There were no significant differences found
between aircraft in the percentage of mean time
devoted to looking at the mathematical task sheet
rather than at the instrument panel (Table #3).

However, when the scores for an individual
aircraft type are examined relative to the absence
(Mode A) or availability (Modes B and C) of
peripheral vision cues, significant differences
(P=<.01) are found. In the Convair, for
example, “eye-time-on-mathematical-task” in-
creased an average of 31.8% when peripheral
cues were made available. In the Boeing the
inerease was almost the same—31.8%.

Problem Solving Task. Examination of the

number of math problems completed (corrected
to a common time period) shows a striking simi-
larity for both aircraft, in relation to each dis-
play mode utilized (Table #4).
In Mode A (no cue lights) the scores were 27.7
for the Convair and 27.0 for the Boeing. When
peripheral vision cues were available, the aver-
ages for Modes B and C combined were 33.6
and 34.4 for the Convair and Boeing, respectively.
These averages, when compared to the scores in
Mode A show an increase in task performance
of approximately 21.4% in the Convair and
27.4% in the Boeing.

Display

Mode Convair 340 | Boeing 720
Mean Mean
A 27.7 27.0

B 33.9 36.3
see aaa
Cc 33.3 32.4

‘Taste 4, Mean scores for mathematical problems com-
pleted (corrected to normalized base).

IV. Summary.

The use of peripheral vision cues as a part of
the flight instrument display in simulators of
two dissimilar types of aircraft resulted in simi-
lar, as well as improved, pilot performance};
bank angle control, number of mathematical
problems completed, and eye fixation time were
about the same in simulators representing @
large, jet-engined, sweptwing airliner and a
medium-sized, piston-engined, straight wing air-
craft.

REFERENCES

1, Hasproox, A. H., and Youne, P. E., 1968: Pilot re-
sponse to peripheral vision cues during instrument
flying tasks, OAM Report No. 68-11, Oklahoma City,
Oklahoma.

2, Hasproox, A. H., and Youne, P. B., 1968: Peripheral
yision cues: their effect on pilot performance during
instrument landing approaches and recoveries from
unusual attitudes, OAM Report No. 68-12, Oklahoma
City, Oklahoma.





Convair 340 Boeing 720
; i Ty jl
Subject #| Hours [ticense| | S*b%8ct#] oe | Lieetce
u 250/ ¢ ’ 8,000] ATR
12 300] P 2 7,000] atR
13 350 c 3 18,400 ATR
14 400 c 4 9,000 ATR
15 550/_¢ 5 6,800] ¢
16 900 c 6 12,800] ATR
17 1,200] P 7 [1,000] c
18 1,400] c¢ 8 8,000] ATR
19 1,500] ¢ 9 7,200] ¢
20 2,500] to [12,000] aTR
Pa 4,600| ATR mn 7,000| ATR
22 4,000] ¢ 12 8,000] ATR
23 7,000] ATR 13 |t2,000] aTR
24 7,400] ATR 14 5,700 c
25 7,900] ATR 15 8,200 ATR
26 8,000] ATR 16 5,600] ATR
27 9,000] ATR 17 19,500 ATR
28 9,000] ATR 18 15,000 ATR
29 8,950] ATR 19 9,500] ATR
30 {12,500} ¢ 20 6,000] ¢

Taste #1. Subject flight hours and type of pilot license
(ATR=Air Transport Rating; C=Commercial;
P=Private).

patterns, each subject also performed an addi-
tional task of mentally calculating and writing
answers to a series of mathematical problems on
a sheet attached to a clip board resting across
his lap. This mathematical task served to divert
the subject’s foveal vision, as well as his mental
attention, away from the instrument panel.

III. Results.

Only data from the last three patterns (those
in which both tasks were conducted simultane-
ously) were used for the present analysis. Each
subject’s performance was rated according to (1)
the percentage of time he kept his aircraft at the
proper bank angle, (2) the percentage of time
his gaze was directed away from the instrument
panel, and (3) the number of mathematical prob-
lems completed (adjusted to a common time
period). The Student test (for two independent
samples) was used for statistical analysis of the
data.

Bank Angle Performance. A comparison of
bank angle scores for the two aircraft (Table
#2) shows that performance was significantly
better in the Convair in Mode A (without pe-

ripheral vision cues) than in the Boeing. This
suggests that when visual and mental attention
is diverted periodically to other tasks, mainte-
nance of desired bank angle in a sweptwing jet
aircraft by use of a conventional instrument
display may be more difficult than in a conven-
tional straight wing aircraft. However, when
peripheral vision cues were added (Modes B and
C), there were no significant differences between
the scores for the two aircraft; i.e., 66.0 vs. 62.7
in Mode B and 59.7 vs. 64.8 in Mode C.

