ge

a

10.

ATR.

. Huelke,

REFERENCES

. Schwimmer, S. and R. A. Wolf: Leading Causes of

Injury in Automobile Accidents, Automotive Crash
Injury Research of Cornell Univ., Ithaca, N. ¥., 1962.

. Tourin, B. and J. W. Garrett: Safety Belt Effective-

ness in Rural California Automotive Accidents,
Automotive Crash Research of Cornell Univ., N. Y.,
1960.

D. F. and P. W. Gikas: Ejection—The
Leading Cause of Death in Automobile Accidents,
CONF. PROC. TENTH STAPP CAR CRASH
CONF., Holloman AFB, 1966, pp. 156-181,

. Vulean, A. P.: Review of the Relative Merits of

Various Types of Motor Vehicle Seat Belts, J.

AUSTRALIAN ROAD BOARD 2:33-40, June 1966,

. Wolf, R. A.: Control of Ejection in Automobile
Accidents, J. AMER. MED. ASSN. 158:220-224,
April 1962.

Campbell, H. E.: Role of the Safety Belt in 19 Auto
Crashes, BUL. AMER. COL. OF SURG. 50:155, 1955.
Frazier, R. G.; Effectiveness of Seat Belts in Pre-
venting Motor Vehicle Injuries, NEW ENGLAND
MED. J. 264:1254-1256, June 15, 1961.

. Gikas, P. W. and D. F. Huelke: Causes of Death in

Automobile Accidents, Can Seat Belts Really Save
Lives? J. MICH. STATE MED. SOC. 63 :351-354,
May 1954.

. Lindgren, S. and B. Warg: Seat Belts and Accident

Prevention, THE PRACTITIONER 188:467~473,
April 1962.
Tourin, B.: Bjection and Automobile Fatalities,

PUBLIC HEALTH REPORT 73 :381-391, May 1958.

12

11. Huelke, D. F. and P. W. Gikas: Determination of
Seat Belt Effectiveness for Survival in Highway
Collisions, CONF. PROC., SEVENTH STAPP CAR
CRASH CONF., C. C. Thomas, Springfield, Ill, 1965,
pp. 403-431.

. Huelke, Donald F. and William A. Chewning: Com-
parison of Occupant Injuries With and Without
Seat Belts, SAE Report No. 690244.

Louton, J. C, and T. W. Ruster: Restraint Systems,
Design and Performance Parameters, PROC. GEN-
ERAL MOTORS CORP, AUTOMOTIVE SAFETY
SEMINAR, July 1968, Safety Research & Develop-
ment Lab., Milford, Mich.

1B.

14. Swearingen, John J.: General Aviation Structures
Directly Responsible for Trauma in Crash Decelera-
tions, DOT/FAA Aeronautical Center, Civil Aero-
medical Institute, Office of Aviation Medicine, Report

AM 71-3.

. Department of Transportation, National Traffic
Safety Agency, Federal Motor Vehicle Safety Stand-
ards No. 209, Title 23, P 255 (FMV 209-seat belt

assembly. FMV 210—seat belt anchorage). Jan.
1967.
16. Roberts, V. L.: Motor Vehicle Restraints, 1970

INTERNATIONAL AUTOMOBILE SAFETY CON-
FERENCE COMPENDIUM, 978-993.

17. Snyder, R. G.: A Survey of Automotive Occupant
Restraint Systems: Where We've Been, Where We
Are and Our Current Problems, SAE Report 690243,

Jan. 1969.


E. Three-point belt restraint system, shoulder
strap over seat back to floor

F.G,H_ Three-point belt restraint system,
I Shoulder strap attached:
H = seat back level of below
(convertibles)
F<] - 8" above seat back level
G = 9-16" above seat back level

Figure 8. Diagrammatic sketches of Types E, F, G,
and H shoulder belt installations.

cedure for donning these four types of restraint
consists of slipping the shoulder straps on like
a pair of suspenders and fastening the lap belt
buckle (See Figure 6). In the three-point belt
restraint systems (Types E, F, G and H, Figure
3), the single shoulder strap is continuous
through the tongue of the buckle to form half
of the lap belt and cannot be detached from the
belt. This type of restraint system is simply
donned as shown in Figure 7.

