increased efficiency has been obtained through
improved equipment design and procedures.
However due to high density passenger loading,
these tests indicate an increase of 11% in the
average time that is required to evacuate the
total occupants from a current jet transport as
compared to piston aircraft of a decade ago.

Total abandonment of an aircraft is the ul-
timate goal of an evacuation, and therefore
must be accomplished within a time envelope
based upon sound consideration of the time
available as influenced by fuel combustibility,
fire propagation rate, fuselage burnthrough
time, and cabin inhabitability.

2. During a recent actual emergency evacu-
ation with fire involving 153 individuals it was
demonstrated that under good conditions it is
possible to evacuate a jet air carrier aircraft
with an average individual time of 1.1 seconds
which compares very favorably with the 1.0
second average for twenty evacuation tests
conducted under experimental conditions uti-
lizing similar jet aircraft. Also, the total evacu-
ation time of 2.3 minutes, for this emergency,
approximates the average of 2.14 minutes for
the experimental evacuation time of jet
transports.

3. A comparison of 39 survivable piston en-
gine transport accidents, which occurred dur-
ing 1948-1951, to 10 turbine powered surviv-
able accidents, occurring from 1959 to 1962,
indicates no significant difference in the fa-
tality rate of the total persons involved in each
of these two categories of aircraft.

4, Each actual emergency evacuation is a
unique incident. Unanticipated and unex-
pected events will occur which will modify, to
a lesser or greater degree, various factors of
emergency evacuation planning.

5. The characteristics of the airframe, its
exits, interiors, seating density, escape equip-
ment, passenger population, and crew capabil-
ity determine the absolute minimum evacu-
ation time. This may be extensively modified
by post crash conditions such as the extent of
distortion and damage to the cabin, condition
of the occupants, resting attitude of the air-

craft, interior/exterior environments, passenger
reaction, and crew behavior.

6. A study of survivable accidents occurring
during 1951-1953 indicate that in only about
one-fourth of these was there adequate time
for warning and preparation for emergency
evacuation. Since this is apparent even today,
it is very encouraging that airlines are furnish-
ing improved descriptive materials, and better
illuminated exit markings, placards, and other
visual aids for education of passengers on exit
routes and emergency equipment.

7. It is vital that those crew members who
are responsible for activation of emergency es-
cape equipment and direction of passenger
evacuation be strategically located and pro-
vided with seating and impact protection which
will insure a high probability of survival and
immediate functional capability following
impact.

8. Conclusion: Passengers should be pro-
vided improved impact protection in order to
provide maximum post-crash survival and in-
sure as much as practicable that they are am-
bulatory and capable of effecting their own
escape.

9. The heterogeneous nature of civil airline
population with regard to age, sex, training,
disability and health dictate a difference in
protective equipment and procedures between
military and civil aviation operations. The
fare-paying passenger may neither be accus-
tomed to, nor responsive to, authoritative com-
mand as in military aviation.

10. Training and indoctrination of all flight
crew members is highly emphasized. Some ex-
periences show that passengers tend to look
and expect instructions and guidance from the
professional crew. This training should en-
compass the concept of the flight crew keep-
ing command of the evacuation to suppress
individual passenger commands which can ini-
tiate confusion. Efficiency of training should
enhance confidence and ability to assess any
emergency and be alert for the unexpected,
which usually occurs, and take alternate courses
of action for a successful emergency evacuation.

—14-—


tion, while in water evacuations, survival de-
pends upon the accompanying equipment.
Actually, in 1962, during a ditching off’ the
coast of Ireland, only one raft was successfully
deployed and boarded, out of a total of five,
fifty one persons were left with only one twenty
five man raft.*

The best treatment of a disease is the pre-
vention of its onset. Until accidents can be
entirely prevented (probably an impossible
goal) we must concern ourselves with the in-
evitable few emergency evacuation situations
which will present themselves each year. Op-
erational experience indicates that we can ex-
pect about one emergency evacuation each
month.

The information which follows provides a
detailed analysis of the factors involved in
emergency evacuations, with particular empha-
sis paid to the human aspects.

II. ACCIDENT EXPERIENCES

During the years 1948 to 1951, in 39 recipro-
cating engine survivable air carrier accidents
identified by the Civil Aeronautics Board, 1394
passengers and crew members experienced 244
fatalities. The fatalities thus represented 17%
of all of the persons involved in these piston
aircraft under these circumstances.

For comparison, during the years 1959-1962,
the CAB identified 10 jet and propjet surviv-
able accidents, involving 704 passengers and
crew members, who experienced 112 fatalities.
Interestingly, the fatalities in these survivable
turbine powered aircraft accidents represent
16% of all of the persons involved.

The actual accident experience indicates,
therefore, insofar as the cited accidents are
concerned, that the current civil air carrier jets
furnish a degree of evacuation efficiency which
is comparable to that existing in piston aircraft.
We shall continue to monitor this experience,
and apticipate that with the newer equipment,
improvements in evacuation time will occur.
For example, in the new Boeing 727, inflatable
slide deployment is accomplished more rapidly
and efficiently due to its attachment to the
hinged door.

Interestingly, a recent incident occurred
which necessitated the emergency evacuation
of a jet airliner containing 153 people. A com-
plete emergency evacuation was accomplished
within two minutes and twenty seconds. This
incident occurred on October 27, 1963, and in-
volved TWA Flight 703, which utilized a Boe-
ing 707-331-B item of equipment.

The aircraft left the ramp at 1200 Zulu, and
its crew of 11 with 142 passengers (including
three infants, a near-term pregnant woman, and
a man on crutches (with one leg in a cast)
anticipated a normal taxi operation to the
runway.

Suddenly, just as the stewardesses were dem-
onstrating the emergency oxygen equipment,
smoke (and, a few seconds later, flames) began
rising from the floor between the second and
third row of seats in the first class compart-
ment on the right at station 540-560.

The Flight Engineer was notified of the
smoke by the stewardess, and, after checking,
returned to the flight deck and informed the
Captain. The aircraft was immediately stopped,
the engines were shut down, and all members
of the crew began to assist with the evacuation
of the aircraft.

One member used a water fire extinguisher
which put out the flames but a dense black
smoke continued to billow forth. Breathing
was difficult, and visibility in the cabin was
extremely restricted (various crew members
and passengers stated that they could not see
the opposite ends of the cabin). As an added
complication, the public address system failed
during the routine briefing.

