## PB85-917002



# NATIONAL**T~tANSPORTATION** 

# SJ.\FETY BOARD

WASHINGTON, D.C. 20594 

# SAFETY REPORT

GENERAL AVIATION CRASHWORTHINESS PROJECT: PHASE TWO

- - IMPACT SEVERITY AND POTENTIAL INJURY PREVENTION IN GENERAL AVIATION ACCIDENTS

NTSB/SR-85/01



# UNITED STATES GOVERNMENT
000001

### TECHNICAl REPORT DOCUMEHTATJOH PAGE**~. ~_eport**  Ho. 2.Government**A~~esslon** No. ].Recipient's Catalog No. NTSBiSR-85/01 PB85-917002 lt. Tltle and SubtItle Safety Report--GeneralAviation 5.Report Date Crashworthlness Project: PhaseTwo

-- Impact Severity March 15, 1985 &nd PotentialInJury Prevention In General Aviation Accidents**~**6.Performlng Organization Code 

### 7. Author(s) 8.Perlrorming Organization Report No.**~.** Performing Organization Name and Address lO.Work Unit No. 3741A NatiohalTransportation SafetyBoard 11.Contract or Grant No. Bureauof Technology**Washl~ton,** D.C. 20594 13.Type of Report and l12.SponsorIng Agency Name Period Covered and Address SpecialStudy 

### NATIONAL TRANSPORTATION SAFETY BOAkD 1982 

### Washington, D. C. 20594**)~.Sponsoring** Agency Code
15.Supplementary Notes

l6.Abstract This report Is the second In a series of reports to be issued by the National

Tro.nsportatlon Safety Board as a result ofIts General Aviation Crashworthiness program. The purpuse of tttls program is to ptovlde lnCormation to supportchangesincrashworthiness design standards for seating and restraint systems in general avlat!on airplanes. A Phase One report presented a methodology for documenting Impact severity. This Phase Two report presents**~Jt)eclfic** data on survivable accidents. The data developed In this study suggest that the survivable envelope is defined by Impact speeds of 45 knots at 90 degrees of Impact angle, 60 knots at 45 degrees, and 75 knots at zero degrees. Data are presented which demonstrate that If all occupants we!lr shoulde!' harnesses, fatalltle3 are expected to be reduced by 20 percent &nd 88 percent of the seriously injured persons in survivable crashes are expected to experience significantly fewer**lif~-threater.ing** Injuries. Thirty-four ptrcent of the seriously Injured occupants of survivable llccldents are expected tobe less seriously injured if energy-absorbingseatsare available.



### 17.Key We.rds general aviationaccidents; f8.0istribution Statement crashworthlness;crashloads; This document is available accident investigation;crashpulse; to thP. public through the Impact severity;lapbf'lt; shoulder harness; National Tt>chnlcal Informsoccupant restraint; er; .-gy absorption; tion Service, Injury; seats;survivability Springfield, VIrginia 22161 19.Securlty Classification 20.Security Classification 21

.No. of Pages 22 .Price (of this report) (of thIs page) 

### UNCLASSIFIED UNCLASSIFIED 46**NTS~** Form 1765.2 (Rev. 9/74) 

# 000002INTRODUC'I10N • • MmJODOLOOY • • • • •

• • • CONTBNTS

• • • • • • • • • •

I I I I I • • • • • • • I I I I I • • • •

• • • • • • • • • • • • 1 3
ANALYSlS

. . . . . . . . . . . . . . .. I • • • • • • • • • • • • 4 Impact Severity.

. . . . . . . . . . . . . . . . . . . . . . . . . . 4 Potential BenefitsofShoulder Harnessesand Energy-Absorbing Seats

. • • 9 EstimatesorShoulder Harness Benefits • •
. . • • • • • • • • • • • • 12 EstimatesorEnergy-Absorbing Seats Benefits

. • • • •
. • • • • • • • 15 CONCLUSIONS. • • • • • • • • , • • • • • • • I I I I I I I I I I I I 15**APPBNDIX~** . . . . . . . . . . . . . . . ' . . . . . . I • • • • • • 17 Appendix A--NationalTransportation SafetyBoard General Aviation Crashworthiness Recommendations with Summaries ofFederal A•Jiation Administration Responsesand SafetyBoard Evaluations of these Responses • • • •

. . . • •

. . • • • • • • •

. •

. • • 17 Appendix B--ComparisonofStudy Data with Natioraal Aeronautics and Space Administration CrashTest Data

. • • • •
. • • • • • • • 22 Appendix C--ExcerptsFrom the General Aviation Safety Panel Proposal 

### to the Federal Aviation Administration

. . • • •
. • • • • •
. • • 24 Appendix D--Methodology • • •
. •
. • •
. . • • • •
. . • • •
. • • 26 Appendix E--Five Accident Examples and Evaluation Results • • • •
. • • 31

ii



## 00000.1NATIONALTRAUSPORTATION SAPIITY BOARD W ASHINOTON, D.C. 20594 SAPIITY RBPORT Ado?ted: March 15, 1985 OBNBRALAVIATION CRASHWORTHINESS PROJBCTz PHASB TWO-- IMPACTSBVBRITY AND POTENTIAL INJURY PP.BVBN'fiON IN GENERAL AVIA'nON ACCIDBHTS IMTRODUC110M
In the years 1972 through 1981, 36,466 accidentsoccurred Involving generalaviation airplanes. 

### orthe 73,596 occupantsoftheseairplanes, more than 18,614 (25 percent) were killed or seriously Injured. The National Transportation Safety Board's Investigations or these accidents found that many of the fatal and serious Injuries could have been prewmted If the occupants had been**usl~** shoulder harnesses and had been seated in energy-absorbingseats. The Safety Board began a General Aviation Crashworthlness Program in 1980 to gather data to be used to further support previous Safety Board recommendations for improved crashworthiness 1/ in general aviation airplanes. Two basic approaches were taken to compile these data. One approach was for a team of trained crashworthlness investigators to complete detailed onscene Investigations of selected survivable accidents 2/to document the structural deformation ofthe airplanes, the Impact severity of tht' crash, end the resultant injuries to the occupants. Acceleration loads were then calculated for each accident. The methodology fer these analyses was described in the S'lfety Board's report, "General Aviation Crasltworthiness Project, Phase One". 3/ Analyses of these selected accidents will be presented later as part of a Phase Three rf'port. Theotherapproach was tocompile, beginning In 1982, moredetailedkinematic 4/ and injury information for all general aviation accidents. This was thu information used as thebasis for this report. This report places emphasis on, and provides support for, efforts to improve P1e crn<Jhworthiness of general aviation airplanes. It presents specific data which help to define survivable accidents, Including informationon impact severityand estimatesofthe potential benefits that are expected to result from the use of shoulder ha1·nesses and energy-absorbing seats. In this report, "real world" occupants (actual survivors and potential survivors) define the limitsorimpact severityin survivable accid<mts. 

## !I Crasfiworthiness refers t-:> the capability of a vehicle to protect its occupantsrturing a crash. 2/ A survivable accident is one in which the forces transmitted to the oceupant through the seat and restraint system do not exceed the limits or human tolerance to abrupt a-::celerations and i•t which thestrueture In theoccupant'sImmediateenvironment remains substantially Intact to the extent that a livable volume is provided throughout the crash sequence. 3/ "General Aviation Crashworthiness Project, Phase One," June 27, 1983 n;·i'SB/SR-83/01). 4/ Kinematics is a branch or dynamfl'!s that deals with aspects 

### ot motion apart from considP.ratlon of mass and force.

### -2-

Federal standards for occupant protection In general aviation airplanes essentially have remainei ·mchanged for the last 30 years. despite major advances in crashworthiness technology, many of which resulted from government/indut;try rt>senrch t\nd investigative projects which began in the late 1950's and et.rly 1960's. These projects, which includetl full-scale crash**test!~** or a variety of alrcraf't, addressed all areas of crr.shworthlness, Including postcrash fires, seats/restraints, cockpit/cabin environments, and crash E·.cceleratlon environments. However, the new technology has been used only in a verv limited way, primarily In agricultural apr!:cation airplanes.**~/** The Federal Aviation Administration (FAA) has been testing upgraded**~eat** and restraint systems since 1970, but to date there has been only one substantive change in the relevant regulations for general aviation airplanes--shoulder harnesses have beP.n required on front seats of**airplane~** manufactured After July 18, 1978, and on some older models used in commercial operations. 6/ Appendix A presents a synopsis of tile mor<: Important recommendations issued by the Safety**~o~rd** to the FAA addressing various Issues ofcrashworthlness, and the FAAts responses to them. The National Af!ronautics nnd Space Administration (NASA) recently completed a program of crash**testi~** general aviation airplanE'<: that began In 1973. Crashes of 24 Instrumented**·~st** airplanes with anthropomorphic dummies provided Jata on structural and occupant responses In specific crash sceMrios. In tnese crashes, survivability was determined by**usin~** accelerometer data obtained from the test articles. (Ad1itional Information on thisImportant program is provided ir; appendix B.) During the last several years, there have been Increasing efforts to promote Improvement in general aviation crashworthiness. ln February 1983, a government/industry group, including representatives of the General Aviation Manufacturers Association (GAMA), met at NASA's Langley, VIrginia, facility to study Issues related to "l')neral aviation airplanes. The findings of the group regarding**~rllshworthlness** Included:

o the mandatory availability and use 

## or**upp~r** •orso rE.:straints (shoulder t:arnesses) in small 11ircraft could provide an Immediate Improvement in crashworthlness;

o there currently is an adequate bc.dy of knowledge for the issuance of Initial rules pertaining to structural**cra~hworthiness** Cor small ail'planes; and

o additional research is needed tudefinea crashscenariorepresentativeof survivable accidents on which crashworthiness pet'forrnance standard•, ce.n bebased. All GAMA airplane me.nuf'lcturers have pledged to Install voluntarily shoulder harnesses on all seats of newly manufactured airplanes. The organization has petitioned the FAA to require such installation on all small airplanes manufactured in tile United States. 

### 5/-WaiilO'lit,--G.--:;:, "Crashworthiness Observations In Gentral Aviation Accident fnvestlgatlons--A StAtistical Overview", Aircraft CrashworthlneJS, University Press oC VIrginia, 1975. 

