USAARL Report No. 87-7

(0

V-- Measurement of Gunner Head AccelerationDuring Firing of High Impulse Guns

on Lightweight Armored Vehiclesand the Assessment of Gunner Tolerance

to such Impactl..., wal 11 ,,0'

By -,LE*C*TETed A. Hundley MAR 2 41IMJ. L. H aley, Jr. c1 1

Biodynamics Research Division

July 1987

:88 2•,• 075Approved for public release; distribution unlimited.

NOTICE

Qualified Requesters

Qualified requesters may obtain copies from the DefenseTechnical Information Center (DTIC), Cameron Station,Alexandria, Virginia 22314. Orders will be expedited if placedthrough the librarian or other person designated to requestdocuments from DTIC.

Change of Address

Organizations receiving reports from the US Army AeromedicalResearch Laboratory on automatic mailing lists should confirmcorrect address when corresponding about laboratory reports.

Disposition

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

Human Use

Human subjects participated in these studies after giving theirfree and informed voluntary consent. Investigators adhered toAR 50-25 and USAMRDC Reg 70-25 on Use of Volunteers in Research.

Disclaimer

The views, opinions, and/or findings contained in this reportare those of the authors and should not be construed as anofficial Department of the Army position, policy, or decision,unless so designated by other official documentation. Citationof trade names in this report does not constitute an officialDepartment of the Army endorsement or approval of the use ofsuch commercial items.

Reviewed:

DANIEL W. GOWER, RMAJ, MSDirector, Biodynam Reseach

DivisionReleased for Publication:

J. D. LaMOTfE, Ph.D. DUDLEY/. PRICEColonel, MS Ccliciel, MCChairman, Scientific Commanding

Review rComm-ittee

S

StA&Y"AI1FAINO F Y HISPAGE

REPORT DOCUMENTATION PAGE For Aproe

I.REPORT SECURITY CLASSIFICATION 1b. RESTRICTIVE MARKINGSUNCLASS IFIED___________________________SECURITY CLASSIFICATION AUTHORITY 3. DISTRIBUTION/I AVAILABILITY OF REPORT

Approved for public release; distribution2b. DECLAS5IFICATION/I DOWNGRADING SCHEDULE u .nlimited~

4. PERFORMING ORGANIZATION REPORT NUMBER(S) S. MONIITORING ORGANIZATION REPORT NUMBER($)

USAARL REPORT NO. 87-7

6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION(if applicable)

Biodynaraics Research Division SGRD-UAD _______________________

6c, ADDRESS (CIty State, and ZIP Code6) 7b. ADDRESS(City, State, and ZIIPCode)US Army Aeromedical Research LaboratoryP.O. Box 577Fort Rucker, AL 36362-52928a. NAME OF FUNDING /SPONSORING 8 b. OFFICE SYMCOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION t~UMBER

ORGANIZATION (If applicable)US Army Aeromf.dical Research La

8c. ADDRESS (City, State, and ZiP Code) 10. SOURCE OF FUNDING NUMBERS

PROGRAM PROJECT ~TASK WORK UNITFort Rucker, AL 36362-5292 62777A 13El62777A871 1 13811. TITLE (include Security ClaWfic- on)Ifeasurement of Gunner Head Acceleration During Firing of High Impulse Guns on LightweightArmored Vehicles and the Assessmnent of Gunner Tolerance to Such Imgact (U)-12. PERSONAL AUTHOR(S)

HundeyTed, Haley, Joseph L.*TYPE OF REPORT 13b. TIME COVERED -114. DATE OF REPORT (Yea. ....jntt,, Da)15. PAGE COUNT

Fnal IFROM _ ___TO 1987 July 7 1 5716. SUPPLEMENTARY NOTATION

17. COSATI CODES 18. SUBJECT TERMS (Continue on reverie if necessary and Identify by block number)FIELD GROUP SUS-GROUP Brow impact; Frontal head impact; Brow pad loads; Tank

gunner's brow impact

-4 ABSTRACT (Continue on reverie if necessaty and Identify bay block number')Ws report provides gunner head acceleration data from the li-ve firing of 105 mm and 152 mm

turret guns on the M-551 and M1-60 tanks. The head accelerations were measured with a gunnervolunteer and with an anthropomorphic dummy with stationary tanks. The head accelerationvalues ranged from 4 Gs in the heavy H1-60 tank up to 14 Gs in the light M1-551 tank. A com-parison of these acceleration levels to the known human tolerance data indicates no problemrfor single exposures for miost gunners, but it is possible that some gunners will experience

heaacesand neck sri.The effect of repeated exposures at the 14 G levcl1 is not known

20. DISTRIBUTION /AVAILABI1LITY OF ABSTRACT 2 BTATSCRT LSIIAO

ClUNCLASSIFIF13iUNLIMITED 5ý1 SAME AS RPT, TC SR UNCLASSIFIED22a- NAME OF RESPONSIBLE INDIVIDUAL 22b. TELEPHONE (include Area Code) 2cOFICE SYMBOL

DDForm 17,JN86 Previous editionso ar obsoigiv. SJECURITY CLASSIFIATION OF THIS PAGE

UNCLASSIFIEDA.

IR

-~~~~~~~~~~~~~~~~~ - - - - - -- - -- - "'' ' -- . K' ý .- W .. .

ACKNOWLEDGEMENTS

The authors are deeply indebted to USAARL researchers Mr. AlanLewis and 2LT Donald Schneider for their unstinting effort inthe preparation of the dummy instrumentation and the fieldmeasurement of the acceleration data. Without Mr. Lewis'considerable background and skill in the instrumentation field,the successful. completion of this project would have been farmore difficult. In addition, the Naval Surface Weaoons Centerpersonnel were very helprul; in particular, Mr. Ron Hundley andMr. Ray Bowen made the research work at that facility a pleasantexperience.

NTIS Cfl,'\&i --

DTIC 3 ,c ]

B y .. .... . . ... .. ...... .. . . .

orrDit ,,

4-/ 'I II'

TABLE OF CONTENTS

PAGE NO.

List of Tables ........................................... 1

List of Figures ............... .......................... 2

Introduction ............................................. 5

Methods .................................................. 7

Materials ................................................ 13

Results and Discussion ................................... 19

Conclusions and Recommendations .......................... 26

References Cited ......... ............................... 27

Appendixes:

A - Manufacturer's Equipment List ........................ 28

B - Plots of Acceleration vs Time for Dummyand Human Head and Chest AccelerationsDuring Tank Gun Firings ........................... 30

LIST OF TABLES

TABLE PAGE NO.

1. Description of Test Tanks .......................... 13

2. Mean Peak Accelerations of Dummmy and HumanHead During Tank Gun Firing Tests ................... 21

LIST OF FIGURES

FIGURE PAGE NO.

1. M-551 Sheridan Test Vehicle with 152 mm

Gun (Aug 81) ...................................... 7

2. Instrumented Dummy in M-551 Gunner's Position ..... 8

3. M-60 A2 Test Vehicle with 152 mm Gun(Dec 81) .... ...................................... 9

4. Instrumented Dummy in M-60 A2 Gunner'sPosition ........................................ 10

5. Instrumented Human Subject in M-60 A2

Gunner's Position ............................... 10

6. M-551 Sheridan Test Vehicle (Dec 81) ................. 11

7. Instrumented Human Subject in M-551Gunner's Position ............................... 11

8. Instrumented Dummy in M-551 Gunner's Position..... 11

9. Instrumented Human Subject ............................ 16

10. Instrumented Dummy Axes ........................... 18

11. Instrumented Human Acceleration MeasurementAxis System ..................................... 18

12. Comparison of the Load versus Deflection of theStandard Tanker's Brow Pad (used in thesetests) to a Pad Constructed with H-HEnsolite- PVC Foam .............................. 22AV

B-i Dummy Head Acceleration - M-551 "Sheridan"with 152 mm Gun - 0 Degree Azimuth,Round 3 (Aug 81) ................................ 31

B-2 DuLmmy Chest Acceleration - 14-551 "Sheridan"With 152 mm Gun - 0 Degree Azimuth,Round 2 (Aug 81) ................................ 31

B-3 Dummy Head Acceleration - M-551 "Sheridan"With 152 mm Gun - 90 Degrees Azimuth,Round 9 (Aug 81) ................................ 32

2'

FIGURE PAGE NO.