With the 707 stopped, the actual evacuation
procedure started, and all four escape slides
were utilized in this gear-down evacuation.
The complete evacuation was accomplished in
two minutes and twenty seconds, in spite of the
smoke, the heterogeneous nature of the pas-
sengers, and the completely unanticipated na-
ture of the incident. A number of the passen-
gers were excited, and some were frightened,
but no panic occurred and no injuries resulted.

All persons were evacuated prior to arrival
of fire and ambulance vehicles. Apparently,
a lighted cigarette butt started the cabin fire.

~3-



Illustration No. 5: A ditching test is shown in which the overhead escape hatch is evaluated
specifically with reference to the evacuation problems associated with an
incapacitated crew member.

Illustration No.6: An aircraft seat back is impacted at the Civil Aeromedical Research In-
stitute, by an accelerometer containing facsimile of the human head, in a
study of seat back delethalization factors (see text).

~18—


Vv. CARI RESEARCH TESTS

1. The Airframe and Exits

a. Density of Seating. In follow-up to ques-
tions concerning high density seating and
evacuation time, Pan American Airways and
the FAA undertook a specific study. On
September 17, 1963, a test of a 189 passenger
and 7 crew B707-300 seating configuration was
made. Utilizing half of the available exits, an
evacuation was effected in 2 minutes and 20
seconds. Another airline conducted an evacua-
tion test in a DC-8 with 177 passengers and-a
crew of 10, using the right exits only. The air-
craft was only evacuated after 3 minutes 30
seconds. CARI’s analyses of these and other
tests, indicate that no passenger should be
more than 22 feet from an exit. The larger
door-type exits should be utilized in areas of
greater passenger densities with exit dimens-
ions not less than 24 inches wide by 48 inches
high.

b. Aisle Width. CARI provided data for
justifying the exemption from Part 4b granted
by the FAA to Remmert-Werner, for the utili-
zation in a Sabreliner of aisle width which are
3.5 inches less than the prescribed 12 inches.
The CARI tests showed that in low density
seating configurations, such as in the seven seat
Sabreliner, a narrow aisle does not significantly
increase evacuation time.

ce. Number, Size and Exit Location. Accord-
ing to tests on exit size configurations, the Type
IV exit represented by 19 X 26 inch dimensions,
with a 23 inch step-up and 25 inch step down,
the average escape time is 2.5 seconds per pas-
senger. For the FAA suggested total evacua-
tion time from jets of 2 minutes, it follows that
47 persons per Type IV exit would exit within
2 minutes time. However, it should be noted
that CARI has demonstrated that this type exit
is in full use only 60% of the total time. There-
fore, some persons will take longer, and 12 to
15 persons should be accepted as the number
to escape through this type exit in the 2 min-
utes time.”

Through Types I, II and III exits, we rec-
ommend the acceptance of 85, 55, and 25

persons, respectively, as maximum numbers for
escape in the proposed escape times under
good conditions.

d. Supplemental Top Hatch. Bulk cargo
loading has lead to difficulties in emergency
evacuation during water ditchings and land
accidents followed by fire. Seventy - seven
water ditching tests have recently been accom-
plished at CARI on 5 types of cargo aircraft
with the condition that the crew has been
“trapped” in the flight deck area. Indications
lead us to recommend an overhead hatch for
the all cargo aircraft. In the L-1049H type
aircraft, it is impossible to get 50% of the sur-
vival gear and approximately 15% of the crew
members through the cockpit windows in case
of water ditchings. Also, the top hatch alone
affords nearly the same escape times for crew
and equipment as do the two cockpit windows.
In addition, a marked increase in the ease of
handling survival equipment was observed.
Furthermore, when the flight deck is sub-
merged, the time to escape is increased when
the top hatch is used, as compared to the time
for the two cockpit windows only. Addition-
ally, the top hatch is available for a longer
period above water than the windows, and the
possibility of panic of crew members not adapt-
able to underwater conditions is averted. In
1943, a Sikorsky S-43 amphibian ditched in
Lake Mead, and while one pilot was escaping
through the cockpit window, the cockpit filled
almost completely with water. The other pilot,
finding it almost impossible to wriggle through
the window as the craft continued to sink, re-
membered the overhead hatch provided in this
airplane, and rapidly evacuated thereby.” The
utility of the hatch is obvious. Early DC-3’s
had these overhead hatches. In recent years,
the placement of switches, etc., overhead, has
complicated the construction of these hatches.

e. Nature of Exit Markings. Within the past
year, the Emergency Equipment and Emerg-
ency Escape Sections of CARI have been work-
ing with tritium powered self-luminous exit
markers. A minimum of 0.019 foot lamberts of
light has been recommended to the Society of
Automotive Engineers by the Emergency Es-
cape Section for emergency lighting during

—8—


thicker skin utilized in jet aircraft (resulting
in a longer burn-through time), the lower
volatility of kerosene, and improved escape
equipment.

Counterbalancing factors, still under scrutiny,
are the larger fuel load carried in these newer
craft (resulting in fires of larger proportions),
and the wider selection of exotic plastics and
materials contained in them, which, upon com-
bustion, yield products whose toxicological
characteristics are as yet not fully assessed.

IV. SELECTED KEY ITEMS

Dr. King and his associates noted in 1951,
that there were 49 U.S. domestic and inter-
national air carrier category accidents.’ Of
these, 30 were pertinent to emergency evacua-
tion, and in only 6 of these 30, was there the
possibility of a previous warning for the pas-
sengers. For 1952, out of 24 pertinent acci-
dents, in only 6 instances was a previous warn-
ing possible, and in 1953, again there were 24
pertinent accidents, and in only 9 cases could
previous warning be given.

The moral of the story is that unanticipated
emergencies must be expected in more than half
of the survivable accidents. Preparation, pro-
cedures, training, and passenger briefing in-
formation for all flights, must be directed to-
ward the unexpected emergency, immediately
prior to and during which, there is little time
for preparation.

Also, the crew members who are responsible
for directing passenger escape, should be pro-
vided with seating and crash protection which
will ensure a high probability of survival. In
this respect, it has been noted by CARI in-
vestigators, that neither stewardesses nor pas-
sengers should be permitted to occupy side-
facing seats during take-off and landing, since
the decelerative forces impose a_ twisting
motion through the pelvis, bringing to bear the
full individual decelerative load on one side of
the belt, exceeding by a factor of 3 to 6 times,
the load burden which would be imposed on
the seat belt as used in the forward facing seat
configuration.”

