/J/ J i... C ., '/ -~ I 

HUMAN FACTORS ASPECTS 

OF LIGHTPLANE SAFETY 

RICHARD G. PEARSON, Ph.D. 

Chi<'/, Engineering f'.,ychulogy Section 

Psychology Branch 

FIIA:1- A.M - 63-35 -----·-

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/ 

I 

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FEDF..R.\L AVIATION AGENCY 

CIVIL AEROMEDICAl. Rt:SEARCII INSTITtJTE 

Af.RONAUl'ICAL CENTF.R 

OKLAIIOMA I:IT\', OKLAIIOMA 

DECE:YIBER 1963 
HUMAN FACTORS ASPECTS OF LIGHTPLANE SAFETY 

RICHARD G. PF.ARSOS. Ph.D. 

ABSTRACT 

This paper attempts to relate aircraft accidt"nt investif,t:at1on and aeromedical research 

efforts for the purpose of clo.rifym~ research needs. Such efforts ultimately can lead to a reduction 10 lightplane accidents, in)unes. and fatahtles Rt"l.'cnt !.tatlstlcal stud1es of 

lightplane crash injunes are summarized, and contnbutions that human biologists, phys1cal anthropolo~asts. and design en~ineers can make toward rt>ducmg or prevcntmg amury in 

future crashes are d1scusscd. Programs of biomedical and human f'ngmeermg research as they relate to hghtplane saiety are·described. Contnbutions •.hat vhysicaans can make to 

this pro~ram are outhne-d. 

,, 

' i Human factors scienti,ts are conterned with Contributions that human factor>, en~incer

the man, machine. :1nd envi;onmentaJ compon· dt"siJ:n. and flight~ standards ~(lel'iali!->b 

ents of a system a,; they interact and. determine make to lilihlplant• -afetv are not oftt'n appa

performancf'. ln!-iofar as romponent intrract!on to tho~t" nnt ,,·ur~ill~ in tht" an•a, Thr pro

is non-optimal. lolal svstfm performance will ~ h~ "hi<'l1 ,.. •• , ...... h and d.-,elopment t>fforls 

I.e inefficient. In the case of private flyinJ:, to / lran-l,tlt•d "·'" 1lw f~:nlalton, modificat

the extent that sy.tem performanee is in~ffici/ and up~radin;: of >landi'rtl" is a dt•liherate 

ent. correlated by-products in the form of acci- Thi> papt•r \.a, written wilh the hope tha

dents and incidents can he expected. !'resenth· bt'llt•r inte~ralinn of .the i~t,·e>ti~:atorv and 

prevailin~ rates of li~:h•.plane accidents and in· sean·h aspt-.·ls of lii!htplane safety could 

cidents.,nd the resulting fatalities and injuries realizl-d. It is an attempt to rdate th.- inves

constitute a challen!!e to human factors scien- tnrv to the rest'llrrh .. Hort for the purpo.e 

lists within the F'ederat Avialion A!\enc:y. darifvin;: 'IJh;:oal> whit·h ultimately ran 

.. 

Portion' o( lhi" IJ&I.er -.~rl' t•r~-.enle•l al the annual mf"~t· 

ing, t'l~ in~t l'hy .. iriaoo. Ato!>ocialwn. Jrkyll f,.bnd, (;a .• 

· Ault:!ll j{), 19f.J'l. 

lo a n~(hu·tion in li:.:ht}~lant" acculenb~ inju

and fatalilie-. In thi, allt•mpl the paper 

focus upon contrihutions !hat the c;,·il A

nwdi<·al Rt·..._·~rch l:tstitule 1 CARl) and o

tfi,·isions of th<' Fo\.\', Offit·~ of Aviation ~l

cinr art'" rnakin~ or ('f.lll rnakf' toward the 

male goaL 

-1-
lion of how the inve~tigatory and r~~ean:h 

efforts rnip:ht lw meaniugfully int<•grah'd a~ ont~ 

proceed~ from the t·ra~h en·ut ibelf to tht• ulti. 

mate gcal. cra:-.h and injury prevention. which 

;ncidentally is the only desiralole product of 

that event. Thi~ !:'ichema can also suffiec as an 

outline for tloe dis<'ussion to folio••· Starlin~ 

with the crash itself the investi~ation of the 

cause of the crash is~ in most aeddents. normallv 

carried forward apart frnm that of the injtu·;· 

and fatality causes. Independent statistical and 

~ase studies of the t•aust• nf the crash and of 

the injuries hopefully yield '"Re>ttlts" from 

which uconelusipns '~ and HRt•commendatinns H 

are ~Pnerate.:l in the an•as noted. The>e end pro· 

duel• provide. in part. the jt .. tification for the 

research scientists" endeavors and the require. 

menls that operations personnel must seek to 

ohtain. The extent to which these indt•petulent 

efforts can be inte~rated upon implementation 

bears upon the de!(ree to which the l(oal of nash 

and injury prevention can loe achie,·ed. 

INVESTIGATION OF THE 

CRASH EVENT 

Let us now he~in to consider the parts of the 

schema in greater detail. First of all. what are 

the sub~oals about which information is required from investi~ation of the crash event? A 

not unrelated question asks: Can prospectivf' 

gains be better realized and b<; 1better inte!(rated? 

The Cause. of the Cr!uh 

-~ lnvestigat'ion into the cause of civil lightplane 

crashes falls within ihe jurisdiction of the Civil 

Aeronautic,; Hoard. Often authority is tlele;:ated 

to the FAA which ~rovides inve~i!(ators out of 

Disllict Offices. Yarious elem~ts of the FAA 

are, of course, intimately corlernf'd with cat:s• 

alive aspects insof-.• as aircraft design. maintenance, navigational aids, pilot pro,ficiency or 

air traffic control involvement are implicated. 

When "pi!'lt error" is suspected, data from the 

investitatinn become of primary interest to the 

Aeromedical Standards Division of the Office 

of Aviation ~ledicine and also of interest to 

certain offices within the Flight Standards 

Service. In tum there may be consultations with 

CARl if environmental toxicities. drugs, poor 

ture. or with the ,\rmt•d 

Patholo~y ur FA:\ cou:-

pn•-erash patholol(y (as i

attack) is likely to have b

The Calise of Inju

Research effort t·xpend

proiJit•ms of crash injury 

known and documented a

devoted to problems of <

27, 49, 51, 52, 5:l, 51). 

affairs ear. he attrilmtPd 

based upon hil!h perform

reason most often dictate·~ 

mandatory if critit·al inj

I.e avoided. ~IiI itarv a

<•fforls ~t·nerallv ha,;. no

the kinds of prololems r~I<

accidt•uts and injurit'~. :

lt-ms of prevt:•nting ain-raf

haps loesl idenllfit•d with 

R~st'arrh. Olll'e part of C

AvSEH division of Fli~h

(6, 7, 8, 16). The dec

Colonel Stapp and a>Soci

and of the NACA are co

m·erlooked (9. 25). The C

Research Labnratorv of t

incorporated into FAA's C

crash fire. resent>, and ev

conducted &nd sponsored 

Standard• Sen·ice. With 

liJ!;htplancs in the U.S.- Ar

o! Aviation Accident Rt

creasin~ly conrerned with 

jury prcveulion. 

