TEST 2

EXITS

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Figure 11. Bgress routes are indicated by symbols on Test 2 through three Type A exits. Areas where passengers split for escape are shown at Rows 18
and 40.


“C” stewardess directed 20 passengers to the rear
exit who had initially started toward Exit 2
from the center area of the cabin. The escape-
time plot in Figure 8 shows similar rates for the
two exits. Table V gives the variations in flow
rates of groups of 20 passengers at intervals
throughout the evacuation. Table VI lists the
overall evacuation flow rates tabulated from the
three points in the evacuation.

TABLE VI.—Flow rates at each exit in passengers per

minute in test 1A, Calculated within 3 different intervals
of the evacuation*

Passengers Per Minute

Start Signal to First Passenger

Start Signal to Last. In Exit to
Exit End of Passenger Last Passenger
Number Evacuation Out* Out**
75.5 75.5 78.1
72.8 72.4 76.6

*Flow rate was determined by the number of escapees
within each time interval and calculated for rate per
minute.

**Excludes crew members.

It is noteworthy that the passenger flow rates
for these same two exits in Test 1 were signifi-
cantly lower (Table III), Exit 2 having an

overall flow rate of 48.7 passengers per minute
compared to 75.4 in Test 1A. Exit 7 increased
similarly in flow rate from 43.7 to 72.8 in Test
1A. The apparent reasons for the increased rate
in Test 1A, based on passenger and crew state-
ments and on the motion pictures, are:

1. Passengers moved more vigorously in Test
1A.

2. The passengers’ and crew members’ previous
experiences in Test 1 enhanced Test 1A flow
rates,

3. Unbroken evacuee lines were maintained in
Test 1A to each exit until the last person was out.

4. Crew members had more time, since the use
of only two exits increased the total time, to
direct passengers to balance the evacuee lines to
both exits.

The 12-inch increase in height of Exit 7 (to
60 inches, compared to 48 inches at Exit 2)
showed no significant influence on passenger flow
rates, although the physical conditions of Exit 7
favored a high flow rate because of the greater
height of the opening and shorter step-down
distance outside (7 inches). Personal interviews
and film evidence indicated that: (1) the vigor-

TEST 1A ESCAPE TIMES

CLASS | EXITS

START SIGNAL

Exit No. Y

Ist PASSENGER
(F] PASSENGER
CREW

2

137 G

(24" x 48")
: Yj
(24" X 60") 135
L 1 1 L L 1 1 1 1 L 4 =
ie} 10 20 30 40 50 60 70 80 90 100 I10 120
TIME IN SECONDS

Fisvre 6. The number of passengers evacuating and a time graph of Test 1A (Exits 2 and 7) shows the similarity
of two Type I exits, one 48 inches high (16-inch step-down) and the other 60 inches high (7-inch step-down)

both 24 inches wide.


in flow rates was apparently due to the step-
down distance being 16 inches outside the fuse-
lage at Exit 8, and only 7 inches at Exit 10.

An escapee-route flow pattern for Test 2A
appears in Figure 14. The passenger load di-
vided at Row 30, the center of the cabin, to the
two exits. Figure 13 escapee-time plot shows
decreases in the flow rate after about 40 seconds,
when one of the passenger lines to the exits
ended, leaving a single-line flow. This decrease
in flow rate is shown in Table XTI, in the analysis
of groups of 20 passengers tabulated for the
evacuation in passengers per minute.

TABLE XII.—Flow rates of segments of 20 passengers
tabulated in passengers per minute to observe variations
in the rate during the evacuation at each exit (Test 2A)

Passengers Per Minute

Exit Number

Passenger
Segment 8 10
1-20. 142,2 192.3
21-40. 144.4 167.6
41-60. 150.7 174.7
60-80 143.0 212.8
81-100. 95.2 133.0
101-320. 77.6 104.4
116-136. 73.2
121-141_ 72.3

NOTE: The groups of 20 passengers were not chosen in
consecutive order due to the varying numbers of
evacuees through an exit in some cases.

VIII. DISCUSSION.

Tests 1 and 2 provide a direct comparison of
the effectiveness of Type I (single) and Type A
(double) minimum-size exits under similar con-
ditions. The test conditions were ideal, without
problems of visibility, baggage in the escape
routes, escape slides, aircraft attitude (flat belly
Janding) or many other factors encountered in
actual crashes. In theory, at least, introduction
of one or more of these encumbrances within the
same environment would increase evacuation
times over those obtained in these tests.

In all tests, many passengers failed to hear and
comprehend the stewardesses’ commands above
the “crash noises” being played on the public-
address system. Passengers in some areas of the
long SST cabin, located between stewardess sta-
tions, heard overlapping commands. Commands
during Test 2 were shouted in unison by the
girls, sitting together on jump seats by the Type
A exits. The words “bend over” were added to

20

the command “grab ankles” for the impact/
brace position; this addition to the command
phrase solicited full passenger response. Evi-
dence from motion picture film shows all pas-
sengers in brace position during most of the
crash-sound period. Personal interviews revealed
that some assumed the brace position from the
example of others.

The average flow rate of the four Type I exits
in Test 1 was 46.8 passengers per minute, indi-
vidual rates ranging from 43.7 to 50.2 passengers
per minute. In contrast, the average flow rate
of the three Type A exits in Test 2 was 126.2
passengers per minute, ranging from 113.9 to
138.9 (Tables III and VIII). From these rates,
the comparative passenger egress ratio is calcu-
lated to be 1 to 2.69 for Type A and Type I
exits, respectively, based upon the total test times.
Excluding crew members, the same ratio was 1
to 2.37.