After each emergency landing, escape should
be conducted as if a fire had just occurred, due

to the high incidence of fires in landing emer-
gencies. Any undue delays can be fatal. Also,
all available exits and pathways should be put
to use, with those having the highest rate of
escape (highest exit potential) readied first.

Dr. King has laid out a two-phase basic plan:

I. Preflight Action

A. Brief Passengers
B. Prepare Emergency Equipment for Im-
mediate Readiness

Il. Emergency

A. Open Exit and Get Passengers Out

B. Issue Concise Instructions from Station
for Use of Exits

C. Instruct Passengers from Station to
Eliminate, or Reduce, Time Losses.

Prior to an anticipated incident, successive
actions include reassurance of passengers, duty
assignments depending upon the specific inci-
dent, special attention to infants and children,
special care for handicapped or elderly individ-
uals, the removal of dentures, glasses, and other
potential hazards, including high-heeled or
stiletto-heeled shoes (which will puncture in-
flatable chutes), and the checking of certain
equipment for working condition. In some
types of aircraft, certain exits will be removed
and stowed.

It should be noted that the common causes
of unanticipated emergencies include the me-
chanical failure of the landing gear, premature
retraction of the landing gear on take-off, the
accidental retraction of the landing gear after
touch down, landing with the gear inadvert-
ently left up, undershooting or overshooting the
runway, power failure on one or more engines,
failure of one or more thrust-reversers, loss of
effective braking (due to blown tires, “aqua-
planing” on wet runways, ice and slush on run-
ways, etc.), ground collision, and the occur-
rence of a fire on take-off.

Dr. King’s report recommends ninety seconds
from the time the plane comes to rest as a
practical goal for evacuating all persons from
the craft. He notes that at times the fuselage
has burned through within seven seconds.

—5-



This incident demonstrates that the absence
of injuries (such as commonly occur during
impacts) and even in the presence of dense
smoke, passengers can rapidly evacuate an air-
craft if all of the exits can be utilized, if the
crew acts efficiently, and if the passengers
don’t exhibit panic or “negative panic” (be-
come “frozen with fear ).

Actually, it has been previously well-
substantiated that in survivable accidents, there
is a forty times greater hazard to a successful
emergency evacuation from impact injury in-
capacitation than from fire.‘ Fire, is, neverthe-
less, a matter of current consequence, as de-
monstrated in a recent DC-8 accident which
involved no impact injuries to the occupants,
but did involve exit blockage, subsequent fire,
and 16 immediate fatalities."

Actually, one potentially safety feature of jet
powered aircraft is their possible use of kero-
sene. This has repeatedly been shown to re-
duce the hazard of vapor flash explosions char-
acteristic of high octane gasoline. As a matter
of fact, in one instance an L-188 aircraft was
evacuated after coming to rest in a shallow
ravine which became ankle deep with kero-
sene.’ A wing was torn loose and began to
burn. It was located about fifty yards from
the fuselage, and was connected to the fuse-
lage through a kerosene filled ditch. The fire
never progressed to the airplane, a result of its
slow rate of combustion, a factor enabling fire-
men to stop its progress.

III. COMPOSITE EVACUATION TEST
SUMMARY

A search of the records of various evacuation
tests conducted by the Civil Aeronautics Ad-
ministration, the airlines, the military groups,
and other organizations, reveals the following
information. Of 46 evacuation tests conducted
between 1948 and 1951 in piston aircraft (C-
124, CV-240, B-377, and L-749), involving
2,710 individuals, the average time per test was
1.9 minutes, the average airplane load was 60
individuals per test, and the average individual
evacuation time was 0.032 minutes (19
seconds),

By way of contrast, twenty recently con-
ducted evacuation tests in turbojet aircraft
(707, 720, 880, DC-8), involving 2,437 individ-
uals, gave an average time of 2.14 minutes per
test, with an average load of 125 individuals
per test, and an individual evacuation time of
0.017 minutes (1.0 seconds).

It is readily apparent that the jets, even with
a doubled passenger load as compared with the
piston aircraft, are being evacuated at an abso-
lute efficiency which approximates that for the
piston aircraft, and at a relative efficiency for
each individual which is almost twice that of
piston aircraft.

It should be noted that whereas door exits
can be evacuated in less than one second by an
individual, window exits may take a little
longer. It was reported in 1953 that window
exits have a probable irreducible minimum of
two seconds.‘ However, with today’s larger
and floor level window exits, having better
step-down characteristics, the minimum time is
less than two seconds and appears to approxi-
mate 1.5 seconds,

It should also be noted that for well over a
decade, ninety seconds has been the practical
goal sought for the absolute emergency evacua-
tion time of a given craft.” This goal was based
in part upon the recommendations of the early
1950’s made by the National Advisory Com-
mittee for Aeronautics following a series of
crash fire tests. These tests revealed that air-
craft cabins became essentially uninhabitable
after ninety seconds following a major fire. The
tests also gave a sixty second figure for those
fires associated with ruptured aircraft.

Recently, in follow-up to FAA Order FS
8400.4, a two minute absolute evacuation test
time has been allowed by the FAA for new
types of passenger-carrying airplanes on pro-
posed increased seating densities. This longer
time is based partly on the fact that jet aircraft
cabins are somewhat longer than the cabins of
piston aircraft, and the time required for a fire
to reach major proportions in these cabins can
be extended accordingly. This two minute
time, however, is not a sacred rule, and is being
further evaluated. It might be noted that ad-
ditional factors leading to the proposal for this
two minute time are considerations such as the

—4—


individual escape can now be reduced to 1.4 to
1.2 seconds per person.”

As pointed out by Mr. Kenneway of the
David Clark Co., the particular aircraft mission
should dictate the nature of the personal pro-
tection equipment.’ Implicit in this observa-
tion, is the fact that the nature of the personnel
involved in the mission also determines nature
of the protective equipment. All aircraft flights,
whether civil or military, can, and should be,
construed as missions. A successful mission is
the delivery of the occupants, intact and in
their original condition, to the surface of the
earth, and to the outside of the aircraft. If the
outside is an hostile environment, then the oc-
cupants must be delivered to the outside with
the proper survival equipment. Mr. Kenneway
describes certain recent developments in one-
man life rafts (suitable for light aircraft), and
underarm life preservers. The latter are very
small in the uninflated state and can actually
be worn uninflated during the trip without in-
terfering with motion.