### 61 Tltte 14 r::ode of Federal Regulations (CFR), Section 23.785, published on June 16, 1977 (4'2 FR 3('1503}.


## OUOOOti

### -3-

In February 1983, the General Aviation Safety Panel (GASP), an ini11lo:;try task for<!c convened at the Invitation of the FAA, issued a position paper conttlining several recommendations dealing with crashworthiness. Likt the earlier government/industry group, the task force ,.ecommended mandatory i'L'>tollation and use of shoulder harnesses as soon as practicable. Also, It recommended that the development of new crashworthlness design standards be expedited. One of the immP.diate goals of this recommendation was to '1, •• provide .:.. means for collecting meaningful accident data on the effectlveness of seat restraints and harnesses. Such 'real-world' data would be compared with experimental**~esults** iil order toprovide a broader b&sis for creatinrrdesign criteria." The Safety Board had b<!Cot gathering the "real-world" crashworthlness data since JaniJary 1982. With that data and the release of the GASP recommendations, the Safety Board approached both the manufacturers and the FAA and suggested that parties cooperate to resolve the technical stumbling blocks which had plagued past errorts to secure crashworthlness improvements. The FAA, manufacturers, and othe,. representativesfrom theindustry responded by reconvening the GASP. Beginning In July 19R3, the GASP held a series of meetings to explore thP. general aviation crashworthiness issues. The Safety Board presented the data gathered in its crashworthiness program which supported heavily the GASP's efforts to develop its recommendations. As a result of the meetings, the GASP forwarded a proposal to the FAA on May 2, 1984, that detined standards for seats and scat restraints, Including requirements for the dynamic test.ing of seat/restraint systems to 26 G's in the longltuainaldirection and provisions for energy managE'r'fiE"nt in the verticAl direction. 

## Y

ME'TIIODOLOGY
To define the impact severity of survivable accidents and to estimate the benefits to be derived from the availability and use of shoulder harnesses and energy-absorbing seat:;, the Safety Board used data available in the investigative reports of 535 selected accidents that occurred in 1982 to perform a detailed analysis of crash kinematics and occupant injuries. Accidents selected as suitai.>lc for this examination were general aviation airplane accidents in which at least one occupant was fatally or seriously injured. 8/ Certain airplanes such asaerial application airplanes, homebuilt airplanes, and older airplanes or fabric and tube construction were excluded. The selected accidents also were limited to airplanes which are expected to continue to be m production and hence wouldbe the most likely**ean~idates** for improved crashworthydesigns. Data available concerning each of these accidents 'w'·ere evaluated by investigato.-s experh:nced in the analysis of ptttterns of injury causation in general aviation airplane accidents. A detailed analysis was made by examining completed io.vestigative forms, narratives, photographs, witness statements, and medical information in order to estimate
7/Generai-Xviation Safety Panel, Proposal to the Federal Aviation Administration,**~1ay** 2, 1984. (For excerpts, seeappendix C.)**~/** Title 49 CFR 830.2 defines "serious injury" as any injui"y which: (1) RquirPs hospitalization ror morethan 48 ho11rs, commencing within 7 days from thedate the injury was received; (2) results in a fracture of any bone (except simf)le fractures of fingers, toes, or nose); (3) causes severe hemorrhages, nerve, muscle, or tendon damage; {4) involves any**lnte~"nal** organ; or (5) involves second- or third-degree burns, or any burns a(fectlng more than 5percent ofthebody surfHce. 

# ooouor;-4-

the extent to which ef:'ch accident was survivable and to compile Information on irnpact speedsand impact angles. For the purposeofthis study, an accident wasconsidered tobe survivable when a livable cabinvolume was maintained throughout the crash sequence and the forces transmitted to the occupant through the seat and restraint system did not appear to have or should not have exceeded the limits of human tolerance to abrupt accelerations. Therefore, an accidtnt was considered to be survivable when at least one occupant either survived or could have survived if shoulder harnesses or energy-absorbing seatshad been used.
Apartially survivable accidtmt**~~a** survivah1E" &cciO.:mt in which at least one fatality occurred that could not have**be~:ii ~** re••t!nted.**f'ot~Jntfal** survivors were identified in each accident by examining accident dat& descl'''l:.g tl-te damage to the airplane and the in.lurics of eac!l occupant. First, the**"livu~le** volume" was evaluated**fo~** each seat. Photographic documentation was the primary source of this information. To be considered livable, each space where an occupant was seated 11ad to have remained large enough for survival throughout thf! crash sequence. lndivt::fual locations consldeted nonsurvivahle were those wher(> the li•Jable volume had been reduced drastically or had bet-n destroyed. An example of a nonsurvivable accident is one in which the**volum~** had been reduced during the crash by a crushing structure that had rebounded, thus giving a finul appearance ofa livable volume. Se'!ondly, the injuriesof (.ach of theoccupants were**evAlu~:ted** separately, taking iitto account the availat:.ility and use of occupant restraints anf.**~he** retention of seat structures in their normal positions, postc1ash fires, and other Important factors. An assessment was mP.de, wherever**po~.sible,** of the**~eg~·ee** to which injuries cou!d have been**les~ened** by the use of shoulder ht

### messes or energy-absorbing seats. (A more detailed discussion of the procedures •Jsed is presented in appendix D. AppE!ndix Epresentsiiveaccident examt:-!es and theevaluationresults.)
ANALYSIS**Th~** study group for this report is comprised of 535 accidents in..,olving 1,268 occupants, of which 391 accidents resulted in at least one fatality. In these 391 accidents, there were 859 fatalities, '!4 occupants who survived with serious**injuri~s,** and 19 occupttnts wh" survived with minor or M injuries. All occupants were fatally injured in 85 percent of the 391 fatal crashes. In 144 accid:mts in which no one was fatally injured, 228 occupants were seriously injured and 87 o.:.."!upants**rec~ived** minor injuries. One occupant's injuriescould not bedetermined. The analysis for this study groJp is presented in two sections: first, impactseveritJ is**discu~ed** in terms of impact angles and impact speeds, and the impact severity envelope (referred to in this report as the survivable envelope) is determined for surlivable accidents. Second, the potential for injury prevention, made pos.;;lJ)e by shoulder harnessesand energy-absorbing seats, is presente1. ImpactSeverity Impact severity was defi,led in terms of impact angle and impsct speed, the most readily available parameters that c&n be related to the survivability of an acci:1P.nt. Each accident was determined to be survivableor nonsurvivable, and, for most ofthe accidents, impact speeds and impact angles were estimated. After the Impact se\·erity estimates were made, each accident and occupant wert representedon thepolar (!lots which follow.
The impact severityIncreases with impact angle because the veloc;ty change during the principal impact becomes greate1· at increasinglv higher impact angles. At shallow 

## OOOOU"i-5-
Impact angles, the airplane "hits and skips" with relatively small velocitJ changes. At high Impact angles, the airplane "hits and sticks," which results In a**~reater** velocity change or a moresevereImpact. The dlsttibutlonsof Impact speedsand Impactangles for surviV9.ble accidentsversus**no~urvlvable** accidents are presented in**figur~** 1. 9/ Each data point represents one airplane. There were a significant number of surviVable occideocs at impact speeds of less than 90 knots and at Impact angles of less than 45 degree-e. There were very few survivable accidents outside this range. In contrut, there**~~re** proportionally fewer notllurvivable accidents at lrnpact speeds ofless than 90 kncts and at impact angles of lessthan 45 degrees. The occupants of the survivable accidents depicted**ii~ fif!"~:-c**  1 are plotted Individually In figure 2. The survivor plot (top) Includes all occupants who survived or who couldhave survived.**'fh~** nonsurvlvor plot (bottom) represents occuptlntsof partially survivable accidents who could not have survived even if they had been usinl shoulder harnesses and/or had been seated In energy-absorbing**~eats.** These fatalities typical!y resulted from trP.e penetration at a specific 

### stat location in the C'abin or from localized cabindisruptions. The occupants of the nonsurvlvable accidents depleted in figure 1 orr! plotted individually in figure 3. Relatively few occupants in nonsurvivable accidcnt1- Jre in the area defined as an Impact speed of less than 90 knots and an impaP.t angle of less thart 45 degrees. Nearly all of the occupants who did not survive were i 1 accidents in which eitheroneor bothofti,ose parameters were excet:rled. Figures 2 and 3 were compared to establish whether the difference between survivable accidents and nonsurvivable accidents**wa~** one of impact severity. Any difference which**~ould** be demonstrated would define the limits of the**surviva~le env~lope.**  First, tl"!e density plots of figure 2 (top) and figure 3 were overlayed. In another comparison, the plots were redrawn as rectangular plots so that dot density of v&:lous sectors could be directly com!)ared. These rectangular plots also were overiP.yed for e.>mparlson. These comparisons produced a boundary, or visible difference, behveen the two group!. The dlfferencP. was most clear as a line which extends from 0 degrees at 75 to 90 knots, to 45 t1egrees at SO knots,**an~** to 90 degrees at 60 knots. Aspecial effort was made to**ev~tluate no~urvlvable**  accidents which fell Inside this limit and to evaluate survivablec;.ccldents which were outside this limit.
Most of the**latte~** accidents differed from tht other survivable or nonsurviveble accidents within their tespectlve severity ranges In some of the following ways. In the lower speed, survivable reglrn, nomur**vivab~e** accidents Included those Involving inverted crashes ordirecttreCJ orotht!robjectstrikestosingleoccupants. In thehigh-speed ar:jiur low-angle Impact region, a survivable accident would Include an airpl&ne cruisintt Into gP.ntly I·lslr.r terrain and sliding over some dlstar.ce to a stop without genet·ating slgnltlcantloads. 9/ Comparisonso!thedot densityofa sector In the low-speed range to the**~ot** density of 

# a sectorIn thehigh-speed range canbe misleading. For example, i'l figure 1 between the Unes**forml~** theanglesof 30 end 45 degrees, the sectorbetwe(;•l 75 and 90 knots !s twice aslarg\! asthe sector between 30 and 4S knots, even though both**repr~ent** equal changes 

### Jn velocity and anglP.. As a result, the relative dot density In differing speed ranges cannot be corr.pared directly. Compa.lsons of dot deMity for differing imi)act angles within a given speed range are valid, however, as are comparisons among tndividual**secto~s** from figure to figure In thisreport. 

# OOOOOH

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# .**/'~~~** 1: t.$'. • • "'>o**:o~** "'.t**-·~** ro

Survivable Accidents

(216 Accidents)

legend: INd> • "''"tsenll**o-.e~t.**

5

ro

Nonsurvivable Accidents

(219 Accidents)



### Figure 1.--lmpactanglesand impactspeeds:

Survlvab!eversusnonsurvlvabla accidents.

### OOOOO~lIO



### Occupants Who Sur!ived orWho Could Have Survived (460 Occupants)

Ugord: ..a. •f1IPO

...ott**one~t.**

IO



### Or.cupants Who

Could Not Be 

### Expected To Survive

(42 Occupants)
Figure 2.--Jmpact angles ttnd Impactspeeds Insurvivable accidents: Occupants who survivedor could have survived versusoccupants whose survival was not expected. 

## 000010

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. •**~-----** -8-



# . . . . 

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. 