A general picture of 

jurieUt li!(htplane ac<"id

individUal accident case a

last 20 years. Injuries ar

to primary crash forces 

factors that are indirectl

forces. principally slructu

failure, and flailing of th

against injury·producin!( 

oceupant's environment 

from this work was know

r'elationships loelween the 

impact, structural collap

fectiveness, and injury 

statistical studies conduct

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FIGURE I. SCHEMA FOR LIGHT PLANE CRASH/ INJURY PREVENTION STUDY 

I 

INVESTIGATION 

RESEARCH 

IIIPLEMEN TA TION 

1 

I EDUCATION i 

I • 

·,/ 

CRASH 

AND CASE 

' j 

CR INJURIES 

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pg qp

based upon over 1400 accident cases now permit more specific statements ( l S, :36, 37, 38). 

Tab!, 1 tabulates statistics that bear upon the 

role played by tie-down chain cor>ditions in 

causing or preventing injury. The dda come 

from a study of 623 cases repr~senting pilots 

and occupants of 342 aircraft involved in accidents occurring during the period 1953-1960 

(38). Analyses were limited to those cases invnh·ing spin-stall crashes or collisions with th~ 

ground while in fli~ht. Data from accidents in 

which the aircraft burned, crashed inverted, or 

cart-wheelt·d a '!cr impact were not used. Excluded from consideration in this study were 

cRses involving collapS'l of major structures adjacent to an occupant's seat and in which there 

was evidence of impact upon the front seat from 

rear-seated occupants. This was done to control 

for conditions likely to cause injuries beyond 

those attributable to tie-down failure. 

As shown in Table 1, statistical comparisons 

were made between six subgroups: one in which 

occupants did not use seat belts; a second in 

which seats tore free; a third in which the seats 

held but the belt was torn, its anchorage failed. 

or its buckle slippffi; a fourth in which belts 

and seats did not fail; and a fifth in which the 

shoulder harness was uied and effective in addition to belts and seats not failing. The sixth subgroup was comprised of 15 occupants whose 

all of whom were thrown 

at or after impact. 

One encouraging fact emer

of Tahle I is that. over al

>everity is consideraf,ly le

from comparahle studies of 

ing the period 19·!2-1952 ( 3

nine percent of the occupan

harne~s as compared with o

earlier data. Those wearin~: 

least sev~rely injured; in fac

ed injury aho;:ether. This fig

pared with the three perce

whose seat failed and the 1

those whose hell failed. The 

provide further support for 

ive tie-down and restraint. 

Contrary lo the earlier fi

occurred more fre<JUentlv tha

Belt failures represented on

recent cases as contrasted wi

earlier cases. Seat failures 

They represent 12.4 percent 

only 9 percent of the earlie

there was an increase in the 

in which tie-•lown could he 

- from 67 percent for the 

77.2 percent for the 1953

occupants, 2.4 percent of the 

use of their seat belt - a s

,, 

i TABLE 1 

.Relatio~;~ of Tie-Down Effectiveness to Sustained Inj

! Hatness, Seat, and Belt Tie-Down 

I. 2. 3. 4. 5. 

·,/ / Harn~"'~ Srata~~at lleh Belt 

) H<id lkh He ·Failed Failed ~ot 

l ' .. f'd 

Number of Obseryationl!< 55 426 77 50 15 

Percentage of Total 8.8 68.4 12.4 8.0 2.4 

PM~entage Fatal 

' 6 II 19 20 27 

Percentage Uninjured I 36 28 .3 16 33 

Cranial II* 8 17 26 27 

~Area Brain 24 22 45 36 33 

Facial Bones 9 13 17 16 7 

of Upper Torso 11 .15 30 22 20 

Injury Lumbar Spine 11 ll 19 10 7 

Upper Extremities II 9 19 24 13 

Lower Extremities 25 22 40 44 13 

• \'alue-e indtcate per<'entalte of total number nf uc"('upant• w1lh1n column reren1na IRJUfY 

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rate of 4.2 pt•rcent found previously. Of 

142 oecupants t•xperieneinf!; tie-down faitor not usinp; ~eat bt>lts~ I 3 f f1r I O.h pern•nt) 

were thrown out of the aircraft - a decn~ase 

,from the rate of 17.:l percent found in the 

earlier data. 

As regards art·a of hody injury iTable I) 

cranial and facial hone fracture,, extremity 

fracturrs or tlhdonttions. and intra-cranial or 

intra-thora<.·ic lesion~ occurred. as one would expect, considerahly more often when tie-down 

-was considered ineffeetive. Particularly promin· 

ent were the followin~ statistics: Brain injuries 

·were sustained hy 4.'> percent of those occupants 

whose seat failed and hy 36 percent of those 

- whose belt failed. Head are1 injuries were "IS· 

, tained hy occupants usinl\ a shoulder hallle>S, 

but the severity was judged to he less than for 

occupants not using a harness. In ap;reement 

_ with the previous findings, lumhar spine, lower· 

\:ex.tremity and upper-torso injuries are obs< --·ed 

occur in significant numl,ers when seats tear 

Lumbar spine fractures are noticeably 

fewer wJwn belts are not worn- another 

firmation of an earlier finding. Data for c

cal spine. thoracic; spine, and lower torso 

juri~s were not ~ubstantial and thus are 

tahulated. 

The data presented in Table I. of course

no: take into account the role played by im

conditions. In accordance with this need T

2 rt•lates injury severity to impact condi

for those o<'cupauls who>e tie-down did not 

Tho'e <'a''" in whieh the shoulder harness 

u~e(! are included in these (lata. 

Considerin!( fir>l the data for Impact Vel

note that iujury se\·erity increases only sli

o\t'r the range of values observed. The bo

row uf this st•(:tion pr~~ents data on tie-

dfectivem·" '" a function of I rnpact Velo

The percenlal!t'S were obtained by clividin

mnnber of cases with effet·Live tie-down an

straint l>y the total number of occur-ants w

a particular calel(ory irrespective of tie-

effectiveness. For example, there were a 

of 8:3 cases in the 30-:39 mph. impact ,-e

category and 70 of these, 84 percent, inv

no tie-down failure. 

TABLE 2 

A. 

B. 

c. 

Relation of Impact Variables to Injury Severity 

For Occupants With No Tie-Down Failure 

I mpael Vt·locity (mph) ',/ 

i 30-39 40-49 S0-59 60-69 70-89 

Number of Ob,t>rvations ' 70 79 Jl3 • 89 52 ' Percentage Fatal • 6 4! 10 11 13 

l'ert·eutage Cninjurcd 39 33 29 .11 29 

P e r<·t•nlal!<' Efft•ct i \'t;,T it'· Do wn;• 8J 75 Ill ll2 75 

-~ngle of I rnpact 1 0'-22' 23 °-37- 38' -52 

' Number of 01.-en·atious 126 ioR 92 

Percenla!!e Fatal 4 6 16 i'ercenta~e l'ninjure.l .52 24 21 

Percenla!!e Effeet;ve Tie-Down• ll6 I 73 74 

St/pping Distance ~ o·.s· 6'-24' 2,5'.,50' .') l '225' 

Number of Observations 8-l 71 Ill 168 

Percenla~e Fatal 26 10 9 5 

Percentage Cninjured 12 l I .1S 34 

~ Percentage Effertive Tie-Down• 74 7S Ill 8-1 

90-over 

42 

14 

14 

71 

53- 

69 

20 

12 

79 

225'

2

5

10

• Compul~ a!l a r~rr~nlall~ uf 1111al numh~r uf uc(·upanh "·i1hin 4'ulumn ralrj,!o.ry irrt,..Jif'cli\·~ of li~·d••.,·n rHrcliv('n

-S-
I 

Only 12 percent of the occupants escape injury 

in high-an~le crashes whereas ;);.! percent escape 

in low-angle crashes. Apart from this relationship, tie-down effectiveness is obserwd lo he 

somewhat greater at high an!(les of impact as 

contrasted with moderate angles ( 2:r . 5:.! ·). 

