35.

FORWD (routine to reassign 25% of
center cabin passengers to forward cabin)

| 5,2]

39, ASSIGN

6,2
40. ASSIGN
41. TEST E

20

Passengers leave the storage
thru this block after the
doors are opened.

Center cabin passengers go
thru this series of blocks
and 25% are routed to the
forward cabin by reassigning
their parameters 4, 5 and 6
to 1, 2 and 2, respectively.
Remaining 75% go to EXITA.

Hold all center cabin
passengers that are routed
to forward cabin until
forward cabin door is open.


10.

ll.

12,

TEST GE

SAVEVALUE

SAVEVALUE

CENTR (center cabin
with six seats per row)

1-,K6

INCRW (routine to
increment row counter)

2+,KL

OW.

14

First six passengers in each
row of center cabin are

transferred to NXROW routine
which increments seat number.

As each of rows 8 thru 24 is
filled, the first passenger
of the next row is routed to
this block and decrements
savevalue 1, which contains
the seat number for this
passenger, back to seat zero,

This block increments the row
counter, savevalue 2, by one
each time a row is filled.


P14

52. DEPART

STR1

53. DEPART (es)

54, SAVEVALUE ( )

P5,Ml

Depart the queue around the
slide whose number is in
parameter 4,

Depart the queue entered
before seizing the door.

Store into the savevalue whose
number is in parameter five the
total time each passenger was
in the model. At the end of the
run the savevalue will contain
the total time for the last
passenger out each exit.


w

Assign Row P2 Seat Pl

5% 10% Ni 30% 55%
J P3 i}
Under 12 Over 60 Females (3 Males
carrying
infants <2
yrs. of age)
T i" I T
L
Hold until
all 124
passengers
have arrived
i
‘ 4 J] 7
— cabin Center cabin Aft cabin
hold for door hold hold
lopening time
21.7 6.7 15.5
Los — L Q6
Fac. 2 Fac. 3 7" Fac. 5 | Fac. 6 | Fac. 8 Fac. 9
J
1 slide time fl slide time
but 2 slides (separate from}
$2 forward) but
R slides S8
Transit time Transit time Transit time
into into into
Savevalue 2 Savevalue 5 Savevalue 8
l
—~

Figure 2. Flow diagram of 124-Passenger Model

oe

3



EXITA (Door exit routine)

42, TEST GE IT2 Each passenger checks to see
whether right or left door is
the busiest to determine which
door to exit. If right door
is busiest the passengers go
to EXIT2, otherwise they go to

EXIT1.
EXIT1 (Right door
exit routine)

43. QUEUE 6) Each passenger gets into line
to exit the door whose number
is in parameter 5 of that
passenger.

44, SEIZE Passenger seizes the doorway.

5)

21



APPENDIX B

Functions Used in Aircraft Evacuation Models

FORWARD EXIT TIME MEAN = 1.57
1 FUNCTION RNL C35
-00132 2 -01662 4
«13949 8 +24221 10
«47262 14 257971 16
275173 20 81485 22
«90190 26 + 93005 28
96562 32 «97625 34
«98894 38 299254 40
+ 99667 44 «99779 46
«99904 50 «99937 52
«99974 56 «99983 58
«99993 62 299995 64
«99998 68 «99999 70

WING EXIT TIME MEAN = 1.70
2 FUNCTION RNL c35
-09200 2 «18634 4
+35437 8 42675 10
54981 14 60161 16
68864 20 «72497 22
«78568 26 -81091 28
285294 32 87036 34
-89932 38 +91130 40
293119 44 293941 46
«95304 50 - 95866 52
«96798 56 «97182 58
+ 97819 62 «98081 64
-98515 68 98694 70

AFT EXIT TIME MEAN = 1,34
3 FUNCTION RNL C28
00071 2 -01493 4
217177 8 «30973 10
«59727 14 «71393 16
~87100 20 ~91727 22
«96835 26 - 98101 28
«99350 32 299627 34
+ 99882 38 «99935 40
-99980 44 -99989 46
-99997 50 «99998 52
1.0 56

27

SD = 0.76

SD = 1.61

SD = 0.58

-06162
235722
«67340
86423
+95070
+ 98373
«99500
+99854
299959
+ 99989
-99997

227422
49172
-64770
«75717
+83322
-88574
«92187
«94665
96362
297521
98312

-06878
«45851
80463
- 94826
«98880
299789
+ 99964
299994
-99999

18
24
30
36
42
48
54
60

12
18
24
30
36
42
48
54
60
66

12
18
24
30
36
42

54



48.

49,

50.

