"AD-A268 952

U.S. Army Research Institutefor the Behavioral and Social Sciences

Research Report 1638

Stinger Team Performance DuringEngagement Operations in a

Chemical Environment:The Effect of Experience

David M. Johnson and Joan Dietrich SilverU.S. Army Research Institute

DTIC_E LTEC T 0G26 19

SAUG B 19

93-19796June 1993

Approved for public release; distribution is unlimited.

1.,/ / (7f

U.S. ARMY RESEARCH INSTITUTE

FOR THE BEHAVIORAL AND SOCIAL SCIENCES

A Field Operating Agency Under the Jurisdictionof the Deputy Chief of Staff for Personnel

EDGAR M. JOHNSONActing Director

Technical review by

Dwight J. GoehringG. David Hardy, Jr.

NOTICES

FINAL DISPOSITION: This report may be destroyed when it is no longer needed. Please do not return it tothe U.S. Army Research Institute for the Behavioral and Social Sciences.

NOTE: The findings in this report are not to be construed as an official Department of the Army position,unless so designated by other authorized documents.

Form Approved

REPORT DOCUMENTATION PAGE oMB No. 070o1.o01Pub~C Dl'ch reotin rdenI |Of thu o lOe1ti0n Of intormatluon . e~ttnatfa to afefrage | hour De 'etore sft~tduitgi~ the time |fo reutemwng ,mttruct;nt. ,earclun eatt|ng data tource.

! gath ng and masttaung the data neded, and comelet0g and Ft.,ewn g the COUocti of nfocmatOn oef i mments lear10f thu buln fttmate 01 any Other 1%00 of thscOllection Of infOrmlatiOn. includng sug5 ets to' rldcin thi ftreen, to Wasa ngttn "eadgueteief" $"VIM. Oerectoeate for Information Owe-atWo. and Rteorts. 121S JeflemonOawtilighway.Suite 1204.AtlIngtOn.V 22202,430a. and tO th O',e of Managment and Budge. P e f hdu firotec 0704-13). WahingttO. D Z0W 1

11. AGENCY USE ONLY Ledvf Darnt) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

I1993. June Final Mar 91 - Dec 924. TITLE AND SUBTITLE S. FUNDING NUMBERS

Stinger Team Performance During Engagement Operations PE 63007Ain a Chemical Environment:. The Effect of Experience PR 793

TA 12016. AUTHOR(S) WU Hi

Johnson, David Mo; and Silver, Joan Dietrich

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) B. PERFORMING ORGANIZATIONU.S. Army Research Institute for the Behavioral and REPORT NUMBER

Social SciencesATTN: PERI-IB ARI Research ReportP.O. Box 6057 1638Fort Bliss, TX 79906-0057

9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/ MONITORINGU.S. Army Research Institute for the Behavioral and AGENCY REPORT NUMBER

Social Sciences5001 Eisenhower AvenueAlexandria, VA 22333-5600

11. SUPPLEMENTARY NOTES

Prepared in cooperation with U.S. Army Chemical School, ATZN-CM-CT, Fort McClellan,AL 36205-5020.

12a. DISTRIBUTION/AVAILABILITY SIATEMENT 12b. DISTRIBUTION CODEApproved for public release;distribution is unlimited.

13. ABSTRACT (Maximum 200 words)This research compared the engagement performance of two groups of soldiers

wearing the standard battle dress uniform (MOPPO) and the full chemical protectiveensemble (MOPP4). The two groups of air defense soldiers varied widely in trainingand experience. Twelve Stinger teams were recruited during their last week ofadvanced individual training to become the low experience group. Another twelveStinger teams were recruited from veterans newly returned from Operations DesertShield and Desert Storm. All teams were tested in the Range Target System (RTS).Measurements were recorded for engagement performance, stress, and workload. Engage-ment performance was poorer during conditions of MOPP4 for both the lower and highexperience groups. Engagement performance was better for the high experience groupthan for the low experience group regardless of MOPP conditions. Stress and workloadratings were higher when Stinger teams wore MOPP4 than MOPPO.

14. SUBJECT TERMS Engagement stimulation 15. NUMBER OF PAGESChemical protective clothing Stinger 61Mission Oriented Protective Posture (MOPP) Stress 16. PRICE CODEForward Area Air Defense (FAAD) Workload --

17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACTOF REPORT OF THIS PAGE OF ABSTRACT

Unclassified Unclassified Unclassified Unlimited

NSN 7540-01-280-$500 Standard Form 29B (Rev 2-89)?90 102ii Pre Isbed y *4I m

Research Report 1638

Stinger Team Performance During EngagementOperations in a Chemical Environment:

The Effect of Experience

David M. Johnson and Joan Dietrich SilverU.S. Army Research Institute

Field Unit at Fort Bliss, TexasMichael H. Strub, Chief

Training Systems Research DivisionJack H. Hiller, Director

U.S. Army Research Institute for the Behavioral and Social Sciences5001 Eisenhower Avenue, Alexandria, Virginia 22333-5600

Office, Deputy Chief of Staff for Personnel

Department of the Army

June 1993

Army Project Number Human Factors In Training20623007A793 Operational Effectiveness

Approved for public release; distribution is unlimited.

ili

4I

FOREWORD

The research discussed in this report was performed by theSoldier-System Effectiveness Team of the Fort Bliss Field Unit ofthe U.S. Army Research Institute for the Behavioral and Socialsciences (ARI). The mission of this team is to perform researchand development in human performance issues relevant to improvingArmy air defense effectiveness. Field tests have shown that theengagement performance of Stinger teams is impaired by wearingMOPP4 chemical protective clothing for long periods of timeduring sustained operations. Is this impairment caused (a) bythe wearing of the MOPP4 clothing itself, (b) by the requirementto operate in this chemical protective clothing for longdurations in sustained operations, or (c) by some interactionbetween the clothing and the duration it is worn? The objectiveof this research was to quantify the magnitude of the performancedecrement caused specifically by wearing the MOPP4 clothingitself. The effect on performance of extended operations inMOPP4 was not investigated. A second objective of this researchwas to determine if extensive prior experience with and trainingin MOPP4 clothing improved engagement performance.

This research is part of a larger team project entitled"Forward Area Air Defense (FAAD) Performance During EngagementOperations in a Chemical Environment," which is funded by thePhysiological and Psychological Effects of the Nuclear,Biological, and Chemical Environment and Sustained Operations onSystems in Combat (p 2NBC2 ) program administered by the U.S. ArmyChemical School at Fort McClellan. The proponent agency for thisresearch is the Directorate of Combat Developments at the U.S.Army Air Defense Artillery School (USAADASCH) at Fort Bliss. AMemorandum of Agreement covering this research project was signedon 7 November 1991 by USAADASCH and ARI.

The results of this research were presented to ColonelSchnakenberg, Chairman, and members of the P2NBC2 Technical andScientific Advisory Group as a final test report in December1991. The final test report was evaluated by the proponent in anAbbreviated Operational Assessment (AOA) memorandum dated 31March 1992. In this AOA, the proponent concurred with theresults in the final test report.

SEDG M. JO SONI IZ. - u- Acting Director

rrs 1 C ji. i ' 3

STINGER TEAM PERFORMANCE DURING ENGAGEMENT OPERATIONS IN A

CHEMICAL ENVIRONMENT: THE EFFECT OF EXPERIENCE

EXECUTIVE SUMMARY

Requirement:

To quantify the extent to which Stinger team engagementperformance is impaired by wearing MOPP4 chemical protectiveclothing. To determine if extensive prior experience with andtraining in MOPP4 will improve engagement performance.

Procedure:

A design was chosen to measure the effects on performance ofwearing MOPP4 chemical protective clothing while minimizingpossible contaminating effects of long duration sustainedoperations. The approach was to test each of two groups ofStinger teams under conditions of MOPPO and MOPP4. The twogroups differed widely in training and experience. The lowexperience group consisted of twelve teams recruited during theirlast week of advanced individual training. This group had beenqualified on the Stinger weapon, on visual aircraft recognition,and had received 9 hours of instruction in MOPP. The highexperience group consisted of twelve teams recruited fromveterans newly returned from Operations Desert Shield and DesertStorm. In addition to individual and unit training, this grouphad received 1 hour of MOPP training every day for 7 months whilein Southwest Asia. Both experience groups were tested accordingto the same methods and procedures in the Range Target Systemengagement simulation facility. No team in either group spentmore than 3 hours in MOPP4. Measurements were recorded forengagement performance, stress, and workload.

Findings:

The engagement performance of Stinger teams was poorer whenwearing MOPP4 than when wearing MOPPO for both experience groups.Analysis of these results suggests that the performancedegradation seen in MOPP4 was attributable to the properties ofthe gas mask. Engagement performance was better for the highexperience group than for the low experience group regardless ofMOPP condition. Reported stress and workload ratings were higherwhen Stinger teams wore MOPP4 than when they wore MOPPO.

vii

Utilization of Findings:

The results of this research, as a final test report plusdata, were provided to the Physiological and PsychologicalEffects of the Nuclear, Biological, and Chemical Environment andSustained Operations on Systems in Combat (P 2NBC2) program.Performance decrement data such as these are integrated into theP2NBC 2 database for eventual incorporation into the PerformanceAssessment Model. Results of P2NBC 2-sponsored tests areperiodically published.

viii

STINGER TEAM PERFORMANCE DURING ENGAGEMENT OPERATIONS IN ACHEMICAL ENVIRONMENT: THE EFFECT OF EXPERIENCE

CONTENTS

Page

BACKGROUND ...................... ....................... 1

METHOD ........................ ......................... 3

Participants ................... .................... 3The Stinger Weapon ................ ................. 4Additional Equipment ............... ................ 4The Range Target System (RTS) ........... ............ 5Procedure ..................... ...................... 7Hypotheses ................ ..................... .. 13

RESULTS .................. ......................... .. 14

Engagement Performance ......... ............... 14Stress Ratings ................ ................... 35Workload ..... ............ ...................... o . 35

DISCUSSION ................... ....................... 39

Engagement Performance .......... ............... 39Stress and Workload ........... ................. 40