B-4 Dummy Chest Acceleration - M-551 "Sheridan"With 152 mm Gun - 90 Degrees Azimuth,Round 9 (Aug 81) .................................. 32

B-5 Dummy Head Acceleration - M-551 "Sheridan"With 105 mm. Gun - 0 Degree Azimuth,Round 1 (Aug 81) ................................ 33

B-6 Dummy Chest Acceleration - M-551 "Sheridan"With 105 mm Gun - 0 Degree Azimuth,Round 1 (Aug 81) ................................. 33

B-7 Dummy Head Acceleration - M-551 "Sheridan"With 105 mm Gun - 90 Degrees Azimuth,Round 8 (Aug 81) ................................ 34

B-8 Dummy Chest Acceleration - M-551 "Sheridan"With 105 mm Gun - 90 Degrees Azimuth,Round 8 (Aug 81) ................................ 34

B-9 Dummy Head Acceleration - M-60-A2 With 152 mmGun - 0 Degree Azimuth, Round 5 (Dec 81) ........ 35

B-10 Dummy Chest Acceleration - M-60-A2 With 152 mmGun - 0 Degree Azimuth, Round 5 (Dec 81) ........ 35

B-il Dummy Head Acceleration - M-60-A2 With 152 mmGun - 90 Degrees Azimuth, Round 6 (Dec 81) ...... 36

B-12 Dummy Chest Acceleration - M-60-A2 With 152 mmGun - 90 Degrees Azimuth, Round 6 (Dec 81) ...... 36

B-13 Dummy Head Acceleration - M-60-A2 With 152 mmGun - 0 Degree Azimuth, Round 20 (Dec 81) ....... 37

E-14 Dummy Chest Acceleration - M-60-A2 With 152 mmGun - 0 Degree Azimuth, Round 20 (Dec 81) ....... 37

B-15 Human Head Pitch Acceleration - M-60-A2 With152 mm Gun - 0 Degree Azimuth, Round 20(Dec 81) ........................................ 38

B-16 Dummy Head Acceleration - M-60-A2 With 152 mmGun - 90 Degrees Azimuth, Round 12 (Dec 81) 39

B-17 Human Ti Acceleration - M-60-A2 With 152 mmGun - 90 Degrees Azimuth, Round 12 (Dec 81)..... 39

3

FIGURE PAGE NO.

B-18 Human Head Pitch Acceleration - M-60 A2 With152 mm Gun, 90 Degrees Azimuth, Round 12(Dec 81) .................................. ..... 40

B-19 Dummy Head Acceleration - M-551 "Sheridan"With 152 mm Gun - 0 Degree Azimuth,Round 38 (Dec 81) ..................... 41

B-20 Dummy Chest Acceleration - M-551 "Sheridan"With 152 mm Gun - 0 Degree Azimuth,Round 38 (Dec 81) ............................... 41

B-21 Dummy Head Acceleration - M-551 "Sheridan"With 152 mm Gun - 90 Degrees Azimuth,Round 32 (Dec 81) ............................... 42

B-22 Dummy Chest Acceleration - M-551 "Sheridan"With 152 mm Gun - 90 Degrees Azimuth,Round 32 (Dec 81) ............................... 42

B-23 Dummy Head Acceleration - M-551 "Sheridan"With 152 mm Gun - 0 Degree Azimuth,Round 22 (Dec 1') .3

B-24 Human T1 Acceleration - M-551 "Sheridan"With 152 mm Gun - 0 Degree Azimuth,Round 22 (Dec 81) ............................... 43

B-25 Human Head Pitch Acceleration - M-551 "Sheridan"With 152 mm Gun, 0 Degree Azimuth,Round 22 (Dec 81) .............................. 44

B-26 Human Head Acceleration - M-551 "Sheridan"With 152 mm Gun - 90 Degrees Azimuth,Round 28 (Dec 81) ............................... 45

B-27 Human T1 Acceleration - M-551 "Sheridan" With152 mm Gun - 90 Degrees Azimuth, Round 28(Dec S ll) ........................................ 45

B--28 Human Head Pitch Acceleration - M-551 "Sheridan"With 152 mm Gun, 90 Degrees Azimuth,Round 28 (Dec 81) ... ........................... 46

INTRODUCTION

The stated intent of the US Army and US Marine Corps tofield a lightweight armored vehicle, eqcuipped with a high-impulse gun, has raised concerns about the possible effects ofthe recoil on the gunner. These concerns are primarily aboutthe effects on the physical and psychological condition of thegunner and on his ability to maintain an opc-srationally-acceptable rate of accurate fire. The Human EngineeringLaboratory (HEL), Aberdeen Proving Ground, Maryland, initiatedan effort to address these questions, but was hindered by a lackof data describing the recoil forces transmitted to the gunner.HEL learned that the US Navy and US Marine Corps also wereconcerned about potential problems and were conducting firingtests with an M-551 Sheridan tank to obtain vehicle responsedata. This represented a good opportunity to obtain transmittedrecoil force data for the gunner's position.

A meeting was held 28 January 1981, at the Naval Biodynam-ices Laboratory (NDDL) at Michoud Station, Louisiana, to estab-lish and coordinate a test plan to gather the transmitted recoildata in conjunction with Navy tests at the Naval Surface WeaponsCenter (NSWC) at Dahlgren, Virginia (USAARL trip report byGoldstein, 4 February 1981). Subsequent to the 4 February 1981NBDL meeting, HEL informally requested the United States ArmyAeromedical Research Laboratory (USAARL) to gather transmittedrecoil data and to relate that data to human head impact toler-ance. USAARL, with the encouragement of the US Army MedicalResearch and Development Command (USAMRDC), agreed to assist HELand NSWC in gathering the recoil data.

Initially tests were scheduled for mid-April 1981, butconflicts in programmed tests at NSWC caused numerous changes inthe schedule, with the test finally being conducred the week of17 August 1981 at NSWC.

A second test series was conducted from 30 November to 7December 1981, at NSWC. HEL desired firing data from an M-60 A2and from an operational M-551 with an anthropometric dummy, andwith a human in the gunner's position. HEL provided the testprotocol, the human subject, obtained human use approval, andprovided the vehicles and ammunition to NSWC for this series oftests.*

The results of these tests were used by HEL to developmathematical equations for the prediction of the gunner's firingresponse in future vehicle configurations, but validation of theequations will require some additional test firings. Theseresults also will be used to program the US Army Tank CommandRide Simulator to evaluate the effects of multiple gun recoil ongunner tiring accuracy.

The dummy and human head and chest accelerations measuredin the tests reporteC here were provided to HEL in the 1982 and1983 time frame, but recent requests for data on repetitive headimpact tolerance prompted the publication of this report.