51.

QUEUE

ADVANCE

LEAVE

<I

(ee

ek 4 4

P5

P14

23

Forward and aft cabin
passengers enter a queue
for the slide. There is
no slide for center cabin
in this model.

Passengers enter a storage
containing the slide.

Advance the clock by the amount
of time the passenger is on the
slide, That time is computed
by a variable whose number is
in parameter four.

Passengers leave the slide
storage,



25.

f 26.

27.

28.

TEST G

ASSIGN

ASSIGN

ASSIGN

le)

>

oS
(ys)

Forward cabin passengers go
to EXIT at this point. All
others go to next block to
have the value in their
parameters reassigned for
respective cabins, Parameter
two contains the row number.

Parameters for center cabin
passengers are assigned
values 4, 5 and 5, respectively.


The results of runs of the 234-Passenger Model
given in Table 2 show that the last passenger
departing the aircraft departed by the forward
exit in 14 of 20 runs and by the overwing exit
in 6 of 20 runs. Similarly as with the 124-
Passenger Model the average utilization was less
for the aft exit than for either of the other two
exits for all the runs. On the average both for-
ward and overwing exits were in use 24.0 seconds
after the aft exit was clear and at least one was
in use 27.1 seconds after the last passenger de-
parted the aft exit.

It should be noted that a much larger number
of passengers departed in a shorter time in the
234-Passenger Model than the 124-Passenger
Model which can be attributed to the larger size
exits which are characteristic of aircraft capable
of carrying large passenger loads. In live tests
we had found that the larger exit allowed ap-
proximately 2.6 times as many passengers to pass
through it in the same amount of time. This
factor of 2.6 was used in the appropriate func-
tions in the 234-Passenger Model in the absence
of completely measured distributions of times
for the larger doors.

IV. Conclusion

The distributions of the total times for last
passenger out for the 124-Passenger and 234-

5
of
2
z
. 3f
°
2
_
=
>
z

i) \
oS PSHPOPHHAH

62 86 90 94 98 102

TIME (Seconds) for last passenger out.

Fiovure 5. Total times for 124-Passenger Model

Passenger Models are shown in Figures 5 and 6,
respectively. The shorter evacuation times
shown in Figure 6 display the effect of the larger
exits throughout the latter model. Both the
models shown here readily permit different func-
tions to be substituted for different door, slide,
and population age-sex distributions. When suf-
ficient data is available on these variables they
will be included in the model in the form of
separate functions for each category or classifi-
cation of the variables.

| _N

So wo

NUMBER OF RUNS

\\ \

A

70 «72 7% 76 78 80 @2 84
TIME (Seconds) for last passenger out.

Fieure 6. Total times for 234-Passenger Model

The two models described above (124-passen-
ger and 284-passenger) are manifestly just two
phases of a continuing model-development effort.
There are additional features not described
herein, for the sake of brevity. Such features
include aids to interpretation, such as graphical
as well as tabular representations of the various
components of passenger flow. There are dif-
fering seat-configurations and door-configurations
in combination, some involving very large num-
bers of passengers (i.e., over 400).

Test results obtained from wide-body jet and
mock-up evacuations are continually being used
as input data for constructing new models. The
flexibility of the GPSS high-level language
makes possible the development and utilization
of many varied computer models in a relatively
small span of time and expenditure of resources.




Assign Row P2 Seat Pl

5% 10% v 30% 55%
y v P3 v N
Under 12 Over 60 Females (3 Males
carrying
infants <2
yrs. of age)
I I ] J
¥
Hold until
all 234
passengers
have arrived!
= s4_ y_s7
‘forward cabin
hold for door Center cabin Afe cabin
opening time
ween nen neeee 16.9 wonnenee---- 16.9
[a3 n Pi
Q3 Q8 Q9
Fac, 2 Fac, 3 Fac. 5 Fac, 6 Fac. 8 Fac. 9
Slide time 1 Overwing ramp Slide time 7 |
time .
&
Slide time 4

Transit time
into
Savevalue 2

Transit time
into
Savevalue 5

l

Transit time
into
Savevalue 8

Fieure 3. Flow

diagram of 234-Passenger Model

5



block 54. If the left queue is shorter when a
transaction (passenger) reaches block 42, a dif-
ferent but parallel series of events takes place
starting in block 56 with the EXIT2 routine.

In order to simulate the condition of all the
left doors blocked, and only the right doors
available, parameter 6 is assigned the same
values as parameter 5 for corresponding exits.
The results of these runs are reported in Table 1.
In this case all passengers take the EXIT1
routine, and the time values resulting apply to
getting all the passengers out of the right doors.
The maximum time to clear the aircraft is then
the longest time for any of the three exits, as
shown in the column on the far right in Table 1.