CONCLUSIONS .................. ....................... 43

REFERENCES ................... ....................... 45

APPENDIX A. OUTLINE OF PARTICIPANT BRIEFING ...... A-i

B. PERFORMANCE PROBLEMS IN MOPP4:OBSERVATIONS, OPINIONS OF SOLDIERS,AND "WORK-AROUND" SOLUTIONS .......... B-i

LIST OF TABLES

Table 1. Task Performance Measures ................. 8

2. Summary performance Measures ....... 9

3. Schedule of Data Collection Activities . . . 10

4. Test Scenario Specifications .. ........ 12

ix

CONTENTS (Continued)

Page

Table 5. Acquisition Range in Kilometers forFixed-Wing Aircraft by Conditions ..... ...... 15

6. Identification Range in Kilometers forFixed-Wing Aircraft by Conditions ...... 15

7. Lock-On Range in Kilometers for Fixed-Wing Aircraft by Conditions ........... .. 16

8. Fire Range in Kilometers for Fixed-WingAircraft by Conditions ... ........... .. 16

9. Fixed-Wing: Percent Aircraft CorrectlyIdentified by Conditions ... .......... .. 17

10. Fixed-Wing: Percent Friendly AircraftCorrectly Identified by Conditions ..... 22

11. Fixed-Wing: Percent Hostile AircraftCorrectly Identified by Conditions ..... 23

12. Fixed-Wing: Percent Hostile AircraftAttrition by Conditions ... ........... .. 23

13. Fixed-Wing: Percent Fratricide byConditions ......... ................. 24

14. Fixed-Wing: Percent Hostiles KilledPrior to Ordnance Release by Conditions . . . 25

15. Time from Target Available to Detectionin Seconds for Rotary-Wing Aircraft byConditivis ......... ................. .. 26

16. Time from Detection to Identification inSeconds for Rotary-Wing Aircraft byConditions ......... ................. 26

17. Time from Detection to IFF in Seconds forRotary-Wing Aircraft by Conditions ..... 27

18. Time from Detection to Weapon Acquisitionin Seconds for Rotary-Wing Aircraft byConditions ......... ................. 27

19. Time from Lock-On to Fire in Seconds forRotary-Wing Aircraft by Conditions ..... 28

x

CONTENTS (Continued)

Page

Table 20. Time from Identification to Fire in Secondsfor Rotary-Wing Aircraft by Conditions . . . 28

21. Time from Detection to Fire in Secondsfor Rotary-Wing Aircraft by Conditions . . . 29

22. Scenario 13: Time from Available to LastAct in Seconds by Conditions .. ........ 33

23. Rotary-Wing: Percent Hostile AircraftAttrition by Conditions ... ........... .. 34

24. Rotary-Wing: Percent Hostiles KilledPrior to Ordnance Release by Conditions . . . 34

LIST OF FIGURES

Figure 1. Range of engagement actions for fixed-wing targets: All conditions ....... ........ 18

2. Range of engagement actions for fixed-wing targets: MOPPO versus MOPP4 (summedover both experience conditions) ...... 19

3. Range of engagement actions for fixed-wing targets: Low Exp. versus High Exp.(summed over both conditions of MOPP) . . . . 20

4. Range of engagement actions for fixed-wing targets: Low Exp. Group in MOPPOversus High Exp. Group in MOPP4 ....... 21

5. Time to perform engagement actions forrotary-wing targets: MOPPO versus MOPP4(summed over both exp. groups) ....... 30

6. Time to perform engagement actions forrotary-wing targets: Low versus High(summed over both conditions of MOPP) . . . . 31

7. Time for perform engagement actionsfor rotary-wing targets: Effect ofexperience on reduction of the MOPP4decrement .......... .................. .. 32

xi

CONTENTS (Continued)

Page

Figure 8. Stress -.vels reported by soldiers inLow Ex-,erience Group and High ExperienceGro"'n before and after the MOPPO andMOPP4 conditions ....... .............. 37

9. Comparison of MOPPO and MOPP4 pretestand posttest stress means for bothexperience groups ...... .............. .. 38

10. Interaction of experience level, MOPPgear, and scenario difficult .. ........ 42

xii

STI4= TERM PE 1OROME DURD~z GENGAEE OPELXTICE IN AiCHEMICAL ENVIRO MT: THE EFFECT OF EXP

The adverse effects of wearing the Mission Oriented Protective Posture(MOPP) ensemble and the detrimental consequences on performance are well

documented. The literature from 1980 to 1988 dealing with the effects of thechemical protective ensemble and extended operations on performance wassummarized by Headley, Brecht-Clark, Feng, and Whittenburg (1988). Theirreview included mostly laboratory and small-scale field tests involvinginfantry performing sustained operations in temperate climates and moderateterrains.

Based on their review, Headley et al. (1988) arrived at severalconclusions. They determined that comunnication in MOPP gear can bedifficult, and that this difficulty is exacerbated by distance and noise. Theauthors further observed that soldiers will devise new ways to perform theirtasks to overcome the effects of the chemical protective ensemble. Theymaintain, therefore, that training in MOPP gear is essential to preventsoldiers from using the battlefield as a place to improvise ways to carry outtheir duties. The reviewed studies provided evidence that practice in MDPPgear can reduce some of the performance decrements, specifically thoseassociated with fine motor skills. Ultimately, according to Headley et al.,most tasks can be performed in the MOPP ensemble, but completion times may belonger.

The performance decrements in MOPP4 described by Headley et al. (1988)can result from a variety of factors such as loss of manual dexterity,degradation of reaction time, deterioration of psychomotor skills, impairmentof speech intelligibility, and reduction of the visual field. In some cases,it has been found that a particular piece of the MOPP ensemble is directly andoften times solely responsible for the observed performance decrement. Forinstance, the mask and hood worn as part of the MOPP gear is known to degradevision and speech functions (Bensel, Teixeira, & Kaplan, 1987; Harra-h, 1985;Kobrick & Sleeper, 1986; and Nixon & Decker, 1985).

One investigation (Harrah, 1985) of the effect of mask and hood onperformance examined visual performance using three prototype XM40 protectivemasks in combination with M19 binoculars. Harrah recorded the field of viewwith each binocular-mask combination and the standoff distance from thesoldier's eye to the mask lens to explore their relationship to scan timeperformance. He found that mean field of view decreased linearly as standoffdistance increased. The decreased field of view resulted in an increase inthe time required to scan the target area.

The elements of the MOPP4 ensemble (suit, gloves, boots, and mask) canact alone or in concert to impede body mobility, psychomotor coordination, andmanual dexterity. While gloves generally make the greatest contribution tothe performance decrement for tests of manual dexterity (Bensel, 1980; Bensel,et al., 1987; Johnson & Sleeper, 1986), reduced body mobility and impededpsychomotor coordination can result from various combinations of thecomponents of the protective ensemble (Bensel, et al., 1987).

1

Although serious problems are associated with wearing MOPP gear, theeffects of the chemical protective ensemble are different depending upon thetask being performed. Some studies (e.g., Posen, Munro, Mitchell, &Satterthwaite, 1986; U.S. Air Force Tactical Warfare Center, 1981; and Glunm,1988) have shown that performance in MOPP4 did not differ significantly fromperformance in MOPPO. In addition, they have also shown that even when MDPP4performance is degraded, in some cases it is still well within militarystandards.

On 9 May 1984 the Army Vice Chief of Staff directed that a program beinitiated to assess the Physiological and Psychological Effects of theNuclear, Biological, and Chemical Environment and Sustained Operations onSystems in Combat (P 2NBC). Key objectives of this program are to (1)quantify the crew performance decrement experienced during operations on theintegrated battlefield; (2) determine how the decrement affects AirLand Battledoctrine; (3) identify methods and procedures to reduce the decrement--including doctrine, training, organization, and materiel changes; (4)integrate performance decrement data into a database; and (5) develop andvalidate a Performance Assessment Model. Results of 1PNBC 2-sponsored testsare being used to provide planning and operational risk factor analyses tofield commanders, to support the development of training programs, to developdoctrine and organization, and to influence the design and acquisition ofmateriel to improve the capability to conduct successful combat operations ona battlefield where NBC weapons are extensively and continuously employed.

The United States Army PResearch Institute (ARI) Fort Bliss Field Unitis conducting a program of research on Forward Area Air Defense (FAAD)performance in a chemical environment under the auspices of the P2NBC2program. The ARI program addresses the P2NBC2 issues of performancedegradation and psychological effects of the chemically contaminatedenvironment by testing air defense soldiers in MOPPO and MOPP4 under differentenvironmental conditions. Unlike some other PINBC&-funded research (c.f.,Headley et al., 1988), this program does not investigate the effect onperformance of wearing MOPP4 during sustained operations. ARI researchparticipants never wear the chemical protective clothing longer than threehours. Rather, the focus of this program is to investigate the effects onperformance of the MOPP4 clothing itself, separate from any effects caused byextended operations. For example, Johnson and Silver (1992) investigated theeffects of MOPP4 gear and target cuing on aircraft engagements by noviceStinger teams. They found engagement performance to be degraded by wearingthe MOPP4 chemical protective ensemble and improved by the addition of precisevisual cues. Use of these cues substantially reduced the degradation due towearing MOPP4. That is, the MOPP4 clothing itself degraded the performance ofthe novice Stinger teams--independent of any effect of sustained operations-and the addition of cues restored most of the loss. In addition, Stingerteams reported higher stress and workload levels in MOPP4 than in MOPPOwhether or not they were receiving visual cues.

2

This paper reports the results of another short-duration investigationof the effects of wearing the chemical protective ensemble on Stinger teamengagement performance. As stated above, one of the conclusions drawn byHeadley et al. (1988) was that practice in MOPP gear can reduce some of theperformance decrement attributed to wearing MOPP gear. The research questionsaddressed in this experiment were these. To what extent is Stinger teamperformance harmed by wearing MOPP4? Is Stinger team performance in MOPP4improved by extensive experience with the chemical protective clothing? Theapproach was to measure the engagement performance of each of two groups ofStinger teams both while dressed in the standard battle dress uniform (MOPPO)and while wearing the standard uniform plus full chemical protective clothing(MOPP4). The two groups differed substantially in their relative level ofexperience with MOPP. The Low Experience Group was a sample of Stinger teamsfrom Advanced Individual Training (AIT). The High Experience Group was asample of Stinger teams recently returned from Operations Desert Shield andDesert Storm. It was hypothesized that both groups would show a decrement inengagement performance under conditions of MOPP4 and that the High ExperienceGroup would perform better than the Low Experience Group on measures ofengagement performance. It was also hypothesized that participants wouldreport greater levels of stress and workload when wearing chemical protectiveclothing.