This finding, also observed in the earlier data, 

appears to be related to a decline in the n.:te 

of seat failures at high angles, which may in 

turn he a function of desi~:o reljuiremenls for 

seals to withstand greater loads in the forward 

as contrasted with the downward direction. 

The value of a long deceleration distance i• 

documented by the fact that at distances exceeding 225 ieel, tie-down failure was not to he 

observed. There are 22 occupants in this cale· 

gory; exactly half of these escaped injury, while 

the other II sustained only facial-Lone and extremilv fractures. On the other hand, note that 

effectfve tie-down hegins to lose imJ.>urtance as 

an element in reducing injury at extremely short 

deceleration distances, as one would predict 

from the load factor CljUation. 

Having con5idered the relation both of t;e. 

down effectiveness and of impact conditions to 

sustained injuries, we next asked the question 

of how critical was the factor of structural collapse in causing injury. Table 3 presents data 

on the reiation of environmentdl damage to injury severity for 268 pilots whose tie-down did 

not fail under impact. Note that in only five 

cases was structural collapse so ~~tensive as to 

preclude survivability.'; In the relnaining cases, 

considerable injury and •fatality were observed 

despite the fact that thesJ cases met the criterion 

of survivability. "l\feari Degree of Injury'' is ' 

derived froll)· ratinl(s ?f injury severity along 

the AvSER IU-point 1Scale of Inrry, where 

with fatal conse<Juences. 

To further clarify the pictu

tions were derived helween the 

variables~ t~n\'ironmental dama

severity. None of rhe impact var

anl(le, or· slopping distance) cor

with injury severity. A mode

was found between environmen

injury severity. but from a kn

vironmental damage, this cor

one lo predict or aecount for on

the variation in injury. At the 

fact need not he inrerpreted to 

lura! collapse CIIU-<cd injury- 

have heen thrown against colla

A numher of factors have 

al;uve as to their role in dct

severity. Tie-down failure can b

minan! of injury. especially wh

tions are severe. However. tie-d

observed in only 2.1 percent of t

and undouLredly many of the 

cases could have heen attributed 

One mii{/rt argue in some cases 

forces were so great as to cau

then they could also he suffic

account for the severe hrain co

lured aorta often found with rap

-even undPr conditions where 

effective ( S). llut when impac

evaluated in this study, onlv a 

cases could he classed as seve

high an11le. short deceleration). 

large n!'mhers of cases for whic

was unaccounted. 

An analysis of the role nf sl

revealed that hy a large marg

injury aqQ.Jatality were still in 

I 

TABLE 3 

Relation of Pilot Environment 

' Damage •to Injury SeYerity 

Pilot's Mean Percent 

Envirnnmer.t Condition N Otol!ree or Injury falal 

Intact 110 2.37 I 

Distorted 74 3.53 14 

Partly Collapsed 79 4.9I 27 

Collapsed 5 8.40 80 

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these injuries if it j:-; not abrupt Jen•leration, 

ie·<ilo~m failure, or 'lruclural collapse'' 

Tire answer, il is ft'll. is flailin~: of the l•ody 

injury-producing ~truc:tures within the 

pant's erwironmt:ut. l'o\\-' it is tnw that the 

of flailing: cannot I.e ol•jectively dctenniued 

po!ol·rra~h data- it cau only l;e inferred. 

who will d .. ny thai flailinf: ,,.·curs'! Studies 

individual easf•s in whid1 t.•ffort was maUe to 

... Jelermine whc.-ther t•ontaet hatl ot'currt•tJ between 

objel'l and a particular body an•a cerlainly 

;~,up,porrlthe al,ove argument. The work of Swear· 

and his associates ( 41 ) is a I so rele\'anl 

They ha\'e phow~raphed the motions of 

I"'"· durin~: deceleration for ]()() sul,jecb 

.:ll-e•slrairred by a lwo.irrch seat l.elt. The obtained 

clearance curve. ,,,Jwn superimposed on an 

of a typical lightplane instrument pau .. l. 

further support to the al•ove conclusion. 

r work al~n ~UtJports the couclusion that in· 

!<ieverity in modern li~htplane crashes i!<i 

a furrelion of st'verily of head irrjurv. 

from a study corrduded l.y Gr<',:~ arrd 

( 1 S) demor>-trate thai 76 pen·<'nt of 

variation in injury ~evel"ity can ),e attril111ted 

severity of head injury. II should I.e oiJ\·ious 

thai violent conlael IJelween the head and 

res musl I.e pre\'enled thmu~:h use of l~e 

harne_., of the crash helmt>l, and of 

·asiJ•Sitle des;/(11 prirrcip!<'s within lht> cockpit. 

At the same lime there is still morn for im· 

rov•rmenl in de!'OiJ!,:U. manufacture. and installa· './ 

of romnonents of tlw tie-down chain. Tlu• i 

at which !"eats tore frpe w.as high~rdor thP 

recent crashes and is rtow hip:hc·r jhan tht• 

al which seal l.ehs fail. r\pparer\tl\' s.•at 

impron•nu•nb lu1ve,/10l kept p•u·p with 

hDJroverrrenls a ion!! other lines ( <".!(., increased 

hell slrerr;:lh). l:nfnrlrrrralt'l\', the 1

dala wNe 

sufficient to detPnnine wh.e1he1· inrrPa·~ed 

of the shoulder harnf"ss would lead lo an irr· 

in the fre<Juency of lumhar spine frar· 

Thi), inference. su~p;ested hy previous 

htplane accident and Ai.l; Force studies ( 28. 

37) is hased upon the premise that adequate 

could conlriiJUie lo lumhar spine in· 

insofaF as il acls as a counler{orce agairrst 

ical forces are applied. Certainly ex· 

price thai one has lo pay for protection aga

say, fatal h.-ad injuries, then even ~:reale

lenlion shnuld he gi\'t'n lo the incorporatio

"nergy·ah>orhing features in seat design. 

From the slalislical studies conducted 

A"SER a fairly good picture is beginnin

emer~c a' to the cause of seal and hell fai

Seals were found lo fail al a lower median a

of impael than !.ells and al a hi!(hcr me

impact wlocily. Bells on the other hand f

al a much shorter median deceleration dis

lhan seats. Gt>ueralizittl!. in low-an~le cra

tht> mass of the occupant is directed down

so that al Ill<' same lime tlw hndy is respon

In the efft•ds of verlicallv·arling forces, 

al~o rontriln1lirJg lo the fa.ilure of lhe sea

moderakl\' hif:h angles, an innt•ascd rale o

failuw can he allrihult•d to the load imp

upon il by the human o<·cupanl underg

tran!'>verse df"releration. Since the occupa

not phy~ically in hi~ seat under th~se rir

shtnrt~~. a reduction in the amount of loa

on it can follow I al least in the case where 

are nol allached lo the seal); this rna\' ac

in pari lor the lower rate of seat failure f

al hi~her· an~:lt>s of impact. 

Results of this work >UJ!gesl another g<.>

zalion: Most lif!hlplarw crashes can hf" clas

into one of two types: I a) the low·angle. hi

spet•d, lon;:-derderalion crash typified h

forct•d Iandin~ and irr which lie.down effec

ne!"~ i!-i of particular importance in red

injury: and I 1,) tlw hi~:h-angle, moderale·s

shorl-dect>leralion na,.jJ typical of tht> spin

accidt>nl and in which the value of effeeli\

down derrea\es in importarwe and the ro

e:nergy-altsorhing forward structures mus

jmphasized if one is l<~luce injury. Be

(tlf'~i)!.n t'on.sider?tion~. thi~1 J!eneralization ha

viuus implications for pilot behavior and 

in~. The first l)·pe of na,h is ol.\'iodsly 

safer•, wht•r<•as the seco11<l type is definite

he a\'oitled. if possible; since injury severi

creases rapidly as a function of impact a

Bul hi!\h·an)lle li~:htplane crashes can he 

\'iv~d if nash safely d~>i;:n principles are a

cd as has l•e~n dont" in rt"rtain agricultura

craft. In these aircraft. structures are des

-7-
tain not a sin~le in:;.tance in which a fatal crash 

injury was incurred ),y an nccupant who was 

making proper us.- of shoulder harne", cra,h 

helmet, and seal hell. 