* Funding for this series was provided by the Mobile ProtectedWeapon System (MPWS) project office at the Marine CorpsDevelopment Center, Quantico, Virginia. (The MPWS wasoriginally a US Marine Corps project.) After Congress mandated ajoint Army-Marine Corps program, the name was changed to MobileProtected Gun System (MPGS) with the program manager residing inthe US Army Tank-Automotive Command (TACOM), Detroit, Michigan.

6

METHODS

The initial test series began in August 1981 with the M-551Sheridan vehicle equipped with the standard 152 mm gun (Figure1). An instrumented dummy was placed in the gunner's positionwith his head against the brow pad of the night-firing sight.Five shots were fired with the barrel pointing straight aheadover the front of the vehicle (0 degree azimuth, 0 degreeelevation). The dummy's head was repositioned against the browpad prior to each shot (Figure 2). Upon completion of the 10shots, the 152 mm gun was replaced with the 105 mm gun and thesame shot sequence was repeated.

Im

A A :- -l

•'NV

FIGURE 1. M-551 Sheridan Test vehicle with 152 mm Gun (Aug 81).

ML:L

FIGURE 2. Instrumented Dummy in M-551 Gunner's Position.

The November-December 1981 test series began with the M-60A2 vehicle (Figure 3). The gun was the same 152 mm gun that isstandard on the Sheridan. The ammunition used 3n all the 152 mmfirings was the standard high-explosive, antitank (HEAT) round.The instrumented dummy was placed in the M-60 A2 in the gunner'sposition (Figure 4). His head had to be bent forwardapproximately 40 degrees relative to his torso in order to havehis forehead in contact with the brow pad. Five shots werefired over the front (0 degree azimuth, 0 degree elevation) andfive were fired over the right side (90 degrees azimuth, 0degree elevation). The dummy then was removed and theinstrumented human subject was seated in the gunner's position(Figure 5). Five shots were fired over the right side (90degrees azimuth, 0 degree elevation) and five were fired overthe front (0 degree azimuth, 0 degree elevation). The seriesthen was repeated in the Sheridan M-551 (Figure 6) with thehuman subject in the gunner's position (Figure 7). The dummy

8

then was placed in the M-551 for the final shots (Figure 8).

Two rounds of ammunition failed to fire, so only three shots

were fired from the side position (90 degrees azimuth, 0 degree

elevation). The final five rounds were fired over the front (0degree azimuth, 0 degree elevation).

S"% I

FIGURE 3. M-60 A2 Test Vehicle with 152 mm Gun (Dec 81).

- - - - - - - - - - -

-- m m .

0

CIO

(L)

H1 N

0 4'0 1

- D 0

C) rL,

FIGURE .M-551 Sheridan Test Vehicle (Dec 81).

AL

FIGURE 7. Instruni A~ Human Subject in M--551Gunner zsition.

I

FIGURE 8. Instrumented Dummy in M-551 Gunner's Position.

All vehicle response data were collected by NSWC. Onlydummy head and chest and human head and torso acceleration datawere collected by USAARL for this report.

12

-k -qkL~ _ J\j

MATERIALS

The vehicles used were two M-551 Sheridans and a M-60 A2(Table '). The table shows the M-60 to be more than three timesthe mass of the M-553. Sheridan. The first test firing used aSheridan that was not considered fully operational because someequipment had been removed. The second firing test used afully-operational M-551 and a fully-operational M-60 A2. Thiswas necessary because a human gunner was bei-g used in thesecond test and only a fully-operational vehicle was Lý.centablefor safety purposes.

TABLE 1Description of Test Tanks

GUN* GUN GUNTANK TURRET BARREL RECOIL

TANK TANK MASS MASS INSIDE MASSIDENTITY MISSION (kg/lb) (kg/lb) DIA (mm) (kg/lb) REMARKS

I 5r ,833/ 10/ 0iz rebs con-Sheridan Mobile 33,500 10,700 2,711 ventional(Modified) projectile.

M-551 Air 15,193/ 4,853/ 152 499/ FiresSheridan Mobile 33,500 10,700 1,100 "Shi. lelaa''"

missile oronventional

projectile.

M-60 A2 Main 51,250/ 14,996/ 152 499/ M-60 chassisBattle 113,000 33,000 1,100 fitted withTank modified

(152 mm) tur-ret. Fires"Shillelagh"or conven-tionalprojectile.

M-60 Main 54,600/ 14,966/ 105 1,230/ Fires con-Battle 120,000 33,000 2,711 ventionalTank projectile.

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

* Monocular sights used in both tanks.

13

I.

The standard brow pad used by the gunner in both the M-551and M-60 tanks consisted of very soft, flexible 4 cm x 6 cm foammaterial of approximately 2.5 cm thickness. The pad providedonly minimal energy absorption.

All Sheridan firings used the standard HEAT round. Thisround weighs 22 kg and develops a muzzle velocity ofapproximately 683 m/sec (2,240 ft/sec). The momentum of theround at the muzzle is approximately 15,000 N-sec (3,374Ib-sec). The M-60 105 mm gun used in the first Sheridan firingtest fired an inert training round that simulates the HEATround. That round weighs 21.8 kg and develops a muzzle velocityof approximately 1,173 m/sec (3,848ft/sac) for a developedmomentum of 25,550 N-sec (5,740 Ib-sec).

The dumnay used in both tests was an Alderson ResearchLaboratories model CG-98*. This dummy was designed for use inparachute testing. The overall dimensions, mass distributions,and range of limb motions match that of a corresponding 98thpercentile human, but the design makes no attempt to match thekinetics of human motion. The joints are simple pinnedconnections with metal-to-metal contact which tend to caulsehigh-frequency "ringing" when loaded suddenly. The head mass isnot rigidly attached to the torso; therefore, it can be used todetermine gross acceleration effects of the head's center ofgravity (C.G.). The torso consists of a metal-walled cavitywhich also is subject to "ringing." As a result, accelerationdata obtained from the dummy usually has a significant amount ofhigh-frequency "ringing" included that would not be present in ahuman subject. The chest data presented in this report wasfiltered at 200 Hz to remove the "ringing."

The instrumentation used in the dummy was a triaxialaccelercmeter consisting of three orthogonally-mounted Endevcomodel 2226C accelerometers* in the head and a Columbia modelaccelerometer was mounted at -the point of intersection of a line

through the external ear openings (center of gravity of thehead) and the midsaggital plane. The chest accelerometer wasmounted on the midsaggital plane of the metal cavity wall at apoint in line with the normal location of the heart. Thetransducer outputs were fed to six Endevco model 2240 chargeamplifiers* stored in the chest cavity. From there the signalsconditioner* which proviided excitation, gain,

* See equipment ma:' factirers at Appendix A.

U 14

and offset as required. All signals were frequency modulated tothe Inter-Range Instrumentation Group (IRIG) constant bandwidthsubcarrier "A" channels (deviation + 2 kHz). The multiplexedsignal was recorded on a Sangaxuo Sabre VI 14 channel "I" bandrecorder*. An IRIG time code format "B" signal obtained fromthe test range broadcast also was recorded for referencepurposes. In addition, a voice channel was used to recordco.ments and to identify the recorded data. The multiplexeddata were demodulated and fed through a 400-Hz, 5-pole linearphase low pass filter to the analog-to- digital converters ofthe Systems Engineering Laboratory 85/Engineering Associated,Inc. hybrid computer* for processing. The signals were sampledat a 5714-Hz rate and stored on a 9-track digita) tape. Graphicpresentation of the traces was done by using a Tektronix 4010terminal and 4631 hard copy unit*. These traces then were usedin preparing this report.