It should be noted explicitly that the independent variable "experiencelevel" was not manipulated directly, but was created indirectly by recruitingtest participants from two groups who differed widely in experience in MOPP4(i.e., AIT trainees versus Southwest Asia veterans). The High ExperienceGroup, therefore, differed from the Low Experience Group in several ways,including: Age, rank, time in service, amount of Stinger training, amount ofStinger training in MOPP4, and total amount of time spent wearing MOPP4. Allresults attributed to experience level should be understood in light of theopportunistic nature of this independent variable. Thus, this research can beviewed as an attempt to quantify the relative cost in readiness of employingnovice Stinger teams versus experienced Stinger teams in a chemicalenvironment.

Method

Participants

Low Experience Group. Twelve Stinger teams from the 1st Battalion, 56thAir Defense Artillery (ADA) Regiment, 6th ADA Brigade served in thisexperiment during December, 1990. Each team consisted of two soldiers, a teamchief and a gunner. The Military Occupational Specialty (MOS) for allsoldiers was MANPADS Crewmember (16S). The mean age of soldiers was 19.0years (median 18.0). All 24 participants were in their last week of AIT atFort Bliss, Texas. All had been qualified on the Stinger weapon and in visualaircraft recognition. All participants had completed nine hours of MOPPtraining during AIT, of which three hours were dedicated to engagementtraining.

3

High Em:e ce Grom. Twelve Stinger teas frou the 5th Battalion,62nd ADA Regiment, 11th ADA Brigade served in this exper t duirq April ardMay, 1991. Each team consisted of two soldiers, a team chief and a gunner.The MCS for all soldiers was 16S. The mean age of soldiers was 22.6 years(median 23.0). 7he mean and meian rank of soldiers was CPL. All 24 soldiershad just returned from ScUhest Asia where they had participated inOperations Desert Shield and Desert Storm. All soldiers had received eitherMDPP training or _perati -al experience in NOPP for at least one hour everyday for the seven months they were stationed in scuthwest Asia.

"The stinme WeORMo

Stinger is a man-portable air defense weapon system. It is a shoulder-fired, infrared-hcming (heat-seekin) guided missile. Stinger requires nocontrol from the gunner after firing. It has an identification friend or foe(=F) s which electronically interrogates tage aircraft to establishfriendly identification. Stinger provides short-range air defense formaneuver units and less mobile combat support units. Stinger is designed tocounter high-speed, low-level, grcund-attack aircraft. It is also effectiveagainst helioapter, cobservation, and transport aircraft (Field Manual No. 44-18-1, 1984).

Gunners maintain proficiency by practicing with the Stinger Training SetGuided Missile (M134). Each training set consists of a tracking head trainer,five rechargeable batteries, an IFF simulator, and a storage container. TheStinger tracking head trainer (1!) simulates the actual live Stinger round insize, shape, weight, and feedback from engagement actions-except, of ourse,no missile is launched. The seeker head inside the noH is the same seekerhead as inside the live missile. hs, its audio feedback to the gunner whiletracking the heat source of an aircraft is the same. 7he IFF simulatorimitates the actual IFF subsystem in size, weight, cabling requirements, andprovides the same audio feedback to the gunner. Mie Training Set GuidedMissile was the weapon used during this research.

Additional Equipment

All soldiers wore the standard battle dress uniform plus pistol belt,load bearing equipnent, canteen, and kevlar helmat during the ?4)PPO codition.During the MPP4 condition all of the above items were worn plus the chemicalprotective clothing. The chemical protective clothing consisted of gloves,overboots, overgarments (worn closed), and M40 mask and hood (worn closed).In addition, each team chief carried a set of 7 x 50 binoculars (M19).

4

The RaMs Tarcnt Svstnem a(fs

cditi. Air defense performams data were collected in the RangeTarget System (HIS), a FAAD empgement siwlation facility. Air defendersenploy their weapons in simulated engagre11t of submcale fixe-win androtary-win; aircraft. HIS is located in the desert near CMdrnM Army Airfieldat Mute Sands Missile Range, New Mexico. IUS is the third FAAD simulationfacility developed by the USARI Fort Bliss Field Unit, having evolved from theRealistic Air Defense EngagM1nt System (RAIE) circa 1984-1985, and themultiple weapon RAEES (MWAES) circa 1986-1989. HIS has been cerationalsince 1989. Details as to the validation of this sinulaticn facility can befound elsehere (Barber, 1990a; Drewfs, Barber, Jihnscn, & Frederickscn, 1988;Johnsnm, Barber, & Lockhart, 1988). To date, Vulcan, PIVADS, Caparral,Stinger, and Avenger units have engaged aircraft in HIS.

HIS uses subscale rotary-win; (helicopter) and fixed-win (airplane)targets. All targets represent US or Soviet aircraft. Aircraft arecamouflaged, three dimensional, molded fiberglass replicas. They are eitherflown remotely according to prescribed flight paths and manieuvers, or pcp-upfrom designated positions via pneumatic stand-lift mecanisms. The flyingfixed-wing (FM) aircraft are remotely controlled by radio signals from expertpilots stationed in the test range. The pop-up, rotary-wi; (Iw targets arepositioned strategically behind sand dunes at scenario prescribed distances.Flying aircraft are tracked by a laser position-location system. Allaircraft are fitted with a heat source which stimulates the infrared-radiationseeker of heat-acguiring missile systems such as Caparral, Stinger, andAvenger.

Air defense weapons are t to the WIS site and emplaced in abattle position. Weapons are cabled to the Data Acquisition Station (W11S) andsignal taps are installed on key weapon pins. The D1S interrogates the weaponevery 250 milliseconds to see if a gunner action has occurred. GunnerengageIent actions are thus collected autcmatically and time coded with aresolution of 250 milliseconds. Team chief verbal actions, such as detectionand identification, are rerded by a human data collector who enterskeystrokes on a cxmprter keyboard located at the weapon position. Ihe DASinterrogates this keyboard every 250 milliseconds to see if a verbal actionhas occurred. In this fashion gunner and team chief engagenmt actions areentered into the trial database along with a time code-time in secods frtarget availability-and a range code-range of target aircraft in kilometersfrom fire unit. 'Thus, at the end of each engagement trial a complete recordof all engagement actions exexted by the team is obtained. This rewrd ismathematically processed in near real time and is available in the form offeedback a few secids after the termination of each scenario trial. When aStinger gunner fires, a mathematical model synthetically flies the missile outto known target position for target intercet (or miss) in real time. In thisfashion the effects of a cmplete engagement can be determined ("kill" or"miss") without necessitating the dangers or expense of live fire.

5

7he primary cceponents of the Range Target System are the Flying TargetSystem (FIS), the Pop-Up Target System (PLS), the Range omtrol Station (RCS),the Data Akxuisition Station (DAS), and the Position Location Station (PIS).The RCS, DAS, and PIS omponents are described in greater detail in Barber(1990b). The PIS and FTS cxqxuents, respectively, are described more fullyin Berry and Barber (1990a&b). The F1S presents flying, scale model offixed-wing and rotary-wing aircraft. In this experiment, the FTS presentedcn-seventh scale EW models of the US A-7 and A-10, as well as the Soviet Su-20/22 and Su-25. The PTS presents con-fifth scale models of rotary-wingaircraft. These helicopters pop-W, p-nemtically, from defilade, hover for ascenario-specified period of time with the rotor turning, and then descend.Each PIS is caiputer controlled by radio-fraqwncy instructions sent frtn theRCS. The IR models used in this experiment were the AH-l, AH-64, UH-l, Mi-8,Mi-24, and Mi-28.

The RCS is the station where voice rcimmications system test andcalibration diecks, initialization of the system, real-tim functions,performance scoring, and printing of feedback are initiated. Control of theRange Target System during scenario presentation is located at the RCS. UheDAS captures all of the team chief and gunner engagement task perfor-a-c andweapon events as a function of elapsed time and aircraft range. Effectsscoring and assessment of kills are also performed at the DAS. The DASprovides scenario feedback on these events. During testing of the lowExperience Grcup there were two separated weapon positions, each with its onDAS and data collector. During testing of the High Experience Group therewere four separated weapon positions each with DAS and data collector. AllDASs are controlled by the -4S and co-municate with the RCS by radio. Priorto eadc trial, scenario information is down-loaded from RcS to DAS. Aftereach trial, engagement data are up-loaded from DAS to RCS. The PLS is ,,zed toregister (ground locate) the weapon, the pcp-up helicopter stands, flyingtarget launch positions, as well as the other IUS stations (RCS, DAS, andPLS). Also, it is used to track flying targets and determine their rangethroughout a scenario. The PLS is accurate to within one meter in threedimensional space. The PLS can automatically detect, acquire, and trackflying targets. It can also be operated manually using its video display andtrackball.

Measures of performance obtained from RIS. The Stinger team wereevaluated on the timeliness of their engageent actions. Ken or how quicklydid the team perform their tasks? This efficiency of engagement wasdetermined by the fourteen Task Performance Measures defined in Table 1. TaskPerformance Measures (ThMs) were collected on a trial-by-trial basis. Thesemeasures describe the time elapsed or the target aircraft range when specificengagement actions were performed. For fixed-wing aircraft these TR4s areexpressed in terms of the aircraft range in full-scale kilcieters when theengagement actions occurred (e.g., detection range, identification range, firerange). Since MTS aircraft are subscale, all ranges are presented in terms offull-scale range equivalents by multiplying the measured range by the scalingfactor. For rotary-wing aircraft, TR(S are expressed in terms of the elapsedtime, in secords, between two engagement actions (e.g., time fra- targetavailable to detect, time frm detect to identify, time from identify tofire).

6

Me Stinger teams wexe also evaluated on the effectiveness of theirernyage it actions. %tat mission-related outocs resulted from theiractions? 7his effectiveness of enpament was calculated by the eight SummyaPerformanoe Measures defined in Table 2. SuNmary Perfonnar e Measures (SPMs)are derived from task actions by summing across trials. SF are expressed intearm of pe nt (e.g., percent aircraft detected, percent hostileaircraft correctly identified, percent hostile aircraft attrition).