A distribution of the experimental vehicle date
of manufacture is shown in Figure 4. It will be
noted that a large percentage of these vehicles
were late-model cars at the time of shoulder belt
installation. Since it was necessary to drill holes
through the body, door post, or roof channel
(including upholstery or headliner) in 80 of these
automobiles, the author feels that the volunteers
must have had a significant interest in impact
protection through the use of torso restraint.

Results.

Ninety-five of Questionnaire #1 (Figure 5)
were sent out two weeks after all restraints were
installed and 93 were returned. Answers to the

questions are indicated in terms of per cent in
Figure 5.

Comments on Shoulder Belt Questionnaire #1
(after 2 weeks of use):

Nore: Representative comments are pre-
sented from the questionnaires demonstrat-
ing satisfaction with the installation, donning
ease, wearing comfort, and protection pro-
vided. The comments were far too numerous
to be published in total.

“I have always felt that lap belts were a
necessity for my safety as well as my passenger's,
but since using the shoulder belt, I realize that
lap belts alone afford only partial safety. They
will always be standard equipment in any vehicle
I own in the future.”

“A very neat installation was made.”

“Very well pleased with how fast and easy
shoulder belt is to connect.”

“I find that belts are very comfortable and are
used by my wife and whole family.”

“With the increased stability of the body dur-
ing curves, decelerations, and accelerations, the
arms are free for steering only. Driving is a
greater pleasure than ever.”

“The shoulder strap combination is much
better than regular lap belts. I feel much more
secure.”

“I find the belt restraint system easy to fasten
and adjust.”

“The shoulder belt is very comfortable while
driving and I would not like to drive without
them any more.”

“In a pick-up shoulder belts let the passengers
relax to the extent they do not have to brace
themselves as much on cornering or stopping.”

“J find on a long run or trip I get less tired
and my back does not ache near as much after
the trip. I wear my restraint equipment snug
so it keeps me sitting in an erect position, Thus
less tiring. Plus a feeling of more security.”

“I feel lost without it now and I’ve become
accustomed to wearing it.”

“Tt is far more comfortable than I thought it
would be! I find it reminds me to sit up straight
and I am not as tired after driving a long ways.
I really am pleased !”

As a result of Question #8, to which 73% of
the subjects said they would like to see improved



RESTRAINT SYSTEM QUESTIONNAIRE #2

It has now been four months or longer since belt restraint systems
were installed in your car and we would like to have your present
evaluation after wearing them for this period of time. Will you
please answer the following questions and return the questionnaire
to AC-119?

et
o
cy

1. Do you still wear this equipment faithfully ?

2. Were seat belt retractors installed on your shoulder straps
to improve the stowage of loose webbing when not in use?

3. If yes, are they working satisfactorily?

4. Have you had any near misses or accidents while wearing
the restraint system?

O00 Ul
O00 UF

5. If yes, please describe in detail.

6. Do you feel insecure and unprotected when riding in a car
not equipped with this safety equipment?

UO
U0

7. Would you like for us to remove it from your car?

8. Other comments you would like to make.

Ficure 8. Copy of Questionnaire Number 2, distributed four months after installation.

8


2.

3.

10.

ll.

RESTRAINT SYSTEM QUESTIONNAIRE #1
(Two Weeks)

Do you find your belt restraint system comfortable?
If no, please state discomfort.

fo = %
Yes No

Do you wear your restraint equipment every day to
and from work?

Do you don it for short trips--2-3 blocks or less?

Can you reach all necessary controls with the equip-
ment worn comfortably ?

How many times have you forgotten to don your restraint
equipment until after_starting to drive?
Never Seldom

Does wearing it make you feel more secure?

Do you feel that the restraint equipment detracts from
the appearance of your car?

Would you be more pleased if stowage was improved to
eliminate loose webbing ?

Does your front seat passenger usually wear this protec-
tive equipment?

Would you like for us to remove the belt restraint system
from your car?

Any comments you would like to make.

Ficure 5. Copy of questionnaire distributed two weeks after harness installation.

