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III, Results.

During an ILS approach, the ultimate result
of the pilot’s control of the aircraft’s pitch and
roll attitude, heading, vertical speed, and air-
speed can be measured in aircraft deviation
around the centerline of the glide slope and
localizer beam. Therefore, data for such devia-
tions were used for the first statistical analyses.

Glidepath deviation data taken from the fol-
lowing approach points and/or areas were sub-
jected to statistical test by comparing: (a) mean
deviation (algebraic and arithmetic) between the
outer and middle markers (approximately 120
seconds of flight), (b) arithmetic means during
the last 30 seconds prior to reaching the middle
marker, (c) total range below and above the
glide slope centerline during the last 30 seconds
prior to reaching the middle marker, (d) means
at the middle marker (algebraic and arithmetic),
and (e) the largest deviation below the glide
slope centerline at any point between the outer
and middle markers.

Comparison of the glidepath deviation data for
the PVFD and conventional displays showed no
significant differences in deviation between the
two displays, nor did the amount of pilot ex-
perience influence the degree of glide slope
deviation noted with the two different displays.
However, the high-time group did have a slightly
smaller arithmetic mean deviation than the low-
time group (P<.05) regardless of the display
used while operating between the outer and
middle markers.

Localizer deviation data taken from the fol-
lowing approach points and/or areas were
statistically analyzed by checking: (a) arithmetic
means between the outer and middle markers,
(b) arithmetic means at the middle marker, (c)
total range left and right of the localizer center-
line during the last 30 seconds prior to reach-
ing the middle marker, and (d) the largest devia-
tion between the outer and middle markers.

Comparison of the localizer data for both dis-
plays showed no significant difference in
deviations (P>.05), nor was any difference in
performance on the two displays noted as a
function of pilot experience.

Heart-rate data were examined for statistically
significant differences during use of the two dis-
plays; none was found at a probability level

of less than 5 percent. However, in keeping
with the results of previous studies of pilots—
during simulated ILS approaches, there was a
statistically significant increase in heart rate
(P<.01) as the middle marker was approached,
regardless of which display was in use at the
time.

Airspeed control with the two displays was
closely comparable (see Table 1). The high-time
pilots showed a mean difference of less than 1
knot in minimum airspeed on the two displays;

TABLE 1. Minimum Airspeed (Knots)

PVED Conventional
High-time group 104.29 103.71
Low-time group 102.87 102.20

for the low-time group the difference between
displays was less than 0.6 knots. The mean
airspeed ranged from approximately 6 to 8 knots
below the selected airspeed of 110 knots.

The mean airspeeds between the outer and
middle markers are shown in Table 2. The
difference between displays for the high-time
group is less than 1 knot; for the low-time group
the difference is less than 2 knots. The means
for the range in variation of airspeed during use

TABLE 2. Mean Airspeed (Knots)

FVED Conventional

High-time group 110.10 109.40

Low-time group 108.37 106.78

of the two displays also are small (see Table 3),
with less than 2 knots between any combination
of experience level and type of display.

TABLE 3. Mean Range in Airspeed (Knots)

PVFD Conventional
High-time group 11.46 11,30
Low-time group 10,58 9.49

Analysis of the pitch and roll control data
shows that pilot performance with both displays
was similar.

After the flights, the subjects were asked. to
rate the specific PVFD instruments. Seventeen
of the twenty subjects provided usable responses.


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ment tape. Pointer position rather than numer-
ical readout provided the pilot with airspeed
information.

The glidepath indicator (C, Figure 1) was
also arranged vertically, with a fixed red “bull’s-
eye” depicting the centerline of the glide slope
portion of the ILS. The instrument, located to
the right of the attitude indicator, utilized a
black two-dimensional symbol of an aircraft as
seen from the rear. This aircraft symbol moved
upward when the real aircraft went above the
glide slope centerline and moved downward when
the real aircraft went below the glide slope
centerline.

The instantaneous vertical speed indicator
(IVSI) (D, Figure 1) was located to the right
of the glide slope indicator. It was also in a
vertical format with a movable tape and mov-
ing black pointer that permitted the pilot to set
the desired vertical speed at the midpoint of the
instrument. The pointer moved upward for
decreased vertical speed and downward for in-
creased vertical speed.

Total horizontal distance across the four in-
struments (airspeed, attitude, glidépath, and
vertical speed) was 8.10 inches.

The horizontally shaped localizer indicator
(E, Figure 1), which also could be used as an
omnibearing indicator (OBI) for VOR naviga-
tion, was located immediately below the attitude
indicator. It was equipped with a fixed localizer
(or VOR radial) centerline, depicted as a nar-
row-based triangle, and a moving aircraft symbol
as seen from above. Deviation of the real air-
craft to the left of the localizer centerline dur-
ing a front-course ILS approach produced a
leftward movement of the aircraft symbol.