For Test 1A, in which reloaded passengers
evacuated their second time, the flow rate in-
creased by 37.5% in passengers per minute.
Comparatively, the rate in Test 2A increased
only 13% during the time the door was fed from
both aisle directions. After passenger flow from
one aisle direction ended, the rate decreased to
nearly one-half because of the single-row effect
of evacuees using Type A exits. Increases in
both tests are attributed to passenger experience
and confidence from the previous tests.

A comparative escapee-time chart (Figure 15)
presents exit times for Exits 2 and 8 from all
four tests. Both of these exits had a 16-inch
step-down outside the fuselage to a ramp with
TABLE XIII.—An aggreagate listing of evacuation times

from all four tests with number of passengers and crew
evacuating from each exit

Exit Test, Total Time | Number
Number Number (seconds) Passengers Crew

1 1 35.7 30 IM*

2 1 61.5 48 1F

2 1A 113.1 137 3F-3M
3 1 67.1 55 2F

4 1 70.7 32 2M

5 1 70.4 30 iF

6 1 66.2 28 1F

7 1 57.7 41 iF

7 1A 112.1 133 3F

8 2 47.4 90 2F-1M
8 2A 81.8 142 2F-3M
9 2 46.9 99 2F
10 2 41.3 95 2F

10 2A 67.8 144 3F

*Male crew member in passenger line.


EVACUATION TESTS FROM AN SST MOCK-UP

I, INTRODUCTION.

The increased passenger-carrying capacities of
transport aircraft have complicated the problem
of establishing adequate emergency evacuation
procedures. Concern for the successful resolution
of this problem has stimulated efforts to properly
define and meet the needs of any given evacuation
event. Studies to define and measure the char-
acteristics and interwoven events of an emer-
gency evacuation can provide data to: (1)
improve the management of evacuating passen-
gers, and (2) serve as a guide for the design of
optimal locations and features of escape routes.

Considered as a system, an evacuation proce-
dure should be evaluated for: (1) briefing of
passengers, (2) prevention of crash injuries so
that passengers are physically capable of escape,
(3) effectiveness of crew members, (4) placard-
ing, (5) emergency lighting, (6) access to exit
areas, (7) absence of potential obstructions to
exits (e.g., baggage), (8) size of exits, and (9)
door-opening procedure, with associated emer-
gency chute deployment. A successful evacuation
depends upon keeping usable exits “fed” with
passengers at maximum egress rates. The threat
of fire, smoke, and explosion makes each second
a lifesaving segment of time.

This study was designed to test. and analyze
the relative efficiencies of exits of four specific
configurations, in terms of passenger flow rates.
All tests were conducted using the full-scale
supersonic transport mock-up, constructed by the
Lockheed-California Company, Burbank, Cali-
fornia, as a test vehicle. Volunteer snbjects were
used as passenger evacuees.

Il. GENERAL DESCRIPTION.

The basic objectives of these tests were to:
(1) evaluate the comparative passenger flow
rates through Type I and Type A exits, using
large groups of subjects, (2) supplement previous
studies on the effects of door heights on evacua-
tion flow for Type I exits with 48-inch and

60-inch heights, and (3) evaluate crew-position-
ing and management of passenger flow through
Type A exits from a single aisle in the cabin.
The information was gathered to supplement and
compare with existing data on these exits, the
ultimate goal being to either confirm the validity
of, or recommend changes in, the current ratings
of Type I and/or Type A exits. It should be
pointed out that at present the Type I and/or
Type A exit ratings have not been finalized.
This matter is currently under consideration by
FAA Flight Standards Service and involves
evaluation of additional emergency evacuation
data submitted by industry.

Test Vehicle. The supersonic transport (SST)
mock-up was moved to the Civil Aeromedical
Institute (CAMI), Oklahoma City, Oklahoma,
during March 1967, to be used primarily as a
general evacuation test vehicle. The mock-up
(less 21 feet of the tail section) included the
hinged nose, flight deck, and the 179-foot cabin
area back to the aft cabin bulkhead. The mock-
up was reassembled in a fenced enclosure with
the cabin floor elevated 32 inches above ground
level. Platforms simulating wing surfaces ex-
tended 20 feet outward on each side of the mock-
up and along its length for 110 feet (from Seat
Rows 20 to 58), as illustrated externally in
Figure 1.

Inside the mock-up, 60 rows of seats, each
five-abreast (three on the right, two on the left),
were arranged as a one-class configuration for
280 passengers. The minimum aisle width of
15 inches specified for transport aircraft was
maintained as nearly as practicable. A 34-inch
fore-aft seat spacing, measured between similar
points on each seat (seat pitch), was used
throughout the cabin. Bulkheads divided the
cabin into three sections.

A public-address system was provided in the
cabin. A movable crew intracommunications
system permitted plugging in at many crew sta-
tions within the cabin for different exit locations


eee

TEST 2A ESCAPE TIMES

CLASS A EXITS

START SIGNAL

Exit No. v

FQ Ist PASSENGER
[_] PASSENGER

CREW

8

(42" X72")

10

(42" X72")

138
141
1 1 1 L I 1 1 1 J
0 10 20 30 40 50 60 70 80 90
TIME IN SECONDS

Figure 12. Total evacuation times of Test 2A are shown with numbers of passengers using each exit, Exit 8 had
a 16-inch step-down; Exit 10 had a 7-inch step-down distance. The door plugs were left out for this test and
time was taken when the first passenger appeared in the doorway from the start signal.

filled the aisle, causing him to continue his way
aft by walking on the seats. He was able to
reach Row 23 by the end of the evacuation (47.4
seconds from the start signal).