5



25

20
no
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co)
mu I5-
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uw
oO
tw IO
a
=
=)
z
5k
3 Ww

LR SS ee
49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68
DATE OF MANUFACTURE (YEAR)

Frauke 4. Distribution chart of dates of manufacture of test vehicles.

stowage, spring-wound belt retractors were pur-
chased and inserted on the various straps to take
up the slack webbing when occupants removed
them.

To illustrate neat stowage by the addition of
retractors, a Type B restraint system representing
the double shoulder strap equipment with straps
held snugly against the seat is shown in Figure
6, and a Type G single shoulder strap restraint
held neatly vertical along the inner side of the
door post by one retractor enclosed in a boot at
the bottom and a second floating retractor at the
top is illustrated in Figure 7.

The discomforts of the 10% noted in Question
Number 1 were studied and it was found that the
complaints were founded by errors in installa-
tion; eg., one strap too short or adjustments
located such that they rested on a bony structure.
Types B, D, E, F and G were represented in the
nine complaints. Corrections were made as
necessary. .

In regard to Question #4, most of the 18
persons complaining of not being able to reach
all the controls were referring to the brake re-
lease lever. They were advised to release the
emergency brake with the vehicle in park before
donning the harness.

Of 95 copies of Questionnaire #2 (Figure 8)
that were mailed out, after four months, 83 were
returned. Twelve subjects had traded cars or
moved and could not be contacted. Answers to
the eight questions ranged as follows:

Question % Yes % No
1. (Still wear faithfully) 94 6
2. (Were retractors installed?) 78 22
3. (Are retractors satisfactory?) 91 9
4. (Near misses or accidents) 7 93
5. (See comments that follow) N/A N/A
6. (Secure feeling) 94 6
7. (Remove restraint system) 1 99
8. (Comments—follow) N/A N/A


A Shoulder strap and half of lap

~ pelt held neatly vertical along
B post by two retractors. Only
one buckle in seat.

belt restraint system.

B Subject dons restraint equipment by
grasping tongue of buckle with right
hand and pulling over left arm and
shoulder.

C Subject wearing three-point

Ficure 7. Type G combination shoulder belt installation.

7



TECHNICAL REPORT STANDARD TITLE PAGE

T. Report No. 2. Government Accession No. 3. Recipient's Cotalog No.

FAA-AM-71-12

4. Title and Subtitle 5. Report Date
ACCEPTANCE TESTS OF VARIOUS UPPER March 1971
TORSO RESTRAINTS &. Performing Organization Code

7. Author's) 8. Performing Organization Report No.

John J. Swearingen, D. Av. T.

9. Performing Organization Name and Address 10. Work Unit No
FAA Civil Aeromedical Institute
P, O. Box 25082 TI, Contract or Grant No.

Oklahoma City, Oklahoma 73125

13. Type of Report ond Period Covered

12. Sponsoring Agency Name and Address
Office of Aviation Medicine

Federal Aviation Administration

OAM Report

800 Independence Avenue, S. W. 14. Sponsoring Agency Code
Washington, D. C. 20590

15. Supplementary Notes
This study was conducted under Tasks AM-A-69-PRS-37 and AM-A-70-PRS-37.

16. Absirect
This study demonstrates that people can be motivated to utilize and, in fact,

eagerly accept the use of upper torso restraint equipment for the prevention of
head and chest injuries induced by flailing during crash decelerations, provided
that specific design criteria are followed by structural engineers. By giving
attention in this study to design of specially constructed restraint equipment to
incorporate the maximum in features for comfort, neatness of appearance, ease
of stowage, and ease of donning and escape, it was found that over 90% of the
test subjects utilized these upper torso restraint systems throughout the two-
year test period. In contrast, only an estimated 3 to 5% utilization of the
factory-installed torso restraint equipment in over 10,000, 000 automobiles
manufactured since 1 January 1968 has been attained to date. General aviation
aircraft manufacturers should give careful consideration to these significant
design criteria, along with incorporating inertia reels for ease of motion, before
launching an extensive program for installation of upper torso restraint in light
aircraft,

17. Key Words Té. Distibution Stotement Availability is unlimited.
Document mav be released to the National
Technical Information Service,
Springfield, Virginia 22151, for sale to
the public.

Restraint equipment, Body flailing,
Crash Injuries, Aviation safety,
Human factors, Aircraft design.