Perhaps it is worth noting that in this 124-
Passenger Model, block 47 provides for center
cabin passengers to go straight to the DEPART
block number 53 after clearing the overwing
exit. It will be seen this is changed in the 234-
Passenger Model, to provide for both an over-
wing ramp time and a further slide time to
reach the ground.

In Table 1 are summary statistics from 20
runs of the 124-Passenger Model. Means and
standard deviations for the twenty runs are
shown in the last two rows of the table. In 10
of the 20 runs the last passenger out had used the

forward exit and in the remaining runs the last
passenger out had used the overwing exit. On
the average the last passenger departing by the
aft exit was out 8.7 seconds before either of the
other two exits were clear and 19.2 seconds before
both of the other two exits were clear. The
average utilization data is consistent with these
results by showing a lower average utilization on
the aft exit than either of the other two exits.
This suggests that diversion of a few passengers
from the overwing to the aft exit would tend to
optimize utilization and shorten the average
overall escape time.

III. The 234-Passenger Model and Results

The 234-Passenger Model is a further devel-
opment of the Boeing 720 evacuation model for
124 Passengers. Essentially, two more param-
eters, P7 and P8 are added to make provision
for overwing ramp time in P7, and time distri-
bution tables are made available from cumulative
times marked in P8. Only the passengers from
the center cabin pass through the overwing ramp,
but all passengers have their time marked in P8.
This is readily verified by looking at the block
listing, Figure 4, while the overall flow diagram
is given in Figure 3.

Some features of the models are not fully
used in a given application. However, it is

FORWARD EXIT OVERWING EXIT
NUMBER ‘TIME FOR AVERAGE]| NUMBER ‘TIME FOR AVERAGE
OF LAST ——UTILI- oF LAST —UTILI-

RUN [PASSENGERS PERSON OUT ZATION ||PASSENGERS PERSON OUT ZATION

1 38 82.2 +582 48 101.2

2 40 663 46 86.9

3039 +576 a7 100.3

4 397 +650 49 97.8

5 al +72 45 83.6

6 40 +704 46 82.9

7 38 661 48 89.8

8 40 snd 46 78.1

9 44 +740 42 76.2

10 4h +720 42 73.7

no 45 +745, 41 75.4

12 4h +738 42 70.8

130038 603 48 90.0

439 +566 47 90.3

13539 710 47 67.8

16 42 Tab 4b 75.2

17 42 +759 4h 84.6

1s AL +730 45 77.5

1935 +673 31 82.3

200 +756 42 73.8

x 40.5 +6876 45.5 82,91

8 2.7 0628 2.7 9.70

‘Tape 1

4

+932
921
+932
+930
+918
+918
+924
+863
780
811
737

+759
+742
+799
+793
+917
+700

«8485,
+0838

Statistical data from 124-Passenger Model


29.

30.

31.

32,

33.

34,

TEST G

ASSIGN

ASSIGN

ASSIGN

ENTER

ADVANCE

Ls)

EXIT (routine to
exit aircraft)

{

J

P10

19

Center cabin passengers go to
EXIT. Aft cabin passengers
go to next block to have their
parameter values reassigned.

Parameters for aft cabin
passengers are assigned
values 7, 8 and 8,
respectively.

Passengers enter a storage
to wait for the door to
open in respective cabins.

The clock is advanced by the
amount of time required to
open the door in each cabin.



simpler in the overall model development process
to leave the general groundwork in place, even
though some of it may be bypassed in a par-
ticular run. For instance, both the 124-Passenger
Model and the 234-Passenger Model were run
using only three exits, to comply with the test
condition of having half the exits blocked.
Other variations can readily be run, using all
doors, or various combinations of doors and door-
opening times.

The data supplied herein for the 234-passenger
test are obtained using three equal delay times
of 16.0 seconds, for the three large, type A doors.
This is in contrast to the 124-passenger test
where the times to open the exits differed, to
conform with historical data on those exits.

Another difference between the 124-passenger
runs and those for 234-passengers, was the fixed
allocation of passengers to each exit in the latter,
while a probabilistic assignment of 25% of the
passengers from the center cabin to the forward
exit, was used in the former. This variability
is indicated starting in block 87 of the 124-
Passenger, Boeing 720 Model.

The two models are alike in that individual
seat and row assignments are made and recorded
in P1 and P2 for each passenger, and appropriate

passengers are marked in P3 as carrying infants.
However, no exit-time variation depending on
these parameters was introduced into the cur-
rently reported runs. These parameter assign-
ments remain to be exploited at a later date.