In this connection CARI investigators have
just completed a series of tests in the CARI
ditching pool on children ranging in age from
2 years to 8 years of age, evaluating children’s
flotation devices in common use today. A cer-
tain number of these devices fail to meet the
prescribed regulations provided in Technical
Standard Order C-31C. The results are being
given to the manufacturers for appropriate
equipment corrections. This study underscores
the statement above, that, the protective equip-
ment must be tailored to the specific nature of
the personnel involved in a given flight, and
emphasizes once again, the heterogeneous char-
acteristic of the civil aviation passenger popula-
tion and the wide differences in requirements
for protective equipment and procedures be-
tween civil aviation and military aviation.

The Federal Aviation Regulations, recodified
as of January 1963, are specifically designed to
accomplish a minimum standard of safety re-
quirements (often exceeded by the manufac-
turers and airlines) consistent with economic
feasibility. Part 4b.362 provides the standards
for transport category aircraft emergency evac-
uation procedures.”

In Part 4b.362, the four major types of pas-
senger emergency exits are described. An ab-
breviated listing is as follows:

Type I — Floor level Rectangular Opening,
24 inches wide, 48 inches high

Type II — Rectangular Opening, 20 inches
wide, 44 inches high

Type III — (usually over the wing) Rectang-
ular Opening, 20 inches wide, 36 inches
high.

Type IV — (usually over the wing) Rectang-
ular Opening, 19 inches wide, 26 inches
high.

Various aircraft may be equipped with com-
binations of the above types of exits. The
Boeing 720 has, for example, for passenger
exits, one Type III over each wing, in addition
to four Type I exits (two forward, two aft).
The Douglas DC-8 has two modified Type IV
exits over each wing, in addition to the four
Type I exits. The Convair 880 is similar in
exit plan to the Boeing 720. By contrast, the
DC-6B, has ten passenger exits, since, due to
the utilization of smaller individual exits, more
are required. The number of passengers for a
given aircraft, determine the number and class
of exits required (see 4b.362).

It should be noted that the cabin pressuriza-
tion requirements have led to the development
of “plug-type” escape exits. These exits are
safe from the standpoint that when the air-
craft is enroute and pressurized, removal is
practically impossible, whereas, on the ground,
removal is quite easily accomplished.

A fatal accident, involving an exit which was
not of the plug-type, occurred on October 19,
1962, over Connecticut, when the pressuriza-
tion system of a Convair 340/440, blew open the
rear service door and the stewardess was blown
out."

More than two dozen cases of persons lost
through exit and window blow-outs have oc-
curred since the advent of pressurized aircraft.
As recently as March 3, 1964, an occupant of
a turboprop air transport category aircraft was
lost at 19,000 feet over Tennessee when a door
blew off. This incident emphasizes the hazards
associated with exits of the non-plug type.

-7—



AM—65—7

HUMAN FACTORS /
OF EMERGENCY EVACUATION

STANLEY R. MOHLER, M.D.

JOHN J. SWEARINGEN, MS.

ERNEST B. McFADDEN, MSS.
J. D. GARNER, B.S.

Approved by Released by
Stank RAW)ohiW Ut Whe
Stantey R. Mouter, M.D. M., S. Wurre, M.D.

Dmecror, CARI Feperar Am SuRcEON

FEDERAL AVIATION AGENCY
OFFICE OF AVIATION MEDICINE
CIVIL AEROMEDICAL RESEARCH INSTITUTE
OKLAHOMA CITY, OKLAHOMA
SEPTEMBER 1964



Cardiac patients may also require help. All of
these persons should be initially positioned in
the airplane so that they are close to a large
emergency exit and can be evacuated in the
shortest possible time.

There are pros and cons concerning the serv-
ing of a few ounces of alcoholic beverages to
passengers. A small number of passengers may
be on board who prior to flight had consumed
a fair amount of alcohol, producing blood levels
in excess of 100 mg percent which represents
the generally used legal level of intoxication.
The additional alcohol may serve to incapaci-
tate these passengers, necessitating special at-
tention to them during the evacuation. One
factor being scrutinized by CARI in this re-
spect, is, whether or not, a small amount of
alcohol served enroute has a beneficial effect
on persons from the “calming” standpoint, thus
resulting in an improved and more orderly
evacuation. Overly anxious persons may be
benefitted. Also, those persons prone to “nega-
tive panic” in the sober state, may not express
this immobilizing fear reaction after a few
drinks, with, consequently, an enhancement of
their evacuation efficiency.

Psychosocial and socioeconomic factors
must not be overlooked in handling a given
group of potential evacuees. For example, large
passenger complements drawn from lower so-
cioeconomic strata, are more prone to undisci-
plined, disorderly, evacuations. This situation
can be further aggravated by passengers who
do not speak the same language as the crew
members. Even the effectiveness of interpre-
tors can be compromised by the excitement of
a given evacuation event.

6. The Accident and its Consequences

a. Impact, Airframe and Seat Strengths, and
Injuries. Air transport fuselages today can
withstand as much as 20 to 25 g’s of impact
decelerative force prior to disintegration (De-
sign of Passenger Tie-Down, Aviation Crash In-
jury Research Report CSDM #1, AvCIR-44-0-
66, by A. H. Hasbrook). Air transport seats are
required to be stressed for 9.0 g’s forward de-
celerative forces, 2.0 g’s upward forces, 1.5 g’s
sideward forces and 4.5 g's downward forces —

assuming a 170 pound occupant (Federal Avia-
tion Regulation 4b.358-1 “Application of Loads,”
and FAR 4b.260 “Emergency Landing
Conditions.”

CARI research is revealing that the seat tie-
down strength should at least equal the basic
strength of the fuselage. Since disintegration
of the fuselage will not be compatible with oc-
cupant survival, seat tie-down strengths above
the fuselage strength would impose an unnec-
essary weight penalty. On the other hand, so
long as the strength of the seat tie-downs is
less than the strength of the fuselages, we will
witness accidents wherein the impact is sur-
vivable, the fuselage remains intact, but the
occupants sustain fatal or near-fatal injuries, or,
at the least, experience considerable confusion,
due to seat and seat tie-down failure with con-
sequent “missiling” of the occupants.’