19. Security Classif, (of this report) 20, Security Clossif. (of this page) Ti No. of Pages | 22. Price

Unclassified Unclassified 12 $3.00

Form DOT F 1700.7 (s-69)



Near Misses and Accident Comments (Ques-
tions 4 and 5):

From the comments received in answer to
these questions and based on speeds and forces
involved, the author estimates that at least one
death and probably 20 serious injuries were pre-
vented in eight separate accidents or incidents
by the use of the combination lap-shoulder belt
restraint system during a four-month period.

Favorable Comments were very similar to those
received on Questionnaire Number 1 and will not
be repeated here.

Questionnaires 3 and 4 were identical (Figure
9) and were distributed at the end of one and two
years respectively. After one year, 75 of the
original 95 volunteers still owned the vehicles in
which test restraint equipment had been installed.
Two of the 75 had removed the test equipment,
reducing the test sample to 73. Of the remaining
18 of the original sample, 8 had resigned and
could not be contacted and 10 had traded cars.
Only three of those that had traded owned late-
model cars with factory-installed shoulder belts.

After two years 13 of the original sample had
moved; 27 had traded automobiles and only 55
still had the original vehicles. Of the 27 that
had traded, 14 had new automobiles with factory-
installed shoulder belts. Answers to the two
questionnaires were tabulated as follows:

One Year Two Years
Question Yes No Yes No
1. (Still have car) 1) 10 55 27
2. (a) Wear on long trips
(25 mi. or more) 95% 5% 9% 2%
(b) 2-25 mi. 92% 8% 92% 8%
(c) 1 block—2 mi. 3% 27% 1% 29%

Question 3 was designed to try and determine
whether or not those that traded for new cars
equipped with factory-installed shoulder belts
were utilizing them. As stated above, only three
individuals, after the one-year test period, owned
late-model automobiles with factory-installed
shoulder belts. One indicated that he was wear-
ing his shoulder belt and two were not. How-
ever, after two years of the test period, 14 had
late-model cars with factory-installed upper
torso restraint equipment. Three indicated they
were using the new safety belts; one said some-
times and ten said no. Of the ten answering in
the negative, as determined by an individual

10

check of previous questionnaires, nine were en-
thusiastic users of the CAMI-installed equipment.
Representative comments for not wearing shoul-
der belts were:

“Shoulder belt crosses across the neck; I’m
afraid of them. We always wear seat belts.”

“Would prefer double shoulder belts as present
shoulder belt cuts and abrades neck. Very un-
comfortable, improperly installed, and of a poor
and potentially hazardous design. Separate from
seat belt.”

“Cuts into neck—will make a loose fit for
comfort.”

“Would like shoulder belt to come from post—
it is too far back for comfort and easy access-
ibility.”

“Roof-mounted diagonal belt. Dislike position
across base of neck. Inability and nuisance of
stowage are also negative factors not present
with the experimental belt system in the ‘old’
cars.”

“Regular . . . installation (new car) uncomfort-
able; bundlesome, difficult to keep up with all
the straps—a pain to keep stored. Wear mine
occasionally.”

Question Number 4: No serious accidents were
reported on these two questionnaires.

In the two final questions—5 in regard to
fraying and 6 as to soiling—7% reported fraying
after one year and 20% after two years. Sixteen
per cent reported their restraint equipment be-
coming soiled after one year and 56% after two
years.

Consideration should be given to replacing
webbing after two or three years of use since
fraying induced by constant usage will have
weakened the webbing to an unsafe level. Per-
haps the manufacturers could also offer the pur-
chaser some instructions for cleaning restraint
webbing as it becomes soiled.

Summary and Conclusions.

Eight types of combination lap-shoulder belt
assemblies were evaluated by a group of nearly
100 informed individuals over a period of two
years. Every effort was made to make the re-
straint installations comfortable, neat in appear-
ance, easily stowed, and easy to use. Response
to questionnaires at intervals of 2 weeks, 4
months, one year, and 2 years revealed that over


RESTRAINT SYSTEM QUESTIONNAIRE #3
(After One Year and After Two Years)

Do you still have the car in which we installed a belt
restraint system?