## . (568 Occupants}

Figure 3.--Impact angles and impact speeds: Oc\!upantsin r.t>nsurvivable 

### seeldents. As plotted, an lmpgct angle of 90 degrees appears to be the limit of the surviva'>le envelope for a 60-koot impact. However, examination ofthe ac1!ident reports shows that the survivable Impacts plotted In tlle 45- to 90-degree sector actually are diatributed much more closely to the45-degree line than is shown by the even distribution ofthe p!ot. Since the data In that secto;· are biased more toward the 45-<.egree line, the survivable impactspeedlimit at anImpact angleof 90 degrees Is rnore nearly ·i5 knots. Similarly, many a<..-cldents in the Impact**sp~.~ ran~e**  t>f 75 to 90 knots were only marginally survlvablP.. The survlva'.>le occupan• density**d~pic~ed** in figure 2in the 75- to 90-knot**~ectors** probabl:· is actualiyaligned more closely with the 75-knot limit. The**resulti~** boundary of the survivable envelope Is depleted in fiwue 4 by a line from zero degreesat 75 knots, to 45 degrees at 60 knots, and to 90 degraes at 45 knots. Figure 5 compares Impact severity for occupants who could have benefitted from usinga shoulder harness with alloccupants who actuallysurvived. The topplot repres(nts all oocupants who actually survived, some of whom were wearing a shoulder harness. The bottom plot Includes fatally and seriously Injured occupants who l!ould have**oe~n** les."'**scrloa~;ly** Injured had they worn a shoulder harness. That the two presentations ore so closely similarIndicatesthat thebenetits tobe gained from shoulder harness use may rot significantly expand the envelope In which accidents are survivable. Rather, the usc of shoulder harnesses will reduce Injuries and prevent fatalities In accidents which basicaily are survivable. The primary reason for this Is that the limiting factor In expanding the survivable envelope, to**l~lude** higher speeds, Is cockpit and cabin Integrity. The loss of cockpit/cabin Integrity results In the loss of a "livable volume" In high-speed, high-angle Impacts which precludes occupant survival**regardle~** 

## ot the Installation of shoulder


## 000011Figure 4.-Survivable envelope for general aviation**,~cidents.** harnesses and other protective systems. To significantly expand the survivable envelope to include higher speeds, the airframe would need to be designed to higher structural limits. Figure 6 depicts the impact severity for occupants whose injuries would have been less severe if energy-absorbing seatsh&d been IJsed. •Yhile the number of occupants who would have benefitted from these seats is relatively small compared to occurants who would havebenefitted from shoulder harnesses, the pattern of impact speeds and impact angles in which benefit is obtained is similar. As with shoulder harnesses, the potential lJene!it of energy-absorbing seats**require~** the maintenance of a livable cockpit/c&bin vc•.ume. PotentialBenefitsofShoulder Harnesresand Knergy-AbsorhlrJ{ Seats In addition to developing data on impact severity, an important part of this study wes to assess the magnitude 

### ot the benefits that \!ould be eJ<pected from the use of shoulder harnesses and energy-absorbing seats. There were five survivable accidentsin which shoulder harnesses**w~re** worn by only oneof two front-seat occupants. Acomparison was made of the relative injuries of each occupant. It was found In each case that injury severity was less for the occupant who wore the shoulder harness. The lmprct angles ranged from near zero degrP.es to 30 degrees, 81"\d Impact speeds ranged from 30 to 7S knots. As expected, the higher speeds corresponded to Impact angles under 15 degrees, and the higher Impact angles (greater than 20 degrees)**~'Orresponded**tothelower Impactspeeds. None ofthe accidentsinvolved postcrash fire. (See table 1.)



## 000012-10-

IO

15

Occupants WhoActually 

### Survived (321 Occupants)

IO

Occupants WhoWould 

### Have Benefittr.td from Shoulder 

### Harnesses (330 Occupants)


### Figure 5.--Impactangles and Impact speeds: Occupanhwho actuslly survlvr:d and occupants

### ot**surv~vablo** 

### accidents who wouldhave**benefltte~** from using a

### shoulderharness.

### 0000\~



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### (93 Occupants)

Figure 6.-lmpact anglesand lmpcctspeeds: Occupants who would have benefittedfrom energy-absorbing seats

Table 1.--Side-bySideInjuryComparison Injury level Impact severity With Without shoulder shoulder Impact speed Impactangle Example harness harness (knots) (degrees)



## --- 1 

### Serious**Se~lous** 

### 45-60 5-10 2 

### Mlno:- Serious 60-75 0-5 3 Minor Seriou& 45-60 0-5 4 M!nor Serious 30-45 25-30 5 

### Serious Fatal 45-60 0-5
In eachoftheseaccidents, the occupant who wore a shoulder harness had fewer and less severe lnjl!l'les than the occupant who dld not. For**e~:ample,** 

### In one accident each of two occupants sustained serious Injuries, but the pilot, wearing a shoulder harnt:ss, sustained a broken leg and a slight concussion while the passenger without a**~houlder** 

### harness sustained severe head Injuries. The differences In the Injuries In tht>se comparisons were related to head and upper body injuries. Those persons who wore shoulder harnesses had markedly fewer head Injuries. As would be expected, ahoulder harnessesdld not prevent Injuriesto thelower torsoor tothe exttemltles.



## 00001t1-12-

Estimatesof Should£r Harness Benefits.--Sin<.'e this study did not evaluate accidents in whieh the injury levels were only mino.- and none, the estimates of shoulder harness benefits present.ed in this report are**con~crvative.** For example, there were a number of Sf:!'/ere accidents in the 1982 data base in which .le<'Upants ret.!eived only rrinor or no injuries, because they were wearing shoul:1er harnesses. While an analy<;is of these accidents would havl:' further**strE:ngthen~d** this study, there was no timely way to isolate those accidents. Further, the estimates of benefit presented in thi-> report are based on the existing fleet .)fgeneral nv;ation airplanes. Any improverne11ts in airframes which are incorporAtec1 in the fature that will result in**i~iprovcd** prcscrvntion of the "livable volume" will ir.r:rense the importanceofsh0uldcr harness use. There are two important**~"lements** whictt must be S3tisfied in order to realize the full beraefits of shoulder harnesses. First, the shouider**harn<~s.s** must be Available for use. Only 40 percent of all airplane occupants examined in this**~•tudy** had shoulder harnesses avAilable. The second element is tttat (jf use; A shoulder harne;;s cL.nnot protect an occupant from injllty in a crash if it is not being worn. Of the 253 occupants whose shoulder harness use**coul~** oc determined, c·•lY 100 persons, Oi' 40 percent, actually used the available devices. (See f.gure 7.) Combining the availability rate (40 percent) a:Jd the usage rate (40 percenti indicates that 16 percent of the occupants were wen.-ing ""oulr1er har·nesses. Oi the occupants examined in this study, 71 percent occupied front seats, And 97 pl.'rcent of the 9ersons wearing shoulder harnesses were front-seal occupants. This indicates that the use of a shoulder harness is <:onfined almost entirely to front seats. Shoulder harness availability was determined for 771 of the 902 front-seat occupants. Fifty percent of those occupants (382 out of 771) had shoulder harnesses available. Shoulder harness use could be established for 240 of the 382 front-seat occupants. Forty percent of these occupants (97 out of 240) wore their shoulder harnesses.



### Shoulder Harness 

### Not Available (843) 

### or Availability 

### Not Determined Use 

### Unknown (172)

Figure 7.--Shoulder harness availability and use. 

# 00001[;-13-

Fewer shoulder '.1arnesses were available for rear seat occupants. Availability was determined for 304 ol the 366 rear occupants. Fourteen percent of those occupants (43 out of 304) had shoulder harness available.**Shoulc~r** harness use could be establi3hed for 13 of the 43 rear seat 0ccupants. Only 23 percent of these occupants (3 out of 13) wore their shoulderharnesses. Many of the occupants who had shoulder harnessP.s available were not required to wear them. Although crewmembers are required to wear shoulder harnesses for takeoffs and landings, many did not. Some crewmembers forgot to put their shoulder harnesses**ba~k** on when it became evident that an in-flight emergency would lead to a crash. These issues will beaddressed in the next reportofthisseries. Each of the 1,268 occupants was evaluated separately. Potential benefits were established for 1,111 occupants. The potential for benetit for the 157 remaining oc<'upants could not. be determined. Detailed data were collected on specific injuries and on the extent to which these injuries eithercould have beenpreventedorcould have been less serious throughtheuse of a shoulder harness. Of the 859 fatally lnjurl!d occupants in this study, the potential for benefit of shoulder harnesses could be established for 800 persons. There were 163 occupants who could have survived but did not. It is estimated that at least 13 percent (106) of the 800 fatally injured**person~** in these accidents would have beeninjured only seriously ifthey had been using shoulder harnesses and that an additional 7 percent (57) of the fatally injured persons would have had only minor or no injuries. The expectedbenefitsare even more pronounced for those who were seriously injured. Fully 88 percent (201) ofthe 229 seriouslyinjuredpersons who couldbe evaluated 1r. this study probably would have received less severe head or**upp~r** llody injuries, (•:1;.y minor injui"ies, or no injuriesatallifshoulder harnesseshadbeen worn. (See figure 8and table 2.1



### Minor/ Fatal Serious Actual Injuries
800 

### 229 Projected Injuries 

### 637 155 319

Figure 8.--Dlstrlbutlonofoccupant Injuriesas actually occurring and as expected with full shoulderharnessuse.

### None

82



# 000016

### -14-

Table2.--Injurydistributionasactually**occurri~**

andas

### prec.ilct,'<lgiven fullshoulder harness U&e. 

### Occupant Injury Original h;jury Predicted injuries level distribution with shoulderharnesses Fatal 800 637 Serious 229 

### 155 Minor/none 82 319 

### 1,111 1'

### 111 Percentage change -20 -32 

### '-41) N.A.



### Table 2presents the net benefits of shoulder harness use. The 163 fatally Injured occupsr.ts who would not have been Injured fatally if a 

### shoulder harness had been worn would have received, Instead, serious, n,fnor, or no Injuries. Likewise, 180 of the persons (79 percent) who were Injured seriously without shoulder harnesses would have h11d only minor or 

### no injuries with a shoulder harness. As 

### a result, the**n~t** 

### change Is a 20-percent reduction In fatRllties and a 32-percent reduction of serious Injuries. In addition to this benefit, 21 persons (9

### percent) of the seriously injured occupants if1 

### this study, while still expected to have serious Injuries even with a shoulder harness, would have had significantlyless serious head orchestInjuries. These additionalbenefits arepresentedin parentht'Ses intable 2.**B~ause** 

### the data presented In table 2 include a 

### large number or persons from nonsurvlvable accidents, the percentage change In benefits orshoulder harness use is not as graphic as would be the case If only survivable accidents are considered. Table 3 presents the potential benefits of shoulder harness use for the occupants Involved in survivable accldent3 only. Por the purpose ofthis presentation, 584 

### ofthefatally injured occupants were removed from the data basebecause they were involved in nonsurvivable accidents. Thus, in survivable accidents only, shoulder harnesses could have prevented 75 percent (1G3) ofthe 216 fatelitles, and 79 percent ofthe 229 serious Injuries. Overall, ofall occupants ofsurvivable accidents who had fatal orseriousinjuries, 82 