VII. TEST 2A.

Conditions. The fore and aft Type A exits
(Exits 8 and 10, each located nine rows from
the ends of the cabin) were used to evaluate
what happens to the evacuation pattern when
one line of passengers “feeding” the exits termi-
nates before the other from a single-aisle con-
figuration. Therefore, Exit 9 (center Type A
exit), which would ordinarily be available during
an emergency situation, was rendered inoperable
for the test. The passengers who had just evac-
uated for Test 2 were reloaded and informed of
the exits to be used during Test 2A.

General Observations. As a result of their
experience in Test 2, passengers responded to
crew direction very well. The test was conducted

Ww

with the door plugs removed at the start signal
for observation of continuous passenger flow
rates with a large passenger sample.

The two stewardesses at each of the two exits
directed the evacuation from positions on each
side of their respective doors. There was no
apparent restriction of passenger flow; however,
as previously mentioned, the stewardess at the
forward side of Exit 8 had insufficient standing
space, resulting in a 34-inch passageway between
the two stewardesses performing the evacuation.
An analysis of passenger positions in the door
opening, including the forward, center, or aft
portions of the exit opening, showed that 50%
of the passengers at Exit 8 and 40% of those at
Exit 10 used the center portion during egress
(Table X). These percentages partially reflect
the fact that the exits were being fed from only
one aisle direction during the last of the evacua-
tion, thus functioning as a single door. Utiliza-
tion of Exit 8 as a single door was comparatively
higher, apparently due to the slight restriction




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evacuation times for Exits 8, 9 and 10 were 47.4,
46.9 and 41.3 seconds. The last passengers (ex-
cluding crew) cleared each exit at 44.4, 44.6 and
40.1 seconds, respectively (Figure 9).

Flow Patterns. Under the conditions of the
test, without escape chutes and in an ideal en-
vironment, the flow rates were 113.9, 126.7 and
138 passengers per minute (Table VII). The
escapee-time chart (Figure 10) shows Exits 9
and 10 to have similar rates, each with a 7-inch
step-down onto the wing surface. Exit 8, with
a 16-inch step-down, had a slower flow rate, with
approximately 14 fewer passengers evacuating
per minute throughout the evacuation. Table
VIII depicts variations in flow rate by timing
groups of 20 passengers during the evacuation.

TABLE VII—Flow rates at each exit in passengers per
minute in test 2, calculated within 3 different intervals
of the evacuation*

Passengers Per Minute

Start Signal to First Passenger

Start Signal to Last In Exit to
Exit End of Passenger Last Passenger
Number Evacuation Out** Out**
8.22 113.9 116.1 134.6
126.7 130.5 142.4
138.0 139.2 156.0

*Flow rate was determined by the number of evacuees
within each time interval and calculated for rate per
minute.

**Excludes crew members.

SST EVACUATION TEST

TEST 2 (TYPE A EXITS) 42 x 72 INCHES

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TIME IN SECONDS

Ficure 10. The number of escapee-time plot of Test 2 through three Type A door exits shows comparative efficien-

cies.
the three exits and a slight passageway restriction

The lag in evacuation rate of Exit 8 is apparently due to the highest step-down distance (16 inches) of

by the forward stewardesses.

14



TEST 1 ESCAPE TIMES

CLASS | AND

START SIGNAL

Exit No. v7

3 EXITS

HMB EXIT opens
[] PASSENGER

CREW
(24" x 48") 30
(24" X 48") 2 83
(24" X 48") . 55
(20" X 36") 32
(20" X 36") _t 30
(20" X 36") = 28 7
(24" X 48") | aI
1 1 t 1 it 1 it it J
-20 -10 ie) 10 20 30 40 50 60 70 80
TIME IN SECONDS

Fieure 3. Escape times for Test 1 are shown for all seven exits.
Also shown—15 passengers evacuating during the crash sounds at Exit 2 within a 14-second

using each exit.
time period before the start signal.

started evacuating when the crash noises began
on the sound-effects tape. Fifteen passengers
evacuated through this exit before the “C”
stewardess effectively got the remaining passen-
gers to “stay in your seats until the plane stops.”
At the other six exits used in Test 1, passengers
remained in their seats until the crew gave direc-
tions to evacuate. Passengers assumed the brace-
for-impact (“grab ankles”) position only in the

Number of passengers (excluding crew members)

area of Exit 7 (aft cabin), apparently because
the cabin attendants in seats 55B and 60B could
be heard.

Passenger lines to all exits were continuous
until evacuation was complete. However, at.
Exit 3, space between escapees occurred near the
end as crew members redirected a group from
the overwing window exits to Exit 3 to speed the
evacuation,



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TABLE VIII.—Flow rates of segments of 20 passengers
tabulated in passengers per minute to observe variations
in the rate during the evacuation at each exit (Test 2)

Passengers Per Minute

Exit Number

Passenger—

Segment 8 9 10
155.6 168.8 170.7
120.7 146.9 170.0
143.2 144,8 144.1
152.3 162.8 163.0
137.0

71-91%. 139.9

76-96*___ 202.4

*The groups of 20 passengers were not chosen in con-
secutive order due to the varying numbers of evacuees
through an exit in some cases, resulting in overlapping
of groups.

During Test 2, Stewardess “D” left her seat
by Exit 9 and immediately stood up in the right,
aisle seat (30C) as soon as the passenger occu-
pant was out of the way. She accomplished her
role in the evacuation by directing passengers
coming from both directions to Exit 9 from this
position. (Figure 11 shows her location, as well
as escape routes of passengers.) An analysis of
the motion pictures and personal interviews with
passengers using this exit revealed that this on-
the-seat position of the stewardess was effective
for several reasons. First, she could be easily
seen above passengers. Second, her instructions
could be heard further down the aisle in both
directions as she turned alternately fore and aft,
continually giving commands interspersed with
enthusiastic admonitions to “Get moving!,” ete.
Finally, from her position above the passengers,
the stewardess could observe evacuee lines feed-
ing the exit and thus more effectively control
passenger movement.