If the answer to #1 is yes:
(a) Do you still wear it on long trips (25 mi. & over)?

(b) Do you still wear it on trips of 2 - 25 miles?

(c) Do you still wear it on trips of 1 block to 2 miles?

If the answer to #1 is no:
(a) State Make Model and Year
of your new car.
(b) Is it equipped with shoulder belt?
(c) If it has a shoulder belt, do you wear it?
Please describe and discuss.

K
a

e

OOO U

OU
OU

|8
fo)

OO8 O

Have you had any near misses or accidents since the last

O

questionnaire? If yes, please describe:

Have you noticed any fraying or signs of wear ?
Are your shoulder and seat belts becoming soiled?

Other comments:

CI
CI

i)
CI

NOTE: If you have an accident in the future, will you please notify us be-
fore you repair your car? We would like to get pictures of it to tie in

with our accident study.

Ficure 9. Copy of questionnaire distributed after one year and again after a two-year period.

9



A Shoulder straps sewn to lap B_ Retractors hold straps smoothly

belt close to seat intersection against seat back when not in use.

to prevent submarining.

—

C Shoulder belts slipped on like
suspenders and only lap belt
buckle to fasten.

Figure 6. Type B double shoulder belt installation.

6


general, they were allowed to choose from eight
different configurations of restraint equipment.
However, certain design models (e.g., convert-
ibles) dictated a specific design of shoulder belt
installation. In addition, volunteers were given
a choice of 11 different colors of webbing to
match the upholstery of the automobile.

Questionnaires, to determine complaints and
favorable comments, degree of utilization, mo-
bility, and whether or not they wish to have the
shoulder belts removed, were sent out at intervals
of two weeks, four months, one year, and two
years after installation. Where possible, modifi-
cations were made on the installations between
questionnaires to eliminate complaints.

The Sample: Fifty-two of the volunteers
worked in the Civil Aeromedical Institute and
were familiar with some of the crash safety
research conducted in the Protection and Sur-
vival Laboratory. The remaining 43 were em-
ployees of other Divisions at the Aeronautical
Center.

Eighty-two of those requesting installation of
shoulder belts were males and 13 females. How-
ever, since two sets of harnesses were installed
in each front seat, female exposure to the use of
the belts, as right seat passengers and alternate

A. Double shoulder straps over seat back to
Moor and continuous with lap belt through
D rings.

|B Double shoulder straps over aeat back to
floor, sewn to lap belt at seat intersection

Fieure 1. Diagrammatic sketches of Types A and B
shoulder belt installations.

drivers, probably approached that for the male
population.

An occupational analysis of the sample group
revealed the following distribution: Profes-
sional—20; Technicians—28 ; Clerical—9; Skilled
Laborers—28, and Laborers—10.

In the selection of the type of shoulder belts
desired, the subjects had a choice among four
different double and four single strap designs
(Figures 1, 2 and 3). Only ten chose from the
double belt selection in the following order:
1 Type A, 3 Type B, 4 Type C, and 2 Type D.
The distribution of those selecting the single
strap belt was: 7 Type E, 11 Type F, 62 Type G,
and 5 Type H.

It should be noted at this point that the eight
types of belt restraint systems shown diagram-
matically in Figures 1, 2, and 3 have one common
feature—there is only one buckle to fasten in
each of the systems. In Type A the shoulder

© Double shoulder straps to single strap
TM over seat back and to floor. Double
straps sewn to lap belt at seat intersection.

D Double shoulder straps to single strap
fastened to body behind seat at seat top
level (pick-up trucks only). Double straps
sewn to lap belt at seat intersection.

Ficure 2. Diagrammatic sketches of Types C and D
shoulder belt installations.

straps are continuous with the lap belt with each
half sliding through a fixed guide ring, while in
Types B, C, and D the shoulder straps are sewn
to the lap belt near the seat junction. The pro-




ACCEPTANCE TESTS OF VARIOUS UPPER TORSO RESTRAINTS

Introduction.

For survival in transportation vehicle crash
impacts, the occupants must participate in their
environmental deceleration. While lap belts re-
duce the possibility of fatalities from occupant
ejection’ by a factor of approximately 75%",
they represent only a partial participation of the
occupant in the deceleration of his environment
and allow the upper torso and appendages to
flail about to produce serious or fatal injuries
during the secondary impact.