### percent could be**exp~ted** 

### to have received a significant benefit in terms of injury reduction through shoulder harness use.

Or'glnalinjury distribution Fatal

Serious

TotalofFatal and Serious Table 3.-oceNpanta

### tnsurvivable

### accidents: Potentialbenefitaofahouldel' harneseuse.



### 216

229

445 Expecteddistrlbutlon with shoulderharnesses Fatal Serious Minor/none Serious Minor/none Total who benefitted 53 106



### 57 49 (21) 180

343 (364)

## !I Percentage 

### 25 49 26 21 79



### 77 (82) 1/ The number 364 (82 percent) Is complied from the 106 occupants coded fatal to serious, the S'7 

### occupants coded fatal to minor/none, the 180 occupants coded serious to minor/none, and the 21 occupants out of 49 who were coded

### serious to seriousbut would have had lessseriousInjuries. 

## 0000 1"/\,r



# .. 

# ·'• ' ' t/ I L I 

# .. •••

, • ' '



### -15-

Estimates of Energy-AOs<>rhing Seats Benefits.--Energy-absorbing seats cannot he expected toprevent many fatalities since thepredominant injuries which they can prevent are spinal injuries. These injuries rarely result in a fatality except when they prevent timely egress. However, they usul.!lly are severe, long-lasting, and costly. Evaluation of the data in this study indicated that about 2 pt>rcent or the fatalities could have been prevented if 

### energy-absorbing seats had been available. Many serious back and neck injuries can be prevented if verti!!al energy management is considered during seat design. This study found that about 34 p<:rcent nf the occupants who had serious injuries could be expected to have had significantly fewer serious injuries if they had been seated in energy-absorbing seats. An importal"'t consideration In achieving these potentialbenefits Is that, inorder for an energy-absorbing seat to provide occupant protection, the occupant must remain in an upright position and tile seat muc;t remain in place. This means that the c.ccupant mustbe restrained by a lapbelt and shoulder harness. Installation of improved seats, in the absence of shoulMr harness use, will not produce the improvements noted above. \toreover, it is important to note that nearly 27 percent of the seats in survivable accidents did not remain attached. 10/ When a seat does notremain securely attachedto the floor, occupant injury protection 'lffered either by the scat or by the lepbelt and shoulder harness Is considerablyreduced. To summarize the benefits that could be expected from the use of shoulder harnesses and energy-absorbing seats, it was established that 20 percent of all fatalities could have been prevented by the use of st;oulder harnesses and that 91 percent of the seriously injured occupants could have hart leJS 

### serious head, upper body, and/or back injuries with the use ofshoulder harnessesand energy-absorbing seatscombined. Shoulder harnesses alone could have prevented or minimized the severity of the head and upper body injuries for 88 percent of the seriously injured occupants; energy-absorbing seats could have prevented or minimized the severity of back**injuri<~s** 

### for 34 percent of the seriously injured occupants. CONCLUSIONS
1. 

### Shoulder harness use is the most**effe~tive** 

### mdhod of reducing fatal**~tnd** 

### seriousInjuries in general aviation airplane accidents. 2. New crashworthy airframe design is the improvement which will most signi.'icantlyexpand**th'~** 

### survivable envelope to higher impact speeds. 3. lmpnct severity, as defined by impact speed and impact angle, Is a principal determinantofa survivable**ac~ident.** 

### 4. The accidents reviewed in thi.l study generally were survivable within the envelope bounded by & 

### line through an impact speed of 45 knots at an impact angle or90 de<t{rees, 60 knots at 45 degrees, and 75 knotsatzerodegrees. 5. Apotential 20-percent reduction In fatalitiescouldberealized ifalloccupants ofgeneral aviationairplanes were to wear shoulder harnesses. 6. Potentially, 88 percent of seriously injured occupants could be expected to Incur significantlyreducedInjuries Ifshoulder harnesses were used.



### lO/-Asea(aifachment failure is defined inappendix Dunder "Seatretention." 

# . -

# .

OOOOIH • • "'1 ••


### 8.

9.

10. -16-

A potential 2-percent reduction in fatalities could be realized wHh the installationof energy-absorbing seats. Potentially, 34 percent of seriouslt injured occupants could be expected to have significantlyreduced injuriesi energy-absorbingseatswereetvailable. Where shoulder harness Availability and use could bt> determined, only 16 pP.rcent of the occupants were wearing a shoulder harness at the time of the crash. Shoulder harnesses were available t.o 40 percent ofthe occupants and, when available, were worn 40 percent ofthe time. Tv.enty-seven percent ofallseatsin survivable accidents underwent some type offailure.
BY TIIB NA'nONALTRANSPORTATION SAPBTY BOARD

:\iarch 15, 1985 

### lsi JIM BURNETT Chairman 

### lsi PATRICIA A. GOLDMAN Vice Chairman 

### lsi G. H. PATRICK BURSLEY Member



# OOOOlB

## . . . ' • •

. • r

_.

. .



## . .

-17-

APPENDIXES
APPENDIX A NATIONALTRANSPORTATION SAFETY BOARD OHNRRAL AVIA110N (,RASHWORTHINKSS RHCOMMBNDATIONS WITH SUMMARIES OF FEDERAl, AVIATION ADMINISTRATION RJI..SPONSES AND SAFETY BOARD EVALUATIONSOFTHBSB RRSPONSBS The**Safet~·** Board has issued a series of general aviation crashworthiness recommendations since 1970. Aseriesof letters to and from the FAA discuss the variot·s fsgues and anticipated actions generated by those recommendations. The last formal FAA response to those recommendations was a letter to the Safety Board that was dated March 21, 1983. That response and the current FAA crashworthiness efforts resu:ted in the Safety Board issuing a letter to the FAA dated September 5, 1984, excerpts of \:hich follow.
Recommendation CY-70-42, Part 4 [Initiate] regulatory action ••• to raise·the "minor crash lAnding'' im

..rtia forces of 14 CPR 23.456 to o level comparable to those produced by a mode:ate-to-severe crash landing. Until a reasonable crashdesign condition is decided upon, Including a specific<! crash acceleration pulse, it is suggested that the longitudinal Inertia force be raised to 20 to 25 and the forces about other axesbesimilarly increased.
The FAA has respooded that attempts at interim regulatory action without a technical d&ta base would not be productive, and that energy management must be fully assessed .iinc€stronger seats have to be stiffer and thereby would transmit more crash loat1s to the occupant. Upon completion of its research activities concerning crash pulse definition andcomputer modeling, the FAA plans toinitiate appropriate rulemaking.
Since Its March 21, 1983, correspondence to the Safety Board, the FAA, at the GASP meeting of September 27, 1983, has made preliminary proposals for crast> 1ynflmie standards which were considered by the GASP committee. A GASP proposal for ;at and restraint standards was agreed upon, and the proposal**ha~** been forwarded to tl'c FAA. If adopted, it would fuUill theintent'.>f ::-'illfety Recommendation CY-70--12, Part '· for higher crash force requirements.
In vlew of thepresent FAA/indu:1try effort tow&rd the development ofcrashlanding design standards and other general a.-latlon crashworthlness requirements, the Safety Board has reclassified the status of Safety Recommendation CY-70-42, Part -1 from "Open--Unacceptable Action" to "Open--**Accepta~le** Action" pending the outcome of these efforts.**R~ommendation** A-77-70
Amend 14 CPR 23.785 to require installationc·fapproved shoulderharnessesat all seat locations as outlined in NPRM (Notice of Proposed Rule**~,aking]** 73-1.

### oooo~oAPPENDIX A 

### -18-

The FAA forwarded to the Safety Board a copy of a cost-benefit analysii for shoulder harness installation, and the FAA intends to consider this cost-benefit analysis, GAMA**~ecommendations** on shoulder harnesses, and the recommendati'lns from the "Smell Airpl8ne StallSpeedSi.udy" committeeir• determining what action to tAke on this issue. Safety Recommendation A-77-70 encompasses two specific areas: (1) installing shotJlder harnesses o'\all seats on newly manufactured airplanes, and (2) requiring existing airplanes to be retrofitted. GAMA has petitioned the FAA to rP.quire shoulder harnesses on all seats of small airplanes manufactured after 1984. Also, GAMA and the Society of Automotive Engineers (SAE) are working on shoulder harness design requirements which will facilitate such installations. Industry reprt.•sentatives also t:ave voiced support ror voluntaryefforts toretrofit the curreilt fleet with shoulderharnessesat most seats. The recommendation for shoulder harness retrofitting at all seat locations should be addressed, and the GASP forum is an ideal one in which to discuss this**is~ue.** The Safety Board recognizes that the current GASP taskof defining dynamic testing and installation requirements must**b~** resolved first. The Board has sut.>mitted data to the GASP which clearly show that many lives can be saved if the current airplane fleet is equipped with shoulder harnesses. Until the FAA responds on the retrofit issue and takes actionon the GAMA petition to require shoulder harnesses on all seats, the status of Safety Recommendation A-77-70 will remainin an "Open--Unacceptable**A~tion"** status. Recommendation A-80-125 Require that those general aviation aircraft manufactured to include attachment points for shoulder harnesses at occupant seats be fitted with shoulder ha1·nes.<;es no later than December 31, 1985, and, iil the interim, require this moJification as a requisite for change in FAA registration.
The FAA stated that Safety Recommendation A-80-125 was addressed in its costbenefit analysis and that it will be evaluated with Safety Recommendation A-77-70. Therefore, pending further evaluation by the FAA of the retrofit issue and in view of thr close relationship of this recommendation to Safety Recommendation A-80-127, the Safety Board will change the status of Safety Recommendation A-80-125 from "Open--Acceptable Action" to "Ope'l--Unaccept'lble Action." Recommendation A-80-126 Develop, in coordination with airframe manufacturers, detailed, approved**inslalla~ion instru\~tions**  for installing shoulder harnesses at each seat location in current models snd types of general av:,tion aircraft in which shoulder harness attachment points werE: not provided as standar<' equipmerat. Publish and provide these instructions to owners or those aircraft by December 31, 1982. The FAA st'ltesthat design functions are the responslb!lityof the manufacturers or owner
.. and that the provisions or Safety Reeommendaticn A-80-126 are not within the scopeofthe FAA's responsibility.