The larger, 284-passenger runs appeared to
very nearly exhaust the capacity of our IBM
360/30 computer with 64K core. It was oper-
ating under the IBM Disk Operating System
(DOS) and 54K of core was actually available
for GPSS/360 system use. Reassignment of
core within the GPSS program was necessary
to provide for 234 transactions in the system
simultaneously, since the 64K version of GPSS/
360 normally provides for only 200 transactions.
“REALLOCATE” cards were used to decrease
the core storage earmarked for the other 15
GPSS entities, where they were not required for
these models, in order to specifically reserve
enough space for 234 transactions. The specifi-
cation of only 6 or 8 parameters in the GENER-
ATE block rather than the 12 otherwise pro-
vided for, helped in savings of core allocation
also. However, further measures will appar-
ently be required to extend the number of pas-
sengers as the maximum plane size and passenger
loading density sought is continually increasing.

OVERWING EXIT TOTAL TIME
NUMBER TIME FOR — AVERAGE |(~ NUMBER TIME FOR AVERAGE] FOR ALL
OF OF LAST OF LAST ——-UTILI- | PASSENGERS
[RUN [PASSENGERS PERSON OUT ZATION SENGERS PERSON OUT ZATION our
1 98 73.8 +748 90 610 46 44.0 +323 73.8
2 98 70.9 712 90 2726 46 47.5 357 7h.
3 98 70.2 749 90 665 46 47.9 344 70.2
4 98 70.1 696 90 659 46 46.0 +346 74.3
5 98 74,6 +753 90 +685 46 45.1 341 74.6
6 98 71.4 +751 90 668 46 49.5 416 71.4
7 98 75.9 +764 90 +689 46 45,1 +310
8 98 73.8 2764 90 +680 46 46.1 4354
9 98 76.5 +763 90 643 46 46.5 2355,
10 98 71.4 674 90 684 46 43.9 2277
n 98 717 +760 90 71.2 1694 46 46.4 373
2 98 72,7 +748 90 73.5 +703 46 50.2 +369
B 98 76.0 +763 90 71.2 662 46 46.4 2349
14 98 70.6 698 90 75.5 685 46 45.9 +330
15 98 71.2 +708 90 75.5 +699 46 49.7 +399
16 98 721.2 746 90 68.8 +666 46 47,2 374
7 98 75.3 +762 90 69.9 641 46 51.8 +384 75.3
18 98 71.0 +749 90 70.5 697 46 45.4 +358 71.0
19 98 73.5 +762 90 71.2 663 46 48.0 +381 73.5
20 98 73.7 +762 90 72.9 684 46 46.6 353 73.7
x 98.0 72.78 +7416 90.0 72,2: +6752 46.0 46.96 +3547 74.09
s 0.0 2.08 0274 0.0 2.9 +0255 0.0 2.07 +0308 2,29
Taste 2. Statistical data from 234-Passenger Model



55. TERMINATE 1 Each passenger leaves the
model thru this block.

56. EXIT2 (This routine is a duplicate of EXIT1
except it is for the left doors).

25



TECHNICAL REPORT STANDARD TITLE PAGE

T. Report No 2. Government Accession No. 3. Recipient's Catalog No.
FAA-AM-72-30
&. Title and Subtitle 5. Report Date

September 1972

6. Performing Organization Code

GPSS/360 COMPUTER MODELS TO SIMULATE AIRCRAFT
PASSENGER EMERGENCY EVACUATIONS

7 auto) Earl D. Folk, Ph.D., J.D. Garner, B.S., 8. Performing Organization Report No.
E. Allen Cook, B.S., and Jimmy L. Broadhurst,
B.S

9. Performing Organization Name and Address ; 10. Work Unit No.

FAA Civil Aeromedical Institute

P, 0. Box 25082 TT. Contract or Grant No.

Oklahoma City, Oklahoma 73125

13. Type of Report and Period Covered

12. Sponsoring Agency Name and Address
Office of Aviation Medicine

Federal Aviation Administration
800 Independence Avenue, S.W. 14. Sponsoring Agency Code
Washington, D.C, 20591

15. Supplementary Notes

16. Abstract
Live tests of emergency evacuation of transport aircraft are becoming increasingly
expensive as the planes grow to a size seating hundreds of passengers. Repeated tests,
to cope with random variations, increase these costs, as well as risks of injuries to
participants.