Instrumentation for the human subject was a problem becausethe package had to be mounted externally and could not be asource of potential injur4 for the subject. No suchinstrumentation package was available "off the shelf." Theresearchers contacted the Naval Biodynamics Laboratory, NewOrleans, Louisiana (NBDL) for guidance because of theirextensive experience in instrumentating human subjects foracceleration measurements. Their system providts an -acceptablyrigid coupling to the head, but it requires custom fitting tothe subject and involves several different manufacturing stepsperformed by different groups. This process usually takes aminimum of 6 to 8 weeks to complete. The scheduled test datedidn't allow sufficient time to procure a mor:;t of their design.

A second problem with the NBDL system was the accelerometerlocation in front of the mouth on a frame that is coupled to theupper teeth and gum. This was viewed as less than desirable for

this test because of the possibility of the subject strikingsome part of the sight with the accelerometer mounted and beinginjured. The researchers elected to modify and use anacceleration measurement device already in our possession. Thedevice used includes five. Entran EGAL125-lOD piezoresistiveaccelerometers* mounted in a bar assembly. It is designed to beused as a mouth-mounted acceleration measurement device.

The device was modified to permit mounting on a rigidskullcap made by forming thermoplastic sheets to a plaster castduplicate of the subject's head. The skullcap was held on thesubject's head by straps attached to a custom-molded chin cup(Figure 9).

The human volunteer subject was chosen to be nearly thesame size as the dummy. The subject's stature was 183.2 cm, hisweight was 195 lb, and his sitting height was 91.1 cm.

1t5

AXA-W1 --a 11x 'IN VI VI Vxx.AVV4VNVV ^L1- llýLVN 1 L p

FIGURE 9. Instrumented Human Subject.

The system was not as rigid as desired in that relativemotion between the subject's head and the skullcap could occur.This tended to introduce higher frequency accelerationcomponents into the data output (especially the z-axis) thatwiould not be present if the measurement device were rigidlyattached to the skull bone.

Additional stiffening and dampening materials were added tothe accelerometer mount itself to minimtize resonant frequencyproblems, but nothing could be done about the basic problemi ofskin movement relative to the skull beyond tightening the strapsas much as the subject could tolerate.

A triaxial accelerometer consisting of three Fnd.cvcc* model2265-20 piezoresistive accelerometers mounted on an aluminumblock was attached to the position of the first thoracicvertebra of the subject by using a plastic cup filled withmolding compound and held in place with a strap harness around

16

the abdomen and over the shoulders. This is similar to themethod used by NBDL. However, the lack of a rigid couplingbetween the subject's skeletal torso and the accelerometertransducer caused the same problem of high frequencyoscillations in the acceleration traces.

Because of the close quarters in the tanks-and the need toremove the accelerometer cables for calibration checks, theaccelerometers were mounted in the dummy with the axes alignedas shown in Figure 10. This alignment should be kept in mindwhen comparing the acceleration traces to other reports onacceleration. A similar problem was encountered with the humaninstrumentation. The accelerometer mount used for the humanhead was designed for mouth installation. The researchersplaced it at the back of the subject's head and thus changed thereference axis system. The human acceleration reference systemis shown in Figure 11.

The movable brow pad was adjustable so that the center ofcontact was aligned with the C.G. of the head and the impactload was oriented along the fore-aft (X) axis of the torso(Figures 7 and 8, pages 13 and 14).

A standard tanker's helmet was not worn by either the humansubject or the dummy. The 1.4 kg mass of the helmet would havetended to reduce the head acceleration value.-; therefore, thepresent acceleration data are conservative. Since tankers tiltthe helmet backward enough to permit forehead-to-brow padcontact during firings, the deletion of the helmet affected thehead mass alone and not the mechanism of energy transfer.

17

I-z

zf

+x- --x

+Z

(

-z

F1GURE 10. Instrumented Dummiy Axes.

ISIHEAD

. ~~Y & 1 z

S-X.Y , & Z A-k-- 4 Accelerometer

TrIaxc Acceoforormotar on_¥Y T-1 Vortorta t1ld byTorso Hmfrfwos

FIGURE 11. Instrumented Human Acceleration MeasurementAxis System.

18

RESULTS AND DISCUSSION

A rather large body of data was generated during thesetests. Rather than reproduce it all in this report, selectedcurves representing the response of the dummy or human for eachtest condition are provided (Appendix B, Figures B-i throughB-28). No significant difference in subject response for eachfiring of a given gun was noted.

The head x-axis acceleration was the most significantmeasurement taken, and these were fairly consistent; however,the "x" accelerometer was orientated at approximately 40 degreesfrom the M-60 A2 tank's x-axis (due to the excessive dummysitting height) so that an upward z-axis acceleration also isread on the head in the M-60 tests.

The z-axis and y-axis curves were comparable in overallshape and time duration, but variations in peak accelerationswere present. These variations are caused by the rigid metaltorso and metal-jointed neck in the dummy, and by the lack of arigid accelerometer attachment to the head in the human.However, the data is usable for making a general head injuryrisk determination for gunners using these type vehicles.

A preliminary analysis was done prior to the actual firingtests to try to predict the x- (longitudinal) axis accelerationsthat would be generated. The US Army Tank-Automotive Command _(TACOM) indicated that the measured reaction force at the guntrunnions during firing was 619,606 N (139,300 lb) for theM-551. Using the turret and tank weights shown in Table ., arange of possible x-axis accelerations can be calculated asfollows:

The gun reaction force is assumed to act along the x-axis of thetank. If the turret moves (displaces in the turret ring)independently of the tank, the peak acceleration will bedetermined by: a=F/m.

Thus for the M-551: atjrrt = 619,606 N 127.7 m/s 2 = 13.0 G4,853 kg

For the M-60 A2: aturret = 619,606 N = 41.4 mr/s2 = 4.2 G14,966 kg

If the vehicle (turret and tank) moves as a rigid body, then thelarger mass must be used in the formula.

For the M-551: atank = 619_606 N z 40.8 m/s 2 = 4.2 G15,193 kg

19

For the M-60 A2: atank = 619,606 N = 12.1 m/s8 = 1.2 G51,247 kg

Therefore, if the dummy or human subject's head wasconnected firmly to the vehicle brow pad, we expected to measurean x-axis acceleration from 4.2 G to 13 G in the M-551 and from1.2 G to 4.2 G in the M-60 A2. The measured test accelerationsagreed fairly well with the predictions. It should be notedthat the dummy's brow was proximal to the brow pad while thehuman subject actually compressed the pad with his brow; thus,the human was subjected to less "dynamic overshoot" accelerationthan was the dummy. Table 2 shows the mean peak headaccelerations for both test series.

An attempt was made to evaluate the performance of the browpad used in the test tanks as indicated in Figure 12.Quasistatic compression tests were conducted to obtain typicalload-deformation data. The pads tested were the standardproduction configuration with a 2.5 cm thickness for thesevehicles. Both the standard production and a proposed newdesign pad were tested. The standard production pad consistedof a relatively soft (latex rubber type) foam while the proposednew pad consisted of a much stiffer polyvinyl chloride (PVC)foam manufactured by the B.F. Goodrich Company under the tradename Ensolite, type H-H. As can be seen in Figure 12, the newfoam absorbs much more energy than does the standard foam, andits use would tend to reduce the "dynamic overshoot" of thegunner's head, especially if the head is not in contact with thepad at the instant the weapon is fired.