The heading indicator (F, Figure 1), placed
immediately below the localizer instrument, con-
sisted of a horizontal case with a lubber line in
the center and a moving, servoed tape imprinted
with heading numerals. An adjustable moving
black pointer indicated deviation away from a
desired heading preset at the lubber line and also
showed which way the pilot should turn to cor-
rect his heading,

Ficure 2. Beechcraft Bonanza 35A used in peripheral vision flight display study.

4


conditioning module and an Astro-Science model
2000, 14-channel analog tape recorder was in-
stalled in the left rear seat area (Figure 4).

Twelve channels of information were recorded
during the study. Pilot heart rate was obtained
by use of an ear plethysmograph, which elimi-
nated muscle artifacts. Aircraft pitch and roll
data were obtained from suitable pickoffs from
the aircraft primary attitude indicator. Vertical
and lateral deviations from the ILS centerline
were obtained directly from the glide slope and
localizer signals. Altitude, airspeed, and vertical
speed data were obtained from special high-
resolution pressure transducers connected to the
aircraft’s pressure and static air system. Ver-
tical acceleration data were taken from a high-
resolution accelerometer installed near the center
of gravity of the aircraft. Deviations from the
desired heading were obtained from the gyro-
stabilized remote compass. Control-wheel move-
ment data (left and right, fore and aft) were
derived from mechanoelectric transducers con-
nected to the aircraft’s control cables. Event
signals were inserted on a separate data channel
by the use of a manual switch.

Twenty professional pilots were used as sub-
jects; half were high-time pilots with a mean
of 1,267 hours of instrument flying, and the other
half were low-time pilots with a mean of 104
hours of instrument flying. The mean total fly-
ing time of the high-time group was approxi-
mately 9,000 hours; the mean of the low-time
group was 1,023 hours. Mean age for the high-
time group was 50 years; that of the low-time
group was 42 years.

The experimental flights were conducted at
Oklahoma City, Oklahoma, and all instrument
approaches were made at Will Rogers World
Airport to either runway 17-R or 85-R, depend-
ing on wind direction. All flights were made
during daytime. Slats covering the windshield
and left side window blocked the subject’s out-
side view while permitting an unobstructed out-
side view for the safety pilot and research
technician. Al] flights were under radar ap-
proach control (RAPCON) surveillance for
safety and to facilitate integration of the re-
peated approaches with other air traffic.

Prior to flight each subject was given a brief-
ing paper describing the PVFD and the routine

to be accomplished during the flight. The se-
quence in which the PVFD panel and the con-
ventional panel were flown was counterbalanced
to control possible sequence effects. Each subject
was allowed 30 minutes of familiarization flight
time—15 minutes at the start of the flight to
become familiar with the aircraft’s flight char-
acteristics and, later, 15 minutes to become
acquainted with the operation of the PVFD
instruments prior to their use.

Each subject made two simulated ILS ap-
proaches using the conventional panel and five
using the PVFD panel. During the first two
PVFD runs, the slats were not used and the sub-
jects were coached in the use of the PVFD panel
by the safety pilot. The last three PVFD
approaches were made with the slats in place.
Since the subjects had many hours of experience
with the conventional instruments, it was thought
that two approaches using the conventional dis-
play would be sufficient. Preliminary work
indicated that five approaches using the PVFD
would be the minimum acceptable. It was also
of interest. to find out how well the subjects
could perform with limited experience with the
PVFD.

The subjects flew the aircraft at all times ex-
cept for a 2-minute rest period on each downwind
leg. The safety pilot handled all air traffic con-
trol communications throughout the flights. The
subjects were instructed to use an approach and
go-around speed of 110 knots, with landing gear
down and 5° of flap extension. The minimum
descent altitude was designated as 100 feet above
runway elevation, and this altitude ‘was to be
maintained until after crossing the runway
threshold, at which time the safety pilot in-
structed the subject to increase power and go
around. The vision-restricting slats remained in
place at all times except for the two PVFD
familiarization approaches.

Data were recorded from the time of entry
on the final approach to 20 seconds after passing
the runway threshold during the go-around.
Data runs consisted of the two approaches with
the conventional display and the last three of
the five approaches with the PVFD. Statistical
comparison of peformance was based on data
from the last conventional panel approach and
the last PVFD approach.



Technical Report Documentation Page

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.
FAA-AM-75-12
4, Title and Subtitle 5, Report Date
PILOT PERFORMANCE AND HEART RATE DURING IN-FLIGHT November 1975
USE OF A COMPACT INSTRUMENT DISPLAY G. Performing Organizorion Code
[B. Performing Organization Report No.