An additional factor which can produce seat-
tie-down failure is the impact of a passenger’s
lower legs upon the underside of the rear sup-
port beam of the seat ahead. CARI research
shows that the breaking strength of human
lower legs is such that they can exert a force
of from seven hundred to fourteen hundred
pounds per lower leg (distal tibia) upon a
seat underside prior to bone fracture.” Since
the lower limbs weigh from seven to fifteen
pounds, the decelerations which can be sus-
tained by these limbs, range within the 100 g
category of force.

As shown by Colonel Stapp (see reference
14) and as reported by Dr. R. G. Snyder of
CARI (CARI Reports 62-19 and 63-15) the
human body is capable of surviving impact de-
celerations far in excess of those which can be
withstood by current airframes. Additionally,
John Swearingen has demonstrated on person-
ally conducted tests, that 100 g vertical im-
pacts can be sustained by the human being
(“Human Voluntary Tolerance to Vertical Im-
pact,” Aerospace Medicine, vol. 31, December,
1960).

In view of the fact that the human being
is capable of withstanding more than 20 g’s
impact force in all axes of the body, and in
view of the estimated 20 g strength of trans-
port aircraft fuselages, it appears logical to
recommend an all-directional 25 g passenger

-l-—


darkness for approaches to exits. In recent
months, most airlines have placed large tritium
powered exit signs for passenger guidance at
strategic points, as a result of the FAA/Industry
Task Group.

f. Strength Required to Open Exits. CARI
has completed a study of the magnitude and
direction that a hostess may apply to an exit
operating mechanism.” These experiments
showed that female subjects could pull with
40-80 Ibs. of force, and males with 100-160 Ibs.
of force, on emergency exit operating mechan-
isms. By accelerating the body and jerking the
handle, male subjects were capable of apply-
ing 300-340 lbs. This information has been
utilized for the design and standardization of
emergency exit operation mechanisms. Another
study has been completed at CARI relative to
the forces that may be applied by males and
females to a variety of main cabin door oper-
ating handles.” This study provides human fac-
tors information relative to the rotational torque
available and the least plus the most advan-
tageous rotation arcs for design of these mech-
anisms. Utilizing an eleven inch handle, a
maximum force of 4,140 inch pounds was ex-
erted by the top male subject. A top female
subject was capable of applying a maximum of
2,400 inch Ibs.

2. The External Environment

a. Night. One project at CARI has resulted
in the development of self-illuminating life raft
light markers utilizing tritium which is a radio-
active isotope of hydrogen. The unit is desig-
nated primarily as an illuminated marker to
orient survivors as to the location and con-
figuration of the life raft, and as a guide to the
evacuation of the aircraft and the boarding of
the raft. The unit is of solid state construction
and is practically fail safe, requiring destruction
to extinguish it. The half-life of tritium is 12.6
years and the unit produces adequate light for
the half-life duration. Small miniaturized flash-
ing zenon raft and life preserver rescue lights
are being evaluated. The life preserver light
produces a pulsed 100,000 lumen flash, where-
as the life raft light produces a 2,000,000 lumen
flash. The flashes are repeated with a fre-

quency of 50 per minute. The light has a color
temperature of 6,200 degrees kelvin, which is
slightly colder than sunlight (5800 degrees
kelvin).

b. Land, On-the-scene participation in acci-
dents has revealed factors on land which either
enhance or hinder rapid escape from a dis-
tressed aircraft.

(1) Flat. A very good wheels up landing
just after take-off is documented on flat fairly
soft terrain. All escaped without injury just
before fire consumed the aircraft which stopped
in an upright position with the doors near the
ground. The accident occurred at Amarillo,
Texas, on August 8, 1962, and involved a Vick-
ers Viscount.

(2) Woods. A crash in woods is subject to
very unpredictable fuselage damage and dis-
tortion. A probable cause of aft door escape
route blockage may have been due to the im-
pingement of a tree against the door in a re-
cent accident.’

(3) Temperature. If rescue is rapid, it is
concluded from circumstances of accidents that
temperature effects are minimal. However,
during the post-crash phase in mountainous
areas of remote places where rescue is slow, ex-
posure may jeopardize survival.

c. Water. Special emergency procedures
are now recognized for evacuation into water.
CARI is now documenting all such incidences
of both transports and light planes to note any
items in procedures which could be improved.
In the last 10 years, 102 ditchings have been
reported. * Inadequate preparation for water
ditchings, has resulted in considerable loss of
life.

(1) Waves. Loss of equipment and surviv-
ors as a result of moderate to heavy seas is
documented in Civil Aeronautics Board reports
and our study of incidences. Due to the fact
that aircraft and raft oscillations, the result of
wave and swell action, may not be in phase
with one another, raft boarding often becomes
exceedingly difficult. The result is serious in-
jury or loss of survivors and significant delays
in evacuation of the ditched aircraft. Seasick-

-9-



Precautionary escape actions should always be
taken without waiting to determine whether
fire has developed or will develop.

Crew knowledge and effective leadership are
the most significant factors identified in pro-
ducing successful escapes. The larger the num-
ber of passengers, the more important is the
role of the crew. It should be noted that due
to the more vulnerable forward location of
many of the crew members, there is a greater
risk of incapacitation on their part, which must
be taken into consideration in planning for
evacuations.

All of the crew members must have knowl-
edge concerning the operation of all of the
items of emergency equipment. At times,
escapes have been unsuccessful because a major
escape route has required the coordinated
movement of two separate levers, one in each
hand, and the occupants had been unaware of
this.

Dr. King has pointed out that the assumption
must be made that when an aircraft comes to
rest, not all of the exits will be available.
Wrenching of the fuselage can bind large exits
and render them impossible to open. The fuse-
lage can come to rest upon a vehicle with sub-
sequent jamming of an exit (CARI Report 62-9
gives an example of a survivable accident which
resulted in the death of 16 out of 122 occu-
pants, a significant factor being the deforma-
tion of the left rear passenger door by a panel
truck which was parked near the runway).

As noted in Dr. King’s work, the escape po-
tential of an exit is defined as the number of
passengers who can escape through it in ninety
seconds from the time the plane comes to rest.
This includes all preparations for opening the
exit, deploying a slide, holding it, ete.

It is readily seen that regardless of the num-
ber of passengers carried in a given aircraft, the
availability of an adequate number of exits ac-
cording to each “block” of passengers, will de-
termine the total escape time. If each block
of passengers can escape through its own as-
signed exit in one minute, then all of the pas-
sengers can be out of the aircraft in one minute
if all of the exits are functioning.