Passengers at Exit 9, with only one stewardess
at the double door, evacuated at a vate comparable
to that at the other two Type A doors (Figure
10). However, an evacuation from a normal
landing emergency with escape chutes in use was
not conducted. Conclusions on the effectiveness
of just one cabin attendant at a double-door in
this condition would require further testing.

Other observations on passenger flow included
the following: (1) positions of the three Type A
exits proved good for effective passenger egress,
as indicated by the steady, even flow from fore
and aft aisles to each of the exits throughout the
evacuation procedure, (2) under the existing
ideal conditions, aisle width (minimum 15 inches)

15

and seat pitch (34 inches) did not delay or di-
rectly affect the evacuation flow to the exits; no
gaps occurred as passengers cleared the exits and
a continuous line was maintained, (3) some
evacuees entered the double door in the center,
thereby creating a single door effect, for a short
interval of time. Table IX shows percentages
of positions used in the doorway by passengers.
TABLE IX.—Percentages of passengers using the forward,

center or aft portions of the double, 42-inch wide,

type A door for egress through the opening. For study,
the opening was divided into 3 portion: (Test 2)

Percentage of Passengers

Section of Door Used Total No.
Exit Passengers
Number Forward Center Aft Using Exit
38 22 40 86
49 7 44 97
54 7 39 93

The stewardesses’ positions at the three Type A
exits were under observation. At the forward
left Type A exit (Exit 8), an assist space was
provided on the aft side of the door for the
stewardess to conduct the evacuation. At the
forward edge of the door (Exit 8), the seat backs
of Row 7 were even with the forward edge of
the door, with no assist space. The passageway
between the two stewardesses working at the door
was 32-34 inches, or 2-4 inches short of the re-
quired 36-inch passageway. At Exits 9 and 10
there was a 12-inch spacing at both fore and aft
edges of the door opening. This allowed full
36-inch passageways to the exits between the two
girls working at these positions. Twenty-two
per cent of the passengers using Exit 8, compared
to 7% of those using Exits 9 and 10 (Table IX),
occupied the center position of the door opening
for a short interval, thereby making it function
essentially as a single door. Motion pictures
showed that passengers were forced to the center
of Exit 8 more frequently than at. the other two
doors because an assist space for the stewardess
was not provided at the forward edge of the
exit. Her position at this exit blocked a portion
of the opening. The stewardess was backed up
against the seat backs of Row 7, leaning back-
wards, trying to minimize her interferences with
passengers moving into the door opening.

The flight engineer left his cockpit. seat on the
start signal after releasing his seat belt. He
reached approximately Row 9 before passengers


nn eee

fessional judgment as particular situations de-
veloped during the evacuations. Stewardesses’
duties included the normal briefing of passengers
for oxygen use, seat belt instructions, and flight
destination information. No indication was
given to the passengers of the events to come.

Duties of the male crew members were coor-
dinated with those of the cabin attendants
through pretest discussions. The Captain would
leave his cockpit position after a short delay
following the start signal and assist the evacua-
tion from inside the forward cabin. The copilot’s
assignment was to expedite evacuation from out-
side the aircraft by soliciting the help of male
passengers at exits and generally maintaining
passenger flow away from exits on the outside.
The flight engineer was instructed to leave the
cockpit at the test signal and proceed aft inside
the cabin as far as possible. This procedure was
included to evaluate the ability of a crew member
to move aft through the passenger flow and reach
the rear door exit.

Iv. TEST 1.

Conditions. The right side of the mock-up
was equipped with four Type I and three Type
IIT minimum-size exits, according to FAR
25.807(a) for a passenger seating capacity of
280. The exits were distributed in relation to
passenger density and exit rating (passengers
per minute). Access to Type I exits was pro-
vided by removal of the adjacent triple seat unit
and the window seat adjacent to the Type IIT
exits. Descriptions of the seven exits appear in
Table I. There were no corresponding exits on
the left side of the mock-up.

The basic purpose of Test 1 was to document
escape patterns with the required combination

TABLE 1—Exit type, dimensions, exit number, and
step-down distances used in tests 1 and 1A

Seat Exit Step-Down
Row Type Dimensions Distance __Exit
Location Exit (inches) (inches) Number
3 ft. forward,

Rowl 1 24 x 48 16 1
Row 12 I 24 x 48 16 2
Row 25 I 24 x 48 7 3
Row 33 II 20 x 36 27 4
Row 40 II 20 x 36 27 5
Row 47 III 20 x 36 27 6
Row 55 I 24 x 48 7 7*

*This exit has a removable insert to provide either 48-
inch or 60-inch door heights.

of Type I and III exits that could be designed
into large aircraft. These data were to be com-
pared with those of a later test using the required
number of Type A exits for a similar passenger
load (Test 2), which could also be designed into
large aircraft, shown in Table IT.

TABLE II.-Exit type, dimensions, exit number, and
step-down distances used in tests 2 and 2A

Seat Exit Step-Down
Row Type Dimensions Distance _Exit
Location Exit (inches) (inches) Number
Row 10 A 42x 72 16 8
Row 30 A 42 x72 7 9
Row 50 A 42 x72 7 10

Following a short delay after the start signal,
the Captain gave a prepared statement, “Get
them out the right side—fire on the left!” over
the public-address system. This indicated that
passengers were to evacuate the mock-up through
right side exits only. Stewardesses were seated
on the forward and center jump seats, and in
Seats 55B and 60B.