The schedule of data collection activities is presented in Table 3.

7

Table 1

Task Perf ce Masres

Fixed-WirK Aircraft

Detection Range: arane of aircraft (in full-scale kilometers) at detectres ("target")

Identification Range: Range of aircraft at identificaticrn response (tacticalID '"ostile" or "friendly")

iFF rane: Range of aircraft at push of IFF button

Acqauire Range: Range of aircraft at weapon acquisition signal

Lock-On Range: Range of aircraft at press of uncage bar (iutddh locks seekeronto target)

Fire Range: Range of aircraft at fire (trigger pull)

Rotarv-_Wirnr Aircraftt

Tim from Target Available to Detect: Tim (in seos) from irm.mxtrecord of target available until detect response (targetavailable is defined as that time when the target has risenfar enough to be visible from the weapon positicos)

Time from Detect to IFF: Time from detect response to push of IFF button

Tim from Detect to Identify: Tim from detect response to identificationresponse

Time from Detect to Acquire: Tim from detect response to weapon acquisitionsignal

Time frEn Acquire to Lock-On: Time fro weapon acquire signal to press ofuncage bar

Tim from Lock-On to Fire: Tim fram press of uncage bar to fire (trigger

Time from Identify to Fire: Time fram identification response to fire

Time fram Detect to Fire: Time from detect response to fire

8

Table 2

Summary Performane Measures

Percent Aircraft Detected: Number of aircraft for which a detect response isgiven, divided by the total nmber of aircraft

Percent Aircraft Correctly Identified: Number of aircraft for which a correctID respne is given, divided by the total rumberof aircraft detected

Percent Hostile Aircraft Correctly Identified: Number of hostile aircraft forwhich a correct ID response is given, divided bythe total number of hostile aircraft detected

Percent Friendly Aircraft Correctly Identified: Number of friendly aircraftfor which a correct ID response is given, dividedby the total number of friendly aircraft detected

Percent Hostile Attrition: Number of hostile aircraft credited as killed,divided by the total numrer of hostile aircraftpresented

Percent Fratricide: Nuimer of friendly aircraft credited as killed, dividedby the total nuirer of friendly aircraft presented

Percent Hostiles Killed Prior to Ordnance Release: Number of hostile aircraftcredited as killed prior to cdna=ce release,divided by the total nmmber of hostile aircraftpresented (ordnance release is defined asa cpading within two kilometers of weaponposition for fixed-wing aircraft. Ordnancerelease is defined as 20 seconds after tajgetavailability for rotary-wing aircraft.)

Conditional Probability of Kill Given Fire (exressed in percent): Number ofaircraft credited as killed (hostile plusfriendly), divided by the total nmber of fireevents (trigger pulls)

9

Table 3

Schedule of Data ollection Activittes

Stirxie Low Log~rierKM Gro~W

AM: cMDPPO 1DPP4 MDPPO1M: MDPP4 MDIPPO WPP4

AM: M3PP4 MDPP0 momPM: MDPP4 MDPP4 MDPPO

StimD= high E~aerience CrWo=

3 0 Avr 1 May 2 MyAM: MPP4 NDPP0 NDPP4PM: MDPPO MDPP4 MDPPO

AM = 0900-1200 hrsFM = 1300-1600 hrs

Field h. Te AIT personmel were tested in the HIS during theirlast week of training. 7hey were brought to the HIS site by an instructor whoin no way interfered with the test or coached them during the test. TheSouthwest Asia veterans were brought to the site by USARI. When participantsreported either to the test site or to the transportation pick-up point, USARipersonnel briefed them in detail on the research, their roles in it, and thespecific tasks they would perform. An outline of the briefing given toparticipants is provided in Appendix A. All personnel were mers ofpreexisting tea. Teams determined their own individual duty assignments(i.e., team chief or gunner). Teams were assigned to weapon positions.

Typically, a new AIT graduate would riot be a team chief. Fbr purposesof this experiment, however, leader-gunner teams were a rituiruin. Sotrainees were chosen as "acting" team leaders. This did not prove to be aproblem, procedurally, since the trainees were knowledgeable and eager toperform as team chiefs.

Once at a weapon position, each data collector reviewed the engagementactions with his team and showed them their sector of responsibility, leftlimit, right limit, and primary target line (PTL). Each team was responsiblefor defending the same 90 degree search sector. Procedures were employed tokeep all weapon positions visually and aurally independent of one another toprevent cross cuing.

10

Each team received 13 data trials under onitios of MPPO and 13 underMDPP4. MDPPO and MOPP4 trials occurred in a group either during the marningor during the afternoon. The scdule of M!PPO and MDPP4 trials was

cucaa across days of the experiment as presented in Table 3. Priorto each rmrning e--d afternoon session a practice trial was run which containiedboth a fixed-wing and a rotary-wing aircraft. Participants received feedbackon their performane at the end of the day after they finished both the MDPPOand the MOPP4 sessions.

The same 13 scenarios were presented to all teame both in the MVPPO andthe MDPP4 sessions--but in a different --- erbalanced order. Thecotmterbalanoed ordering of scenario presentations varied both across sessionswithin a day and across test days. The cmteshamancin s wasconstrained by the practical necessity not to have two fixed-wing trials back-to-back (i.e., to save preparation time). The 13 test scenarios are describedin Table 4. These 13 scenarios presented the participating teams with avariety of aircraft targets. Scenarios varied in aircraft type, intent,model, number of aircraft per scenario, range, aspect angle, aircraft ingressazimuth, duration of availability, and level of difficulty.

All data were collected during Weapons Cxntrol Status Tight. This meantthat soldiers were required to make their tactical identification based uponvisual criteria (e.g., Soviet aircraft were hostile, US aircraft werefriendly). All trials were alerted.

Each trial began when the data collector gave the team a verbal alertingmessage. This message stated that air activity was inminent and reminded theteam of their Weapons OCntro1 Status (i.e., "%ed! Tight!"). The datacollector verbally signalled the end of a trial by alerting the team that thecurrent air attack had subsided ('"eturn to Condition Yellow."). Each teamwas instructed in the discrete trial procedure employed and reminded of thetrial-begin and trial-end signals.

Soldiers cxrpleted stress and workload questionnaires as part of fieldtesting. Me stress questionnaire (Self-Evaluation Qustionaire,Spielberger, 1983) was administered twice during each session-once just priorto beginning and again just after finishing each session. The workloadquestionnaire (TLX Rating Scales, NASA-Ames, 1986) was administerediummdiately after each data trial during both M)PPO aid M!PP4 sessions.

11

Table 4

Test Scenario Specificationm

Scen. No. A.C. Cl. Degrees KK Pres. Sec. Level of

No. Targ. Type Intent Model Az. Aspect Range Order Avail. Diff.

01 1 NW F A10 2i 45 ** - - Medium

02 1 NW F A7 1 45 ** - - Medium

03 1 NW H Su25 13 45 ** - - Medium

04 1 PW H Su2O/22 1 45 ** - - Medium

05 2 Mix H Su25 12 0 ** Simul - HighH Mi24 12 90 3.5* Simul 50 High

06 1 lRW F UH1 i1 270 3.5* - 50 Low

07 1 IW F AHl 12 315 3.5* - 50 LOW

08 1 1W F AH64 1 90 3.5* - 50 Low

09 1 1W H Mi28 11 315 3.5* - 50 LoW

10 1 1N H Ni24 12 90 3.5* - 50 Law

11 1 1W H Mi8 1 45 3.5* - 50 Low

12 3 1W F UH1 ii 270 3.5* Simil 100 HighIW F AHI 12 315 3.5* Simul 100 Highra F AH64 1 90 3.5* Siuul 100 High

13 3 RW H Mi28 Ui 315 3.5* Sinul 100 HighIW H Mi24 12 90 3.5* Simul 100 HighIW H Mi8 1 45 3.5* Simul 100 High

** Target becomes available for engagent at a ranue of at least 16kilometers. Target is within team's seardc sector but outside visualdetection ran=e. Target flies an irressing pattern until reacing iqekilometer fros team, then turns and flies back to base.

* Target rises from stationary, defilade position to become available forengagms-it, hovers for predetermined nmber of seconds, then returns todefilade position.

12

The procedrae followed during a data trial ws this:

"* Data collector shoxuts alert.

"* Team meers, sitting with their backs to the rang bet trials,stand up and take their positica--uner shoulders Stinger while team chiefsearce sector for aircraft.

* Upon detection of aircraft, team performs stadard tacticalengagemnt sequence including team chiief using binoculars to identifyaircraft-if a muzltiple target scenario, the engagement seq~Wn~ is repeatedanew for each target.

* Team searches sector for aircraft until data collector shouts redcexdalert status.

* Ginner returns Stinger to rack.

e Team menbers return to seats at weapn position.

* Finally, team cief and gunner cumplete workload auesticzmaire forthe trial just finished.

At the end of the test day, after all trials and feedback, soldiersweregiven an cutbriefing. (Time consraints prevented som soldiers fran beinginterviewed.) During this informal interview, both team dciefs and gunnerswere given an opportunity to express their opinions concernin the MDPP4clothing itself and their problems atteepting to engage aircraft while dressedin this clothing. The results of these interviews plus cervaticns by IMARItest perscmel are presented in Appendix B.

7he design of this experiment was a mixed factorial with two levels ofthe MDPP factor (0 and 4) and two levels of the experience factor (low andhigh). The MDPP factor was a within subjects mnipulaticn, with allparticipants receiving both the MDPPO and the IDPP4 caxnitians. Theexperience factor was a between subjects manipulation, with all participantsin the Low Experience Group being Afl trainees and all participants in theHigh Experience Group being veterans newly returned from Operaticns DesertShield and Desert Storm.

Air defense engagement tasks were expected to be performed less wellunder ccrditicxs of MVPP4 when coapared to the MDPP0 crnditicns. Air defenseengagement tasks were expected to be performed better by the High ExperienceGroup than by the Low Experience Group.

Participants were expected to report greater stress during the MOPP4conditicns when campared to the MDPPO conditicrs. Participants were alsoexpected to report greater workload during cditicrs of wearing MPP4.