## 000021-19- APPENDIX A

As statedin its November 5, 1982, letter, the Safety Board recognizes that the FAA does not perform detailed desigr, work; however, the FAA, on an almost dailv basis, tests and evaluates crashworthiness designs at the Civil Ae.•omedical Institute :CAMI). The s•arr at CAMI has**b~en** constructive In suggesting imi>rOVE.ll1ents in seat and restraint designs developed by**manufacturP.r~.** It is that type of ccordination to which the Board refers. Members of GAMA are voluntarily invoived in pursuing the intent of this ree:ommendat!on. GAMA has stated that the three ma)or manufacturers now have FAA-approved kits to :-etrofit shoulder harnesses to**old~r** airplanes and that tt intends to promote the retrofitting or such restraint devices. The Safety Board recognizes that there may besome olderalr!)laneo; inwhich retrofitting is not possihle, butthe majority cC the fleet now can be retrditted with**ex~sting** kits. However, to be most eCCective, this effort will require FAA support If shoulder tlarnesses are tobeinstalled ina largenumber or airplanes. The FAA has informed the GASP committee that it ir.tends to pHblish !in Advisory Circular to assist designers in developing bPtter restraint and seat systems, and that it will promote the inst11Hation and use of shoulder harnesses in gener3l aviation airplanes. The Safety Board considers the proposed FAA action as fulfilling the intent or Safety Recommendation A-80-126. Tt.erefore, Safety Recommendation A-80-126 has been reclasshied from "Open--Una<'ceptable**~ction"** to "Open--Acceptable Alternate Action." The Board encourages the FAA to expedite the develcmment of the Advisory Circular, and it requeststhat the FAA provide the Board its plans tosupport the voluntary retrofit effortas announced at the GASP meeting. Recommendation A-80-127 Require that those general aviation ail'craft for which FAA-approved harness installationinstructions have been developedbe fitted with shoulder harnesses at each seat location no later than December 31, 1985, and, in the interim, require this modification asa requisite Corchange in the FAA registration. The FAA stated that Safety Recommendation A-80-127 was addressed in the costbenefit analysis and that it will be evaluated with Safety Reco:nmendation A-77-70. Therefore, pending FAA':o; further evalu&tion of Safety Recommendations A-77-70 and A-80-125, the status of Safety Recommendation A-80-127 also will remAin "Open--Unacceptable Action." Recommendation A-80-128 At established intervals, extend the application of all newly established occupant protection provisions of 14 CFR**2~** to all newly manufactured generalaviationaircraft. The FAA has responded that the broad general scope or such a recommendation makes it difficult to determine what occupant protection provisions the Safety Board is addressing. The FAA believes that periodic Part 23 regulatory reviews, now part of its regular process, adequately address the Intent of Safety Recommendation A-80-128. Moreover, retroactive application of new regulations must comply with Executive Order 12291 and cost-benefit analysis, "illustratu tt.at retrofit schemes are t)opically very costly, with littleIdentifiablebenefit." It was not the Intent of Safety Recommendation A-80-128 that airplanes already manufacturedbe retrofitted. Rather, itsintent was to eliminate the "grandfather" clause under which airplanes type-certificated many years ago still can be manufactured today without**lncorpo~·ating** known safety improvements. Manufacturers repeatedly introduce


# 000022APPENDIX A -20-
significant new features !n aircraft during yearly model changes using the same type certificate. The Beech Bonenza, Cor**exampJ~,** has had many new seat designs during the 35 years since itstype certificate was issued. The Safety Board believes that newly established occupant protection provisions, such as improved seat designs in newly certificated airplanes or in new models of existing alrplsnes,**~hould** be extended by regularly scheduled Part 23 t1esign reviews to all newly manufactured airplanes. Pending further FAA review, the -;tatus of Safety Recommendation h-80-128 will remain "Open-Unacceptable Action." Recommendation A-80-129 Revise 14 CfR 23.785(J) to incorporate performance standards and test criteria to lmure that ttn acceptable level of occupant safety is achieved through cabin "delethslization." The FAA has restated itsbeliefthat it Is not feasible to o!"oceed in accordance with**Sa~ety** Recommendatlon A-80-129 becauseofitsbroadgeneral**:..~~cpe.** Moreover, the FAA suggest3 that advisory material developed In the FAA general aviation crash dynamics program will be sufficient to supplement regulatory actions. Both Safety Board and FAA acddent investigations have identified numerous areas where present cabin delethsllzation ml•asures did not work. No standarlis exist to define acceptable methods to prove that the delethalization designs perform as intended. The Safety Boar<' is not attempting to limit the many ways in which these problems can be solved; it only seeks to limit the manufacturing of aircraft with inadequate safety provtstons. If the FAA wiU not specify test and performance standards that ensure adequate safety designs, so called "delethalized airplanes" th3t cause Injury will continue to be manufactured. Since the FAA will not act on this recommer.daHon, Safety Recomme1dation A-80-129 hasbeenplacedin a "Closed-Unacceptable Action" status. Recommendation A-80-130 devise current standards for seat and restraint systems to Incorporate needed crashworthiness improvementsidentified in FAA Research Project reports. Although the FAA concutatd with the intent of St.fety Recommendation A-80-130, it planned no definitive action without specific information**~llncernlng** crashworthinest improvements. Since this response, the Safety Board haslearned informally that the FAA is In the process or developing an Advisory Circular tor crashworthy seat design because investigations have disclosed that there are deteriorated seat pans in the fleet which rip easily when a tear starts. Although the FAA's staff has stated that Part 23 will never provide the standardstosolvecrashworthinessproblems, the Boardbelievesthatseatsand restraints need to be designed to standards other than just strength**req~.&!r~ments.** However, based on the FAA staff's proposed development of an Advisory Circular to establish broader guidance, the status of sarety Recommendation A-80-130 has been changed from "Open--Unacceptable Action" to "Open--Acceptable Alternate Action." The Board encourages the FAA to expedite the development of the**Advl~ry** Circular and would like to receive a**tlm~table** for Its development aswellasanC'ltUreofitsproposed content.



# 00002**:~**

### -21- APPENDIX A**h~commendatiOil** A-80-131 Estab!ish standards for the dynamic testing of occupant protection devices required in general aviationaircraft. The FAA stated in a response of April 3, 1982, that it was waiting to determine dynamic load characteristics, end it asked the Safety Board to identify other "devices" to which it might have had reference. Based on the Safety Board's further clarificationin its letter of November 5, 1982, the FAA stated on :\1arch 21, 1983, that it appears that the intent of Safety Recommendation A-80-131 would require testing of all immediate components ofthe cockpit/cabinenvironment without sufficient rationale orjustification. The FAA concluded that testing would be an enormous undertaking and inconsistent with the Regulation by Objective concept the FAA was then advocating, and that the Safety Board should reconsider itsposition. The Safety BMrd recommended that dynamic**t~sting** ofoccupant protectiondevices be required in general aviation aircraft. The reason the word "devices" was used is that there are many ways to protect occupants. The most straightforwardapproach led to the design of the seats and seatbelts and shoulder harnesses as we know them today. l!owever, in the future, a manufacturer may opt f.o use energy-absorbing cabin structures to reduce O<!cupant crash loads. Such energy-absorbing devices should be proven by dynamic testing. For instance, an effective enm·gy-absorption device could be a better landing gear design. A manufacturer's representative at the GASP meeting agreed that standards for dynamic testing are needed. The CAMI has been testing full-scale fuselages for years, and many deficiencieshavebeen found in occupant protection .1evices thnt would not have surfaced except for dynamic testing. This type of testing of new aircraft models would not be an enormous undertaking; it is the only valid way to test the effectiveness of devicesthat are to function in a dynamic environment. Again. with the formation of the GASP crashworthiness committee, the upcoming Par! 23 regulatory review, and the FAA's crashworthiness program plan, the Safety Board looks forw.ud to progress in increased occupant protection in generAl aviation airplanes. Therefore, in view oftt.esepositive steps, thestatusof Safety Recommendation A-80-131 has been changed from "Open-Unacceptable Action" t'> "Open--Acceptable Action" pendingthe resultsofthese activities.



# 000024-22-

APPBNDIX B
COMPARISON OF STUDY DATA WITH NATIONAL AERONAUTICS AND SPACR ADMINISTRATION CRASHTEST DATA In 1973, the National Aeronautics and SPflce Administration (NAS.A.i initiated full-scale crash testing of general aviation airplanes in an effort to define the dynamic response of airplane structure, seats, and occupants during survivable crashes. The 24 tests, which wt-re concluded in 1982, WE're accomplished by cushing airplanE's into concrete ot dirt under controlled flight conditions. The impact angles and Impact speeJs for the tests were chosen to closely approximate impact speeds and angles of actual general aviation airplane crashes. These tests provided data about structural and occupsnt response which are useful to designers involved in the development and tesdng of new crashworthy systems. Acomparison of the NASA data with data from the actual crashes of general aviation airplanes described in this report is useful in confirming that the tests were representative of actual survivable accidents. The current Safety Board study of impact data confirms that the NASA testing scriPs represented real-world general aviation survivable crashes. Impact severity data presented in NASA Tect.nical Paper 2083 

## !!Iwascompared with thedata in thisstudy. The 24 sets of impact speeds and impact anrles generated by the NASA tests are shown In figure 9. This figure shows that most ofthe NASA tests fall within the impact severity envelope of survivable accidents presented in this study. The**thr~t** tests outside the envelope were**consi~c:red** survivablebecause the impactstoconcrete ;.;;suited in small velocity changes and small accelerations. One test within the survivablE- envelope (45 degrees and 52 knots) was only partially survivable because of the crust.ing in the cockpit area. Another test within the survivable envelope was considered nonsurvivable because of the high accelerations and extreme crushing (loss of a livable volume). That test consisted of an airplane impacting soft dirt. The dirt impact resulted in an abrupt stopand high acceler'ltions instead of the typical impactand slide exhibited in other tests ·.vhich impacted concrete. In summary, the NASA tests end the results of this Safety Board crashworthiness study combine to provide a foundation for future crashworthiness design efforts. The present SafP.ty Board study has yielded real-world data conC(!rning the limits or the impact severity envelope of survivable eccidents, and the NASA test results provide the precise engineering dP.ta which are the basis Cor the mathematical models needed for desig!lingbettercrashworthyequipment.

11/Nationaf-Aeronautlcs and Space Administration (NASA) Technical Paper 2083. "Correlationand Assessment ofStructural Airplane Crash Data with Flight Parameters at Impact,**19~2."**

### oooo2~)**~--**

# --~ 

# -- ro**~:**

## _,

# . ...,.._,

# .. oneiMCIWI APPENDIX 8

- Ropr-'llht<>Mvable limila M**do!er~** bythe study

Figure 9.-Impaccangle aoo Impact speed: Comparison ofNASA tellt crashesand Umltsofthesurvivableenvelope.