General Observations. There were wide varia-
tions in how clearly passengers heard and how
accurately they interpreted the stewardesses’
commands of “Grab ankles,” and “Stay down
until the plane stops.” Statements made by the
passengers indicated that even when commands
were heard, they were difficult to interpret. This
also applied to the later command, “Leg-body-
leg.” The commands seemed unfamiliar and/or
unexpected, and, therefore, failed to elicit the
expected responses from passengers. Apparently,
the stewardesses’ commands were not heard and/
or understood more than eight rows of seats
forward of the stewardess stations. Commands
to the rear of these stations were audible for only
three or four rows, depending upon such factors
as bulkheads, passenger proximity to loudspeak-
ers (from which crash sounds were coming), and
how much the stewardess turned her head aft
while giving commands. When the crash noises
ceased, crew commands were more readily heard,
as found in special passenger interviews.

Passengers in the area of Exit 2 (Row 12)
were approximately 12 rows from either of the
two nearest stewardess stations. Since they could
hear neither stewardess clearly enough to follow
directions, they immediately opened the exit and


BC eee

SST EVACUATION TEST

a
140 - COMPARISON OF TYPE I AND TYPE A EXITS ae
BOTH WITH I6" STEP DOWN DISTANCE. A °
i A °
Aa °
120 + a °
L a °
a
L a °
it 100 a °
i L a x °
& a xx °
G so} ax °
8 ax °
. ax °
i} Ax °
60 ax fo}
& a x °
ao L a x ° oo
= ax ° e
2 L ax oe
z 40 ax oe EXIT 2 @ (TEST 1!) } 2a" 48"
L ax ol. EXIT 2 o (TEST IA)
Ax 0 @ EXIT 8 x (TEST 2) }aatx 72"
20 + ax o°@ EXIT 8 4 (TEST 2A)
ax 0 e
L ao @
Lx @
oleaxe f 1 1 1 1 A 1 f a
° 10 20 30 40 50 60 70 80 90 100 «110
TIME IN SECONDS

Fieure 15. A Type I (Exit 2) and a Type A (Exit 8) door from all four tests are plotted together for direct com-

parison of flow rates during evacuations.

minimum required openings for Type I exits
(24x48 inches) and Type A exits (42x72
inches).

An aggregate table of times and the number
of passengers and crew using each exit is given
in Table XIII. Door-opening times were simu-
lated and were not considered too realistic for
actual conditions, but merely to help create the
atmosphere and environment desired.

IX. CONCLUSIONS.

Because of the inaudibility of verbal commu-
nications during the crash sequence, emergency
public-address systems need to be considered and
studied for use in large aircraft with high pas-
senger-seating capacities.

21

Step-down distance was 16 inches.

Commands should be informative, concise,
clearly spoken, and readily interpretable by pas-
sengers not familiar with emergency procedures.

Crew “assist” spaces are an important consid-
eration at Type A doors to allow crew members
to remain out of the required 36-inch passageway
for passenger egress during evacuation. Loca-
tions of Type A exits in an aircraft should pro-
vide ample cross-aisles or routes to maintain two
continuous lines from two different sources, thus
adequately feeding the two openings.

Passenger flow rates through Type I exits of
48-inch and 60-inch heights did not show a sig-
nificant difference in this study (and in others),
to indicate a change in the minimum Type I
door height requirement.


AM 70-19

EVACUATION TESTS FROM AN SST MOCK-UP

J. D. Garner
and
John G. Blethrow

Approved by Released by
°o
Stembey & YM okL mo
Sranuey R! Monter, M.D. P. V. Steéet, M.D.
Cuer, ArRomEpIcaL APPLICATONS Feperat Air Surceon

Division

December 1970

Department of Transportation

FEDERAL AVIATION ADMINISTRATION
Office of Aviation Medicine


60 TEST | (ALL 7 EXITS)
- a a
50 - ee a
L e a
2 EXIT | 0
40 | EXIT 2 © ea wx OX
a EXIT 3 4
oO Lb EXIT 4 e4 x
a EXIT 5 oO .
uw 30 P EXIT 6 a * of | 9
a
aan EXIT 7 x ew x ao .
lJ
2 20 + eax ao a8
D>
Zz L eo a og
lob am ace
L oxao 6
° oace, 1 1 n 1 4 1 1 1 1 n rn 4
° 10 20 30 40 50 60 70
TIME IN SECONDS
Fiovure 5. A plot of the number of escapees and time shows relationship of the seven exits in Test 1. Exits 4, 5

and 6 are window, overwing, exits with a 27-inch step-down to the wing surface which is evident by the rate
of escapees for these ‘Type III exits compared to the four ‘Type I exits.

A noticeable lower number of passengers used
the Type I exits located at each end of the cabin.
Thirty passengers used Exit 1 and 41 used Exit 7
compared to 63 and 55 passengers for Type I
exits 2 and 3, respectively.

Evacuation Times. All passengers and crew
members evacuated the fuselage through the
seven exits on the right side in 70.7 seconds, the
last. person, a stewardess, leaving at Exit 4. The
last passenger was out in 66.6 seconds. Evacua-
tion times for each exit are shown in Figure 3.

Exit-opening times (Figure 3) determined
from the start signal until the exit was perceiv-
ably “cracked open”, averaged 4.5 seconds, with
a range of 3.2-5.0 seconds, for six of the seven
exits (excluding Exit 2, prematurely opened).
These exit-opening times are about 60% less than
the average of 11-14 seconds found in an analysis
of airline evacuation demonstrations performed
for certification of various aircraft.

