.-.-- K

A --

FIGURE3

7 F 1 ±R~~L ZV 7~

_K -1 - )

70 -a d W4 + -11

Vpstc No~ E<I ERO RF OR.

jj V ~ ibtd 1-e e n s e~ -of na/

w 1 b t- I0 s p e 4 t y i .

r '1

LL

B4OTtM. tj4ýE

FIGURE 4

:14 lTY ROT1_-T ~ i LOf-Ei

Ky 'f'~zr j%77c~s:(m14' D+±ýA4J l.Q tLT,

N ... ...

~ riOI : T,

a: Z. i C

C, Tt , I I

_Wl --

Y 0i --------. k

I.. L.LNL3 /

J_1 i f

U)! I 4-

_T 1 7._IIi.i'jL-d It 1 4.KJ2%-*-ý

FIGURE 5

24 4 1~ L.4 ITS ..

1uJ

A A -I 4 I

W-100- -_0 OfEaO

T- c QD1a il e 3--r-

110 nI 'I

i LLf'ct ue.t in-. n160 _

K-t K-h ~T~Ith j .

Z 4 --

1- TO V ,SOE6 C

FIGURE 6

om ._ A 0 ID - , - I

1 itio 0~. 1I _

14 Lowls'pe rt~ ta-~'ne ~

' I __A

:__r_1_IT

20I~F K

~ F -I - __LF r ,

4 L 0F- - * - P- J - - - . - -

F FMELifJ

F~R VRRf tt:Vt *~**~~40-[

F 1

/ i i

d- I -'4I

CH LI _ FR': sKF j -

FIGURE 7V*In rr nr$ F1~T ~R aiTnr V 1 I

E.I al

I ~ I t : .i..

ltQ1 ~

- i II

j jNOTiS: U 11Ott ipr~bt On u~b 16 6 r4

'I. I, I-aa a nd

70 - T/

-to,

30_ .

i.j_. 4;.~I

61.0 L. 14 . 8 F Tlt1)K C i

A T n r F IG U R E 8 F T . T

1in

- -~ L. Lj3 77§I-- ~ ~ p I .7 l+

-46 -I -<i r'IiiI-~ f~ -I ~ I -

- -~~~- -4 -- 1-_ 4...K*T[.4

FIGURE 9E.I-

T- ... 2 Of -T

It -2V-

i.~I t-4-

I,,ES 'IF l I --I-- eo in r 4 d c 4I ~ u t_ ' o I F

SO -

Fj f

, :7 40-

4.... ~4

AL, fii 4 RIR EEl...q.-4

)7 1 - .

F IGURE 10~~r--~--.T- - 7-~E .~H'l~.sa/N &..~8 4 6~ TLIL i E ILR A YS Lii a I I~

Yff GRS 'OF tIY A

000... .1 .3 M X180 -E

N : 951. q1ict-Probion -nor-l n.N )

T : 1 i 01I-.,-. s e ef-~ ý i ,ediE otapae -i-r:-. me - - -

.j. I ~ -¾J

-A 44.~. .. 4-4-i '. J7'1~

.---

40t -- *1- _

_ IE I.

U 3 O -4 .7 t

2i0 -7-- f

36 H

FP- I LT-j-ivI-j..~ ~ - RTIED, ~j~ R ' I ii

FIGURE ii

~~wmivla U5.8 7- 1 844 T .1 ' R E -Yin

I~ ~~~G j DENSrY DR - _ K

(D20 MI 1.f-

.1 I

A A

oQ . -f" 1(PSfti(n fJCO 717 -A' c~',mth .-

-U= -- -ý60 r

K ;.EiUt j~bbIE2a., ~~i1Ql

2~ h0 4 I

I~ ~ -4- -4

LK

j~- ~ F-At IRO

10 R~ 5 I 0 K'

32

F IGURE 12I ~ ~ 14 1' 9 4A'.

0~~w tzVS. ME 1 Y OIDI-Y$Bcj or I r EDT m-Aoy

(18*- 74. L- - 1-~I-i1 n4b -r c4 Int y.