A method of simulating such repeated tests, by use of computer models based on
statistics from measured components of the escape path, has been developed. The
models utilize GPSS, a computer programming language, to represent various features
of the escape process: passenger mix, seating and exit configuration, door-opening
delay, time on the escape slide, and slide capacity.

Two particular configurations of aircraft have been simulated: the Boeing 720 124-
Passenger Model and a 234-Passenger Model. On the former the total time for all
passengers to get out averaged 89.23 seconds, with a standard deviation of 6.38
seconds for 20 randomized runs. On the latter the corresponding average and standard
deviation were 74.09 and 2.29 seconds, respectively. There were larger exits
throughout the latter model. Both models indicated under-utilization of the aft exit.
Flow diagrams, GPSS block diagrams, and listings are included.

At this time the computer model is for research purposes and its use is not intended
to replace the evacuation demonstrations required of aircraft manufacturers and
airline operators.

17. Key Words 18. Distribution Statement
Emergency Evacuation Availability is unlimited. Document may be
Simulation released to the National Technical Informa-
Computer Model tion Service, Springfield, Virginia 22151,
for sale to the public.
19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages | 22. Price
Unclassified Unclassified 28 $3.00

Form DOT F 1700.7 (e-69)





REFERENCES

1, IBM General Purpose Simulation System GPSS/360
Version 1, Modification level 0.

2. Garner, J. D.: General Guidelines to Specifications
for the Evacuation Simulator, unpublished report,
1966.

8. Kendall, M. G., and Stuart, A.: The Advanced Theory
of Statistics, Volume I, Charles Griffin and Company,
Limited, 1958.



1 GENERATE
2 TEST LE

3 ASSIGN

4 ASSIGN

5 ASSIGN

6 TEST G

7 TEST G

8 TEST NE

9 ROWS TEST GE
10 SAVEVALUE.
ll ‘TRANSFER
12 ROW3 TEST GE
13 ‘SAVEVALUE
4 ‘TRANSFER
15 ROWS TEST GE
16 SAVEVALUE
17 ‘TRANSFER
18 CENTR TEST LE
19 ASSIGN
20 ASSIGN

21 ASSIGN

22 ASSIGN
23 ‘TRANSFER
24 APT ASSIGN
25 ASSIGN
26 ‘ASSIGN
27 TEST LE
28 ‘TRANSFER

29 INCRW SAVEVALUE
30 NXROW TEST E

31 ASSIGN
32 ASSIGN
33 ASSIGN
34 NXRI ASSIGN
35 SAVEVALUE
36 ASSIGN
37 ASSIGN
38 TEST E
39 TEST LE
40 SAVEVALUE
41 ASSIGN

42 SEAT TEST E

43 EXIT ENTER

44 ADVANCE,
45 ‘LEAVE
46 EXIT1 QUEUE
47 SEIZE
48 MARK
49 ADVANCE
50 RELEASE
51 TEST E
52 QUEUE
53 ENTER
54 ADVANCE,
55 ‘LEAVE
56 DEPART
57 STR1 QUEUE
58 ENTER
59 ADVANCE
60 LEAVE
61 DEPART
62 DEPART
63 ‘TABULATE
64 SAVEVALUE

65 TERM TERMINATE

992234, ,8
‘X2,20,CENTR
4,1

5,2

6,2
X2,4,ROWG
2, 10,ROWS
X2,11,ROW3
X1,5,NXROW
1-5

+ INCRW
X1,3,NXROW

P4,4,STRL
P7

P7
FN6
P7
P7
Pa
PS

PS

P5,ML
1

GENERATE 234 PASSENGERS; 8 PARAMETERS EACH
PUT 21 ROWS IN FORWARD CABIN, REST TO CENTER AND AFT CABINS
ASSIGN VALUES 1,2,2 TO PARAMETERS 4,5,6, RESPECTIVELY
OF PASSENGERS (TRANSACTIONS) IN FORWARD CABIN. CENTER AND AFT
CABINS WILL HAVE 4,5,5 AND 7,8,8 IN THESE PARAMETERS
PUT 4 SEATS INTO FIRST 5 ROWS
PUT 5 SEATS INTO NEXT 6 ROWS
PUT 3 SEATS INTO ROW 11
PUT 5 SEATS INTO ROWS 12 - 20
ROW IS FULL - ZERO OUT SEAT COUNT
AND GO TO INCREMENT ROW COUNT
PUT 3 SEATS TO THE ROW
ZERO SEAT COUNT AND GO TO INCREMENT ROW
COUNT
PUT 4 SEATS TO THE ROW
ZERO SEAT COUNT AND GO TO INCREMENT ROW
COUNT
PUT ADDITIONAL ROWS UP TO 38 IN CENTER CABIN, REST
IN AFT CABIN