Using ninety seconds as an ideal maximum
escape time takes into consideration the pos-

sible unavailability of several of the exits in an
aircraft where a one minute escape time is pos-
sible. In its Memorandum No. 10 (page 35)
dated 1959, the Joint Committee on Aviation
Pathology considered ninety seconds as a
reasonable maximum time for emergency
escape."

As previously mentioned, two minutes is now
being tentatively utilized by the FAA in as-
sessing the emergency evacuation of aircraft
having new high density seating arrangements
up to 189 in number. At CARI we are now
studying this time from the human factors
standpoint. It may be that the extra thirty
seconds will not prove necessary if certain
compensatory arrangements are made (more de-
tailed and effective crew training, better pas-
senger briefing, improved exits, etc. ).

An important human factor in emergency
escape is that when possible, use a “single
method” (such as jumping into an escape slide).
This gives the door guard better control over
those about to leave the plane, reassures those
who are waiting to escape because of the speed
of egress ahead of them, and helps the older
persons and the obese persons to get moving
more quickly.

Each airplane type will have its own con-
figuration of escape routes, and the respective
crews must be trained for their specific craft.
Of special importance is the matter of training
for proper departure through an exit. Excel-
lent pictures on this point are provided in Dr.
King’s report.

Dr. McFarland points out that the prevention
of crushing injuries, which would enable a pas-
senger to move quickly following a crash, is 40
times as important as fire prevention alone in
eliminating deaths in accidents which involve
fire. He calls attention to the contemplation
by ICAO of doubling its seat strength require-
ments to 20 g’s (1953). He also notes that the
probable irreducible minimum time for 1953
vintage window exit escapes is two seconds.
However, as is clearly demonstrated in recent
years, the increased size of window exits, ac-
companied by improved location, can definitely
reduce this individual escape time. One excel-
lent study on jet window exits, show that the

-—6—


and his associates in the Bureau of Safety of the
Civil Aeronautics Board, will be useful in
evaluation of emergency evacuation equipment,
procedures and training.

Through on-the-scene studies at selected air
carrier accidents in cooperation with the Civil
Aeronautics Board, through study of the de-
tailed CAB reports concerning accidents, and
through other sources, including our own
research and the findings of FAA accident spe-
cialists, we are led to the following four prin
ples with respect to the human factors of emer“
gency evacuation:

Principle One: Each real life emergency
evacuation is essentially a unique incident. Un-
anticipated and unexpected events are almost
certain to occur during each evacuation;

Principle Two: The characteristics of the
airframe, its exits, and its interior, determine
the absolute minimum escape time which is
possible under ideal conditions with stereo-
typed occupants;

Principle Three: The nature and post-crash
condition of the occupants, and the behavior of
the crew, comprise the main variables in deter-
mining the outcome of an emergency evacua-
tion of a given aircraft;

Principle Four: The final resting attitude
of the aircraft, the extent of distortion and
damage to the cabin, its exits and interior, and
the environmental conditions, contribute to the
actual evacuation time.

At this junction it is well to call attention to
the following point: There is a tendency for
many of those in aviation to think of an emer-
gency evacuation in “isolated terms”, that is,
as an event which is self-contained and essen-
tially uninfluenced by the pre-emergency and
post-emergency circumstances.

We now know that emergency evacuation is
vitally affected by (1) the impact protection
features which are built into the aircraft and
its equipment; (2) the fire inerting features
contained near the power plants and other
structural elements, plus the nature of the fuel
and the fuel cells; and (3) the geographic
longitude and latitude, the season, and the
presence or absence of daylight. Even rain has
been known to inhibit some persons from evacu-
ating a distressed aircraft.

In other words, the study of emergency
evacuation is an interdisciplinary subject, and
requires the coordinated contributions of aero-
nautical engineers and biologists, of flight sur-
geons and behavioral scientists, of pilots and
others who are engaged in air commerce. The
analysis which follows contains information
gleaned from these several sources plus our
own studies.

The circumstances within which the emer-
gency evacuation occurs, involve the following
steps:

1. The events leading to the accident;

2. The impact profile, including secondary,
tertiary and additional impacts, plus
twisting and other angular positive and
negative accelerations;

3. The immediate post-impact period, which
may be complicated by smoke, fire, panic,
submersion, wave actions and other
factors;

4. The later period which may be character-
ized by exposure to the elements, rough
water, and a lack of appropriate survival
gear.

If the occupants of a craft which is headed
for a ditching are worried about step 4, this
concern may modify their ability to accomplish
an efficient evacuation during step 3. In the
same fashion, an inefficiently handled step 3
may produce difficulties during step 4 because
certain essentials to long-term survival were
left within the ditched and sinking aircraft.

The point cannot be emphasized too strongly
that the emergency evacuation itself is but one
vital step in the several steps which comprise
the “evacuation continuum”. A survived step
2 means relatively little if occupants perish dur-
ing step 3 or step 4. Therefore, we must think
in comprehensive terms, and visualize and pre-
pare for the successful achievement of ell four
steps in the evacuation continuum.

For example, a major difference in accom-
plishing successful evacuations on land versus
water evacuations, is that in land evacuations
no delays should be imposed by removal and
transport of paraphernalia during the evacua-

-2-


10.

ll.

12.

13.

14.

15.

16.

. Tennyson, Lord Alfred:

. Civil Aeronautics Board:
. Civil Aeronautics Board:

|. McFarland, Ross A.:

. Civil Aeronautics Board:

. Kenneway, A.

REFERENCES

“Locksley Hall”, quoted in
The Sounds of Wings, edited by J. B. Roberts and
P. L. Briand, Henry Holt and Co., New York, 1957,
page 46.

“Aircraft Accident Report,
File Number 10025”, Released February 6, 1962.

“Aircraft Accident Report,
File Number 10028”, Released September, 13, 1963.

Human Factors in Air Trans-
portation. ' McGraw-Hill Book Company, Inc, New
York, 1953, pp. 1-830.

Hasbrook, A. Howard, Gamer, J. D., and Snow,
Clyde C,; “Evacuation Pattern Analysis of a
Survivable Commercial Aircraft Crash”, CARI Report
62-9, Federal Aviation Agency, May 1962, pp. 1-10.

“Aircraft Accident Report,
File Number 10018”, Released September 19, 1963.

. King, Barry G., Ostrich, Ralph and Richardson, Mary

C.:” “Emergency Escape Procedures”; Technical Re-
port of the Air Force Cambridge Research Center,
prepared by the Medical Division, Civil Aeronautics
Administration, CRC-TR-54-56, Washington, D.C.,
August 1954, pp. 1-96.