The above diseu,sior• should suffiee for an 

overview of the de!<:rminants of IIIJIIry se\·crily 

in lir,htriane ('rasht's. Various factor~ that 

should he mnsid,•rcd in hoth nasiHausalion 

and ~njury cau~ation are outlined in Figure 2. 

In effect this fil(ure muld s<•ne as a form of 

investi~:ato.-'s eh<'cklisl. In searehin~: for ilu• 

cause of tht~ cra~h~ the accide11t investi~ator will 

consider the pussiltle contrilmtior~;.; of wealher. 

air traffic control. and navaid operations: the 

design of the aircraft and its maintenant't' n~cord 

will 1.., studied: also the health. altitude, and 

proficiency level of the pilot as they might contrilmte lo "pilot error" would 1.., inveslil(alecl. 

In allemprin11 lo isolate the cause of injurie:; tlw 

contrilmtlons of fu~elag:e and e

would I.e evaluated as to their 

causation or prevention; t~ffec

restraint fo;ystem and of protecti\

prevcnlin~: or reducin~ injury w

led inlo the pi~lure. With ~rea

o!.jeclive data collected on the f

2, the ~eneration of conclusions 

dalions that can define furthe

operational re<Juiremenls is facil

At this point it may '"' well 

lh<' ~hema pre-enled at 1he !.

paper thai outlines the relations

ve~tigatory and research efforts 

r,oal. Pre\'ention. Havin~ discu~

peels of crash and injury causati

to a discussion 'f aeromedical 

goal is crash and injury preven

FIGURE 2 

Factors to be Consioered in Lightplane Crash 

and Injury Causation. 

I. The Crash 11. The lnjuril's 

A. The Context 

I. Weather 

2. Air traffic control; 

navaid failure 

3. Other aircraft; 

occupants 

B. The Aircrnft 

' ' ' l. Airworthine,s 

,, 

i 

2. Maintenance ;· 

3. ln;lrumenll reliability 

4. Poor human engineery{g in 

cockpit design 

C. The Pilot 

1. Training; experience: al>ilit}' 

2. General health; physio-

,Jogical impairment dt1e to 

adverse environment. toxins. 

A. ThP Conlext 

I. I mpacl configuration -

velocity, angle, altitud

2. Terrain charnclerisli

water, trees, soil. roc

physical structures. 

3 .• Post-crash fire; other 

craft: occupants 

' B. The A ircrnft 

1. Crashworthint:ss 

2. ~in structures 

• .3. l"slrurnent panel desi

4. Control ..-heel desi~n 

C. Perwruzl Equipmrnl 

I. Crash helmet effectiv

2. · Shoulder harness and 

belt effectiveness 

3. Seat tie-down failure 

etc.: fatigue; drugs, 

including alcohol 

~..-~~.;,;;,.;.;__~-

.3. Psvchologiral stale 

-8-
under the lollowinl( three heading,;: Binllledical. 

Design Safety, and Human Engineering. 

Biomedical Aspects 

I:1 ordt>r lo arhieve the ~oal of lteUer pilot 

heuU!J, reasoual1le and oltjeclive physieal standards are required. Faets are also rwetled altout 

•.he hazards of commonly-used drugs, alcohol, 

toxic chrm ica Is, etc. 

lllore specifical!y there is a need to know 

more alwut the relationship lot'lween agillg arul 

~eno;;orimotor functions. i.e., when is a partieular pilot too old to fly'! Research nu auditnrv. 

visual. and vestilmlar tests that are more com· 

mensurate with the demarul' of pilo1rv is under 

way. In the area of pharmaeology there must he 

studies of the effects of antihistaminics and 

lran<fuillizers upon perceptual-motor apt! cog· 

nitive processes in particular and airercw proficiency in general. Also in need of •lluly is the 

interaction between alcohol and altitude. 

The hazards associated with crop dustin;: receive a good deal of allenllon. Here CAHI 

scientists are trying to determine what dusts and 

sprays affect bodily functions and are searching for w.;ys to better protect the pilot (40). 

In the area of pathology the effect of loio· 

chemical changes on the functional capacity of 

the heart is being evaluated. Clinical re;earch 

is focused upon the evaluation of eardiovascular 

function prior to and following mvocardial infarction and of the effects of emphysema upon ,

1 pulmonary function at altitude. i 

Design Safety Aspects ' ,' 

I . h . ' ·1 ... J d t 1s t e engmeer s respon~1 JJIItv to .1

!)rf) uce 

full-:->cale ain·rdit i!'> bt•ginniu~ to jw·•tify its co

Strain !!ages rf.":onJ the ma~nitude of era

fon·f>:-; to J,e eorn•latetl tim~·Wi!'e with the resu

of hi~h-spt•ed motion picture covPra~e in ord

to lrarc the lrdnsfer of en.-rJ:y thru aircr

~tructun•s, and delt•rmine ,..,·hrrc energies a

muhiplit•d or al~>torlwtl (·18). T!m1 the 11>e 

inslrunwnted anthroponwrp!1ir dummies in ~u

lt•sls, tlata can also lw ~atherecl to postulate 

dynamic n·~pon~t· of tlw human structure ~o 

cra~h en·nt. ~u<'h tt·~ts cau al:-o he used to eva

ate both ('3U~ative and pn'\"eutati\'P fadors 

the area of po~t-cra~h fire!". Tht~ evaluation 

~eat desi~ns incorporaliu~ e~rwq.~y-altsorpt

ronet~pts is. of rourst•. an inherent part of 

pro;:ram underway at CARl. 

Rt•eent lal,oralorv >ludie' cor•dueted at CA

have dPnl(llr.lralt•d ·,hat nearlv iralf of tlw J.o

wei~.d1t. is supported on t~i~ht pt>rrent of the s

tiug area ur!der or adja("ent to the ischia! 

I.ero,ites (·B). Kt•t•pin;: this fael in mind. t

p:irtePrs and physicai anthropologists nf'"t>d to c

ordinate their ef~orts if a :-oeal is to he tle!"ign

pro,·iding t~omfcrt . ..,upport, yet a minimum 

enerl!y lransmission to the \"ertehral column 

the t~\·ent of rupi~: ctppli<'ation of vertical fon~e

Relevant to this ueed, anthropolof!i>ts at CA

are currently inve,liJ:alin~ the loreakin;: f.'O

ol lumbar vertebrae throu~:h a prop:rarn of d

namic h•,tin~. Helated work has demonstrat

that >Udr >uhstances as polyvinyl chloride a

crushahle foam t•an !(really attenuate vertical i

J>.~ct forc·es and thus should be considered in se

an airworthy aircraft. The definition of air· 

worthiness that puts empha'sis upon 'airframe 

details •mrst also include consitlt•rutiml of crashworthiness, comfort, and workplace layout cri· 

teria. Design of a cra•hworthy, human-engineer· 

ed lightplane should Joe part ,,f the same de· 

velopmental prop:ram that leads to an airworthy 

aircraft if,he rate of lightplane fatalities is to 

be re<l!lce . A coordinate effort is needed. Evi· 

dence that this view is ai,ll:ady accepted within 

the government, military, and industry is 

heartening. 

construction. Parentheticallv it mi;:ht be not

that the U>t' of foam ,.,ibber seat paddin~ is n

the answt>r 1\> preventing spinal injury, sin

such patldinl! rnt>rely increases the vertical <

fleration di>lance whil~t providing much 

/the way of en~~·gy absorp}ion. 