PASSENGERS USING RAMP HAVE 6 IN PARAMETER 7

CENTER CABIN HAS 5 PASSENGERS TO THE ROW

APT CABIN PASSENGERS HAVE VALUES 7,8,8
‘ASSIGNED TO PARAMETERS 4,5,6, RESPECTIVELY

ROWS 39 AND 40 HAVE 4 SEATS, THE REST HAVE 5

INCREMENT ROW COUNT SAVEVALUE 2 WHEN SEATS ARE FULL
99th PASSENGER ASSIGNED TO AFT CABIN

GROUP OF PARAMETER VALUES, 7,8,8 IN

PARAMETERS 4,5, AND 6, RESPECTIVELY

LOAD SEAT NUMBER (SAVEVALUE 1) INTO EACH PARAMETER 1
INCREMENT SAVEVALUE 1 BY 1 FOR EACH NEW PASSENGER

LOAD ROW NUMBER (SAVEVALUE 2) INTO EACH PARAMETER 2
ASSIGN AGE~SEX GROUP TO PARAMETER 3 OF EACH PASSENGER
SEND MALES TO SEATS WITHOUT INFANT

SEND ALL BUT FIRST THREE FEMALES TO SEATS WITHOUT INFANTS
COUNT FIRST THREE FEMALES IN SAVEVALUE 3

USE 5 IN PARAMETER 3 TO INDICATE INFANT FOR FIRST 3

SEAT ALL PASSENGERS BEFORE STARTING ESCAPE THRU EXITS

ENTER STORAGE AISLES AWAITING DOORS 1,4, and 7

OBTAIN DOOR TIME-DELAY FROM FN9, WHICH USES PARAMETER 4

LEAVE STORAGE 1,4, OR 7 FOR FORWARD, CENTER, OR AFT EXIT

LINE UP FOR 2,5, OR 8 SLIDE, I.E., FORWARD, CENTER, OR AFT SLIDE

SEIZE CORRESPONDING FACILITY (EXIT 2,5, OR 8)

PUT CLOCK-TIME OF EXIT-SEIZE INTO PARAMETER 8 OF THE TRANSACTION

USE VARIABLE 2,5, OR 8 FOR RESPECTIVE EXIT TIME

RELEASE FACILITY (EXIT) FOR NEXT TRANSACTION (PASSENGER)

WING (CENTER) EXIT ONLY HAS ADDITIONAL RAMP TIME

RAMP QUEUE IS NUMBERED: 6 FROM VALUE IN PARAMETER 7

STORAGE NUMBER IS ALSO 6 FOR USING RAMP

RANDOM TIME 1S DRAWN FROM FUNCTION 6 FOR RAMP DELAY

PASSENGERS LEAVE THE WING RAMP STORAGE

PASSENGERS DEPART QUEUE FOR WING RAMP

ENTER QUEUES 1,4, AND 7, SET UP FOR STORAGES 2,5, AND 8 IN PARAMETER $
‘TRANSACTIONS (PASSENGERS) ENTER RESPECTIVE SLIDES (STORAGES) PARAMETER 5
DELAY PASSENGERS ON SLIDES ACCORDING TO VARIABLES 1,4, OR 7 GIVEN BY PARAMETER 4
PASSENGERS LEAVE SLIDES

QUEUE STATISTICS COMPLETED FOR SLIDES

QUEUE STATISTICS COMPLETED FOR EXITS-PLUS- SLIDES

TABLE PROVIDED FOR QUEUE STATISTICS

PUT THE TOTAL TIME FOR EACH PASSENGER INTO THE SAVEVALUE GIVEN IN PARAMETER 5
TERMINATE TRANSACTION REPRESENTING PASSENGER

Ficure 4. Program listing of 234-Passenger Model


P12

45, ADVANCE VAS

46, RELEASE

47, TEST NE STR]

22

Advance the clock by the time
the passenger spends in the
door. This time is computed
by a variable whose number is
in parameter 5,

Exit the door.

Center cabin passengers go
to routine to depart the
model, others go to next
block.