## 00002h

## I ( I I 

# . ' I ' 

### ·. ' 

# / I ' I '1.- • 

### ,0

### . I r .



# . ·- 

## ;,! ·' • 

### . 

## \



# ...

-24-

APPHNDlX C KXCnttPTS PROM THE GRNERAL AVIATION SAPIITY PANEL PROPOSALTOTIIB FEDERAL AVIATION ADMINISTRATION '

Dynamic:: TestingofSeftt.s Recommer1ded seat criteria for small general aviation aircrnft &pplying fer initial type certifi.!ation after December 31, 1985, for operations with**fe~1er** than 10 passenger seats.(a) Each seat, bench or other device for crew or passenger occupancy must succfllsfully completedyne.mic tests with an occupant weight of 170 pounds in Accordance with eachoftheconditionsstatedbeiow. (1) A change in velocity of not less than :!1 feet r"r seccnd when the seat, bench or other seating device is oriented in its nornin.1l position with respect tothE; aircraft'sreference system and the aircrdft'slongitltdinalaxisis canted upward 60 degrees with respect to the impact velocity vecto.· ond the aircraft's laterdl axis is**perp~ndicular** to a vertical plane containing the impact velocity vector and**th~'** aircraft's longitudinal axis. For the aircraft's first row of seats, peak deceleration must occur in not more tha'l .OS seconds after impact and must reach a minimurn of 1g g's. For all othe;o seats, peak decleration must occur in not more than .06 seconds after imoal!t Anti muc:t reach a minimum of 15 g's. {2) A change in velocity of not less than 42**r~et** per second when the seat, bench or other seating device is oriented in its nominal position with respect to theaircraft'srefErence system and the aircraft'slongn\ldinolaxisis yawed 10 degrees eitherright orleft ofthe impact velocity vcPtO!' (but in such a way as to cause**th~** greatest loari on the upper**to~so** restraint system), the aircraft's lateral axis is contained in a horizontal plane containing the impact velocity vector and the oircrdft's vertical axis is perpendicular to a horizontal plane containing the impact velocity vector. For thP. aircraft's first rov• of seats, peak deceleration must occur in not more thsn .05**second~** a(t«·r impact and must reach a minimum of 26 g's. For all other seats, peal. deceleration must occur in not more than .06 seconds after impact and must reach a minimum or 21 g's. (Note: The aircraft's reference system is defined asconsisting of three mutually perpendicular axes where the vertical axis is perpendicular to a waterline reference system of the aircraft and parallel to the station reference system and the ltlngitudinal ftxis is perpendicular to the station reference system. The velocity change shaH be pure translation wltit no angular acceleratlon considered.) (3) The floor ralls used to attach the seating device to the airframe must be •nisallgned with respect toeachotherby &t least 10 degrees vertlc&Uy (I.e. outofparallel), with the direction at theoption

## or the manufacturer, to account for noor warp. · 

# .

.

### .

### -25- APPENDIX C
(4) Dynamic tests in accordance with the conditions stated in paragraph (a), subparagraphs (1), (2) 

### and (3) 

### are considered to be successfully completed when theperformance measures(4a) through (4n aredemonstrated. (4a) Loads in individual upper to.-so straps do 

### not exceed 1,750 pounds. If 

### dual straps are used for retelning the upper torso, the total strap loads do not exceed 2,000 pounds. (4b) The maximum pelvic load as measured in a 11 CFR 

### 572 dummy does not exceed 1,50') pounds. (4c) The occupant's upper torso strap or straps remain on or in the immediate vicinity oftheoccupant's shoulder during theimpact. (4d) The lapbelt remainson theoccupant'spelvisduring the impact. (4e) the occupant's head either does not contact any portion of the cockpit or cabin or if it does, the head Impact does not exceed d 

### Head Impact Criteria (HIC) of 1,000, as determined by the test procedures defined in SAE J921.(4() The attachment between the seating device and the aircraft's structure remains intact (although the structure can have exceeded its limit load) and tha restraint !>ystem remains intact (although it also can have experienced separation that is Intended as part of its de.slgn) as long as the conditions contained in (4a), 4b), (4c), (4d) and(4e) are met. (b) In a<ldition to the dynamic tests and criteria defined in paragraph (a) and its subparagraphs (1) 

### through (4f), 

### all seats, benches, or other seating devices and its supporting structure must be designed to withstand the static loads 

### Imposed by a 215-pound occupant when subject to the aircraft's design loadsasdefined in theaircraft'sapproved flight/ground envelope. (c) Paragraphs (a) 

### and (b) 

### above specify a 

### minimum standard for new aircraft with application Cor typecertificationdatedafter December 31, 19S5. An applicant for a type certificate has the option to depart from th£> criteria presented in paragraphs (a) 

### and (b} above provided a'l alternate approach that achieves the same or equivalent level of occupant crash tolerance can be substantiatedon ArAtionAl 

### 1-,asis. Mandatory Equipage

### ofShoulder Harnesses The General Aviation Safety Panel affirms itsearlier recommen<!

....tlon that all 

### PAR Part 23 general aviation aircraft menufacturedafter December 31, 1984 be equipped with upper torso restraint systems. We further recommend that the the FAA considerwaysto facilitate the installation of upper torso restraint systems In older general aviation aircraft, and that the FAA work with the SAr. Upper Torso Restraint Committee to formulate acceptable standards for harness material and attachments to be used In aircraft manufacturedafter December 31, 1985.



# 000028

### General -26-

APPBNDIX D MBTHODOLOOY

In 

### 1982, the Safety Board began collecting substantially more detailed informatioa on general aviation accidents than it had in the past, which could be used to define crash severity and Injury causation factors. For the first time, more**comple'.·~** 

### Information on airplane speed, Impact angles, and terrain condition was available for analysis as was more completedocumentationofseats,restraint systems, and occupant injuries.
In order to select accidentsparticularly suited for a studyon the potential for injury reductlon, the Safety Board's most recently completed general aviation data base (1982) was examined. A subset of accidents in this data base was selected which represented only**flxed-wi~** 

### airplanesIn which atleast one occupant sustained fatal orseriousinjuries. From this subset, certain accidents were eliminated: principally those which involved older airplanes of fabric and tube construction, home-built airplanes, and agricultural application airplanes (crop dusters). Also eliminated from this study were aircraft involved In on-ground collfsions. The remaining airplanes were those which are or could continueIn production and which would notbe expectedtobe eliminated from the general aviation neetin anysubstantialnumbers inthe next few years. The resulting set of 535 accidents was evaluated by Safety Board investigators experienced in •.t.e patterns ofInjury causation in general aviation accidents. All records pertaining to each of these accidents were collected, including reporting forms, narratl.,es,**photograp~~.** 

### witnessstatements, and medical Information. Adetailedanalysis was made ofthis Information and qulllitative estimates**wer~** 

### made of the extent to which the accident was survivable. The Injuries ofeach of the 1,268 occupants were evaluated separately, taking lntn occount the availability and use of occupant restraints, the retention of seat st.uctures in their precrash position, postcrash fires, and other important features. The formats used for recording the occupant injury and airframe Impactseverity lnforma·don arepresentedon thener.t two pages. Potentialsurvivors were identified by examining injuries and airplane damage. This examination was appliedon a seat-by-seatbasis for eachoccupant ineachairplane. First, it was determined whether a livable volume was available aroun•J t:!\ch seat. Each space where an occupant was seated had to •emaln esentially unconpromised throughout the crbSh sequence. Photographic documentation was the primary St.'urce of this Information. Seat locations considered nonsurvlveblc were those where the iivablc volume had been destroyed or where ,**~l** 

### volume had been violated severely during the crAsh by a crushing structure that had rebounded, thus giving a final appearance of a livable volume. Some spaces were considered nonsurvivable while tt**~** 

### rest of the airplanr. was t-nnsidered survivable. For example, a tree lrnpinging into one seatlCJCatlon may render thatposition nonsurvivable whlle other seat locatlons are not affected. Proximity of an occupant to the crush line (fiat spot on the airplane caused by ground contact) also affects survlvablUty. Investigative experience has shown that an occupant located near or below the crushliMnormally will

### receive fatal accelerative Injuries.

### 00002~1

### 0 0 0 0 

### w 0 •**~1n~~at1es** 

### Study

-**Alr~lan~** 

### Oata Page**13~7**

### --~-----~---~~~----~--~--------~---~----~--------------~--------------------**fil~ oat~**  

### Loeat1on Injuries**l>aol·a~e** "'i'l•·r**~·at s~r** **~in** NOn 

### Unk

... 0**~** •: lb03 Auq-21-19t12 APf,.;uf.l p;(l 0 () 0 4 0 01:."**~U(II,~.)** "·2v**~** 

### Aeeident HUrnber j.)t'last> 

### Fire**~ot** 

### A'-'Plieable t./1. F..t-ason Initl.**Ot:t~~820A17CJ** 

### LA:\i u

...**~.** 

# ---

---------- 

# - - F'l1QI'\t Patl'l Terrain liiiP«tC'l 

### Fire Angle AnQlt" 

### Velocity



# --- 

# ----- ----- -------- 1.**Yt;~** 1• liP 1. UVSL.OPE 1. 1.1 

# -**1~** :l. NG 2. L'N 2.**"'~1\.Sl.O.,.E** 2.**1~**

# - 3t.• J. U·•F<t..LATt.O 3. () 

# - 5 J. 

# ·.

# - s 3. )\,I

# - 45 

## . 4.**~** 

# .. 10 4. 

### 5

# - 10 4•**4~**

# - Ml :>. 1(1

# - 15**~-** 10

# - 15**~-** t){l

# -**7~** t>.**1~**

# - 20 

### 6. 15

# -20 b. 75

# - ':10 7. 2•} 

# - 25 

### 7. 2v

# - 25 7. 9\.1

# - 120 8. 2: 

# - 30 

### s.**1~**

# - )0 tt. 

### 1:eo-**1~()** 9. 30

# -**4~ ~-**  30

# - 45 

### 9. 

### 150- ll:j(1 

### 1u. 45 

# - (i(I 

## lv. 45 

# -**~0** l(,. 1b (i•

•

### ·--------------------------------~----------------------------------·**~otes** 

### :

### --------------------------~-----------------------------------------~------ 

# ----------------------.
___________,

# ___________

# ·-----------·---..

# ------**--~-----------·-----------~-----------------------------~-------------** 

# ..

# ------**-------~---~---------------·---~------·-------------._._._**

# _____ 

# -------------------------------·----·----------- - ;:J (I 3 I» 

# - C) In en 

# - 5. '<


### >


# - ... 'E. I» ;:J (I 0 I» 

# - I»

I IS) -.:a I



### > 

# "" "" 1:1:1 

### z 0


# - X 0APPENDIX D -28-

Kinematics Study- Occupant Data

File

Region of

Injury

Initials

Notes O:cupant Position Sloulder Available



### 1. Yes 2. fb 3. lhk. Harr.ess Used



### 1. Yes 

### 2. fb 

### 3. Ulk. Seats**llier~w** Absorber



### 1. Yes 

### 2. tb 3. U1k Stayed in Place



### 1. Yes 2. !b 3. llik.

Table of injury improvanents Rerluced by Harness FA Sloulder Harness Seat**(FA~** Retention)

yes no yes no



### 1. Fatal to Fatal 

### 1. Fatal to Fatal



## -- -- 2. Fatal to Serious 

### 2. Fatal to Serious



## -- -- 3. Fatal to t1inor 

### 3. Fatal to flinor



## -- 

## -- 4. Fatal to tbne 

### 4. Fatal to None



## -- 

## -- 5. Serious to Seriouc; 

### 5. Serious to Seriou

.. o:;