T 5; t E oI- .~Ii spe? I' rceeh-- d.-K- .-----. -

IIT'f,T t4_t-i -----

*13 * ICD-*

F . .(D

-~~~~~-K *- - cd. 0 4.d-

2-I

-4-

crrifL~4 ~' 4iu-av*~. i-~ ~I ..1-

q~~- -L BL1D,1 IK

~~-~~-'--3 i-.- Lt~L 0 ~ -

R lIRSPýE Cr-LI#~RaTI

YfljI T- -Lo&j~ r~ie -..1.~K~ ~ .. j _ ias

to1 *

mfu4 iti roe'n Cb~jkado 7! Oa2,. ILaw-Ppee ref~re~l bat lnt-e týy ~ f:

pae tCe r ethed

710- --

ccL II. .04 -~ ;e.1

t= K .'L LIIu~L I LI __ LiI-

VV iJ H. n FrRl T F T .

T -Tv.-

-a 7),

P- -ID :-ý

__p OU 0. 1 . .I ~I t - --j- -L -A - - d*K iK- 477

-r-r~. v- -Z K-r-----4--4b. .. ~> .7LI

ANI )FR& I i - T*.1'- ~ ~ ~ ~ ~ ~ ~ E 0i- .- -- ~t---

cc

opF.4j.C .3 - -.14 I/ 3~A4-t

K 41 A~ ~ ~ ~o1 -r1--

- - -

-2 1 A 0- - -4 0..-

7i , r -d~ KLC -1I-.

FIGURE I5

ALL 0i týT.1

-~~~

-- ;v {0

7 I V

M R.0 Don_ _ _

-_Oý:_1 __C 10-i it-

I can D2pj nouht ork~t V~ on.r. 8)

2 ýyOab~e car retho aoti

-7-i--f

i140-

-4.K

L ti475 ' M E K n6

-i .17 1 "

lii I - J-

FIGURE 16

1 hf4OI ILIhO8E-. ~ýl TF Pdi r~ D~- 4~IYTIL

I T{ O T10 4 PI 7o..I ONE. OT41

I" N 0 q '1.!Ei'l ioti robe oni aft'i 6nbo canop ~ i

2:Low Yseeef renc{ a o3btain!2. ec- T1 yp~ec h

7'*-~ A-- L 4

F~ 7

1 ~ L 17F

2DL ~RF

m C3R40o7

F IfiI(j I .- H.,. . .

czIF

* :20'

u F

3J-0 - FM4

W H~

Li...4 +VV. .2~1

C31 Sr30 I..p.-

4LIATJ_ I

FhI GURE 17

64-3- L

v~ ' -- -- 1 A -

iibr

- iO .. L -1...

# lrP, 4 -V 4a a4.

I -0 -- -4--br 4- -~

i )

~�.--4 •4- ...L'-4 -

a 40 SID- 11 - I

j_. F T X RS

FIGURE 18

Sol L 14

K K 530.1 194 aw e 3

K-f F ".. -. -.

..-..

:.,-.

-T"

I .... .. li i.4 u llI-K- J- .-i . .. ........ .....

....-t -,

jo in

2b40I

I till

i .J i .-- - - -....

I ' ; .. .I. '-

i !I

S' i + .. "+t t ... . .

'1 4 o

" i J L ; iK" • i i 1 0I . . .... .... ...

1- t -Z Iii. I

VFIGURE 19

M1 I 4

I I _I

~ d.-on d-4

A-55 I b e n-t I i-srt-Iu~j & ~ '* atopylc unrt- 1Ei o ;i2In.t-t~i L Re

- I

46-

j{~f7~~ 7 17H{ j

"--*- o .-~-. 4-f--j t----- -K - -4 --tI tJ A-~

Ij I -0

i 20 -- -- - Al.,-

0 0 0.-nI-a Ia Y1JJJ p I .l4i

13 1 4-II ~~~08 -j

IF IGURE 20

KRRjZT r F ' rW

8 TY

2yD T, I' R TI eJo. of

x I t 0.tIIý3 5 !0

meIot II

u 0

-- I---1

I C7K -171LLim ) a

-~~~~ZR + -. , I I..I R .

F40 *-4.4 I*j-I In,

I *I~i~i)K.X,-..wI...I I

ID oo--K"

B. TE i IR DE1 1

~4~BTAli4Ezj L4.~iAf

. fRSEE~c~~8gRFIGURE 21USI A f 0 3a, f sm 7- 1i 44 K [L O 10 T L 4 - 1 -4 Rx F I T hI- /'4-0 1.74. .