FORWARD SLIDE TIME

4 FUNCTION
0.0 4
.03283 10
~41720 16
~85257 22
- 98193 28
-99868 34
«99993 40
1.0 70

AFT SLIDE TIME
5 FUNCTION
0.0 10
.00119 16
202322 22
212925 28
34927 34
60701 40
-80718 46
292139 52
- 97268 58
299172 64
-99777 70

AGE- SEX DISTRIBUTIONS
10 FUNCTION
+049 1
2999 4

DOOR OPENING TIME
9 FUNCTION
1 217

MEAN = 1.73
RN1 c22
. 00038 6
«10818 12
+ 59486 18
«92152 24
+99207 30
+99950 36
+ 99998 42
MEAN = 3,82
RN1 c31
00005 12
«00389 18
04572 24
~19179 30
+ 43660 36
«68311 42
285424 48
«94381 54
- 98139 60
+ 99458 66
RNL D4
+149 2
P4 D3
4 67

28

SD = 0.45

200559
«24270
«74445
96112
+ 99669
.99981
299999

SD = 0.93

-00028
.01032
-08053
26625
«52382
«75013
«89195
-96051
«98750
99650

2449

14
20
26
32
38
44

14
20
26
32
38
44
50
56
62
68

155


FORWARD CABIN

CENTER CABIN

AFT CABIN

, _ ,

PERCE ESL ESERCESER Ee -

eur 3

Ficure 1. Seating configuration of Boeing 720 aircraft

inside and outside the aircraft. The seating
configuration of one aircraft used for such tests
at the FAA Aeronautical Center is shown in
Figure 1. Passengers departing the forward and
aft exits slide down a smooth inflated chute or
slide to reach the ground. Passengers were con-
sidered as having evacuated the aircraft if they
were on the ground, for passengers using exits
1 and 3, and if they were on the wing clear of
exit 2 (window exit) for overwing exiting pas-
sengers.

Statistics were accumulated for the time pas-
sengers hesitated in the exit before jumping on
the slide. The time on the slide for each pas-
senger and the times between successive pas-
sengers arriving at the door were also computed.
Distributions of these times were computed for
four passenger categories: (a) males aged 12-60,
(b) females aged 12-60, (c) children under 12
years of age, and (d) adults over 60 years of age.

II. The 124-Passenger Model and Results

Figure 2 is a general flow diagram of the 124-
Passenger Model used to simulate the evacuation
of passengers from an aircraft. Basically in this
model 124 passengers are generated and seated
according to the seating arrangement of the
Boeing 720 aircraft. Characteristics such as age
and sex are assigned to each passenger, for use
in later tests, as their significance becomes better

‘established. Gamma functions fit to empirical

data by the Method of Moments* were used to
determine time delays incurred by the passengers
as they exit the aircraft. In some delay blocks
the model references the functions directly; in
others, the block references a variable which in
turn references a function.

Appendix A is a detailed flow chart of the
model; Appendix B is a list of functions used

to provide the time delays in the model. Sta-
tistics such as total time for the evacuation of
each exit, average utilization of each exit, and
the distribution of time spent by each passenger
in various facilities of the model were gathered
and tabulated for analysis.

The details of operation of this model are
spelled out block-by-block along the side of the
flow chart in Appendix A. However, certain
features are worthy of emphasis at this point.
Following the generate block, there are 14 blocks
devoted to producing the seating arrangement
of passengers shown in Figure 1, and five more
to designate three of the females as carrying
infants. All passengers (model transactions)
are held until this is complete, in block number
21. From block 22 through block 32, parameters
have values assigned to distinguish the exits and
slides to be used by the passengers from the for-
ward, center, and aft cabin, respectively. Block
33 begins the EXIT routine for passengers to
leave their respective seats, wait for their respec-
tive doors to open, and proceed with the escape.
There is provision in blocks 37 through 41 for
one-fourth of the passengers from the center
cabin to use the forward exit, whenever it is
available.

Block number 42 provides for a division of
flow between each of the respective right and
left exits, according to which has the longer
queue. That is, when the length of the queue
whose number is given by parameter 6 is equal
to or greater than the length of the queue whose
number is given by parameter 5, the EXIT1
routine between block 43 and block 55 is fol-
lowed. Thus, the model uses the parameters and
variables, etc., associated with the right doors
and slides, and the results for these are stored
in the savevalues of parameter 5, as shown at


13.

14,

15.

SAVEVALUE

ASSIGN

ASSIGN

NXROW (routine to add
one to seat counter)

P6

15

Increment seat counter by one.

Put the value in savevalue 1
(seat counter) into the first
parameter of each passenger.

Put the value in savevalue 2
(row counter) into parameter 2
of each passenger.



SEAT (routine to assign values to
passengers, i.e., parameters which
indicate door they will exit).

21, TESTE

22. ASSIGN (

23, ASSIGN

24, ASSIGN

17

Hold all passengers in the
model until 124 have entered
block number 2.