20

Ir~wwxwa'a ~AVJAd fl V1XUI WM VKtL;d KYA-w V,;4 r~w v x Wj X-. r J w-Vrj IN WV w'. Y K-KPA wi Au VIA

TABLE 2

Mean Peak Accelerations of Dummy and Human HeadDuring Tank Gun Firing Tests

TANK ANDGUN

IDENTITY AXIS 0 DEGREE AZIMUTH 90 DEGREE AZIMITH

AUG 81 TEST - DUMMY ONLY

M-551 x-axis 11.2 + 2.1 g* 17.2 + 2.0 g152 mm y-axis -3.7 + 4.0 g 1.9 + 7.1 g

z-axis 3.6 + 5.0 g -8 + 1.8 g

M-551 x-axis 13.8 + 0.6 g 11.8 + 4.6 g105 mm y-axis 2.0 + 3.5 g 3.5 + 4.6 g

z-axis 0.9 +- 2.3 g -0.1 + 4.1 g

DEC 81 TEST - DUMMY

M-60 A2 x-axis 3.5 + 0.9 g 3.4 + 0.4 g152a mm y-axis -0.2 + 2.0 g -1.0 ±0.2 g

z-axis -2.2 + 0.5 g -1.6 - 1.1 g

M-551 x-axis 10.9 + 0.9 g 10.8 + 2.0 g152 mm y-axis 3.8 0.5 g -4.1 + 0.7 qg

z-axis 2.6 + 0.3 g -3.9 4 0.9 q

DEC 81 TEST - HUMAN

M-60 A2 x-axis 3.6 + 0.4 g 3.6 + 0.6 g152 mm z-axis 1.9 + 9.2 g -0.9 + 9.5 q

M-551 x-axis 7.5 ±- 0.8 g ±J.±.l. + 0.8 9152 mm z-axis -6.2 + 0.8 g -6.1 + 0.6 g

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

* Standard Deviation

21

1334.5

1112.1

" 66787.2

o444.82J

L |L

0.2 - 0_51 0.76 1.02 1.217 1.12 1.70 2.03

DEFORMATION ( cm)

FIGURE 12. Comparison of the Load versus Deflection of theStandard Tanker's Brow Pad (used in these teststo a Pad Constructed with 11-f1 Ensoliteb'(Polyvinylchlioride Foam)

The principal acceleration axis in the tank-gun firing isthe x-axis and the gathered data for the dummy and human headalong that axis is acceptably accurate for assessing thehealth hazard. of tho vehicles tested, the M-551 generatedthe highest levels of head x-axis acceleration. Mean peakvalues for the dummy ranged from 10.8 G to 17.2 G for atriangular pulse with an average initial positive pulseduration of 33 milliseconds. The 17.2 G mean was generated bythe 90 degree azimuth firings from the first M-551 firingtest. The second series of M-551 tests were more consistentwith a 10.9 G mean for the 0 degree azimuth configuration anda 10.8 G moan for the 90 degree azimuth configuration. Thesecond test series used a ftully-operational M-553 wihile thefirst test series used a partially-stripped M-551 which was

22I

equipped with an incomplete sight assembly. This may haveresulted in a less rigid load transfer path to the brow padand thus may have introduced some dynamic overshoot.Therefore, the data gathered during the second test will beused to assess potential health hazards. The threat pulsewill be defined as a triangular pulse of 30 to 35 millisecondsduration with a peak of from 10 to 14 G.

The available research into the physiological effects oflow-level impact acceleration is very limited. The principalarea of investigation has been related to sports injuries,principally those from boxing and football. Furthermore, mostof the investigations have consisted of postinjury reportingof the amount and type of damage, and the course of recoveryor death. Almost no work has been done in evaluating thekinetics of boxing. One of the prominent researchers in thefield has published a fairly comprehensive review of boxinginjuries with some analysis of the kinetics and injurymechanism (Unterharnscheidt, 1975). In one experiment, he hadtwo physical education students with no boxing training fightfor 10 minutes while wearing headband-mounted accelerometers.The boxers used 12-oz gloves rather than the 6-oz gloves usedin most professional fights. The 12-oz gloves are thicker andsofter and have a cushioning effect that reduces the peakforce generated by a given blow. The measurements obtainedindicated that 21 blows acce.Leratd the head b-7A- r_, 12.blows by 6-10 G, three blows by 11-15 G, threE blows by 16-20G, and two blows by 21-25 G. Some of the measured pulses inthe 0-5 g group were actually defensive movements of the headrather than blows. No injuries or physical problems werereported. Dr. Unterharnscheidt also conducted an experimentto evaluate the severity of a representative blow in aprofessional boxing match. He used a gloved pendulum torepresent the striking fist and arm and a wooden pendulumcovered with wool cloth to cepresent the head. He determinedthat a representative blow with a 6-oz glove generatedapproximately 100 G of translational acceleration of the head.

A similar experiment to Dr. Unterharnscheidt's was donein England (Johnson, Skorecki, and Wells, 1975). Theresearchers instrumented volunteer subjects and struck them atincreasing impact velocities with a gloved wooden fist mountedon a rigid pendulum. The glove was a 6-oz professional type.The total impacting mass was 5.5 kg. The impact severity wasincremented upward from low levels until the subject'svcluntary tolerance was reached. Higher intensity blows wereevaluated using an inflated dummy head weighted to duplicatehuman head mass (4.5 kg) and mounted in such a way as toduplicate the dynamic response characterstics ot the head-necksystem. The human volunteers sustained blows up to 14 G peakhead acceleration with durations of initial positiveacceleration of approximately 35 milliseconds. The

9 §3

", p

acceleration-time curve (from the Johnson study) is describedas a short-period triangular positive peak followed by along-period negative acceleration with a peak of about 40percent of the positive peak and a duration of about twicethat of the positive period. The head acceleration curvesmeasured in the M-551 are very similar to those described in.the Johnson study. Although the inflated dummy head wasstruck by professional boxers and 260 G peak (13 millisecondsduration) recorded in the head form, such an impact isdefinitely assumed to be a "knockout" punch and not to besustained repetitively.

An earlier experiment was conducted to determinevoluntary tolerance to helmeted-head impact (Lombard, et al.,1951). Subjects were fitted with a variety of football andflight helmets and then struck with an instrumented pendulum.The 14 peak accelerations, due to blows to the forehead,resulted in an average tolerance level of 22.6 G with a modetolerance level of 16 G. The reasons given for the volunteerstop points were local pain, bruising, and neck pain. Noevidence of any change in consciousness or reflex action wasnoted.

Some work has been done in the area of human tolerance toacceleration applied to the whole body while restrained in aseat. ne of the major efforts tn 4-i.s3 area has boenconducted by the NBDL. They have subjected numerous humansubjects to whole-body (-gx) acceleration of from 5 to 15 G atthe sled. The measured x-axis head acceleration has reachedpeaks as high as 24 G with no reported adverse effects (Ewingand Thomas, 1972).

A somewhat similar study was done in England (Reader,1979). Reader looked at the effect of head acceleration onpsychomotor performance. The subjects were restrained in aseat on a sled and subjected to whole-body acceleration. Thehighest peak x-axis head acceleration experienced was 26.9 G.A tracking task and EEG recording were used to evaluate theeffects of acceleration on psychomotor performance. Thereport states that a statistically-significant decrease inshort-term performance was detected for mean peak head x-axisaccelerations greater than 5.3 G. However, the limited numberof subjects used in the experiment makes it very difficult tomake a general statement about the overall physiologicaleffect of low-level head acceleration on psychomotorperformance. The only subject complaints reported were two

cases of slight headache, two cases of stiff neck, and severalstatements of a short-term feeling of detachment or isolationimmediately following deceleration.