An extensive educational program over a 10-
year period utilizing all the news media and
many other innovations has succeeded in raising
lap belt usage by automotive occupants to about
30% in those vehicles equipped with lap belts.
On the other hand, in a recent study of seventy
light aircraft accidents conducted by Swearin-
gen,* it was found that better than 95% of the
occupants involved were wearing their lap belts.
In general, the light aircraft pilot has, for one
reason or another, accepted the use of lap belts
in the aircraft. For these reasons, the acceptance
of upper torso restraint in general aviation air-
craft would be expected to be higher than in
automobiles.

Upper torso restraint is not generally provided
in light aircraft, but the critical need for addi-
tional body restraint in crashes is clearly demon-
strated in the study identified by Reference 14.
It should be noted that this additional restraint
equipment is required in general aviation aircraft
conforming to the requirements of Part 23 of the
Federal Aviation Regulations and manufactured
under Approved Type Certificates issued on or
after 14 September 1969.

Since 1 January 1968, all automobiles manu-
factured for sale in the United States have been
required by law?* to be equipped with a combi-
nation lap-upper torso belt system for the two
outboard front seat positions. The author esti-
mates that there are over 20 million automotive
vehicles in use in this country at present that are

equipped with both lap belts to prevent ejection
and shoulder belts to prevent the head and upper
torso from jackknifing forward and striking the
steering wheel, instrument panel, or windshield.
Unfortunately, only a very small percentage
(3 to 5%)** of these upper torso belt devices are
being utilized by the motoring public. Snyder’”
has discussed in detail the many variations of
current automotive shoulder belt installations and
the current problems involved in their use and
acceptance. He states that “the major problem,
from a protection standpoint, in the 1969 auto-
motive vehicles appears to be that the restraint
systems provided simply do not fit properly a
large segment of the automotive occupant popu-
lation. Too often the upper torso belt rides
along the side of the neck or even off the
shoulder.”

It is the purpose of this study to evaluate the
acceptance of various types of upper torso belt
restraint equipment in terms of comfort, ease of
donning, neatness of stowage, and freedom of
movement which, along with Snyder’s analysis
of the problems of the system installed by the
automotive industry, should serve as a guide for
the general aviation manufacturers for the in-
stallation of restraint equipment that will be
generally accepted by the flying public.

Procedure.

An invitation for volunteers to participate in
an automobile shoulder belt research study was
circulated in January 1968 in the Civil Aero-
medical Institute and some other portions of the
Aeronautical Center. Information was released
that the Protection and Survival Laboratory
would install, free of charge, two sets of combi-
nation lap-shoulder belt assemblies in the auto-
mobile of each of the first 100 volunteers. Actual
installation was terminated in March of 1968.
By this time 95 automobiles had been equipped
with dual sets of combination lap-shoulder belt
assemblies. Volunteers were assured that their
cars would not be used in crash testing. In





90% of the participants were utilizing the re-
straint equipment on long trips throughout the
entire test period. Usage on short trips dropped
from 82% during the initial portion of the test
to 71% after two years, indicating that a few
people were tiring of donning the protective
equipment for very short drives. This high rate
of usage compared to the extremely low rate for
factory-installed shoulder belts may be attributed
to the fact that most of the test group in this
study were aware of the need for additional
crash protection and were pleased with the com-
fort, appearance, ease of donning and stowage.

An educational program along with good hu-
man engineering design will be necessary if the
majority of the general public can be expected
to utilize shoulder belt/seat belt restraint equip-
ment.

iL

It is suggested that the general aviation air-
craft manufacturers take heed to current designs
and installations in late model automobiles that
discourage acceptance and use of upper torso
restraints and the results of this study before
embarking on an extended program of installa-
tion of shoulder belts in light aircraft. Since
reach is much more critical in the operation of
aircraft, inertia reels or similar devices to allow
freedom of motion must be incorporated in the
installation design of upper torso restraint sys-
tems in general aviation aircraft.

It is considered feasible by the author that a
selection of shoulder belt assemblies could be
offered at the same time an aircraft purchaser
selects exterior and interior color and pattern

designs.