Flow Patterns. Passengers chose to use the
nearest available exit for their routes of escape,

the exceptions being those who were directed to
other exits by crew members. All units, except
Exits 3 and 7, maintained a fairly even and
steady flow rate until all passengers were outside.
Exits 3 and 7 had gaps between escapees near
the end of the evacuation until some were di-
rected to these exits from the lines back up at
the window exits. Motion pictures of the evac-
uation tests revealed that crew members directed
passengers to exits with shorter lines in their
management of the evacuation. The passenger
flow pattern and exit routes are shown in Figure
4. Moving aft, the flight engineer passed by
Exit 3 during the 32nd second, from the start
signal, and arrived at Exit 4 during the 39th
second. After diverting a mother and two chil-
dren from Exit 4 to Exit 3, he made his way
aft and arrived at Exit 6, 51 seconds from the
start signal. He gave assistance at Exit 6 until
near the end of evacuation at which time he
went out Exit 4,

Figure 5, an escapee-time plot of all seven
exits, shows that the three window exits (Exits


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and test configurations. Figure 2 shows the floor
plans of the exit areas and the passenger seating
arrangements.

Test Subjects. Two groups of subjects, each
consisting of 280 volunteers, were made up of
FAA Aeronautical Center employees, their fam-
ilies, friends, and neighbors, and approximately
three official observers who filled vacancies cre-
ated by “drop-out” subjects.

Each group was selected to simulate the normal
passenger distribution aboard transport aircraft
for evacuation demonstrations performed by air
carriers. The following passenger distribution,
prescribed in Federal Aviation Regulations
(FAR) Part 121.291 (Appendix D), was ad-
hered to:

(1) At least 30% females.

(2) At least 5% over 60 years of age (the
percentage of females in this group being
>30%).

(8) Between 5% and 10% children under
age 12 (the percentage of females in this group
also being >309%).

(4) 55-60% (i., the remainder) males be-
tween ages 12 and 60.

At least three life-size dolls simulating infants
under 2 months of age were also stipulated in
the FAR’s, but additional children under the age
of 6 were substituted in the present study.

Crew Members. The six cabin attendants were
furnished by United Air Lines. These stew-
ardesses served as cabin crew members in the
management of the passenger load. Three ex-
perienced male flight crew members were ob-
tained from the Air Carrier Operations Section,
FAA Academy, Aeronautical Center, and per-
formed the duties of flight deck personnel.

Observation Methods. Cabin activity was re-
corded by four microphones equally placed in
the hat rack, two on each side of the fuselage.
Motion picture cameras, 16 mm., documented the
evacuations from both interior and exterior.
Personnel with stop watches were stationed out-
side each exit as a redundant system to the
electric clocks in view of the cameras. Further
observations were gathered from the passengers
by a questionnaire and also by a group of 22
special interviews with passengers selected
throughout the fuselage for specific information.

Ill. GENERAL TEST CONDITIONS.

Standard Procedures. The volunteers were
told to report for a test on the SST, being given
no further details, Consecutively numbered
jackets were placed in each seat, by rows, front.
to rear, with jacket numbers 1, 2, 3, 4, 5, and 6
in seats 1A, 1B, 1C, 1D, 1E and 2A, etc.

A magnetic tape played music over the public
address system while passengers loaded. This
was replaced by a sound-effects tape, audible to
both passengers and crew, for the test. It in-
cluded approximately 15 minutes of engine-start
and taxi-out noises and seven seconds of take-off
thrust, as heard (and recorded) from inside the
cabin of a jet aircraft. About seven seconds
after the beginning of the take-off thrust, crash
noises were heard on the sound tape to create as
much realism as practical—although, of course,
the physical sensations normally experienced
while one is seated in a moving vehicle were
lacking. The end of the crash noises served as
the start signal for the crew to initiate the evac-
uation procedure.

During the taxi-out portion of the sound-
effects tape, the “A” stewardess gave the regular
passenger briefing and announcements, followed
by a seat belt check. The door and window
exit plugs were pushed open from inside the
cabin and immediately removed by assistants
stationed outside the mock-up exits. Therefore,
exit. opening time and methods of opening were
not planned as a factor in this study.

Each test simulated an aborted take-off crash
with wheels up. All tests were performed in
daylight, with no baggage obstructions or visi-
bility problems.

General Instructions to Crew Members. Crew
members were briefed on the complete test plans
so that their performance would not constitute a
variable on the tests. The tests were designed
to compare the efficiency of exits relative to width
and height and to determine rates of passenger
flow, with the same flight deck and cabin crew
members participating in all tests. The public
address and intracommunications systems were
demonstrated to the crew members for their use
during normal passenger briefing and emergency
procedures.

The stewardesses were asked to conduct the
evacuations in accordance with their company’s
training and policies, but to exercise their pro-



of the passageway between stewardesses at the
door.

TABLE X.—Percentages of passengers using the forward,
center or aft portions of the double, 42-inch wide, type
A door for egress through the opening. For study, the

opening was divided into 3 portions. (Test 2A)
Percentage of Passengers
Section of Door Used Total No.
Exit Passengers
Number Forward — Center Aft Using Exit
29 50 21 138
31 40 29 141

Evacuation Times. The total evacuation time
for Test 2A was 81.8 seconds. One cabin at-
tendant did not participate in Test 2A because
of an injury sustained in a fall outside the
mock-up at the end of Test 2. The last passenger
passed through Exit 8 at 79.2 seconds. Total
evacuation time through Exit 10 was 67.8 seconds,
with the last passenger out in 66.1 seconds (Fig-

ure 12), An escapee-time plot is presented in
Figure 13.

Flow Patterns. The evacuation flow rate in
Test 2A is of interest because exits were located
nearer the ends of the cabin than in previous
tests. The average flow rates for Exits 8 and 10,
in passengers per minute, were 104.1 and 127.5
seconds, respectively (Table XI). The difference
TABLE XI.—Flow rates at each exit in passengers per

minute in test 2A, calculated within 3 different intervals
of the evacuation*

Passengers Per Minute

Start Signal to First Passenger

Start Signal to Last In Exit to
Exit End of Passenger Last: Passenger
Number Evacuation Out® Out**
104.1 104.5 109.7
127.5 128.1 134.2

*Flow rate was determined by the number of evacuees
within each time interval and calculated for rate per
minute.