13

imults

Zniagmea Performance

Data for fixsd-wing Task Nrfmne Measures (e.g., detecticn range,identification range, etc.) were aggregated across PW scarios (Scenarios 1,2, 3, 4, and the NW portion of 5) for each conditicn for each team. Data forrotary-wing Task Performance Measures (e.g., time from target available todetect, time fra detect to IFF, etc.) were agregated across 1W somnarios(Scenarios 6, 7, 8, 9, 10, Ii, and the first RW detected in Scenarios 12 and13) for each ocrdition for each team. Scores for each Task PerformanceMeasure were aggregated across similar scenarios (either FW or 1W by takingthe arithmetic mean of the engagement measures recorded in RaS.

Summary Performance Measures (e.g., percent aircraft detected, percentaircraft correctly identified, etc.) were calculated over relevant scenariosfor each cm-dition for each team. For example, NW percent aircraft detectedwas calculated over Scenarios 1, 2, 3, 4, and the FW portion of 5. *W percentaircraft detected was calculated over Scenarios 6, 7, 8, 9, 10, 11, 12, and13. For another example, FW percent fratricide was calculated over Scenarios1 and 2. 1w percent fratricide was calculated over Scenarios 6, 7, 8, and 12.For SPfs (but not TM) all three IW targets in Scenarios 12 and 13 wereincluded.

Engagement performance was analyzed by a mixed two factor Analysis ofVariance (ANOVA). The within subjects factor was MOPP level. 7he betweesubjects factor was experience level. one such mixed ANOVA was performed foreach of the measures of eage performa using the SPSS/PC+ AdvancdStatistics software package (Norusis, 1986, pps. B153-B181). 7he effect ofexperience was tested against between-subjects variability, while both theMOPP effect and the experience by MOPP interaction effect were tested againstwithin-subjects variability. Due to the relatively soall saxples collectedplus the notoriously large variability commo to applied field research, alphaprDabilities as high as ten percent will be reported for the ernagementperformance results. Due to the large number of masurmnts recorded,results (raes, times, pecetages) and analyses (1-ratios, p-values, etc.)will be presented in detail by conditios only where there were statisticallysignificant differences.

Data presented in tables are the arithmetic mean (Mean), the standarddeviation (=), and the number (Wi of data points (i.e., the numter of teams)upon which these descriptive statistics are based. It will be noted that thenumber of data points for NW targets is smaller than the number for 1Wtargets. Ths is because technical difficulties with the P1S prevented soteamsE fro being given the NW scenarios. No make-u ware possible due to thetight schedule of testing. 7he difference in ]a between the AIT sample and theSothwest Asia sample for the 1W scenarios (10 versus 12) reflects a loss ofdata for two teams due to rain.

Results for fixed-wirW aircraft: Task Perf-ornmice Measures. Positiveranges are inoxuing, negative ranges are outgoing. Generally, the greater theincoming ranges, the better the performance. The mean detection ra-ge overall conditions was 6.91 kilometers. 7he mean overall range for IFFinterrogation was 6.07 kilometers.

14

Table 5 presents weapon acquisition range for the aircraft as a functionof MPP level and experience level. mere was no effect of MDPP level [F(I,14) = 0.16, R>.10]. Acquisition range was significantly greater for the HighExperience Group (3.65 kilumeters) than for the ILw Experience Group (1.55kilocmeters) [E(1, 14) = 6.75, 2.10].

Table 5

Acquisition Range in Kilometers for Fixed-Wing Aircraft by Cnditicos

Low Experience High ExperienceStatistic MDPP0 MDPP4 MDPPO MCPP4

Mean 2.04 1.07 3.55 3.75

SD 3.26 2.88 1.60 2.03

S8 8 8 8

Note. Positive ranges are incning.

Table 6 presents identification range as a function of MDPP andexperience. Aircraft were idenrtified at significantly greater range undercnxditios of M)PPO (2.54 kilcmeters) than under cxzditims of MDPP4 (0.89kilcueters) [F(l, 14) = 7.10, p

Table 7 presents the range at weapon lock-on as a function of M)PP leveland experience level. There was no effect of HOPP level on lock-cn range(I(1, 14) = 0.09, R>.10]. Lock-on was, however, performed at a significantlygreater range by the High Experience Group (1.45 kilcawters) than by the lowExperierne Group (-0.97 kilan.ters) [(1, 14) = 4.61, R.10].

Table 7

iock-On Range in Kilcmeters for Fixed-Wing Aircraft by cOditions

Iiw Experience High ExperieneStatistic MOPP0 MDPP4 MPP0 MOPP4

Mean - 1.07 - 0.86 1.77 1.14

SD 3.04 2.15 2.69 2.64

N 8 8 8 8

Note. Positive ranges are inocming; negative ranges are outgoing.

Table 8 presents the range at fire as a function of MDPP and experience.There was no significant effect of MDPP level on fire range [E(i, 14) = 1.59,p>.10]. Fire was performed at a significantly greater range by the HighExperience Group (0.32 kilcmeters versus -1.85 kilaneters) [F(1, 14) = 3.46,R.10].

Table 8

Fire Range in Kilometers for Fixed-Wing Aircraft by Orditicns

Low Experience High ExperienceStatistic MOPPO MOPP4 MOPPO MOPP4

Mean - 1.79 - 1.91 1.13 - 0.49

SD 3,11 2.00 2.55 2.84

H 8 8 8 8

Note. Positive ranges are inxuing; negative ranges are outgoing.

16

Figures 1 through 4 display the EW aircraft ranges for rnggentevents. Figure 1 displays the results for all oxnditicos of the exerimen.Figures 2 through 4 display subsets of these results which highlight keyeffects implicit in the analyses described above.

Figure 2 shows the range of engagmnt actians for the MDPP0 versusM)PP4 couparison for data summed over both experm-ie groups. Performnce onthe identification task was significantly wrse under corditians of MDPP4.Figure 3 shows the range of engagement actions for the comparison between theLow Experience Group and the High Experience Grcup for data sumned over bothconditions of mDPP. Performance was significantly better for the HighExperience Group on the acquisition through fire tasks by a mean range of 2.22kilameters.

Figure 4 presents a cuparisn etween the low Experience Group in MDPPOand the High Experience Group wearing MOPP4. In this comr[aisan, the M)PP4cordition was not inferior to the MDPPO condition during any of the sixengagement tasks. That is, the perfomance of the High Experience Group inMDPP4 was not degraded relative to the Low Experience Group in NDPPO. Thsfigure provides an estimate of the extent to which the d-radationattributable to wearing MDPP4 can be alleviated by extensive experience.

Results for fixed-wina aircraft: Summavy Performance Measures. Themean percentage of aircraft detected over all conditicrs was 98.13. The meanccrditianal probability of a kill given fire summed over all conditions was63.81 percent.

Table 9 presents percent aircraft correctly identified (hostile plusfrierdly) as a functian of MDPP level and experience level. There were nostatistically significant differene as a function of HOPP level LF(I, 14) =0.75, R>.10]. Aircraft were identified correctly significantly more often bythe High Experience Group (81.87%) than by the Inw Experience Group (56.93%)[E(l, 14) = 17.11, R.10].

Table 9

Fixed-Wing: Percent Aircraft Correctly Identified by Conditions

Iaw Experience High ExperienceStatistic MDPPO MDPP4 MDPPO MDPP4

Mean 56.37 57.50 77.50 86.25

20.28 22.52 7.07 11.57

I 8 8 8 8

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Table 10 shows percent friendly aircraft correctly identified as afunction of MDPP level and experience. There was a statistically significantinteraction between MDPP level and experierne group [E(i, 14) = 9.00, 2

Table 11 shows percent hostile aircraft correctly identified as afunction of MDPP codition and experience level. Mimre was no statisticallysignificant difference in performance by MDPP level [E(1, 14) = 0.52, p>.10].The correct identification rate was, however, significantly greater for theHigh Experience Group [fE(, 14) = 10.26, R.10].

Table 11

Fixed-Wing: Percent Hostile Aircraft Correctly Identified by Conditions

low Exprience High ExperierKeStatistic MDPPO MDPP4 MDPP0 MDPP4

Mean 52.00 66.63 95.87 95.87

SD 43.17 39.92 ii.167 11.67

N 8 8 8 8

Table 12 displays hostile aircraft attrition aggregated over MDPPconditions and experience groups. There was no statistically significantdifference in attrition between MDPPO and MDPP4 [F(1, 14) = 0.15, R>.i0].Attrition was, however, significantly greater for the High Experience Grop(73.00%) than for the Low Experience Growp (32.31%) [((1, 14) = 7.89, R. 10].

Table 12

Fixed-Wing: Percent Hostile Aircraft Attrition by Conditions

I.w Experience High ExperienceStatistic M)PPO gOPP4 MDPPO MDPP4

Mean 27.13 37.50 75.13 70.87

SD 30.89 37.62 23.59 37.57

N 8 8 8 8

23

Table 13 displays the fratricide rate for frierdly aircraft aggregatedover the xitics of MIPP and experience. Fratricide rate was significantlygreater in MDPPO (37.50%) than in MPP4 (15.63%) [Z(i, 14) = 12.70, R.10], and no !PP by experienceinteraction [F(l, 14) = 2.33, R>.101.

Table 13

Fixed-Wing: Percent Fratricide by cmrditicns

low Experienc High ExperienceStatistic MDPPO MDPP4 MDPPO MDPP4

Mean 31.25 18.75 43.75 12.50

SD 25.88 25.88 17.68 23.15

N 8 8 8 8

24

Table 14 shows the percentage of hostile aircraft credited as destroyed("killed") prior to ordnanc release as a function of MDPP level andexperience group. (The ordnance release point for hostile FW aircraft wasdefined as two kilometers from the weapon position. Killing an aircraft priorto ordnance release was defined as firing early enough in the engagentsequence to alow the missile time to intercept the flight path of theaircraft prior to the incoming aircraft reaching the two kilometer point.)Mere was a significant interaction between )MDPP level and experience group[F((, 14) = 8.04, R

Results for rOt L-5dW aircraft: Task Perfo _-Ke MOMaSu .Generally, the shorter the egagemnt ti e, the better the performiuxe.Table 15 presents the time fram target available to detect as a function ofMDPP level and experience level. Detection times we significantly longerduring the MCPP4 conditiou (8.25 seconds) than during the N)PPO cordition(7.09 se s) [F(1, 20) = 6.44, p.10], and nointeraction between MDPP level and experience (fi(, 20) = 0.53, 2>.10].