Collaboratiou of human biologists and a

thropolo~:ists is needed in the design and la

out o'f t'Qntrok Hese11rch•on the strength of gr

retprin·d to npt·r~le controls and the ease 

which they can J,e n·adwd at various locatio

:.Hottnd t!w· n){'kpit is ri"lc"·aut. Installations 

inertia reels with the shoultler harness net'd 

-9-
he t•valuatt•d t,l clt•lt•rmirw wlwthe-r forwanl •·on~ 

trois l'an l•t' n·tu·hed at all po:-itiou!'oo of thf" :-t•at 

if the ret·! ,Jwuld happt•n to 1 ... a•·ti\'al<-d. 

Finally. !-olali:-.tit·al :oolwlic·~ f,a~t·d t•pun laq!t>r 

11\tntbPr uf «"a~t·~ kr1uwn to he• .a random !'~ample• 

from the pop11latiou of all li)!htplaut• an·id•·ut, 

are e~sential iu nrdc•r In rt•lah• tfamagt· tu tht• 

hum<in ~trueturt• in a tTa!-oh to !'>lldt fat'lors <l!'i 

conlrol wlwt>l dc·:-.i;,!n. Iandin~ ~ear charadt·r· 

isli<'s. wiug alladmwnt. and c-aJ,in lol'ation. 

Findings wuuld J,ear on n-•t·nmmt•mlation for 

rrashworth iness. 

If u ma11 E11gillt't'riltg 

The lar~e~t sin1-dt- cau:-.e In whirh li:,!htplant• 

accidents are attrilmt«"tl is pilot error ,,·hid1 

stt•ms hnm inallt•nlinn. poor jwl~rnent. di:oolrac~ 

lions and fati~ue. It is in thi~ an•a wlwn• tht• 

~realest contrihution •·an he made toward tl.t• 

rPductiou of aeridents. llt•nce it is fittin~ that 

somewhat r:reatrr dt>tail he tle\oled to thf" topi('~ 

of this ~ection roncerned with optimization of 

perforrnanc~. 

Performance decrenlt'nt which can have ha7.· 

ardou~ effeeb is normally anrilnltt~d to hfati~ue·· 

and hstre~~ .. -terms which fre<1uently imply 

a physinlol-!ical impairnwnt. If this imJlliC"ation 

wer-e accepted then thr topif of pt•rfnrmatwe cle· 

crement would Jilave ltf't"ll ~ov<'rt"d f'adit~r in thf" 

discu~sion of lt io~llt'tii('al rf'~ear<'h. Tht" p:reat 

majorit\· of the tJrn~ tlrt• ha,is of prrforrnatW<' 

decremf'nt i~ p:.;y/·holo~i('al. rathrr than p\,y:ooin· 

logicalt invol\'in.;: !oollrh thin~s a:o> lulrf'dom. tli:ootractiOns. tlisl'mlJfort:-:. fru~. tr linn. and WHnv 

( ~£.2). Pilots slwuld ha\c ' fficit·~tt r~tnii\'atin;, 

With whwh to off~et t

1

1tt• f" P<'b o. dlsn·at'lron!'i 

inherent in opf'rationa'l requirrmt•nts. of wnrrie!'> 

caused J,y famil~· proldt•rn:oo. of fn~:o-tratinn~ re· 

Mrltin~ from delavs ant! atlwr"' wf.atl1er. ancl of 

discomfort~ due to f't\\'ironmt•ntal strf':->!"tll"~ that 

sho'\!,d ha\·~ heen tle•i~rwd out of tlr<• ,,·,tern or 

othcrwis<' nuu:t' minimal in tlw first plan•. But 

to the extrnt that motivation nr training art- not 

the answer Jn tlw,t• prublt•nl'. tlwn pt•rhaps 

human t•ngine~ring i~. ln:-:nfar g~ tht' indict•s of 

perfnrmauce dt·cremcnt indutle >tll'h thinl!s as 

stimulus equindence. lo!-0:-. nf n~·xiltilitv of !<Of'l. 

and nanowPd altcntinn. tlwn it is uil In th.-. 

human factors :oocit•nti:-:.t In pnn·itl~ a task f'll· 

vironmt'nt charach•ri7f"tl J,, ,·nntrol (li~rimini· 

hility, variety of !-if"n~ry .input. ('ontrol mOVf'· 

ment·display mo\·,.nwnt f'umpatihilit~·· a n d 

pffj,·it•nt di .. play tl

tilt' ~u·t·umpli:-!mlf'n

tainly not l;11·kinl! 

Out• wav to makt

tlw pritH·ijJit• of S-

patibilit~. Thi!-0 prin

lion uf nmtrol flto\

with ultl hal,its of 

tfi!-Oplay nwn•nwut~. 

a dial tu turn c·l

mo\'t•nwnt :oohuuld ~

Hpopulalion slt'n•nt

pallt•rn:-: that an• 

population uf ind

pilot!-0 J. llt•,ign t•n

~uch patte-rns ln tlu

I rul~. 

I Ltl,it intt•dt•n•Jw

situation in whil'h 

n.tl !Oolimulus situatiur

t•:-:. J,ut in~h·ad idPut

t•xamplt>. in two •·u

f'urnparai•lt• in pt•d

urw uf uur militou·~

handlt·~ found in m

lnl'atimt in thf' :"t-.:·

pemlt"cl upun here

alluwt•tf tu t•xi:-:1 it 

in I 9(, I. HO I i ghtp 

.,..t"l'«~ attrihutt'cltu i

Fiudings frnm 

appear to han· imp

of. information-inpu

El'JT(;it•nt furwticmir

pea .. ~ In he dt"p<·llclt

slimulalinn ('OIIIllt•d 

tin• hrain ~tf"m u·tic

lu, a n•la. '\ ,-~~ utu

environnwnt nut le

lion. Ht•c•t•nt ~tuclit·

found that. under c

tlw wurkloatf can 

t2:J). Optimal util

important lno. t'.~ .• 

in~ r~at·tion time~ 

~en~e modalitit>~ tn 

f'(l in choit•t•s anum;

(2~l). With the ft"a

munit·ation as a t.•

mi~~inn now df'tnu

-10-
(_ i9), tlu~ u .. e of cutarwou.., :o.i~nalin;: for warn· 

ing urul ah•rling ~lwultl tHA Itt~ ovt~rlnokt•tl. 

llurnau fa<"lnrs' 'cienti•t• at C:\ HI art• inte· 

n•sh•cl in a m1mhPr of otlwr prohlt·m~ reh•vant 

to oplinwl pt>rformanct•. The~e indude the dc-

~.ign of di<d"' for maxir-u1m ll'gil•ilily. t•\·aluation 

of colon•tl JiJ!.hl~ for in ... rnmu•nt illuminatif•n at 

night. tlw dt•sign of di~play~ for maximum information trall)ol.tnission~ tht' layout of di~plays 

so as tu at'hit•vt' optimum \'i!'<oual ~ward1 without 

di\'t>rtin}!: ath·ution from tasks n•tptir("d duringcritical st~l~t·:-. of fli~ht. tlw loc;.llion of dials and 

l'ontrols sn th~tl attr•ntion to tlwrn dot•s not ind!h.'t' Vf•rli;_!o. and t'\·alualitlll of till' t·mulitinns 

untl~r \\hid1 a1ulihH'\' signal!'- ··au nw~t efficit>ntly l•e ~dt~·tt·d from Lad.:~rnunrl IIOi'-f'. 