Parameter 4 indicates what
cabin the passengers are in
(forward, center, or aft).
Parameter 5 and 6 indicate
right and left doors,
respectively, for each cabin.
Al in parameter 4 indicates
forward cabin and 2 in parameter
5 and 6 indicates all passengers
in this cabin will exit right
door. Left door is blocked for
this model,



GPSS /360 COMPUTER MODELS TO SIMULATE
AIRCRAFT PASSENGER EMERGENCY EVACUATIONS

I. Introduction

Computer methods are being applied to an
increasing variety of problems. A recent appli-
cation is simulating man and his motions to
analyze environmental conditions and present or
suggest more efficient ways to perform tasks.
This paper describes use of the general purpose
simulation system, known as GPSS, in the
unique situation of simulating you as a passenger
aboard an airliner confronted by an emergency
demanding quick evacuation of the aircraft.

The IBM Corporation developed this computer
programing language originally to determine
the most feasible arrangements of such facilities
as grocery store cashiers, bank tellers, and fuel
truck dockings to minimize length of lines and
waiting times which add to costs in terms of
time and convenience. The versatility of GPSS
allows entries of statistical functions to control
variables and at the same time to advance time
parameters in various combinations to estimate
overall aircraft escape times and permit detailed
analyses of escape processes.

Some background information will give you a
picture of the conditions surrounding this appli-
cation. At present, aircraft manufacturers
(Douglas, Boeing, etc.) and the airlines must
demonstrate by actual tests that a transport air-
craft can be evacuated in 90 seconds using only
half the available exits. These tests are per-
formed in darkened emergency lighting condi-
tions with a specified age and sex ratio of
passengers. On the large capacity high density
aircraft, these certification tests are frequently
failed and must be repeated until they are
passed. This process requires a large number of
people—in the hundreds—and involves a great
deal of money. The major failures are usually
mechanical malfunctions while the human ele-
ment performs at a more predictable level. An
ultimate goal with GPSS is to very nearly
simulate or model actual evacuations on the com-

puter. At this time the computer model is for
research purposes and its use is not intended to
replace the evacuation demonstrations required
of aircraft manufacturers and airline operators.
The model must have the capability of being
easily refined or changed, and have been tested
in enough situations with good results that there
is confidence that the model is sufficiently ac-
curate to be usable. An advantage of such simu-
lations is that there may not be a need to place
human beings in conditions that can result, and
have resulted, in personal injuries. Further re-
finements are being made to the computer pro-
gram and its use is being validated. However,
the GPSS model may be used as a research tool
to obtain information on aircraft in the plan-
ning stages by constructing simulation models
with various arrangements of exits and exit sizes.

The basic statistical information to be utilized
by the computer is collected by research on each
portion of the total evacuation process. These
physical tests furnish information to make up
and refine the models. Human tests like these
can be kept small in size and repeated until a
certain degree of confidence can be obtained for
particular parameter values. This approach can
be taken without a large facility and research
budget, as would be encountered with continued
large-scale testing. This means that at the FAA
Aeronautical Center in Oklahoma City the 75
foot long mock-up? with lift, roll, and pitch
capabilities, can be set up to test any physical
portion of the evacuation route without the costs
associated with a full scale facility. GPSS
offers a means to then simulate a full load of
passengers and test for total time to escape. In
this paper two such models for escape are
presented.

These models are based on many years of re-
search on escape procedures. Actual evacuations
have been studied by use of motion picture film
from cameras at varying positions and angles,









APPENDIX A

GPSS Aircraft Evacuation Model Flow Chart
Boeing 720 -- 124-Passenger Model

Block Number

1. GENERATE (_.. Vu Generate 124 passengers

with 6 parameters each.

Routine to assign seat and
row number each passenger

2, TEST LE Savevalue 2 is used for a row
counter with an initial value
of zero. All passengers are
routed thru this block until
first eight rows are full,
then remaining passengérs go
to CENTR (center cabin)

routine,

3. TEST LE All passengers routed thru
this block until first 3 rows
are filled, remaining go to
SEC2 (section 2 of forward
cabin),

[e)

ll



16.

17.

18,

19.

20.

ASSIGN

TEST E

TEST LE

SAVEVALUE

ASSIGN

SEAT

16

Place the value generated
from function 10 (age-sex
function) into parameter 3
of each passenger,

Female passengers will have
a 3 in their third parameter,
therefore; all females will
be routed thru this block,
remaining will go to SEAT
(routine to seat the
passengers).

First three female passengers
will go thru these three

blocks and the value 5 will be
placed in their third parameter
indicating that they are carrying
a small child,