Table 15

Time fram Target Available to Detection in Seconds for Rotary-Wing Aircraft byConditions

low Experience High ExperienceStatistic MDPPO MDPP4 MDPPO MDPP4

Mean 7.00 8.50 7.17 8.00

SD 0.82 2.37 0.72 2.05

N 10 10 12 12

Table 16 shws the time from detection to identification (ID) as afunction of corditions of MDPP and experience. Times from detect to ID weresignificantly longer in the MDPP4 condition (10.61 secns) than in the MDPPOcondition (8.83 seconds) [_f(1, 20) = 4.89, 2.I0], nor was there a MDPP by experience interaction [_F(1, 20) =0.02, p>.10].

Table 16

Time from Detection to Identification in secods for Rotary-Winu Aircraft byorlditions

lo Experience High ExperienceStatistic M)PPO MDPP4 MDPPO MDPP4

Mean 9.00 10.90 8.67 10.33

SD 2.31 4.75 2.15 3.U1

N 10 10 12 12

26

Table 17 displays the time from target detection to IF? interrogtion byconditicos of the experiment. Interrogation time were significantly longerin the MDPP4 condition (4.13 secds) than in the MOPPO cmditicu (2.99seomids) (F(1, 20) = 2.99, p_

nhe man tim from weapon a- dsition to lock-on 3n oer allcxnditi d was 4.09 seconds.

Table 19 displays the time from lock-cr to fire as a function. of MWPPlevel and experience level. Times were significantly longer for the 14DPP4condition (3.84 seconds) than for the MDPPO cKliticr1 (2.81 seconds) [E(l, 20)= 15.00, R.10].

Table 19

Tim frE Lock-On to Fire in Seconds for Rotary-Wing Aircraft by Conditicns

Low Experienice High ExperienceStatistic MDPPO MDPP4 IMDPPO MDPP4

Mean 3.20 4.60 2.42 3.08

SD 1.40 2.17 0.79 0.90

N 10 10 12 12

Table 20 presents the tum from identification to fire as a function ofMDPP level and experienc group. Times were significantly longer in the MVPP4cr-dition (8.60 seconds) than in the MDPPO condition (5.95 seds) [E(1, 20)= 6.72, R.10], and no interaction between MDPPlevel ard experiene [_F(l, 20) = 2.60, R>.i0].

Table 20

Tim fEln Identification to Fire in Seconds for Rotary-Wing Aircraft byCorditions

Law Experience High ExperienceStatistic MDPP0 MDPP4 MDPPO MDPP4

Mean 6.40 10.70 5.50 6.50

SD 3.50 7.33 2.94 3.03

N 10 10 12 12

28

Table 21 presents the cumulative time of the egagement frum detectionto fire by ccroditicns of the experiment. Times were significantly longer inthe MDPP4 oxndition (18.16 seounds) than in the KDPPO conditicn (14.10seconds) ([f(1, 20) = 10.22, Z.01]. There were no statisticaliy significantdifferences in times as a function of experience level [Y(1, 20) = 2.58,p>.1O]. Also, there was no MOPP level by experience level interaction IF(1,20) = 1.67, p>.10].

Table 21

Time from Detection to Fire in Secrmds for Rotary-Wing Aircraft by Ocrditicrs

Iow Experience High ExperienceStatistic KDPPO M1PP4 MDPPO M:PP4

Mean 15.20 20.90 13.00 15.42

SD 3.97 10.74 3.86 4.79

N 10 10 12 12

Suimarizing the results presented in Tables 15 thrulgh 21 it can be seenthat engagement actions required more time to be performed in MDPP4. Of theeight statistical tests of the MDPPO versus MDPP4 differene in performance(one test each for eight TR4s), seven met the criterion for statisticalsignificance. These differences can be seen when the results are presented ingraphic format. Figure 5 displays the MPPO versus MDPP4 comparisons for allTMs for data suemd over both experience groups. Of the eight statisticaltests of the low experience versus high experience differences in performance(one test each for eight TRPs), two met the criterion for statisticalsignificance. Additional experience served to reduce some eragent times.This experience effect, however, was not pruionced. 7hese results arepresented graphically in Figure 6 for data summed over both conditions ofMOPP.

An estimate of the effect of high levels of experience upon thereduction of the MEPP4 decrement is displayed graphically in Figure 7. Thisfigure presents all eight engagement action times for the Low Experience Groupin the MOPPO cronition, the Low Experience Group in the MOPP4 crxiition, andfor comparison the High Experience Group in the Ml'PP4 ocniition. Note thatthe High Experience Group in MOPP4 required less time than the Low ExperienceGroup in M)PP4 for seven of the eight engagnt actions. The High ExperienceGroup wearing MOPP4 required 5.48 seconds less time to perform the enagementsequerne from detection to fire than did the Low Experience Group wearingMDPP4-a reduction of the MDPP4 decrement by 96.14 percent. 2hat is, theMVPP4 decrent recorded for the Low Experience Grop was almost entirelyremoved by the employment of Stinger teams who had received high levels oftraining in and experience with the chemical protective ensemble.

29

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Two special Task Performance Measures were analyzed--ane each forScenarios 12 and 13. Scenario 12 presented three friendly rotary-wirg targetssiiultaneously for a total available duration of 100 seccnds (see Table 4).Scenario 13 presented three hostile rotary-win targets simultaneously for thesame duration (see Table 4). In each scenario, the task was to process allthree targets before they descended. hes two scenarios were chosen forspecial analysis because they were high-difficulty, multiple-target scenariosand, therefore, were expected to tax the Stinger tmE. Eah of the twospecial measures was a record of the total time in secods fra initial targetavailability until the last action was performed on the third target. Thatis, eadc of these measurs represents the total time required to service allthree simultanecusly-presented targets. The "last action" to be performedwould be a cease fire for a third target identified as friendly and a fire fora third target identified as hostile. It was hypothesized that this "timefrom available to last act" would be longer for the MDPP4 condition andshorter for the High Experience Group.

The mean time f available to last act for Scenario 12 summed over allconditions was 47.76 seconds. Table 22 displays the time from available tolast act for Scenario 13 for the conditicrs of the experiment. Times weresignificantly longer in the MDPP4 condition (59.34 seconds) than in the MDPPOcondition (51.61 second) ([f(1, 20) = 9.93, 2.10], and no interacticn between MPP and experience[f(1, 20) = 0.68, p>.10J.

Table 22

Scenario 13: Time from Available to last Act in Seconds by Oonditions

low Experience High ExperienceStatistic MDPPO MDPP4 MDPPO MDPP4

Mean 54.90 60.60 48.33 58.08

S D 10.43 13.98 11.04 12.78

N 10 10 12 12

Results for rotarvMn-W aircraft: Summary Performance Measures. Themean overall percentage of aircraft detected was 98.06. The mean overallpercentage of aircraft correctly identified (hostile plus friendly) was 72.48.The mean overall percentage of friendly aircraft correctly identified was57.91, while for hostile aircraft the percentage was 86.71.

33

Table 23 displays percent hostile aircraft attrition as a function ofMWPP level and experience. Significantly mre hostile aircaft were killed inMrPPO (84.78%) than in KD)P4 (64.99%) [Y(1, 20) = 13.05, .10], and no 14DPPby experience interactiaon [(l, 20) - 0.01, p>.10].

Table 23

Rotary-Wing: Percent Hostile Aircraft Attrition by Conditions

Low Eqperience High EerimenStatistic M!PPO MOPP4 MDPP0 MOPP4

Mean 83.30 63.30 86.25 66.67

SD 22.25 24.67 16.99 15.83

N 10 10 12 12

Table 24 presents the percentage of hostiles credited as killed prior totheir releasing ordnance by conditions of moPP and experience. (The ordnancerelease point for hostile 1RW aircraft was defined as 20 seccods fromavailability. That is, a hostile aircraft was assumed to be capable ofreleasing ordnance if not killed prior to 20 seconds frun availability. Inorder to prevent ordnance release the team mist fire at the taze earlyenough in the scenario to allow missile flight tine to target within 20seconds from availability.) The percent hostiles killed prior to ordnancerelease was significantly greater in MDPPO (28.01%) than in MDPP4 (16.79%)[f(1, 20) = 7.77, 2.10], and no interactionbetween M)PP and experience [E(1, 20) = 0.13, p>.0].

Table 24

Rotary-Wing: Percent Hostiles Killed Prior to Ordnance Release by conditions

Low Experience High ExperienceStatistic MOPPO MDPP4 MDPPO MOPP4

Mean 22.70 10.00 33.33 23.58

SD 26.15 13.97 20.05 17.96

N 10 10 12 12

34

7he mean fratricide rate over all conditions wa s 36.39 percn. 7hemean crditicnal probability of a credited kill given a fire was 97.20percent.

lbe stress questicmire (Self-Evaluation Qestomaire, Spielhexger,1983) was administered twice during each sessicn-une just prior to beinningand again just after finishing each session. 7he Iarm-49hitney.U test forbten r. icparison and the Wilomon T test for within-groupcmarsons (B&ning & Kiztz, 1977) were used to analyze the stress ratingsgiven by the Low and High Exqerience Groups. on three of four ocntrasts, theIw and High Experience Groups differed significantly froE each other inreported stress levels (see Figure 8). Prior to MiPPO and IDPP4 trials and atthe conlusion of MDPP0 trials, the stress levels reported by the LowEerience Grou wre greater than those reported by the High Eqeriene Group[Pretest HDPPO: V(24, 24) = 122.5, R

T experience by HOPP [!(1, 30) - 0.39, 2>.o5], aepriffK2 by mseariodifficulty [Z(2, 60) = 1.17, p>.05], and EPFP by scomwro difficulty [f(2, 60)= 1.00, 2>.05] werrs e t significant. Hwever, the eT erience byMDPP by scenario diffioulty inter was significant (X(2, 60) - 3.47,2

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Ej-wij aircraft. 7he only statistically significant effect ofwearing MPP4 an NW task perf was to delay ide.ificati range by 1.65ki t . 7his decemnent in identification range could have been caused bythe difficulty team chiefs re;orted (see Appemdix B) in attespting to identifyflying aircraft with binoclars wile wearing the mask. It bas already beenreported (Harrah, 1985) that the mask-birxwlar interface produces a narrowfield of view. This narrm field of view makes tracking a vansnrmerr, flyingaircraft difficult. In addition to this tracking problem, team diiefsreported double images. In an attempt to alleviate the double-image problem,team dciefs closed one eye or otherwise used only ame optic of the bintoulars.