**Excludes crew members.

SST EVACUATION TEST

140; TEST 2A (TYPE A EXITS) 42x72 INCHES 5 08 ie
b a e
o e
L a e
120 a .
oa e
oO e
100 F a bd
wo | ao le ® EXIT 8 @ (I6 INCH STEP DOWN)
4 o . EXIT 10 0 (7 INCH STEP DOWN)
8 o e
rf] .
e
8 e
.
ce
Wy
a
=
2
Zz
1 fl f ! fi ,
30 40 50 60 70 80 90
TIME IN SECONDS

Ficure 13. The escapee-time plot on Test 2A shows effects of the 16-inch step-down at Exit 8 and where the exits
began to be fed with evacuees from only one aisle at approximately the halfway point during the evacuation.

18






TEST IA

&

“a a0it oo!
ooo" aol
e90%00
20 t00

[eeerac

esas

oeo+oa
Joeeneo
[avenoo
leo0-e0

—

il

Rows 29 through 33.

16" step down
7" step down

2°95 24"; 48"
7 © 24x60"
Ficure 7. The passenger escape routes for Test 1A using Exits 2 and 7 shown by indicating symbols. Passengers split in the center cabin area within Seat


The test conditions changed from Test 1 were:
(1) right-side exits were not usable (in contrast
to left exits in Test 1); (2) seat units were re-
moved on the left of Type A exits to provide
the 36-inch passageway, and the right side seat
units removed for Test 1 were reinstalled (Figure
2); (8) cabin attendant stations (public-address
and intracommunications systems) were moved
to the Type A exit locations; and (4) the Cap-
tain’s emergency announcement was changed to
“Get them out the left side—fire on the right!”

General Observations. After the experience
gained from Test 1, the stewardesses conscien-
tiously shouted their commands in unison during

ee

the crash sequence. The unison command, “Bend
over, grab your ankles, stay in your seats until
the plane stops,” appeared to have been heard
and understood better than the commands in
Test 1, resulting in all passengers bending over
into brace position. It was surprising to learn
from special personal interviews that, even
though all passengers assumed the brace position,
many failed to hear the commands clearly. Some
passengers apparently responded by copying
others and not entirely by hearing commands.

Evacuation Times. Complete evacuation
through the three Type A double-doors (42 x 72
inches) was accomplished in 47.4 seconds. Total

TEST 2 ESCAPE TIMES

CLASS

A EXITS
HB OEXiT opens

START SIGNAL PASSENGER

Exit No. v 77} CREW

” 8 uo a 8 6
(42" xX 72")

9

(42" X72") i 97 A

10
(42"X 72") 95

it I it 1 it J
(0) 10 20 30 40 50 £460
TIME IN SECONDS
Fieurr 9. The comparative total evacuation times with numbers of passengers through each Type A double-door
exit.

13


IL.

II.

Iv.

VI.

VIL.

Vill.
IX.

TABLE OF CONTENTS

INTRODUCTION -______--_- =o

GENERAL DESCRIPTION
Test Vehicle ______.________ -
Test Subjects __
Crew Members _
Observation Methods -

GENERAL TEST CONDITIONS
Standard Procedures

TEST 1 _-_--------

General Observations _
Evacuation Times
Flow Patterns ___

General Observations
Evacuation Times
Flow Patterns -___

TEST 2 _.
Conditions
General Observations
Evacuation Times -
Flow Patterns ____

TEST 2A __
Conditions __
General Observations
Evacuation Times _
Flow Patterns ____

DISCUSSION ___---- oon

»
§

COSCCSTD DHA PRA RR Ree




ACKNOWLEDGMENTS

The authors wish to express their appreciation to the large number of
passenger volunteers, the photographers, and the technical assistance—
especially to Gale Braden for the Time-Path system design; to Judy Ander-
son for arranging and tabulating the 560 subjects; to Jo Ellen Holt for
assistance with subjects; to Leland Brooks for design and operation of the
sound systems; and to the Staff of Communications Processes, Psychology
Laboratory, for the sound effects recordings. All of these individuals con-
tributed significantly to the test program. The suggestions from and dis-
cussions with John J. Carroll, NTSB, and industry representatives from
AAL, CAL, PAWA, TWA, UAL and Hartman Systems, were also most
helpful. Special appreciation is extended to both the United Air Lines
stewardesses and the male flight crew from the FAA Academy, who per-
formed the evacuations with outstanding dedication and professional de-
meanor, thus contributing directly to the success of the test program.

Qualified requesters may obtain Aviation Medical Reports from Defense Documentation
Center. The general public may purchase from Clearinghouse for Federal Scientific and
‘Technical Information, U.S. Dept. of Commerce, Springfield, Va. 22151.


eee

4, 5 and 6) had slower flow rates. Among the
four Type I exits, Exit 2 maintained the highest
flow rate, with Exit 7 lagging slightly behind
Exits 1 and 3. A further analysis of Test 1
flow rates (Table III) documents the evacuation
times for three different time segments for the
evacuation. Also, groups of 20 consecutive
evacuees were timed during the evacuation at
each exit to determine variations in flow rates
as the evacuation progressed (Table IV).