l\fany a~ped~ of the work iu human fa\'lnrs 

<lis.·ussed >O far are rt•lt•vant to l'roj.·ct Littlt' 

Guy. FA:\'~ program t:unccrnt'd with the tr:.till· 

in;; aud skill• of tlu• an•ragt' li;:htplane pilot and 

with lhe aircraft instrtJillt'llls n•quin•tl fur l-'afe 

fli~ht from l'oiut :\ to Point ll uudt•r lonth VFR 

and IFR conditions. :\ fn·•h approarh to tht' 

dcveloprnt•nt of the Littlt• Cuy c01·kpit is ht're 

r~comrut•ruf<'tf. This would r<'g:nrd tht• pilot n~ 

a part of a man-nwchim· ~~·~tt•m in which the 

systems t'nf!:illt't'l'in~ apprn;.u-h woultl IJt" followf'tl in an ath•mpt to achit•n• optimum allocation 

of task fuuctious (II). This approaeh would),,.. 

gin with a :--tudy of rnis:.-iuu and ta:.-k profile:.- in 

order to sp!'Cif y control and informatipn rt'· 

quiremenl~ ha~it· to n•a ... ona·I•IP prrfn~-rnanc<'. 

~-;tudie:.- of t•ontrnl-di~play «'on\hinatinn:-;. can he 

madf' ltl a~~··~ ... t·mnpliaun• \\·itjl lmnwn en~inrcrinA prineiplPs pn•viou~ly tfi~t·usst~d arul with 

~xistin~ ... t .. wdanf~ ~n!·h a~ llw ,At•rmututical Rt•-

f'onunt'Jldt·cl Pradic~~~ nf liH' ~ot•ipf\· of :\(Ito· 

motiH· ~:ngirwc•rs. llotwfull~'· prar1i('al ;{up .... tion:... ~uch a:-o llu• following. will rwt ht• i;.:W(lt't'.l: 

How much mom do<'• tl~t• pilot n••'Juirt•? \\'ill 

re~~~idion:o tlu~ tn fu~dage ~tructt:rt•!'O he• ~Ut·h 

as to interft•n• with dt>~irahle t•nnlrol l(}t·ation~'!' 

H<lltv far awa\' ami in what clil'l'<'linn ,Jtnultl <'on· 

trnls I.e loeated?~an eoutrols ht> id••ntific<l 

tactually and or ope•·••h•tl efficit•ntly <lurin~ 

turlllllt•ut wratht'r? Cl .. arl\' th.- Little• (;,.,. o•fforl 

~to Hchie\'~ its gnal will rt>~ruin· t'(HI:.;.idt•n~f,)t' t'n· 

operation anti t•ornpromi~t· amnii;! t'llAinet•rs. 

human factors st•ientists. aruJ UJWnttinnal :.-aft•ly 

personnel in intlustry and f!O\'f"rtnnent. 

Tlwre is one more area where hu

p..inc•t•rin~ rt>~t·an·!~ j:-; vilnl. This i~ the 

•·ra-h a11tl <'ra,h-iujury im·•••lif\alion it

n·~~~~~~ of rt•st•an·h hast•cl upon <U't'idc•nt 

oul\' '"' as rPiiillolo• a' the data it•rl

lhc.•;t. is :t strou~ tu•t•tl for n•!:.t•an·h ou 

~alivf' prot•t•dun·~. nn tlw cft·~i;!,n of t:H'«

injury rq>orl fnnn•. ami nn the relia

damage jud;.:nl<'nls (d. 11. IS. :10). 

amplt•. ou-cident n•purt form~ typiea

urmect·~~.<n~· I m nJt·n~ upun I hf' i 11\'C'~I i

l't"«ftw~tiug infonnarion that t·illwr j.,. no

or ean J,c~ olttilirwcf t·l ... t•wiH"n". Ont"t> t

and rnntiPI nf tlu~ air,·ntft i~ knowu. for 

('t'rtain dt•:-;.eriptin· data imnwtliatt•ly 

'"'"ilalolt• to tl~t• anah•l. n ... niteriou 

elusion uf an ih-rn un ~ n·pnrt form lty 

tle:-oi;.ms it "'hould lte n·~oln•d hv an~wc

'l""'timl '·\\'hat data do I need 'to """'

tion X nr to IP~I llypothc:.-i:o Y?" R

rt'•Jililt't1 of inn·~li:,!altus tn ih•ms inc

a report form slmuld takt• into at·couu

tions in human jwJl!mcnt. \\"hy, for 

a~k inn"stigntors If) rr•port angle of im

••rash In the nea r~sl d<'!!ree when it ma

po~t-cra~h eslimatt"s cannot be made 

lialoly thau In the ncare"t l<•n de!!r•es? 

more. statistical 'tudies would prolo

demand more prt>cise estimates: ~tud

automatic data pnK'e!"~ing: equiprnf"nt

nmpiP. would normally •·ocJe impnd a

tween ot> and f).J a "0'". thn!"t' 

JO' autll9' a hr·. etc .• u~in~ a sin~l

of a pundwrl ~arol. 

' CONCLUDING REMARK

As will loe ro•call•·•l frnrn Figure I 

ma!<• ~nal nf tl~·•·-.•arch pffnrt. in 

nwcJieaL clf'~i~n :--afrt\'. ami human f•n

area~ di~t·u~~t·cl al.ov~ is nne of pr~venl

achit'\'t>nlf"nl of t.hi!O l!JHII rt•quirt·~ that 

t•ollitluu·nte with otwralions' pt·r~onne

fJw rt-comnu•rH,alionS erner~ing. from 

will he- c·onsitl~n·tl fnr imp!Pmenltttio

than lot' l .. ft in tlw l"wk !'"!!"'of a l<'<

port. This llt't'ol is r..Cio•t·ted iu tlw inw

nf Ppt•ratinual o•ffnrt• in tlw "·lu·ma. 

o•t•ntralizatinn nf CARl a1ul olh<'r ••l

tlw Of(;, ... nf ·hiation \lt•olicino• in nt•w 

at \\'ill Hn~t·r• Fieltl. Oklahoma C

nwtli•·al n·~t"nrdt t•ffurls will lu• .. U('Xf 

-II-
Center. :\dditiouall\' it is clc•ar t~::•t for the im· 

pl~mentation uf n·s~an·h fiudin}!~ lo han• ;!H'ltlest value in prPvt·nti•m al~n n•,ruirei prc•}!ram~ 

of hcahh education~ profieit•lu;y tntinin~. and 

flying ~afety indoctrination. 

Because of the important f'nntril.utiHn matl~ 

lty Aviation ~lc•dic'al Examinc•rs 1 :\\IE's) to the 

work of thl' F:\ :\ it i> appwpri,ttf' to cow·lud .. 

with a (t_•w n•rnark~ in nns\o':t•r to the <1ue~tion 

u\Vhat can tlu· physician t•ontriluJte tn this 

pro,: ram? .. 

Fit'S! o( all, the physician can h<'lp provide 

hettl'r nash· in jur\' da Ia I 44, <I(,). r\ I thl' rntsh 

toile. comJtrelwnsive extrnwl t•xamination of tlu· 

hody may re\'t•al specific causes o( injurit>s. 