24

fIA lt.)tA K C FxU(AJx rL ( f XA &A _. ' TU U F.M ý,!"A FtW AU F. WA am kju U ý A ý I. ~ 4~

Although the whole-body acceleration experiments use adifferent loading mechanism to accelerate the head than doesthe direct impact method, there are some similarities. Withcomparable acceleration-time histories, the total velocity andmomentum changes will bE the same. Human tolerance datagathered from whole-body acceleration experiments can be usedas backup for direct impact tolerance data. In this case, itis desirable because of the limited amount of data concerninghuman tolerance to low-level direct impact acceleration.

As indicated under the Methods section nf this report,consideration was given to the effect of the stiffness of thepad on the acceleration of the gunner's head. The existingsoft latex foam pad acts too much like a "soft" spring inwhich both theory and experiment reveal that the movement ofthe tank turret and pad at velocities up to two meters persecond will "bottom" (totally compress) the pad before thehead velocity is increased. This results in a sudden increaseof head acceleration called "dynamic overshoot." The commonidea that a soft "comfortable" pad is best is not true; arelatively stiff pad is preferable for this application.

Regardless of the pad stiffness used, the gunner shouldpress his brow firmly against the pad to minimize the "dynamicovershoot" Fffect. Firm brow Pressure wl ted to keep thegunner's head in place with the turret pad motion.

25

CONCLUSIONS AND RECOMMENDATIONS

Thre conclusion reached after comparing the measured humanand dummy gunner head accelerations along the x-axis topublished human tolerance data is that the gun firing in thetest vehicles does not exceed human tolerance for singleexposures. It is not possible to state that no person will everexperience any discomfort. Based on the limited data availableand the large variation in the human population' it is quitepossible that some gunners will experience headaches, transitoryhead pain, and neck strain. If the weapon is fired while thevehicle is in motion (resulting in potential decoupling of theforehead from the browpad), higher recoil forces than arereported herein likely will occur. Furthermore, no conclusioncan be reached as to the effects of repeated exposure in termsof number of exposures or frequency of exposures. Studies onboxing imply that subinjurious blows have a cumulative effectthat is injurious (Unterharnscheidt, 1975). Unfortunately, themechanisms of head injury are not well defined in quantitativeterms. Therefore, the effects of repeated low-level blows willhave to be determined through future research.

The recommendation is that research continue into theeffects of recoil on tank gunners by conducting experiments withhuman volunteers and animals to establish a tolerance level tolow-level impact accelerations that includes the effect ofmagnitude, frequency, and total dose. Such experiments couldalso provide tolerance data for impacts from boxing. Thetolerance limits will have to be the volunteer's own sense ofphysical well being. Monitoring of physiological parameterssuch as heartbeat, respiration, brain wave activity, andtemperature should be done, but their value in predicting theapproach to injurious acceleration levels is not yet explicatedfully. Tests that evaluate reflex reaction, fine motor control,and memory may provide better measures for evaluating theeffects of acute acceleration if baseline levels of performancefor such behaviors can be established and then evaluatedimmediately after exposures. The use of this approach willpermit an assessment to be made of both acute, postinsulteffects and (with continued monitoring of the behaviors) of anycumulative and/or chronic deficiencies which result.

To minimize the effects of recoil acceleration "dynamicovershoot," a stiffer foam pad is recommended (with performancesimilar to that shown in Figure 12).

26

REFERENCES CITED

Ewing, C.L., and Thomas, D.J. 1972. Human Head and NeckResponse to I Acceleration. Pensacola, Florida: NavalAerospace Medical Research Laboratory. NAMRL 21 and USAARL73-1.

Goldstein, G. 4 Feb 81. U.S. Army Aeromedical ResearchLaboratory Trip Report of visit to Naval BiodynamicsLaboratory, Michoud Station, LA.

Johnson, J., Skorecki, J., and Wells, R.P. 1975. "PeakAccelerations of the Head in Boxing." Medical and BiomedicalEngineering. 13(3) :396-404.

Lombard, C.F., Ames, S.W., Roth, H.P., and Rosenfeld, S. 1951."Voluntary Tolerance of the Human to Impact Accelerations ofthe Head." The Journal of Aviation Medicine, 22(2):109-116

Reader, D.C. 1979. "Head Acceleration and PsychomotorPerformance." Aviation, Space, and Environmental Medicine.50(3) :267-270.

Unterharnscheidt, F.L. 1975. "Injuries Due to Boxing and OtherSports." In: Vinken, P.J., and Bruyn, G. W., ed. Handbook ofClinical Neurology. New York: American Elsevier Publi.shingCo. 23:527-593. 37V.

27

APPENDIX A

EQUIPMENT MANUFACTURERS

Alderson Research Laboratories390 Ludlow StreetP.O. Box 1271Stanford, CN 06904

Columbia Research LaboratoriesMcDade Boulevard and Bullens La.Woodlyn, PA 19094

EndevcoRancho Viejo RoadSan Juan Capistrano, CA 92675

Entran Devices, Inc.10 Washington AvenueFairfield, NJ 07006

BF Goodrich500 S. Main StreetAkron, OH 44318

Humanoid Systems747 East 223 StreetCarson, CA 90745

Kistler Instrument Corp.75 John Glenn DriveAmherst, NY 14120

Metraplex Corp.Berkshire Industrial ParkBethal, CT 06801

Nicolet Instrument Corp.5225 Verona RoadP.O. Box 4288Madison, WI 53711

Sangamo Data Recorder DivisionP.O. Box 3041Sarasota, FL 33578

Systems Engineering Laboratories6901 W. Sunrise BoulevardFort Lauderdale, FL 33313 Z.

28

b:

Systron Donner Corp.888 Galindo StreetConcord, CA 94520.

Tektronix, Inc.P.O. Box 500Beaverton, OR 97077

29

29!

APPENDIX B

PLOTS OF ACCELERATION VERSUS TIME

FOR DUMMY AND HUMAN AIEAD AND CHEST ACCELERATIONS

DURING TANK GUN FIRINGS

FIGURES B-I THROUGH B-28

30

LA

-PE-

4-1

oc 9 I)C-) M '

00 0g ý4

-r. IQ)0%

114

Ln

0. 0

49 A

4 4 4 a a -P -0. 4J 0

'4 ý

(0) NOLVUIBO0

31'- O~

Ln

Zo

OH z

U)

U8 4J¼

* w00I- '~ H

#; ip 18 0 o0 0 o8 to1 16 0 1

(0) thoIWM9133oV 44

0i LA

4 4 4

wc 0

.r CO ~

-0 4

o0 00

(0) NOLVM31330V

32

U~)U')

0 0

(0 HI

V HM

00

'1 H1

174,~

ot

#94

~0-4

#4 0

w LA10

00 l 4 -).

A-E-4

0o 0

ý'i.4 ý4

"4~

()NOIUVV133DV

33H

LO

a * 0

0 4-

4.)

j -H

oovvsn~oo

oOCd0

co*___________o 0 0 00 0 0 0 0 0

Cd " wI v S0

0

4 4-'

0 0

oc

34H

01. 0

z LA

I 4Q )

I) -4

0j0

1 i0 0 0 10 0 10 000 '

L.4

\0*z

C,

4J 0

01

('1

(0) NOWVU31300v

35

0

0 to

oFi

U: A

U .3.

* 11

E-4

(0)~0 coLU9I0

4N

0~0

36) 44

0

00

N 0

400 Cd ~ 4J

o~~~ 19 C) W4 t))0SO 0 6 6

(V) N0 r=: ID 0) :

C41

N

410

K r$0.0

4-)

-rd -, 0 F

(9)~C NýiV31

PQ

37~

10001

a00.