## -- -- 6. Serious to ttinor 

### 6. Serious to Hioor



## -- -- 7. Serious to None 

### 7. Serious to 

### NonP 

### 8. Minor to ttinor 

### 8. Hinor to Minor 

### 9. 11inor to None 

### 9. Hinor to None 

### 10. tbne to None 

### 10. fbne to None 

### 11. Fatal to Unl<Jlor..ln 

### 11.**Fat~l** to**Ln~n** 

### 12. Serious to U1J<noo..n 

### 12. Serious to Unkno

... ·n 

### 13. Mioor to Unl<nown 

### 13. Mimr to lJnknoo,.Kl



## 00U03.l-29- APPENDIX D


### Injury Informationcameprimarily from medical reports and autopsies. Injuries that could h!ve beet: reduced or eliminated by the use of shoulder harnesses or energyabsorbing seats \';ere noted. The evaluator then attempted to determine whether the occupant couldha\·e survived Ifthe inJurieshad beenless severeoreliminated. Each accident was evaluated by examining OC!cupant injury and evidence supporting estimates of impact speed and impact angle. Data were documented that detailed shoulder harness availability and use, seat retention, and shoulder harness and energyabsorbing seat**~tre~tiveness.** 

### These data were recorded on an occupant injt•. •y 

### form and an airplane Impactseverity form.

An occupant Injury form was completed for each occupant even if 

### the Injuries of that occupant were minor ornone.

Shoulder harnesses available.--3houlder harnesses were considered avaU,\ble If 

### the accident report 

### so statedor for front seatsof airplanes manufactured after July 18, 1978. AU 

### seats on Beechcraftairplane models from 1975

### on wereconsideredtobeequipped with shoulder harnesses. While some models of general aviation airplanes had shoulder harnesses lnstrlled 

### as options before 1978, 

### the number was considered to be small. Data recorded frorn the older airplanes confirmed that few older airplanes had shoulder harnesses. Shoulder harness use.--In many cases it could not be determined whether shoulder harnesses wereused. Determinationswere made predominantly on the strength of written documentation ofthe investigation and on occupant or rescuepersonnel statements, when available. Energy-absorbing seats.--The only seatsthat werecom:ictcred energyabsorbing were Piper's 

### "S" tube seats. In fact, otherseat designs, such as the Beel'h Musketeer seats, can absorb significant amounts of energy, but they were not coded as energy absort)ing since energyabsorption wcs not a partofthe seatdesign concept. Seat 

### rttentlon.--Ir

### a seat separated from its r.

### ttachment points, or If

### severill ofthe seat feet or

### legs became detached, the seat was classified as loose. 

### Aseat that Is loose, even If it 

### stays close to Its normal position, offers little protectlon. Loose seats were**C~>ded** 

### as "notstayingIn place." AetualInjuriesVersus PredictedInjuries Tf.t.'Jle of predicted lnjurles.--These data were compiled under the assumption that shouldei' harnesses were not worn and energy-absorbing seats were not available. The available data were evaluated to determine the original Injury Index and the predicted Injury Index Ifshoulder harnesses anjenergy-absorbing seatswere used. 12/



### !_!/ Injury Index: The level orInjury-fatal, serious, minor, and none.


# 000032APPENDIX D 

### -30-

In cases where shoulder harnesses or el'\ergy-absorbing seats**w~re** 

### used, the level of injury which would have occurred had these devices not been used was determined. For example, If a seriously injured occupant would have received fatal injuries if that occupant had not worn a shoulder harness, "fatalto serious"WC'uld havebeen coded. For a complete evaluation of the benefits of shoulder harnessP.s and energyabsorbingseats,itis necessary to go beyond the injury index level. Serious injuries range from a fractured bone to severe Internal injuries. An occupant'sskull fracture andbroken leg would result in an Injury index ofserious. If 

### a shoulder harness would have prevented the critical head injury, the occupant still would have a broken lev and the Injury index would remain ''serious." Such a circumstance woul':i '>e coded as 

### "serious to serious," thus Ignoring the significant head injury improvcmant provided by the shouldel' harness. Therefore, a further breakdown ofinjuries w&o;

### required. Region ofinjuryreducedby shoulder harness and energy-absorbing seat.--Body regions ofinjury were given numerical codings when a significant Injury was documented. The Injury then was evaluated to determine whether shoulder harnesses or energyabsorbinz seats would have prevented the injury. The evaluations were done even though theoverallinjurylevel might not have been reduced. Airplane

## nata Fire.--Information about fires was examined to determine whether each fire was theresultofa crash or was an unrelated fire such asthat from a dropped cigarette. PUS:pathangle.--The (light path angle is the angle of the pathof the airplane as it dcsce or climbs relative to the horizon. Flight path information data is a direct entry item in the Safety Board accident investigation forms. When tt-"3e data were not recorded, photographs, drawings, witness statements, and the acciaent report's narrative were reviE'wed todetermine the flight path angle. Terntin angle.--Terrainangle is theangleofthe terrain relative to**tl~e** 

### horizon with reference to the direction of airplane travel. When an airplane impacts sloping terrain, the terrain is considered to have an "up" angle, if the airplane impacts into rising terrain relative to thedirection of**fli~ht. lm~ct**  

### angle.--The Impact angle is thedifference between the flight path angle and the terran angle. A 30-degree impaP.t angle could result from a level flight impact into 30-deg,·eerising terrainor from a 30-degreedive intoflat terrain. lmnct Speed.--lmpact speed is the airplane's speed in knots during the principal impact. 1 1 

### The velocity was estimated based on the aerodynamic properties of the alrplane;-such as stall speed and cruise speed, and also was based on airplane configurations, such as power setting, flap and gear posltior.s, and aircraft weight. In most cases, there was surticient Information to establish whether the airplane was In a stall, near stall, 

### or cruise Immediately before impact. It Y''IS 

### more difficult. to estimate Impact speed in some cases, in particular high-speed dives, Intermediate speeds between stalland cruise, and impactsInvolving multiple strikes.
nrPrrnclp8flmpact occurs when the most severe**d~celeratlve** 

### forces are experienced and the most damage is sustained by the fuselage. The principal Impact may not be necessariiy theInitialimpact.

### onnn:~3-31-

A.PPBNDIX B
PIVB A.CCIDBNT BXA.MPLI!S AND RVA.LUA.TION RBSOLTS 

### Five accidents are presented as examples to show the coding procedures that were used**d~.:ring** 

### the course of this study. These accidents ranged in severity from survivable tononsurvivable. These analyses show the various considerations involved in a crashworthlness evaluation. In each case, occupant movement must be evaluated with respect to the existing or desired occupant protection system. Ho'Ulever, the ultimate consideration In predicting thebenefits provided by crashworthy occupant protection systems rests in the definition of survivability, I.e., a livable vo!ume must be maintained and the accelerative forces must besurvivable.**A.~tdent** No. l 

### (photographs 1 

### through 4) 

### This accident, which resulted from fuel starvation, was totally survivable. During theemergencylanding, the right wing struck a 25-foot-illgh tree.**Th~** 

### airplane contacted the ground 102 feet later and the airplane slid 45 feet. There were three seriousinjuries and one minor injury. Shoulder harnesses were available for the front-seat occupants only, but the shoulder harnesses were not used. All seatsremained attached to the floor structure. The measured night path angle was 14 degrees. Apilot statement Indicated that the airplane was near a naps-up, power-off stall. ThP. Impact angle was coded as 10 to 15 degrees, and the impactspeed was coded as45 to 60 knots.



## .

## , 

# , \\'

Photographs 1and 2. 

# 000034APPENDIX E -32-

Photographs 3 And -1.**oooo:~;)**-33- APPENDIX E


### Occupant 1.

### --The pilot's head had impacted the ir,o;t;ument par.el, and he sustained facial and scalp lacerations, a possible basilar skull f.·ncture, a knee laceratiol", and a fractured right thumb. The energy-absorbing seat in which he was seated had stroked about 1 inch. Since the cockpit area near the pilot's position was intact, it was assumed that the shoulder harness, had it been used, would have prevented the face and head injuries. Therefore, the injury data on the pilot wascoded as "SerioJsto :\1inor" toreflect the sht>ulder harnessbenefits. The energy-absorbingseat benefit was coded as "Serious to**Seriou~"** 

### since the energy-absorbing scat would not have prevented the head injuries. The fact tnat the stroked seAt probably helped to protect the pilot from spinal injuries was disregarded. Occupant 2.--The right-front seat occupant sustained multiple facial, head, and upper body injuries from impacting the instrument panel. These Injuries included facial fractures and lacerations, cerebral concussion, fractured left clavicle, chest wall contusions, and probable pulmonary contusions. It 

### was estimated that the use of a**shouh~er** 

### harness would have prevented the injuries; therefore, shoulder harness benefits were coded as "Serious toMinor." Occupant 3.--The right-rear seat occupant sustained a compressed fracture of the f,S 

### vertebra. The rear seats were not of an energy-absorbing type, so the energyabsorbing seat benefit was coded as "Serious to :\1inor." The shoulder harnessbenefit was coded as**"Seriou~** 

### toSerious"becauseitcould not be determined whether shoulder harness use would have prevented the back Injury, even though there wasthatpotential asa result ofbetterspinal positioning created by

### a shoulder harness.**~ant** 

### 4.--This occupant had minor injuries consisting ofbruises and tenderness. Shoul<Iernarness benefits and energy-absorbing seat benefits were both coded "Minor to :\11nor" since these minor Injuries probably would not have been eliminated by a crashworthiness device. Accident No. 2(photographs 5 through 7) During a night go-around, the airplane impacted gently rising terrain, damaging the propellers. With the loss of power, the airplane then descended down a shallow hill and impacted into level terrain. The airplane was flying at slightly above the naps-up stall speed and in a right wing-down condition. The speed was estimated at 75 to 90 knots, anJ the impact angle, based on ground scar reconstruction, was estimated at 5 to 10 degrees down. The decelP.ratlon was moresevere thanthatIn accident No. 1 because the soft dirt allowed significant gouging. The pilot was injured seriously, although these Injuries were consideredpreventable. Occupant 1.--The pilot was not wearing the available shoulder harness, and he sustained significant head injuries. The cranial bone above the bridge of the nose was driven into the sinuscavities, the rightcheekbone was fractured, the nose was fractured, theright ankle was fractured, and the left ankle was sprainec1. Back spasms were present due to minimal compression of the Tl2 vertebra (no fracture). The hE:ad impacted the Instrument panel at the Kollsman knob of the altimeter and at the bug knob of the HSI. The kneesimpactedInto thesubpanel, and theseatpan was torn from downloading.