7he overall effect of high experience was to imprvve the range at hidcheigagan et events took place. Of the six engagement actions measured, theranges of four (acuisition, identification, lock-cn, and fire) were greaterby a statistically significant amount for the High Experience Group. The meaniuprovement for these four tasks was 2.22 kilcmeters (see Figure 3). Notethat this In attriutable to inrieased experience did rot occur earlyin the engagement sque (detection), where performan is stronglyinfluenced by visual sensitivity (Barber, 1990c), but later (acx1isiticnthrough fire) where performance may be more strongly affected by increasedknowledge, training, and skill.

Also, the High Experience Grau identified both friendly and hostileaircraft more accurately, killed more hostile aircraft, and killed a greaterpercentage of these hostile aircraft prior to ordnance release. 7=s, theHigh Experience Graop were both =ore efficient and more effective atperforming their engagement tasks than the LIA~ Rqrience Grou~p.

By providing Stinger temwith extensive experieeras wearing andtraining in the MDPP4 cheica1 protective clothirq, is it possible to reducethe deradatict in performance attributable to MDPP4? 7he arnwr appears tobe a qualified yes. Compare the performance of the High Experience Group inMDPP4 with that of the Lnw Experience Group in MPPO (see Figure 4). Theperformance of the experien- group in M)PP4 show no degraatin whatsoeverrelative to the novice group in MDPPO. This cncclusion is qualified, however,by the fact that these to groups of soldiers were dcosen as the cpportunityarose and, therefore, were not matced on all potentially relevant criteria.

BgZ-d i~f.Overall, the effect of wearizq !CPP4 was to:ease the tim r e for an engagemet. of the eight engagement action

recorded, seven required statistically significantly -ore tim to be perforumedwhen wearing MDPN (see Figure 5). Over the engagemt seq ce frmdetection to fire, the extra time required for the M)PPN cotdition was 4. 06seconds (see Table 21). This was a 29 percent increase (4.06 / 14.10 - 0.29).

39

Further, waring PP4 har me the ew mn-t efficierny of both the teamchief and the gunner. The engagement period detect to identify was entirelydeperdent upon the time taken by the team chief, using binoculars, to identifythe target. The enpge ent period identify to fire was entirely deperdentupon the gunner. The effect of wearing MDPP4 was to increase the timerequired by both memrs of the team. There was no eviden in these datathat the effects of wearing MDPP4 were limited to a single "bottleneck' in theergagant sequenc.

Specifically, what was it about wearing MPP4 that caused thisdegradati in eag penrformia? 7he increased time F availableto detect was most likely caused by the restricted field of view of the mask(Bensel et al., 1987; Kcbrick & Sleeper, 1986). 7he increase in detect toidentify time could have been caused by the difficulty team chiefs reported(see Appendix B) in attempting to use the binoculars with the mask. Teamchiefs reported a double-image problem with consequent visual disorientationand "solved" it by using only one eye. This could have delayed identificationof the RW aircraft which, being 3.5 kilometers distant, were not identifiablewithout magnification.

At least part of the increase in time from identify to fire could havebeen caused by the difficulties reported by gunners (see Appendix B) inattempting to use the Stinger sight reticle while wearing the mask. Gunnersreported difficulty acquiring aircraft in the reticle while wearing the mask.Perhaps more importantly, gunners reported difficulty inserting superelevateand lead angle because the mask prevented them fram seeing the superelevateand lead reticles in the sight. This interpretation is supported by thesignificant increase in times froE lock-on to fire shown for the MDPP4condition (Figure 5 and Table 19). Insertion of the superelevate and leadangle takes place, between lock-on and fire. Thus, it is a reasonableassumption that the primary cause of the performance deqradation shown for RWaircraft in this experiment was the mask.

Under conditions of MDPP4 the percentage of hostiles killed was lowerand the percentage of hostiles killed prior to ordnance release was lower.These results can be explained in terms of the increased time requir. forengagements in M)PP4. The more time the erqagsent sequence requires, thegreater the probability that the hostile aircraft will have released itsordnance and then have returned to its defilade position, thereby beingunavailable to kill. Thus, wearing MDPP4 harmed both engagement efficiencyand engagement effectiveness.

Stress And Workload

Compared to the M)PPO ondition, participants reported both greaterlevels of stress and greater levels of workload when wearing the dcemicalprotective clothing. This was true both for the Low Experience Grcup and forthe High Experience Group.

40

The statistically significantly different stress ratings given by theLow Experience Group prior to MOPPO and MOPP4 trials and after MVPPO trialslikely reflect their minimal experience, their uncertainty about acting as ateam, and also their apprehension about performing in the chemical protectiveclothing. The non-statistically-significant stress levels reported by bothgroups at the conclusion of the sequence of MOPP4 trials may suggest thatwearing MOPP4 gear is a stressful event regardless of the extent of priorexperience with the clothing.

The higher workload reported by both the Low and High Experience Groupswhile wearing MOPP4 gear appears to have as its source the reduced field ofview created by the chemical protective mask. The lenses of the gas maskproduce a stand-off prcblem for both the team chief and gunner which reducesthe field of view when the mask is used in conjunction with the MI9 binocularsand Stinger sight. The reduced field of view makes it much more difficult toperform the tasks of the engagement sequence such as detecting, tracking, andidentifying targets.

Although the rubber gloves initially interfered slightly with manualdexterity, they did not appear to create serious problems for either the teamchief or gunner. The overgarment and boots were reported as beinguncomfortable and awkward, but again, they did not produce serious orpersistent problems for the teams.

Examination of the statistically significant interaction of experience,MOPP level, and scenario difficulty (see Figure 10) revealed that the level ofworkload reported by the High Experience Group increased as scenariodifficulty increased under both clothing conditions. This was not true forthe Low Experience Group, however. Under conditions of MOPPO this groupviewed the low and medium difficulty scenarios as being of equal andrelatively low workload, while under conditions of MOPP4 they viewed all thescenarios as being of nearly equal and relatively high workload.

These results are understandable when one takes into consideration thatthe soldiers in the Low Experience Group were working together as team chiefand gunner for the first time and that they had minimal training in thechemical protective clothing. In this experiment, the soldier of lowexperience who was not encumbered by a gas mask found one target scenarios,whether they consisted of fast moving or static scale models, to be equallyeasy. However, when encumbered by the gas mask and handicapped by the fieldof view problem it created, this same soldier found the engagement of alltargets in all scenarios to be relatively difficult.

However, neither the behavior of the participants during thisexperiment, nor the resultant data suggest that the amount of stress andworkload experienced by either group was excessive. All participants finishedthe sequence of MOPP4 trials uneventfully. No individual needed to remove hisprotective gear during the sequence of trials nor did anyone request to bewithdrawn from the experiment. It is very important to recall here, however,that these data were collected under benign environmental conditions whereparticipants were not subjected to heat stress, to movement stress, or tosustained operations.

41

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The engagement performanoe of Stinger t as as deraded by wearing theM)PP4 ceiical protective ensemble. The visual identificaticn. range forfixed-wing aircraft was dreased by 1.63 kilcmaters. 7he tim required tocomplete an engagement of a rotary-wing aircraft was increased by 4.06 sec&ndsor 29 percent. Wearing the d=ical protective clothing adversely affectedthe perfor-a-ce of both team chiefs and gunners. ie article of mDPP4clothing responsible for this reductian in engagazent efficiency was judged tobe the gas mask.

Stinger teams were less effective in performing their air defensemission while dressed in MDPP4. Mm en ergaging rctary-wing aircraft udercorditicns of MDPP4, Stinger teams killed a lower percentage of hstilesoverall and killed a lcoer percentage prior to ordnance release.

The engagement performance of the High Experience Group (veterans ofOperations Desert Shield and Desert Storm) was better than that of the LowExperiene Group (AMT trainees) both in MDPPO and NDPP4. The overall eff etof high experience on the ernagement of fixed-win aircraft was to increasethe range at which engagement events occtred. 7he veterans acquired,identified, locked-cnto, and fired at fixed-wing aircraft an average of 2.22kilometers earlier than the trainees. This hip rovement in eragementefficiency was attributed to their extensive training with and experiencewearing MDPP4. The veterans also performed their air defense mission moreeffectively by identifying aircraft more accurately, killing a greaterpercentage of hostiles, and killing a greater percentage of these hostilesprior to ordnance release.

Reported stress levels were higher when Stinger teaus wore MPP4 thanMDPP0. Reported workload levels were higher when Stinger teaus wore MDPP4than MDPP0.

43

References

Barber, A. V. (1990a). Short Rance Air Defense (SHORAD) enqgagentperformance criteria development and validation (ARI Research Note 91-06).Alexandria, VA: U.S. Army Research Institute for the Behavioral and SocialSciences. (AD A229 197)

Barber, A. V. (1990b). Range Target System (RTS) operations manual (ARIResearch Product 91-01). Alexandria, VA: U.S. Army Research Institute forthe Behavioral and Social Sciences. (AD A230 095)

Barber, A. V. (1990c). Visual mechanisms and predictors of far field visualtask performance. Human Factors, 32(2), 217-223.

Bensel, C. K. (1980). A human factors evaluation of two types of rubber CBprotective Qloves (Technical Report 80/005). Natick, MA: U.S. ArmyNatick Laboratories.

Bensel, C. K., Teixeira, R. A., & Kaplan, D. B. (1987). The effects ofUS Army chemical protective clothinM on speech intelligibility, visualfield, body mobility and psychomotor coordination of men (TechnicalReport Natick TR-87/037). Natick, MA: U.S. Natick Research Developmentand Engineering Center.

Berry, M. G., & Barber, A. V. (1990a). Ranqe Target System (RTS) operationsmanual: Annex 1: Pop-Up Target System (PIS) operations and maintenancereference manual (ARI Research Product 91-02). Alexandria, VA: U.S. ArmyResearch Institute for the Behavioral and Social Sciences. (AD A230 096)

Berry, M. G., & Barber, A. V. (1990b). Range Target System (RIS) operationsmanual: Annex 2: Flyino Target System (MTS) operations and maintenancereference manual (ARI Research Product 91-03). Alexandria, VA: U.S. ArmyResearch Institute for the Behavioral and Social Sciences. (AD A229 890)

Bruning, J. L., & Kintz, B. L. (1977). Computational Handbook of Statistics.Illinois: Scott, Foresman and Company.