3. Joint Committee on Aviation Pathology: “Escape from

Aircraft and Survival from Aircraft Accidents”, Mem-
orandum No. 10, Armed Forces Institute on Pathol-
ogy, Washington 25, D.C., 1959, pp. 1-89.

J.:_ “Integration of Personal Equip-
ment”; Technical Documentary Re; ASD-TDR-62-
601, Air Force Systems Command, Wright-Patterson
Air Force Base, Ohio, September 1962, pp. 1-30.

Roebuck, J. A., and Littlewood, R. A., “Overwing
Emergency Exist Study”, Douglas Aircraft Report No.
SM-22573, December 28, 1956, pp. 1-353.

Earley, John C.: “Belt Loads in Side-facing Seats”,
Memorandum Report to FS-120, Federal Aviation
Agency, December 7, 1961.

Code of Federal Regulations: Title 14—Aeronautics
and Space, Part 4b.362 “Emergency Evacuation”,
Federal Aviation Agency, January 1, 1963.

Civil Aeronautics Board: “Aircraft Accident, Report,
File Number 1-0029”, Released July 18, 1963.

Stapp, John: “Human Exposures to Linear Decelera-
tion Part 2, The Forward Facing Position and the
Development of a Crash Harness”, AF Technical Re-
port No, 5915, December 1951 WADC, Research
Division of Wright-Patterson Air Force Base, Dayton,
Ohio.

Federal Aviation Agency, Proposed Rule Making,
Regulations, Procedures, and Equipment for Pas-
senger Emergency Evacuation; Flight Attendants; and
Assignment of Emergency Evacuation Functions for
Crewmembers, 14CFR Parts 4b, 40, 41, 42 Notice
63-42, Docket No. 2033, October 29, 1963.

Federal Aviation Agency, Aircraft Maintenance Bul-
letin Large Aircraft, Manual of Procedure 304, Miscel-
laneous No. 18, November 26, 1962.

17.

18.

19.

20.

22.

23.

25.

26,

27.

28.

29.

SL.

32,

~15—

. Lippert, S.:

. Swearingen, J. J.

King, Bamry Gu: “Elimination of Some Time Losses
in Emergency Evacuation of Passengers from Air-
planes,” Office of Aviation Safety, CAA, Aeronautical
Engineering Review Volume 12, No. 3, March, 1953.

Federal Aviation Agency: “Maintenance of Pas-
senger Seats”, Manual of Procedures 304, Miscel-
laneous No. 17, November 26, 1962.

Swearingen, J. J. Wheelwright, C, D., and Garner,
J. D.: “An’ Analysis of Sitting Areas and Procedures
of Man”, CARI Report 62-1, Federal Aviation Agency,
January 1962.

Swearingen, J. J., Hasbrook, A. H., Snyder, R. G.,
and McFadden, E. B.: “Kinematic Behavior of the
Human Body During Deceleration”, CARI Report
62-13, Federal Aviation Agency, June 1962.

“The Passenger”, presented at a Sym-
posium on Ecology of Air Transport, Los Angeles,
California, December 7, 1956.

Townshend, B, W.: Safety in Over-Water Flights —
A Study of Ten Years Losses of Aircraft Over Water”,
R.F.D, Company Ltd., Godalming, Surry, England,
March 1963.

Hasbrook, A. Howard, Earley, John C.: “Failure of
Rearward Facing Seat-Backs and Resulting Injuries in
a Survivable Transport Accident”, CARI Report 62-7,
Federal Aviation Agency, April 1962.

.; “Determination of Centers of
Gravity of Man”, CARI Report 62-14, Federal Avia-
tion Agency, August 1962,

Snyder, R. G.: “Human Survivability of Extreme
Impacts in Free-Fall”, CARI Report 63-15, Federal
Aviation Agency, August 1963.

McFadden, E. B., Swearingen, J. J. and Wheel-
wright, C. D.: “The Magnitude and Direction of
Forces’ that Man can Exert in ting Aircraft
Emergency Exits’, Human Factors, Vol. 1, No. 4,
November 1959.

McFadden, E. B., Swearingen, J. J. and Wheel-
wright, C. D.: “Forces that May Be Exerted by Man
in the Operation of Aircraft Door Handles”, Human
Factors, Vol. 1, No. 1, September 1958,

Swearingen, J. J.: “Protection of Passengers and Air
Crew From Air Blast Effects of Explosive Decompres-
sion”, Civil Aeronautics Medical Research Laboratory
Project No. 50-516, Report No. 1, Department of
Commerce Civil Aeronautics Administration, Aero-
nautical Center, Oklahoma City, Oklahoma, August
1950.

Swearingen, J. J, and McFadden, E. B.: “Studies
of Air Loads on Man”, Human Factors, Vol. 2, No. 2,
May 1960.

. Gamer, J. D., and Blethrow, J. G.: “Evaluation Test

on the Telescape System for Emergency Evacuation
from Aircraft”, Report No, 1, Federal Aviation
‘Agency, October 1962.

McFadden, E. B., and Simpson, J. M.: “Flotation
Characteristics of Aircraft Passenger Seat Cushions”,
Preliminary Interagency Report, Federal Aviation
Agency, February 14, 1964,

Von Rosenberg, C, W.: Personal communication.



Illustration No. 3: Indoor ditching pool at Civil Aeromedical Research Institute is shown dur-
ing a test, illustrating the means by which the movements of individuals
are recorded on film from different angles.

Illustration No. 4: Close-up of anterior fuselage and six man raft illustrating high water line
in cockpit. Complete submersion is possible, together with the creation of
additional simulated environmental Rotors, including total darkness and
cooled water (34° F).

-17-



HUMAN FACTORS
OF EMERGENCY EVACUATION

STANLEY R. MOHLER, M.D., JOHN J. SWEARINGEN, M.S.,
ERNEST B. McFADDEN, M.S., AND J. D. GARNER, B. S.*

I. INTRODUCTION

More than one hundred years ago Lord Ten-
nyson prophesied “Saw the heavens filled with
commerce, argosies of magic sails, pilots in the
purple twilight, dropping down with costly
bales”.' He possibly did not foresee certain
complications associated with such aerial com-
merce, particularly the “dropping down” with
more than the usual drop force.