TABLE III.—Flow rates at each exit in passengers per

minute on test 1, calculated within 3 different intervals
of the evacuation*

Passengers Per Minute

Start Signal to First Passenger
Last

Start Signal to In Exit to
Exit End of Passenger Last: Passenger
Number Evacuation Out® Out**
- 50.2 58.7 63.9
= 48.7 60.8 68.5
: 44.7 50.9 7. 9
: 28.9 28.8 32.5
7 26.4 29.0 31.7
: 26.3 26.3 29.2
2 43.7 46.2 52.3

*Flow rate was determined by the number of escapees
within each time interval and calculated for rate per
minute.

**Excludes crew members.

TABLE IV.—Flow rates of segments of 20 passengers
tabulated in passengers per minute to observe variations
in the rate during the evacuation at each exit (Test 1)

Passengers per Minute

Exit Number

Passenger.
Segment 1 2 38 4 5 6 7

1-21 59.97 72,29 26.47 36.10 31.47 29.48 51.79
60.10

6-26* 31.58 29.03
11-31*
21-41* 85.29 69.81 52.93
26~46* 77,17
31-51* 49,02

*The groups of 20 passengers were not chosen in con-
secutive order due to the small number of evacuees
through an exit in some cases, resulting in overlapping
of groups.

Vv. TEST 1A.

Conditions. The basic purpose of this test was
to evaluate the effect of a 12-inch difference in
door height (i.e., raised from 48 inches to 60
inches) for minimum standards on Type I exits.
Door width remained the same (24 inches).
Data obtained from this test supplemented other
test data based on the same height difference

under other conditions. Thus, the aft right exit.
(Exit 7 with a 7-inch step-down outside) was
converted from 48 inches to 60 inches in height
for Test 1A and passengers were reloaded who,
a few minutes before, had evacuated the aircraft.
during Test 1. The exit plugs were previously
removed and not used in the test.

All conditions for Test 1A were similar to
those in Test 1, except that the passengers were
instructed to use Exits 2 and 7 and the sound
tape began running at take-off thrust, about one
minute before the start signal. The objective
was simply to evaluate the flow of a large number
of passengers through two specific size openings.

General Observations. The egress lines moved
steadily, with practically no gaps in the passen-
ger flow. The copilot, assigned to assist outside,
was the 62nd person out of Exit 2, and arrived
at the aft exit as the 65th person was leaving.
The fifth passenger, a man, out Exit 2 turned
around and assisted other passengers out until
the end of the evacuation. No passengers as-
sisted at Exit 7 from outside.

Evacuation Times. The evacuation time for
Exit 2 was 114.0 seconds (137 persons) and for
Exit 7 was 112.1 seconds (133 persons) (Figure
6). Excluding crew members, the passenger
evacuation times were 108.1 seconds (132 passen-
gers) and 110.2 (130 passengers) for Exits 2 and
7, respectively.

Flow Patterns. Passenger separation occurred
within Seat Rows 29 and 33 toward the two
exits shown by the exit routes in Figure 7. The

TABLE V.—Flow rates of segments of 20 passengers
tabulated in passengers per minute to observe variations
in the rate during the evacuation at each exit (test 1A)

Passengers per Minute

Exit Number
Passenger
Segment 2 7
1-20. 70.63 71.86
90.70 78.00
89.89 82.70
72.95 78. 33
66.74 82.25
79.21 75. 66
86.10
72.20

Average: 79.46 Average: 77.20

*The groups of 20 passengers were not chosen in con-
secutive order due to the varying numbers of evacuees
through an exit in some cases, resulting in overlapping
of groups.


SST EVACUATION TEST

140 - TEST IA (TYPE I EXITS)
x
L ox
Ox
120 ox
a
- a
Ox
00 F ox
w ox
b ox
& ox
QB sor ox
2 °o x EXIT 2 0 (24x48 INCHES)
uo fe o.* EXIT 7 4
uw oe x (24x 60 INCHES)
aw 60F ° x
ra x
- ox.
3 o*
Zz 40- ox
o x
- ce} x
ox
20 ox
Ox
- Ox
ox
ol 9 x ot 4 n 4 4 4 1 wm 4 ne 4
0 i) 20 30 40 50 60 70 80 90 100110

TIME IN SECONDS

Ficurr 8. The escapee-time plot of Test 1A through Exits 2 and 7 shows very little difference in evacuation flow
rates. The 12-inch difference in exit height was under evaluation in this test.

ous physical contact by the stewardess on each
passenger at Exit 2 improved the egress rate;
(2) passengers and crew had more experience
and confidence resulting from Test 1; and (3)
due to location, Exit 2 received escapees from
two aisle directions for a longer period than
Exit 7, which was located only four rows from
the aft bulkhead.

The chart of time and number of escapees in
Figure 8 shows the similar flow patterns at the
two exits.

VI. TEST 2.

Conditions. The plan for Test 2 was to use
all Type A (double width) exits for the evacua-
tion and compare the efficiency of Type A exits
with that of Type I exits (Test 1) under the
same conditions. Another group of 280 passen-
gers was recruited for Test 2, with the same
passenger age and sex ratios as for Test 1. Stew-

12

ardesses were seated on the three jump seats by
each exit.

Three Type A exits are required for a passen-
ger load of 280 according to the revised FAR
25.807(a) (7). This requirement defines the exit
as a floor level opening with a minimum width
of 42 inches and height of 72 inches. In addi-
tion, a 36-inch unobstructed passageway is re-
quired from the nearest main aisle. In Test 2,
an additional 12-inch space was provided on each
side of the Type A doors, at Exits 9 and 10, to
permit crew members to assist passengers and
not interfere with the stream of passenger flow.
This additional “assist” space was not provided
at the forward side of the door at Exit 8, as a
condition under evaluation. A 12-inch space was
provided aft of the Exit 8 opening. Table IL
and Figure 2 illustrate the Type A exit dimen-
sions, locations, and step-down distances.