Display .
Mode Convair 340 | Boeing 720
(Mean %) (Mean %)
A 53.3 42.9
B 66.0 62.7
Cc 59.7 64.8

Scores for mean time (%) at desired bank
angle.

Taste 2.

Visual Attention Time. The data were also
examined to find if there was any significant
difference between the amount of visual time the
subjects devoted to the mathematical problem
solving task in the two aircraft.

Display + .
Mode Convair 340 | Boeing 720
(Mean %) (Mean %)
A 49.7 46.9
B 65.7 62.2
Cc 64.9 61.5

Taste 3. Scores for mean time (%) devoted to problem
solving task.


Froure 1. Convair 340/440; a medium weight, straight wing transport aircraft powered by two piston engines.

Ficure 2. Boeing 720; a modern, “heavy” weight, sweptwing transport with four jet engines.

4


AM 68-22

A COMPARISON OF EFFECTS OF PERIPHERAL VISION
CUES ON PILOT PERFORMANCE DURING INSTRUMENT
FLIGHT IN DISSIMILAR AIRCRAFT SIMULATORS

A. Howard Hasbrook

Approved by Released by

J. Rozert Diziz, M.D. P. VS Srecen, M.D.

Cuter, Crviz AEROMEDICAL Fevers AiR Sureron
INSTITUTE

September 1968

Department of Transportation

FEDERAL AVIATION ADMINISTRATION
Office of Aviation Medicine



Fiaure 3. Peripheral vision cues relating to aircraft
bank angle were provided by two sets of small
colored lights attached to pilot's control wheel
(arrows). Upper bulbs were red, lower ones green.

Froure 4. In conventional instrument display, attitude
indicator (arrow) provides pitch and bank angle
information,

Ficure 5. With attitude indicator covered, bank angle
information was provided by cue lights (arrow #1)5
pitch information was derived from vertical speed
instrument (arrow #2).



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.


A COMPARISON OF EFFECTS OF PERIPHERAL VISION CUES ON PILOT
PERFORMANCE DURING INSTRUMENT FLIGHT IN DISSIMILAR
AIRCRAFT SIUMLATORS

I. Introduction.

Two recent studies'® on the use of peripheral
vision cues for bank angle information, and their
effect on pilot performance during simulated
flight, utilized two different aircraft simulators;
one represented a medium weight, straight wing
aircraft, powered by two piston engines (Figure
1); the other, a “heavy” sweptwing transport
with four jet engines (Figure 2). Data from
these two studies were compared to determine if
the differences in flight characteristics of the two
aircraft produced significant differences in pilot
performance—with and without peripheral vision
cues.

II. Procedure.

As described in the previous studies, the periph-
eral vision cues were provided by two sets of
colored lights located on the pilot’s control wheel
in each simulator (Figure 3). Turns (banks) to
the left triggered illumination of a left-hand
light; turns to the right illuminated a right-hand
light.

“Relationship of cue light illumination to bank
angle was as follows:

. A Cue Light
Convair 340 | Boeing 720 IMumination
o°-3° o°- Ihe None
3°-10° ge —10° | Flash /Sec.
(Green)
10° -18° 1oe—22° 2 Flashes/Sec.
(Green)
18°—22° 22°-26° Steady
(Green)
22°-90° 26°-90° 4 Flashes /Sec.
(Red)

The slight differences in bank angles used for
the various illumination ranges were due, in part,
to small differences in the roll stability and head-
ing divergence characteristics of the two air-
craft; these angular differences, however, did not
affect the results of the study in any significant
manner.

Subjects. Twenty pilot-subjects were used in
the “720” study; thirty others participated in
the “340” study; for purposes of this analysis,
data for the “highest twenty” of the subjects in
the 340 study (those with more than 200 hours
flight time) were used to provide two groups with
more equal flight time and experience. Flight
hours and type of pilot license for each subject
are shown in Table #1.

Instrument Display Modes. ‘Three different
instrument/cue light displays (modes) were used
alternately in each of the two “aircraft”; they
were:

Display
Mode
“A” Complete instrument panel, including
the attitude indicator (artificial horizon
instrument) without peripheral vision
cue lights (Figure 4).

“B” Complete instrument panel, including
attitude indicator and, in addition, func-
tioning peripheral vision cue lights.

“C” “Partial” instrument panel (without at-
titude indicator) with peripheral cue
lights as the only source of bank angle
information (Figure 5).

Flight Task. After a “flight” familiarization
period of approximately 30 minutes, each subject
performed six standard (right-hand) holding
patterns at maneuvering speed while alternately
using each of the three instrument/cue light dis-
play modes described above; in the last three