The “costly bales” which comprise the topic
of this paper, are the soft protoplasmic masses
encased within aircraft. The aim of emergency
evacuation is to get these soft protoplasmic
masses from the interior of a distressed aircraft
to the exterior, without irreversible damage.

This paper will focus on what we term the
human factor in emergency evacuation.

Anything which unduly impedes the proces-
ses of emergency evacuation is deleterious and
must be avoided. The word unduly is used be-
cause certain impediments, or “constraints”, are
essential to an orderly evacuation. In the ab-
sence of constraints, utter chaos is generated,
and, as was indicated in a recent survivable
crash landing of a transport-type aircraft, trag-
edy may result.’ The evidence indicates that
the loss of 77 lives in the conflagration which
followed the survivable crash landing, resulted
from the inability of the occupants to open the
main door, possibly greatly aggravated by the
pell-mell collection of the occupants against
the door.

*Dr. Mohler is Director of the Civil Acromedical Research
Institute, Federal Aviation Agency, P. O. Box 1082, Okla-
homa City, Oklahoma. Mr. Swearingen is Chief of CARI’s
Protection and Survival Branch, Mr. McFadden is Chief of

this Branch’s Survival Equipment Section, and Mr. Gamer
is Chief of its Emergency Escape Section.

Perhaps the apparent lack of knowledge of
the occupants concerning the location of the
various window escape doors accounted for
their failure to utilize these routes. In ignor-
ance, they apparently sought their route of en-
trance. It should be noted that these persons
were relatively unsophisticated with respect to
air travel and air carrier equipment. Hence,
the recent trend by the various airlines to pro-
vide the passengers with an increasing amount
of descriptive information concerning emer-
gency evacuation procedures and exits is to be
commended and encouraged. Also, the in-
creasing use of better exit marking and lighting
marks definite progress.

In previous decades, the mere mention in
the presence of passengers of the possibility of
aircraft accidents was considered anathema by
public relations personnel. We have come a
long way. We have still a way to go.

For example, preliminary evidence indicates
that the “anxiety level” of passengers as a group
is diminishing in general. Almost all of us have
in recent times seen an irate crowd of pas-
sengers besieging an airline ticket counter on
a bad-weather day, and beseeching the airline
to dispatch them (in the wisely grounded air-
liner) into the soup and cumulonimbus, post-
haste. Can the fright of flight be very high
among the repeat passenger? We feel that it
may not be so. As a matter of fact, we have a
psychologist and a sociologist currently measur-
ing this anxiety level. They are paying particu-
lar attention to the subsequent flight experience
of passengers who have previously survived
major air carrier disasters. This study, con-
ducted in cooperation with Mr. Bernard Doyle

-1-





restraint system. This must take into account
serpentine floor movements which frequently
accompany the successive decelerations, to-
gether with the other harmonic motions and
flexions in all axes.

A current study in the CARI Protection and
Survival Branch, bears further upon the above
statement. This study is developing reference
data with respect to the immediate environ-
ment surrounding a given passenger, such that,
an Ine is recommended for the material of the
structure concerned. The Ine (Impact Never
Exceed) is analogous to the Vne (Velocity
Never Exceed) quantity determined for each
aircraft.

The above paragraphs are presented to point
out the crucial nature of the actual accident in
determining the degree of success of an evacu-
ation. It is stressed here that the crew mem-
bers who will be closest to the passengers, and,
thus, will be playing key roles in directing the
evacuation (particularly the stewardesses),
should be positioned in locations which have
the lowest possible Ine rating.

A factor which has just come to light, has re-
sulted from the determinations at CARI of the
center of gravity of more than one thousand
children, ranging in ages from three years to
eighteen years. In the seated position, the c.g.
of small children is four to five inches above
the standard seat belt as normally worn in the
standard aircraft seat. The adult c.g. is essen-
tially located at the belt, and during decelera-
tions, the adult is held in the seat due to the
balance of forces above and below the belt
while jack-knifing is taking place. The small
child, however, tends to rotate out of the seat
over the belt during decelerations, and, conse-
quently, receive injuries.

The development of improved restraint sys-
tems for children is underway. Available on
demand infant restraint systems, are especially
needed. Today, the mothers’ arms not infre-
quently attempt to serve this role.

Of course, appropriate aft facing seat would
solve most of the above problems.

An interesting comparison in the prevalence
of injuries which accompany survivable acci-
dents, between piston and turbine-powered air
transports, shows that among 1394 persons in-

volved in piston air transport accidents, 13 per-
cent received injuries, whereas among 704 per-
sons involved in turbine-powered air transport
accidents, 8 percent received injuries.

b. Attitude of Aircraft. Many unique fac-
tors may accompany a given crash. One acci-
dent occurring at LaGuardia Airport a few
years ago, resulted in the aircraft coming to
rest in an inverted position. Nevertheless, all
passengers evacuated within minutes, one ben-
eficial factor being the absence of the seats as
obstacles, leaving, in effect, a wall-to-wall aisle.

7. Miscellaneous

Surprising factors in situations which may
precipitate emergency evacuations continue to
arise. For example, during March of 1964, a
shipment of “Sun Guns,” which are battery op-
erated portable floodlights used by the major
TV networks, exploded in flames just after
being unloaded at Washington National Air-
port from an air carrier aircraft. The implica-
tions for a possible inflight emergency are ob-
vious. We must be continually on the alert for
these potential emergencies which may be as-
sociated with new types of electronic apparatus
shipped by air. We also must be alert to the
requirements of the newer exotic aircraft for
emergency evacuation procedures, particularly
the helicopters, the vertical-and-short-take-off-
and-land (V/STOL) aircraft, and the super-
sonic transport.

The Committee on Medical Criteria of the
Aerospace Medical Association has pointed out
the medical criteria for passengers in today’s
airliners (Arch. Environ. Health 2:124, 1961).
A further refinement is being made with re-
spect to additional criteria relative to the
emergency evacuation factors associated with
these ill persons.

CONCLUSIONS

1. An analysis of evacuation tests conducted
over the years since World War II indicates
that the evacuation of the average “stereo-
typed” individual from a modern jet airliner
may be accomplished in approximately one-
half the average time required for his counter-
part from a piston aircraft. It appears that this

-—13-



Illustration No. 1: Stewardess slides down deployed “Telescape” pole during evacuation test
at Civil Aeromedical Research Institute.

Illustration No. 2: Three year old child prepares to exit Convair during CARI evaluation of
the Telescape system utilizing all age groups.

—j16—