Bodit>s should he photo)!:raphed in the position 

where they came to rest. Color plates provide 

more information for the case analyst than do 

!.lack-and-white plates. During autopsy the phy· 

sician should look for signs of pre-existing 

disease that may have been a cause of the cr11sh 

( 12). Complete details on all lesions, fractures, 

etc .. are essential. For example, it is not enough 

!o know that multiple internal injurit>s caused 

d~ath. There is a need to know in such a rase 

whether ribs or vertehrae were fractured 111 

order to specify the biomechanics of injury. 

Secondly, the phpician can aid in the prevention of crash~s by helping the pilot main· 

lain his health. In this regard, t'fforts of A:\IE's 

in adtfr,.ssing pi,lot groupsjlue to he commend· 

ed. The physirat< t'xamination can he an oppor· 

tune time' to establish rapport and educate the 

pilot on pilot he./Ith. The pilot should he ap· 

praised of the ~ffects that recent illnesses or the 

proct"sw' of aging: can have on 1his skills (26). 

He should be ca,utioned in the/use of drugs that 

may affect performancr (3V33, 35). 

Recentlv a case was' brou!(ht to our attention 

where a highly compelt>nl and experienced pilot 

refused to exercise reasonahle judgment and 

took off shortly before noon to fly thru a thun, 

dersl~m in mountainous country. Why authori· 

ties Wt"re ignored under the circumstances we 

may never know. As a matter of interest, certain 

airport employt'es observed the pilot to l>e un· 

usually hyperactive anti euphoric. Could drugs 

have Leen a fartor? A bottle of rapsules found 

on the pilot at the crash scene stimulated a con

This physician w

therefore. not thf' 

his flight phy;ical

mg. of <lt•xtro·am

sull' form. lube la

a do~a1~e of six tim

allhouJ!.h ron:--ider

a rf'asonahle wei~

the pilo! was als

side effects of :-.t

mine certainly mi

in)!: a pil01's jtoclg

A final poin

support of rouj:h

A\IE's to aicl in 

as part of thl' 

Standards Oi,·isio

sicians with thes.

while there exist~ 

to serve the FA:\ 

the rt'sponsihilitif

find these lopi<>s 

line of Prot·edure

Participating in 

lion." This docum

gional Fli~ht Sur

sion of recomme

R

l. Barry. F. R. and 

in air('raft atride

590-593. 

2. Rarrley, S. H.: 

Rnif'tt'J, l9Si .. J7

3. Baxter. N. E. Ch

cinr, 1962 •. U .. 39

4. Bru~,znik. C.. "-· 

prot~lion durin~ 

Jl'arrh t:omma"d· 

._~, 

5. Cammadc. K .. Ra

ll~rleratinn injur

ius ol Sur,,.r.•·. 1

6. Ot-Ha,·cn. H. Th

injury .. u~totainrd h

·f.ta!!h Injury Rr .

lr,:c. !\'rw ltf•rk. 

7. OrHavrn. H. Or

rer~nal. f!x~uli..,

jury Rto .. rarl·h. C

YMk. 1953. 

R. llrHa\rh, U. Cr

C".tllih drlr-ip:R • ..-ft

J-7. 

Q. Eib•nd. A. ~f.. 

Anrif'rati""" and 

full ""<"a I~ litht ai

2991. 1953, 

-12-
10. Fryer. n. I. p ..... t'n~f't 

Uf\i\al in atrna:t rra .. ht!o. 

Anonaurin, 1959, -111, .ll-37. 

11. Ga~ne, R. ~~- 1Ed.t I'Hrho!o~t'al fJTI'IUfl/r,, tn Htlf'nt 

dt>t·~/ofJtnt'nl. ~.Y.: Huh, Neinltarl. & \\ in .. tun, I'Nt:Z. 

12. (;Iantz, \\'. \I., and ~temhndl!t-, \". A. c .. runttr' artt-r) 

alhf'ro:r.derd"i"' ... a fac·r.•r in aunah atTirf,.,u fataltttf' ... 

Journal of .4t·tatwn -~f,•dtnn,., 19.W, .10, 75-WJ. 

13. _Graybiel, A. Pruhlt'nl~ im-ohin,r the pilot and hi._ ta .. k. 

Journal ol Al'ialicm .11,.Jrnnf', 19;)(,, :!i, .!9-:--lOt't. 

14. Cre~p:. 1.. W., Prar .. tm, R. (; .. and Harne .... A. C. Jr. 

Predirtiun of cfi"'J!tt"t' nf injun· f.-um impal't ancf cbma~e 

\ariahlr'!l in lij:htplane an-i•lt"nt ... TrftflJporttJtwn R,.H·arth 

Command, 1/. S . .-frm• Ht'fWrl td-9$. :\uJ!u ... t i 1H:tl. 

15. Cretttt• L. \\·. ancl Pt"at .. un, R. (~. t'arturi.1l --trm·tu~ n( 

imttarl anti dartUt!!e \anahlt-" in lit~:htl'lant- a•·ndent~. 

/Iuman fartorJ, l%1. .l, 2.17-21-t. 

16. Ha .. hrnok, :\. tl. \\iattun na--h injun rt" .. t'~ttt·h. lot~rnal 

o/ At·iation .U,.didnt>, 1%5. :!r,, IRtl-Ht-1. 

17. Ha:r.!!l, (;, \1. 1\pe-. uf Ulff"rnal IIIJUrlf'· uf l'f'hc:mnl"'l 

invulv~cl in airc-raft acndf'nl .. }munal ol ,4ualion \f,.Jr. 

rim•, 194-1, 15, ii -8-l. 

18. I. ~ufy, C. T .. and Pa}'ne, H. B. .\liti~atinn of wnrk ~1"'­

rrement. Journal ol f:.tfu•nmt'ntal P.orholt•~-·-. )Q:..,-;, ·1'1, 

60-67. 

19. Hawke'-. G. R. Pult'nlial aMwf'r"' In c-c.mmunic·atiun rroh· lem~. At'rOJpac <' .\lt',/u·inf', 1962, .U, b57-M2. 

20. Hendlf'r, f., l.inf'ar arcdpration o~ a "un·h·ahle huard 

in adation. Jot.lrnal ol .-fdatron \lrdi,·inf', 11155, 26, 495. 

21. Hent)-. ). P. ~mne c:·nrrf"latiun., lte-twet-n p .. yc-holottic and 

physiulu~ir e\-·enl!< in aviatiun biolujit:y. }ournol of Al'la· 

tion .\frt/irint>, 1958, 29, 171-1-:9. 

22. Hnlcomh. (:. A. Applit·ation nf ba .. ic human rn,rinet-rinR 

prinriple"' ru a C'O('kpit c:te .. i,:n. ArroJpat-,. .\(t"drc-rnt'. 1960, 

31. 674·fl77. 

23. Holland. J. C. Human ,-if!ilanc-e. Sri,ncf', 1958. 128. 

61-67. 

2-1. Howell, \l'. C.. and llonald!<on. J. E. Human l'hOh'e tf"· 

al'lion time wilhin and amHRfll: o.en~ mudalitie~. Srit>ncf', 

l%2. 1.15. 42'l·4.l0. 

25. lewi~. ~. T .. ancf Starr. 

craft !leat ht'h r~"•lraint. 

1958. 2'>. 187·1%. 

J. P. Human t<:lleranrf' lo airJournal ol .•h·iation \f,.~ircnf'. 

i 

26. ~lohler. ~- H. AJt:inp: in nilot perf:trl'flance. Gt'fiatricJ, 

1961. /6. 112·88. I 

21. ~fo,~le)'. U. C., antf ~tt-mhrid~to. \'. A.t The ho!liile en· 

virunmenl ao. a rau"'" of airc-raft arddent•. }ollrnal o' 

Ar·ial;on .\I,.Jrri'lt', 195-:, 2R . . 'i'\;",.;).J(l. , 

28. \fo.,elf'y, If. r. .. T,"~'""'to~-:t F. \1.. anJ ~t,.mhrid,::r. \'. ). 