OL 88 oi IE -Yor A T_ 0W IG T , .a r L j j

Fo -3 4 ~7- r1 740--141-1:1mtO5 - 1T

L~ af

41ht

- "V+VH , IT

* C4 -

00i~Ur~~TTI~~ ~4tNOTE~ 1. E)1t I A$E o ) ron~ cbni ral21tirqcAr za t, bAI Jr'u! A~ d~d to,

go "i thesvtLTZra,1 3,Low~ sPiOe referen e da *ob tain

. . by. ~c r ta ~ -

40-4

30O -f -

I I I X

- o + 6 T T t0 01 -10-I fE30~ t. i so 1 ~ o0 A04.!12

4 L RTONS EO 10A _ o4

FIGURE 22

4 -NO EL4 l r ~ 1 L i f -e1 A 10- i1ii iL 14i 4 I4 .

--- II IFI

Al -I ft r -

Vy RT6S 0.1

22.LiL$izt0-r !t a. _Y! te..1-ITki ef it I L

fI I

r~rIZ 3

-2o-

-50( -4_ 3_,2 2 0 E

t IiLB-O1 jSEE 0AAS

' I I - - - 4A

DISTRIBUTION

Director of Defense Research and Engineering 2

Deputy Director of Test and Evaluation, OSD (OAD(SSST&E))

Assistant Secretary of the \rmy (R&D), Deputy for Aviation 1Deputy Chief of Staff for Research, Development,

and Acquisition (DAMA-WSA, DAMA-RA, DAMA-PPM-T) 4US Ar.,iv Materiel Development and Readiness Command (DRCPM-CO,

DRCDE-DW-A, DRCSF-A) 7US Army Aviation Systems Command (DRSAV-EQ) 12US Army Training and Doctrine Command (ATCD-CM-C) 1

US Army Materiel Systems Analysis Activity (DRXSY-CM) 2US Army Test and Evaluation Command (DRSTE-AV, USMC LnO) 3US Army Electronics Command (AMSEL-VL-D, AMSEL-EL-VL-E) 6

US Army Forces Command (AFOP-AV) IUS Army Armament Command (SARRI-LW) 2US Army Missile Command (DRSMI-QT) IHq US Army Air Mobility R&D Laboratory (SAVDL-D) 2

US Army Air Mobility R&D Laboratory (SAVDL-SR) IAmes Directorate, US Army Air Mobility R&D Laboratory (SAVDL-AM) 2Eustis Directorate, US Army Air Mobility R&D Laboratory (SAVDL-EU-SY) 2Langley Directorate, US Army Air Mobility R&D Laboratory (SAVDL-LA)Lewis Directorate, US Army Air Mobility R&D Laboratory (SAVDL-LE-DD) IUS Army Aeromedical Research Laboratory IUS Army Aviation Center (ATZQ-D-MT) 3US Army Aviation School (ATZQ-AS, ATST-CTD-DPS) 3US Army Aircraft Development Test Activity (PROV) (STEBG-CO-T,

STEBG-PO, STEBG-MT) 5

US Army Agency for Aviation Safety (IGAR-TA, IGAR-Library) 2US Army Maintenance Management Center (DRXMD-EA) IUS Army Transportation School (ATSP-CD-MS) IUS Army Logistics Management Center IUS Army Foreign Science and Technology Center (AMXST-WS4)US Military Academy 3US Marine Corps Development and Education Command

I=

••"- • - -• - -, -• - -•i . ... I~ '"7 --•- .- - "-

US Naval Air Test Center 1

US Air Force Aeronautical Division (ASD-ENFTA) IUS Air Force Flight Dynamics Laboratory (TST/Library) IUS Air Force Flight Test Center (SSD/Technical Library, DOEE) 3US Air Force Electronic Warfare Center (SURP) IDepartment of Transportation Library I

US Army Bell Plant Activity (SAVBE-ES) 5

Bell Helicopter Textron 5

Frankford Arsenal 5Elliott Industrial Associates Corporation 5

Defense Documentation Center 12

-- ,q

N1