# ooooar.APPENDIX E

Photogrnphs :i Anrl 

### n.APPENDIX E

.Photof{t'aph 'i.·

·Slr,N! sh<>Ulder h&l'twss usc would l'ln(!Xp(:cted tohaveproventod the hend irijuries1 · ·.the shoulder**har'n(;•~s** bcrwfit wf!f: (!odcd as "Serious·to Minoi'.il ·. Hn<l onenergy--absorbit1(f sNit tHwn nvrti1nble, the rnin:H' bn(•l< injtH•ies possibly could huvc been nvoided. The

·· m1ergy'·nhs()rtliflt! f>(•;,t btmefit .vns coded as "Scl'ious to Set'ioits'1since**tiH~** seat nlono woulrl not hnve Pl'eventHd tho sel'ious hcwl ii'IJHt·IPs. · ··· · · 

### ACc.iiiontNo,**:~** (pll<)lnf{t·nph:i 8 through 11) ,."

# Y··--~~l~s**~~~::~tknt** N!C!mred on a gusty

# d~y, nnd tl)o pilot lost control oftilenirplilnc on .npproach .to 

### landing. 'l'he akpluoc mnrle n lmrd rigl1t turn 1**ci[(~I)J'C<l** 

### some tt•ees, and then ·.· lnHde.a stiJop, ri!l,'ht**dc~iiqending** ·turt1• into the t{1'0ttnd. Ground 

### scilr recotlsthtctlon ·· indjcnted

### that the

### itnpn(~t. un!* wn$ tienl' 35

### ~legrees ntid 

### tM t'ol\ nn!rle was 

### near. 90

.. dogrc<Js, (See rigme 10.) The flaps**Wtll'(~** llJ), nne!**~he imp~;ct**  speed 

### was tclStiii1Ht(}(\ at GO to



### · 75 I<nots: Since.tho riKllt 

### wing wns down 

### ilt impll.ct, 

### thoiwc was sqhstnntiar 

### cilbin

· ... /II)fol'IO(tfi(m in.(he upper**rit~hl** front <51' t**h~:.cockpit.** The leftcockpit**l:ll'~ll** hod on)y minor. defCol'Illation. T!JCI'OV•I!lS**QlV~.fiJtality** nndtwo BBI'ioUfl injUt'iC;S.

. . . . .. . . . .. . . .



### . ·.

## Q%!-tffi.\!.n.~ l.:

## ~...

## ~'~'h~~ l:lrt-front 

### seat

## oeeup~rHSustttln()dfatn!**injurl<~sby**itn[)!\Ctlng

### .the ·.

... .:radro (>tll(lk. 1'hese HIJIP'Jos I!Ofl:-llstl'!d of multtple blunt trmllnrt to tl1e headand m.ulttplG! ' > frachirM 

### or**tiH~** slwll 

### .resulting in 

### lnceratloi1 ond**h<~tnQI'l'l1nge.** uf 

### tl)e britin. 

### Su(l<)n(')nry.

··. ·. · Injur•ies inclurle<l diffli:iocl pulmonm•y lJemurrhnge. ·NearlY ilU

### Mthcsn in)uries> oo\titi.l)fi\/.t;; .·

... J)l1QIJprcivt,lnted 

### had the;1.\VHil!M·o i!hi)Uldt)l' hal'J1CSS.

### been U?Od' : 

### It113 poRslble tharserioUs .•
. injuries still might !'lltVi:uJ<.l(Hwl;t'ld 

### 6N!.Hus¢ of the 11ft 

### movcfnciil (ift11c f1oorbJ>&rds ut1d 

### the) ··.•.· irV:ltrum(:nf pnncl; howe\let' 1 

### it is**~tl\c)f'(i** pt•iJl)flble 

### ttwt the**inj\H'y·l(~Vf:l}would** haye been .·· 

### ··redUci9<'J.tO mi11M hy.the shoulder ·**hnl·rt(ls~.** Thet'()for·a, 

### the shoulder hiir'i1ol5s tH>.r)(lJ'It wns ·**·~o'd~d** 11

### l1nta1

### to**\1irH~:w.** tJ · · · • · · · ··•· .·· · · ·· · · / · · · · · • · · · ·· · • ·..· .....•..

. . .

-**~** .•\PI'E:\Ill'\ ··**~** ·.I r

fltloto;;rftphs 

### xHnrl 9.**i}l)ill':~:~**,.. ' • 

# I I •,• 

### jAPPENDIX B 

### -38-

00' 

## f-6'--i

64 

### 48' 42' 

### 36' 3:l' 18' 12' 

# 163' 

# 149' 

# I 141. 22'9"



# -**~** RH Wing Tip Timber



### Plgure 10.-Reconstructlonof 'lllpaot

### angleand attltudt

### using 

### groundscarInformation. 

### 6' 0'



# 000041

### -39- APPENDIX E


### Oeeupant 2.--The right-front seat occupant sustained serious injuries. The injuries were more widespread than the left-front seat occupant beeause of the closer proximity to the focal point of the Impact. This occupant sustained a mid-faeial bone fracture, closed-head injury, multiple lacerated wounds of the face, cervical sprain, contusion of the chest, fracture of the transverse process of the 1.5 

### vertebra, feet fraetures, and a hand fraeture. Although there was aft dis(Jlaeement of the instrument panel, the upper body Injuries would have been less severe had the available shoulder harness been worn. The seat also came loose. Had it stayed in place and been of an energy-absorbing type, the baek injuries would have been less serious, and possibly lesser loads would t.ave been imposed on the feet. Therefore, the shoulder harness benefits and energy-absorbing benefitswere coded "Serious to Minor." Oecupant 3.--This occupant's lapbelt separated at the buckle when the adjustine**~am** 

### cutthrough thewebbing. Other areasof the belt also showed evidence of high loads. This occupant was ejected from the airplane and sustained serious injuries. His injuries were a perforated small bowel, a fractured clavicle and scapula, a fractured arm and leg, a head laeeration, ftnd a generalconcussion. Had he worn a shoulder harness, the lal"belt loads would have been better distributed, resulting In a lesser load to the lower abdomen. Ashoulder harness also would have reduced the likelihood of the lapbelt separation and subsequent ejection. The shoulderharness would have resultedIn a lesser Injury level and, therefore, theshoulder harnessbenefit was coded "Seriousto :\Unor." Accident No.4(photographs 12 through 15) This accident was relatively severe for a survivable accident. The airplane cartwheeled and susequently stopped inverted. The pilot was killed, and the two passengers suffered significant head injuries. The attitude atprincipal Impact was 28 t::> 30 degrees nose down with a 90-degree roll. The speed \\as estimated at slightly above stallorbetween 45 to 60 knots. Oecupant 1.--This occupant, the pilot of the airplane, sustained fatal injuries. The Injuries consisted of fractures of the sternum extending Into the chest cavity with severe hemorrhaging, fractures of the second, third, fourth and fifth lef' anterior ribs, and multiple brain contusions. These Injuries resulted from Impact lnt'J the control column and instrument panel. The Instrument panel onthepilot'sside moveo aft far enough tohit the doorpost,reducing the livable volume. It Is 

### believed however, that the fatal injuries could have been prevented with the use of a shoulder harness even though the oecupant still would ha•1e sustained serious upper body Injuries. Therefore, the shoulder harness benefit was coded "Fatal to Serious." The stroked energy-absorbing seat probably prevented severe back injuries. The energy-absorbing seat benefit was coded "Fatal to Fatal"since such a seat would not havepreventedthe fatality.**Occu~~mt** 

### 2.--This occupant was In the right-front seat near the crush line on the airplane

# an sustained serious Injuries. Typically, the crush line can be regarded as the grouoo line, and If t.he crush line moves near the seat area, the occupant usually sustains very serious or fatal Injuries. However, she did receive significant protection from the stroked energy-absorbing seat. Her Injuries Included a fractured sacrum, fractured hand, and facial laceration. The facial lacerations were not classltled !lS 

### serious, but they did present a danger since she was hanging upside down. Alocal far"Tier had to clear her mouth and throat ofblood toprevent suffocation. The shoulderharne:sbenefit was coded

### 0000~2APPENDIX E -40-



# ... :

# ................._

PMtographs 12 and 13.

### -- 

### -- '·

# ~)~ I 

## I I

. ,.**~** .., 

### .· .**~...** - I

. I**Phc~to~mphs** 1·1 nnd 15. .\PPI:NDIX EAPPENDIX E 

### -42-

"Serious to Minor." The energy-absorbing seat probably prevented very serious !njuries but would not have prevented all of the serious injuries. The injury level woulc'l have been serious with or without an energy-absorbing seat. The energy-absorbing seat benefit was coded "Serious to Serious," but it 

### was flagged so that the protection orrered by the seat could be accounted for in this study. Occupant 3.--The right-rear seat occupant alsohad seriousInjuries. She sustaineda burst-type fracture and dislocation or the J,2 

### vertebra. No neurological effects were noted. A shoulder harness could have benefited this occupant only by providing a better sittingposition at impact and thus giving the back better protection. Since this is not a function orshoulder harnesses and only wouldorrerlimited injury protection, theshoulder harness benefit was coded "Serious to Serious." An energy-absorbing seat could have orrered a great deal or protection. The energy-absorbing henefit was coded "Serious to Minor." Accident No.5(photographs 16 

### through 18) 

### This accident wss considered nonsurvivable even though the cabin remained relatively Intact and two or the four occupants survived for several hours. The Impact attitude or the airplane was the prime reason that the decelerative loads and secondary Impactloads**preclud,~** 

### survival. The**alrpla~a** 

### contacted trees causing a wing to separate and the fuselc.ge to yaw. The airplane decended to the ground along a 39-degree flight path. The fuselage hit sideways with a nose-down attitude or about 25 degrees and a roll attitude of about 30 degrees. (See figure 11.) 

### Since the predominant impact force would have driven the occ•.pants to the left, neither shoulder harnesses nor enerl7)'-absorblng seats would have pro•1ided the lateralprotection that was reQuired for survival. All occupants were coded "FataltoFatal" (01" 

### both shoulderharness and**en~rgy-absorbing** 

### seatbenefits.**Oc~1pant** 

### 1.-The pilot was very near the crush line and sustained more severe injurle3 thb'l the other three passengers. He had a depressed fracture of the skull with profuse hem'lrrhage, complete cervical fracture, multiple pelvic fractures, ruptured aortic arch, Md a ruptured bluod vessel In the chest cavity. No head contact area could be identified in the airplane, but evidence or body contact could be seen on the sidewall next to the pilot': position. It was assumed therefore that the head contacted theground throughthe pilot's $ide window during theimpact.**Occu~ant** 

### 2.-The copilot also had severe upper body injury, but he did not receive extenslveower body Injuries. lie had 8 

### frActured cervical spine, with incomplete transection or the spinal cord, severe brain hemorrhage, fractured sternum and ribs <nailed cnest), and 8 

### fractured leg. Again, no evidence or occupant contact was round on the Instrument panel. Occupant movement was lateral (to the left) which precluded shoulderharnesserrectiveness. Occupants 3and 4.--The left-rear seat occupant had severe bleeding due to significant facial fractures and a flailed chest. The right-rear seat occupant survived brlefiybutdiedora severebrainhemorrhage.



## 0000t1flAPPENDIX E

Photographs 16 and 17. 

## 0(}

## 001f)APPENDIX E -44-

Ph()!O<;:r11ph I:<.



### .2 - 1.67 ft. 

### Crush

Figure 1I.--HC'l'Onstrw•tion •>f irnpud •tnhh· 11nd**Httit11~l1•.**


## 0000·1 (