600, 500 RAD/SEC 2

'U

- • -400.

1C

zI -600-

ccW

'U

"-800.

400

-00

0 20 40 60 80 100 120

TIME (MS)

FIGURE B-15. Human Head Pitch Acceleration - M-60-A2with 152 mm Gun - 0 Degree AzimuthRound 20 (Dec 81)

38

L..

0 0.,.j 10

xx4- 4-

00 Nai E 1~

F OD

ow r )

FL~-M.~PWAM

CaV'-4

3b. 1 0

rz4

aW

E-0

x N

14 0)00 04in ýD q

UrCý 0 0 0 0 0 l 0 w

939

1000]

goo-

-~600-

w /450 RAD/SEC 2

0"- 400-

Z 20004AO -200

-J -400

"-8-00t

'-SOO0

0 20 40 60 80 100 120TIME (MS)

FIGURE B-18. Human Head Pitch Acceleration - M-60-A2With 152 mm Gun - 90 Degrees Azimuth,Found No. 12 (Dec 81 Test).

40

tiI-

0

41 pr0O

IK 4) N 00)

I4-

)00

0n 0

0 C0

l44

0)

oc

0C

44 N

I~~~L U) .. .-. UCd~r- H .I

(0)~U NOV31OP

141 fX4

00 0

o- N 0 4i

U =

* ,ap~( .*r

0 >1 H OD

(0) NOV333

N

H mrL4J

.34 0

q 0n

UU

(0) NILVV130o

42H

04

4 h444

0 00 f

4~I U)A

a 4U) H)N -

ODo0O 0

oc

(0 H4OIAH31IUOOV

o 0

K K 0

4J 0

44 C4 0

0 4)Lo CC? H

0 C4

44 r-

50 0 H4

1-0H 0

43o

1000-

800.

60 /,630 RAD/SEC 2

600.

S400-

z 2000A

Fw I I I

-40

-800-

0 20 46 6'0 80 t0 0 120

TIME (MS)

FIGURE B-25. Human Head Pitch Acceleration - M-551Sheridan With 152 mm Gun - 0 Degree Azimuth,Round No. 22 (D0c 8! Test).

44

£!

1 04 44

00

0 OJA w co

'4 0

0 lu 0.

CH 1 10

V to

-0

o 00 0o 00 00

0

r- I'-r-

x 0 . . Io.

) N II N

4 -P 0F

x co(44

S1 v- I I

VD) NOILU313I00IOV

45 Ii

iH

10001

o800 /750 RAD/SEC 2

6 00-.4

4 00- .,o o iZo 200

g, -400"c 0Aw

0-200-

0 20 *40 s 0 80 100 120TIME (M$)

FIGURE B-28. Human Head Pitch Acceleration - M-551 SheridanWith 152 mm Gun - 90 Degrees Azimuth, RoundNo. 28 (Dec 81 Test).

46

Initial distribution

CommanderUS Army Natick Research and Development CenterATTN: Documents LibrarianNatick, MA 01760

CommanderUS Army Research Institute of Environmental MedicineNatick, MA 01760

Naval Submarine Medical Research LaboratoryMedical Library, Naval Sub BaseBox 900Groton, CT 05340

US Army Avionics Research and Development ActivityATTN: SAVAA-P-TPFort Monmouth, NJ 07703-5401

Commander/ DirectorUS Army Combat Surveillance and Target Acquisition LaboratoryATTN: DELCS-DFort Monmouth, NJ 07703-5304

US Army Resehrch and Development Support ActivityFort Monmouth, NJ 07703

Commander10th Medical LaboratoryATTN: AudiologistAPO NEW YORK 09180

Chief, Benet Weapons Laboratory ILCWSL, USA ARRADCOMATTN: DRDAR-LCB-TLWatervliet Arsenal, NY 12189

CommanderNaval Air Development CenterBiophysics LabATTN: G. KyddCode 60BIWarminster, PA 1.8974

7

CommanderMan-Machine Integration SystemCode 602Naval Air Development CenterWarminster, PA 18974

Naval Air Development CenterTechnical Information DivisionTechnical Support DetachmentWarminster, PA 18974

CommanderNaval Air Development CenterATTN: Code 6021 (Mr. Brindle)Warminster, PA 18974

Dr. E. HendlerHuman Factors Applications. Inc.295 West Street RoadWarminster, PA 18974

Commanding OfficerNaval Medical Research and Development CommandNational Naval Medical CenterBethesda, MD 20014

Under Secretary of Defense for Research and EngineeringATTN: Military Assistant for Medical and Life SciencesWashington, DC 20301

DirectorArmy Audiology and Speech CenterWalter Reed Army Medical CenterWashington, DC 20307-5001

COL Franklin H. Top, Jr., MDWalter Reed Army Institute of ResearchWashington, DC 20307-5100

CommanderUS Army Institute of Dental ResearchWalter Reed Army Medical CenterWashington, DC 20307-5300

HQ DA (DASG-PSP-0)Washington, DC 20310

48

Naval Air Sy-,•te•ns CommandTechnical Air Library 950DRm 278, Jefferson Plaza IIDepartment of the NavyWashington, DC 20361

Naval Research Laboratory LibraryCode 1433Washington, DC 20375

Naval Researoh Laboratory LibraryShock and Vibration Information CenterCode 5804Washington, DC 20375

Harry Diamond LaboratoriesATTN: Technical Information Branch2800 Powder Mill RoadAde]phi, MD 20783-1197

DirectorUS Army Human Engineering LaboratoryATTN: Technical LibraryAberdeen Proving Ground, MD 21005-5001

US Army Materiel Systems Analysis AgencyATTN: Reports ProcessingAberdeen Proving Ground, MD 21005-5017

CommanderUS Army Test and Evaluation CommandATTN: AMSTE-AD-HAberdeen Proving Ground, MD 21005-5055

US Army Ordnance Center and School LibraryBldg 3071Aberdeen Proving Ground, MD 21005-5201

Director (2)US Army Ballistic Research LaboratoryATTN: DRXBR-OD-ST Tech ReportsAberdeen Proving Ground, MD 21005-5066

US Army Environmental Hygiene Agency LaboratoryBldg E2100Aberdeen Proving Ground, MD 21010

49

CommanderUS Army Medical Research Institute of Chemical DefenseANIN: SGRD-UV-AOAberdeen Proving Ground, MD 21010-5425

Technical LibraryChemical Research and Development CenterAberdeen Proving Ground, MD 21010-5423

Commander (5)US Army Medical Research and Development CommandATTN: SGRD-RMS (Mrs. Madigan)Fort Detrick, Frederick, MD 21701-5012

CommanderUS Army Medical Research Institute of Infectious DiseasesFort Detrick, Frederick, MD 21701

CommanderUS Army Medical Bioengineering Research and Development LaboratoryATTN: SGRD-UBZ-IFort Detrick, Frederick, MD 21701

Office of Naval Research600 North Quincy StreetArlington, VA 22217

Defense Technical Information CenterCameron StationAlexandria, VA 22314

CommanderUS Army Materiel CommandATTN: AMCDE-S (CPT Broadwater)5001 Eisenhower AvenueAlexandria, VA 22333

US Army Foreign Science and Technology CenterATTN: MTZ220 7th Street, NECharlottesville, VA 22901-5396

CommandantUS Army Aviation Logistics SchoolATTN: ATSQ-TDNFort Eustis, VA 23604

50

'a , -4- i -•, • . V• - , W • • ' , - '• •• ' R

Director, Applied Technology LaboratoryUSARTL-AVSCOMATTN: Library, Bldg 401Fort Eustis, VA 23604