Drewfs, P. R., Barber, A. V., Johnson, D. M., & Frederickson, E. W. (1988).Validation of the Realistic Air Defense Enraqement System (RADES) (ARITechnical Report 789). Alexandria, VA: U.S. Army Research Institute forthe Behavioral and Social Sciences. (AD A198 289)

Field Manual No. 44-18-1 (1984). Stinqer team operations. Washington, DC:Headquarters, Department of the Army.

Glumm, M. (1988). Physioloqical and psychological effects of the NBCenvironment and sustained operations on systems in combat (PNBC):Tank systems climate controlled trials (Iron Man) (TechnicalMemorandum 9-88). Aberdeen Proving Ground, MD: U.S. Army HumanEngineering Laboratory.

Harrah, D. M. (1985). Binocular scanning performance for soldiers wearingprotective masks (Technical Memorandum 14-85). Aberdeen Proving Ground,MD: U.S. Army Human Engineering Laboratory.

45

Headley, D. B., Brecht-Clark, J., Feng, T., & Whittenburg, J. A. (1988).The effects of the chemical defense ensemble and extended operations onperformance and endurance of combat vehicle crews (ARI TechnicalReport 811). Alexandria, VA: U.S. Army Research Institute for theBehavioral and Social Sciences. (AD B131 688)

Johnson, D. M., & Silver, J. D. (1992). Stinger team performance duringencrapement operations in a chemical environment: The effect of cuing (ARITechnical Report 957). Alexandria, VA: U.S. Army Research Institutefor the Behavioral and Social Sciences. (AD A254 524)

Johnson, D. M., Barber, A. V., & Lockhart, J. M. (1988). The effect oftaret backqrouq d and aspect angle on performance of Stinger teams inthe Realistic Air Defense Encaqement System (RADES) (ARI TechnicalReport 822). Alexandria, VA: U.S. Army Research Institute for theBehavioral and Social Sciences. (AD A207 283)

Johnson, R. F., & Sleeper, L. A. (1986). Effects of chemical protectivehandware and headgear on manual dexterity. Proceedings of the HumanFactors Society 30th Annual MeetinM, Dayton OH, 2, 994-997.

Kobrick, J. L., & Sleeper, L. A. (1986). Effect of wearing protectiveclothing in the heat on signal detection over the visual field.Aviation, Space, and Environmental Medicine, 57, 144-148.

NASA-Ames Research Center, Human Performance Group (1986). CollectinM NASAworkload ratings: A paper-and-pencil package (version 2.11. Moffet Field,CA: NASA-Ames Research Center.

Nixon, C. W., & Decker, W. H. (1985). Voice communications effectivenessof the all-purpose MCU-2 chemical defense protective mask (AAMRLTechnical Report 85-050). Wright-Patterson Air Force Base, OH:Armstrong Aerospace Medical Research Laboratory.

Norusis, M. J. (1986). SPSS/PC+ Advanced Statistics. Illinois: SPSS, Inc.

Posen, K. J., Munro, I., Mitchell, G. W., & Satterthwaite, J. S. (1986).Innovative test of physiolocical and psycholocical effects of NBC andextended operations on Mechanized Infantry Squads (TRADOC ProjectNo. 0000663). Fort Benning, GA: U.S. Army Infantry Board.

Spielberger, C. D. (1983). State-trait anxiety inventory: Form Y. PaloAlto, CA: Consulting Psychologists Press.

U.S. Air Force TAWC. (1981). Shooter qualification standard for M-60machine gun and M-16 rifle while wearinct defense equipment (FinalReport). Elgin Air Force Base, FL: U.S. Air Force Tactical WarfareCenter.

46

outline of Burild2=n Brainfax

1. o we are: USARI.

2. eat we do: Applied hzmri performanB research related to perfonaceevaluation, trainirg, aptitude I, and WMS classificaticn.

3. Present project: ollect Cram data from Sting te underc-oditicrs of wearing or not wearing chical protwtive clothing. Data willbe collected in th Range Target System. Proponet for this research isDirectorate of Cmtbat Developnents, US Army Air Deferne Artillery School.spaiso for this research is Directorate of Omaat Dwelpa.ts, US ArmyCln ical School.

4. Your job:(a) Engage aircraft using the Stirger T-I under cuditicns of EPpo and

!VPP4.(b) Fill out self-evaluatirn, qestkinaire and workload questicrmaire.

5. Mat is RMS? Egagmnt simulation. Air defenders, with their airdefense weapon syste, in field envIrmnI, in simulated egagemnt ofsubscale friendly and hostile fixed-wivi and rotary-wirg aircraft. Weaponsare connected to P ,S couputer maork. Gunner events recorded a ticalyvia voltage taps n key weapn pins. Team d f verbal respunses (detect, ID,cc.mInd engage, or cease engagumet) recorded by data collector at weaponposition. Data collected are ergagment tie, enagent rages, and percentcorrect actions. Laser Position Ication System. stinger missile math model.Give examples of perf-rmance measures.

(a) Fixwd-wir, targets are flying scale models of US and Soviet attackjets.(b) Rotary-wing targets are static scale models of US and Soviet attack

and utility helicopters, which ppc- from behind sand dunes, hover with rotorturning, and descend.

6. Weapon position: 7here are forr separated weapon positicon. Each team isresponsible for 90 degree search sector. Ieft sector limit, right sectorlimit, and primary target line are marked. At each position: Ome team chief,one gunner, cne Stinger '1' cabled to MIS, and one data collector. Datacollector is in communication with MIS Control. Data collector is not on yourteam, has a jab to do, and will not help with your engagement.

7. Trials and procedurs: TWO data collection sessicns in a day (one sessionin AM, one session in PM; one session is M1PPO, one session is M)PP4).Thirteen data trials and Mat practice trial per aessicn. Always aircraft in atrial, no false alarm. Aircraft always in youw search sector, no deatirg onowr part. We are only here to measure your performance wearing mKPPo andMDPP4.

(a) You will be in weapons cotrol Status Tight: Positive visual IDrequired. Hostile criterion is aircraft origin; us mdels are friendly,Soviet models are hostile. Use aircraft siflhoutte for visual ID.

A-1

(b) Trial limits:- Trial begins with alert message from yoar data collector ("Red

Tight") - Trial ends with chre in alert status fro your data collector

(,I"trn to Condition Yellow$').- Betwen trials put Stinger TM dmn, sit with backs to range,

fill out work a ti aire.(c) Aircraft:

- On any given trial you can expect to see fixed-Win, rotary-wing, or a mix of the two; friendly or hostile; single or multiple.

- Scenarios have been dcsen to vary frca easy to difficult.- Reeer to continue searching for aircraft until your data

collector tells you that the trial is over.

8. Responsibilities:(a) Team Chief:

- Detect plus clock azimuth plus point (say 'Target, 12 o'clock"and point with free hand). Do riot use binoculars for detection, they willharm your perf-- .

- Visual ID, tactical ID (say "hostile" or "friendly"). Usebinoculars for ID.

- Enag-ent or cease engagement commard (say "engage" or "cease

- Control your gunner. It is your responsibility to band offtargets to gunner, to control the engagement, to be certain your gunner isengaging the target you have identified.

(b) Gunner:- We want a complete engagement: IFF interrogation, Stinger

activation, track, acquire, lock-on, superelevate, fire, or cease engagement,depending upon ID.

- One fire only per hostile target. Remember to recycle batterybetween target eingagements.

- You are under team chief' s control. Do not engage any targetuntil ordered to do so.

(c) Both: Hand off targets to each other. You are a team, worktogether. If gunner detects a target before team dcief, hand it off to teamdcief. If gunner krows aircraft ID, tell team dcief.

9. Questionmaires:(a) You will fill out two questionnaires-the self-evaluation

questionnaire and the workload questionnaire. Give them examples of both.(b) MTis is the self-evaluation questionnaire. It contains a series of

statements. After reading each statement, you will decide how well itdescribes what you are feeling at that particular moment and fill in theappropriate circle. You will fill out this questionnaire four times, beforeand after both the MOPPO and MPP4 sessions. Do exmzple. Questions?

(c) Thds is the workload questionnaire. We are going to ask you tofill out one after every trial today. You will see a line below trial rumberfor scenario number. At the end of each trial, the data collector will tellyou which scenario it was and you will place that rzter on the line. Usingthis questioinaire, we are asking you to tell us how nxh workload youexperienced on that particular trial along six dimasians--mental demad,physical demand, teaoral demard, prfomance, effort, and frustration. Placean "'I on the appropriate line along the scale for eadh dimension. Doexample. Questions?

A-2

10. Feedback: Yo. will receive feedbadck an ya= psrftance at the end ofthe day's activities, not trial by trial.

11. Safety: You are in the desert, so drink water wbether you feel thirstyor not. If you nm cut of water we have more.

12. Anorrymity: All research results are reported by unit designatia oly.Your personal anonymity is assured.

13. Questionse?

14. Travel to weapon positicns. Introduce each team to their data collector.Show team left and right sector limits and primary target line.

A-3

4

Performa.nc Problems in MDPP4: Cmervations. Opinicns of Soldiers. and "Work-Around" Solutions

M40 Mask And Hood

Problems usIM M19 binoculars with mask. AUl team chiefs interviewed(more than half were interviewed) reported prblem using the binoculars withthe mask. Mwey reported tumnel vision; double vision; visual disorientation;difficulty tracking maneuvering aircraft with the small field of viewavailable; cannot get the binoculars close enough to their eyes; eyepieces ofbinoculars slipped on surface of mask eyepieces. One of the authorsexperienced all of these problems when using the binoculars with the mask.The '"ork-aroud" solutions employed by team chiefs were to (1) close one eye,(2) close one eye and only look through one optic of the binoculars by turningthem sideways, or (3) not use binoculars at all.

Problems using the St=r siog with ask. AU gunners interviewed(more than half were interviewed) reported problems using the Stinger sightwith the mask. They reported difficulty tracking manaiverin aircraft withthe tiny field of view available; cannot get the sight close enough to the