Prevr-nliun . uf dt"ath ;md injun: it\ airaaft at·riclj'lt"-

A\1.4 .Archu-,.,, ,,, lrulu.Hnal lf,.a/tiJ, JC6R. 17, lll. ~ 

29. ~lo,.eley. II. C .. and ]t"llrr, :\. t'. P.t>latinn bf in_iur,· lo 

forre!l and ditt'l'finn nf dl"','f"ltoratinn in airrraft ani,fl'nf*-. 

Journal ol ,..!r·iatw" ltt·diriru•, I%R, ;!Q, i39-7-J9. 

.10. Nf'rly, ~- E., and ~hannun, R. H. \'t-tlf'hral fra.·tuft'o. in 

~u~·hnfll. uf m1litar" airnaft af'c-idenf!l, Journal rJl .4r·iali- .l/,-Jirinr, )9:lH, ltl, 7:.o:;;;3_ 

31. Payne. H:. B. Tht' f'~l'f!l uf clru,z. .. upon f•!I\'Chnlnp:il·al 

efficienq. Journal 01 ,4t·ratwn lf,.Jirint", 1953, :N, :t23-529. 

32. l'ayne. R. A., and llauh·. (;, T. Fat'lor"' lifff'('tint the 

endurance uf l'l'\'t'homulvr .. ki 11. Juurnal ot .-4natl••n \lrdimi,;,, 1955, 2b, ·.182-.189. .. 

33. Payne. R. B .• ancl \toure. E. u·. The efft'rt, of &flme 

analer•lic and dt'J•re ..... anr dru~;:. upon lrarkan~r ht'ha"ior. 

Journal ol l'ltarmarolotn and f:xpnrmt>nta/ Thrra-'""''"~· 1955. 115. 48().~. 

;u_ lfar .. u!l, H. (;, Ta,.k r•r•,fidPnn ami fr,.Jin~ .. 

S, houl ol .41l'ulion .1ll"'tilnnf', (1.'\AI-', ltt>pon 57

IIJ.'li. 

:G. l'f'ar,on. K. t:. f',."·hnmutur effl"'rt .. of dir,hen

lt}drtwhlorulr an,f diml"'nhydrlnal-1". J••tln!al flf t

'~'~" I'IJarmar I'IIIUal . ..fucn tntltm, I ~l'irnrifir 

)'J;i7, Jr,, i'O:Z-703. 

:v •. J>t'ar .. un. R. C. Impact-injury r~lation .. hiJ•!l in 

3('rult't\lo,, Arrllit·rs ol f:ru·irunm,.ntal 1/,.a/th, 

51·1·518. 

.17. l"t"ar--un, R. (;. Jit"latiun .. hil• flf'IW~II lit'-duwn 

llf""'" ami aniuri"'" .. u-.rainl"'d 1n li,::ht,.lan«" 11c-idf'

11J:l2). Af'tOJ/IQ{I' lfNiit '""· JIK,2, .u, !'>fl-S-9. 

.'\H. f•l"'ar .. un. R. (;,, an1l l"iuaa. \tilclrt"d H. \ll"'fh

illtur~- in nuuft'tll hJ.:htplane t•ra .. Jtl"' ... Tran~flor

Jf'arc'J (.ommand, l'.S. Army, Tuhniuzl H,.,

l%2. 

:19. ~IJ... ~- B .. and Ut-rn. C .4.. I Eckl /Iuman 

Jt>l and li)Qf'l' trat·t>l. :\.)'.: Hunalct, 196). 

JO. ~rnith, P. \l'. Tuxir ha1.ard .. in al"'rial af't•li•

I"'" 62-R. 4:i,il .-\,.rmnediral H .... l"'an·h ln .. titu

Oklahuma Gry. Oklahuma. l%2. 

-11. ~"'t>arinll-t'll, J. J .• lfa-.lmook. A. ff .. ~nvder. R

\ld'adden. E. U. Kinf'matic lleha,inr u{ thl"' hu

durin,: d«f'leralion, ArroJ/Itlt',. \trtlirinf', 19fJ2

197. 

42. ~"'·earinJ!en. J. J.. \JrFadc:lt'n, E. It, Carntr. J

Hlethntw, J. G. Human tult>ranrto In \·rrfil"a

. .f,.roj/)fl(.,. \f,.Jirin,·, 1960. :n. 989-998. 

-U. ~"'·earin,::t'R, J. J.. \\'het>l"'·ri~tht. c. n .. and Gar

An anah'i"' of ~<ittinf! area,; and flt""'"urf'"' of m

fJ2·1, Ch·il Af'tflmf!'dical R,. .. t>arrh Jn .. titute. FA

huma City. Oklahoma. ltA't2. 

"-4. Tf"ar~. 0. Po,;t mortem examination~~o on air 

rim!'. Bri:ish \lt'di.ral Journal, 195L 2. iOi·iOII. 

45. Thorndike. H. L. The human fal'tor in a(_"ri

"-Jlerial rf'ferrnc:·e In airnaft al"ritlt-nl~. I'S.-4F 

.4n'ation .11t>dicin, l 1rnJI'f"t Rt'port, 19-51. Pr

21-.10·001. Hept~rt Nl". J. 

46, Town--end. F. \1, The palholo~iC' inve .. tip:alin

naft anidr-nt latalitie!l-. hmrnai of Ar·iauon 

1957, 2R. -J-.1-468. 

47. Tnwn~end. t'. \~ .. Uavid!'on. W, If .. and Ooy

T•·u }·~a,-...· t!'ll.flf"rient•e in ("omiJined entlinl"'l"rinp: 

nlo~l in\'t'"'ti~tation in airrrafr arrident!l. A,.roSp

rjn,.. J%2 •. ll, 91.1-919. 

-18. Turnbnw, J. \\'. t:.s. Army Jf-25 hf'li("opter 

TranJportation H".H:IJT.(It f:.ommand, 1/.S. Arm_Y, 

ltt'port 60-76. 1961~ 

49. \\'f!'bh, }\'. R The predil"lion of airnaft arcid

pilut·l't'nte~d ntl"'a .. urr!i. Jmlrnal ol At'iation 

l%h, '17, I Jl-l-t7. 

f)(l. U',.J,h, u·. B., \tillf't, E. E .. an.-1 ~t'alr. L \1

attt'llll•l!l in l"odin~ 11ircraft arridl"'nl!l. Jo11rnal o

1lt>du·inf', 19.~. ;.!'J, 220-225. 

51. Zt'ller. :\. F. fluman 01*-J"C'I:r. nl m:rt-air rolf

't'ntitln, .4nMparf' \l,.dirin,., 1959 • . 10, 5aJ-5tlO. 

52. Zt'll~r. A. F. (:url"f'nt fh·in,: antJ arridt-nt 

.-4t>roJpar,. \f,.Jirinf', l%2 .. n. '120-929. 

5.1. ZPller. A. r .. .ind .\l(> .. l"'lev. H. G. .\in-uft ar

rrlared In rtilut aJ:t' aQd f-•1)f'rienre-. /ortrnal o

1/,-Jirinl'. 1957. :lR 171-18-1. 

;'H. 7.t"lle-r, .\. F .• :\umu11nd. (;. H .• and Hurkt". J. \1

a<"dcff'nt ... and airc·rafr in .. trtltnf'nt•. At'ro.•parf' 

1961 • .12. 42·51. 

-13-