US Army Training and Doctrine CommandATTN: ATCD-ZXFort Monroe, VA 23651

US Army Training and Doctrine Command (2)ATTN: SurgeonFort Monroe, VA 23651-5000

Structures Laboratory LibraryUSARTL-AVSCOMNASA Langley Research CenterMail Stop 266Hampton, VA 23665

Aviation Medicine clinicTMC #22, SAAFFort Bragg, NC 28305

Naval Aerospace Medical Institute LibraryBldg 1953, Code 102Pensacola, FL 32508

US Air Force Armament Development and Test CenterEglin Air Force Base, FL 32542 (0

Command SurgeonUS Central CommandMacDill Air Force Base, FL 33608

US Army Missile CommandRedstone Scientific Information CenterATTN: Documents SectionRedstone Arsenal, AL 35898-5241

Air University Library(AUL/E.SE)Macwell AFB, AL 36112

US Army Research and Technology Labortories (AVSCOM)Propulsion Laboratory MS 302-2NASA Lewis Research CenterCleveland, OH 44135

51

AFAMRL/HEXWright-Patterson AFB, OH 45433

US Air Force Institute of Technology(AFIT/LDEE)Bldg 640, Area BWright-Patterson AFB, OH 45433

University of MichiganNASA Center of Excellence in Man-Systems ResearchATTN: R.G. Snyder, DirectorAnn Arbor, MI 48109

Henry L. TaylorDirector, Institute of AviationUniversity of Illinois--Willard AirportSavoy, IL 61874

John A. Dellinger, MS, ATPUniversity of Illinois--Willard AirportSavoy, IL 61874

CommanderUS Army Aviation Systems CommandATTN: DRSAV-WS4300 Goodfellow BlvdSt Louis, MO 63120-1798

Project OfficerAviation Life Support EquipmentATTN: AMCPO-ALSE4300 Goodfelluw BlvdSt Louis, MO 63120-1798

CommanderUS Army Aviation Svstems CommandATTN: SGRD-UAX-AL (IAJ Lacy)Bldg 105, 4300 Goodfellow BlvdSt Louis, MO 63120

CommanderUS Army Aviatioi, Systems CommandATTN: DRSAV-ED4300 Goodfellow BlvdSt Lo,.I , MO 63120

US Army Aviation Systems CommandLibrary and Information Center BranchATTN: DRSAV-DIL4300 GoodfelThw BlvdSt Louis, NO 63120

52

Commanding officerNaval Biodynamics LaboratoryP.O. Box 24907New Orleans, TA 70189

Federal Aviation AdministrationCivil Aeromedical InstituteCAMI Library AAC 64DIP.O. Box 25082Oklahoma City, OK 73125

US Army Field Artillery SchoolATTN: LibrarySnow Hall, Room 14Fort Sill, OK 73503

CommanderUS Army Academy of Health SciencesATTN: LibraryFort Sam Houston, TX 78234

CommanderUS Army Health Services Co'tmandATTN: HSOP-SOFort Sam Houston, TX 78234-6000

CommanderUS Army Institu&te of Surgical ResearchATTN: SGRD-USM (Jan Duke)Fort Sam Houston, TX 78234-6200

Director of Professional ServicesAFMSC/GSPBrooks Air Force Base, TX 78235

US Air Force School of Aerospace MedicineStru.hold Aeromedical LibraryDocuments Section, USAFSAM/TSK-4Brooks Air Force Base, TX 78235

US Army Dugway Proving GroundTechnical LibraryBldg 5330Dugway, UT 84022

Dr. Diane DamosDepartment of Human FactorsISSM, USCLos Angeles, CA 90089-0021

53

il

US Army Yuma Proving GroundTechnical LibraryYuua, AZ 85364

US Army White Sands Missile RangeTechnical Library DivisionWhite Sands Missile Range, NM 88002

US Air Force Flight Test CenterTechnical Library, Stop 238Edwards Air Force Base, CA 93523

US Army Aviation Engineering Flight ActivityATTN: SAVTE-M (Tech Lib) Stop 217Edwards Air Force Base, CA 93523-5000

CommanderCode 3431Naval Weapons CenterChina Lake, CA 93555

US Arm': Combat Developments Exoerimental CenterTechnical Information CenterBldg 2925Fort Crd, CA 93941-5000

Aeromechanics LaboratoryUS Army Research and Technical LaboratoriesAmes Research Center, M/S 215-1Moffett Field, CA 94035

CommanderLetterman Army Institute of ResearchATTN: Medical Research LibraryPresidio of San Francisco, CA 94129

Sixth US ArmyATTN: SMAPresidio of San Francisco, CA 94129Director

Naval Biosciences LaboratoryNaval Supply Center, Bldg 844Oakland, CA 94625

54

CommanderUS Army Aeromedical CenterFort Rucker, AL 36362

CommanderUS Army Aviation Center and Fort RuckerATTN: ATZQ-CDRFort Rucker, AL 36362

Directorate of Combat DevelopmentsBldg 507Fort Rucker, AL 36362

Directorate of Training DevelopmentBldg 502Fort Rucker, AL 36362

ChiefArmy Research Institute Field UnitFort Rucker, AL 36362

ChiefHuman Engineering Laboratory Field UnitFort Rucker, AL 36362

CommanderUS Army Safety CenterFort Rucker, AL 36362

CommanderUS Army Aviation Center and Fort RuckerATTN: ATZQ-T-ATLFort Rucker, AL 36362

US Army Aircraft Development Test ActivityATTN: STEBG-MP-QACairns AAF, Fort. Rucker, AL 36362

PresidentUS Army Aviation BoardCairns AAF, Fort Rucker, AL 36362

5 5.

55

Distribution to foreign addressees

ChiefDefence and Civil Institute of Environmental MedicineP.O. Box 2000ATTN: Director MLSDDownsview, Ontario Canada M3M 3B9

USDAO-AMLO, US EmbassyBox 36FPO New York 09510

Staff Officer, Aerospace MedicineRAF Staff, British Embassy3100 Massachusetts Avenue, NWWashington, DC 20008

Canadian Society of Aviation Medicinec/o Academy of Medicine, TorontoATTN: Ms. Carmen King288 Bloor Street WestToronto, Canada M55 1V8

Canadian Airline Pilot's AssociationMAJ (Retired) J. Soutendam1300 Steeles Avenue EastBrampton, Ontario, Canada L6T IA2

Canadian Forces Medical Liaison OfficerCanadian Defence Liaison Staff2450 Massachusetts Avenue, NWWashington, DC 20008

Commanding Officer404 Squadron CFB GreenwoodGreenwood, Nova Scotia, Canada BOP INO

Officer (tmmandingSchool of Operational and Aerospace MedicineDCIEM P.O. Box 20001133 Sheppard Avenue WestDownsview, Ontario, Canada M3M 3B9

National Defence Headquarters101 Colonel By DriveATTN: DPMOttowa, Ontario, Canada KIA 0K2

56

I,',

Commanding OfficerHeadquarters, RAAF BasePoint Cook Victoria, Australia 3029

Canadian Army Liaison OfficeBldg 602Fort Rucker, AL 36362

Netherlands Army Liaison OfficeBldg 602Fort Rucker, AL 36362

German Army Liaison OfficeBldg 602Fort Rucker, AL 36362

British Army Liaison OfficeBldg 602Fort Rucker, AL 36362

French Army Liaison OfficeBldg 602Fort Racker, AL 36362

57