7 hottos) ) Yoward Hasbrook, Paul G. Rasmussen,

and David M. Willi:
9. Performing Organization Nome and Address 10. Work Unit No. (TRAIS)
FAA Civil Aeromedical Institute
Pp. 0. Box 25082 M1. Contract of Grant No.

Oklahoma City, Oklahoma 73125

13. Type of Report and Period Covered

12. Sponsoring Agency Name ond Address

Office of Aviation Medicine
Federal Aviation Administration
800 Independence Avenue, S.W.
Washington, D.C 20591

OAM Report
14, Sponsoring Agency Code

15. Supplementary Notes

Work was performed under Task AM-D-75-PHY-44

16. Abstract

Instrument panels in many general aviation aircraft are becoming increasingly
crowded, presenting the pilot with an instrument scanning problem. Because most
aircraft instruments require use of central (foveal) vision, the pilot must look
directly at each instrument to obtain needed information, taking time that may not
be available during an instrument approach to published minimums. It was thought
that the problems of adequate scanning of the instruments might be alleviated by
reducing and changing the size of certain instruments and utilizing the pilot's
peripheral vision. An in-flight study of pilot performance was conducted while
using an experimental instrument display. The display was used in flight by
low-time and high-time professional pilots. The major findings of this study
indicate that pilot performance with the high-contrast instrument display, which
employs a vertical and horizontal format and occupies substantially less space
than conventional instruments, is equal to pilot performance with conventional
instruments, in spite of little familiarization time and without regard to pilot
experience. No difference in stress (as measured by heart rate) was evident
between the experimental and conventional displays. Subjective reaction of the
pilot-subjects to the new type display was favorable. Panel space requirements
can be reduced by at least 25 percent by use of the design concepts outlined in
this study,

17. Key Words 18. Distribution Stotement
Aircraft, Aviation Safety, Instrument Document is available to the public through
displays, Instruments the National Technical Infotmation Service,

Springfield, Virginia 22151

19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages % Riso
Unclassified Unclassified .95 MF

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized



many of the subjects) and the lack of need for
extensive familiarization time suggests that this
type of display might decrease the time required
in learning to fly by instruments. Also, there
is a strong subjective impression that this type
of display reduces the need for wide visual scan-
ning of the instruments and provides early visual
warning of minor flight deviations, thereby pos-
sibly reducing the overall workload and fatigue.

Further design evaluation of the present
PVFD indicates that it could be reduced in size,
possibly enhancing its visual effectiveness. Build-
ing the PVFD as a single unit with modular
inserts and combining the heading indicator with
the localizer indicator would reduce the space
required by an additional 35 percent. This
would result in a primary instrument flight dis-
play that would not only require 50 percent less
panel space, but also would place essential in-
formation in a narrow visual cone of attention
and thus reduce the need for wide visual scan-
ning. Also, the performance obtained in this
study by use of the PVFD suggests a means for
increasing the visual effectiveness of flight direc-
tion instruments and head-up displays used in
military and air carrier aircraft.

10

Vv. Summary.

A high-contrast instrument display, employ-
ing a vertical and horizontal format requiring
substantially less space than conventional round-
faced instruments, provided equal pilot perform-
ance (regardless of the type of display used)
without requiring a large amount of familiariza-
tion time. This was true for both low- and
high-time pilots. Heart-rate indications of stress
were not influenced by the type of display used;
it is clear, however, that heart rate increases as
the pilot approaches the runway threshold, re-
gardless of the display.

Since pilot reactions were generally favorable
to the PVFD, and since there are no perform-
ance or stress penalties associated with the use
of the display, it would appear that this design
can be employed to reduce the size of the area
required for presentation of primary flight in-
formation by at least 25 percent. This would
also serve to reduce the total area of key instra-
ments required for scan in approaches to landing
under IFR conditions.


The overall ratings are shown in Table 4. It
shows that, with the exception of the altimeter,
ratings of excellent and good were used more
often than fair and poor to describe the pilot’s

TABLE 4, Pilot Rating of PVFD Instrunents*

PvED Excellent Good Fate Poor

Arspeed indicator as 2
Glide slope indicator ° 7 1
Localizer indicator a 8 1
Vertical speed indicator 5 8 3
Heading indicator 5 5 ‘6
1 4 3

Meimeter

‘athree pilots did not complete rating scale on PVFD instruments

subjective likes and dislikes of the specific
instruments.

When the subjects were asked if they experi-
enced any particular difficulty adjusting to the
PVFD, 18 provided usable responses. Of these,
seven said no, three gave a qualified no, five said
yes, and three said some or a little. Of those
experiencing one or more difficulties, five men-
tioned use of the altimeter, one apparently dis-
liked the increased sensitivity of the instruments
in general, and six were initially bothered by
the movement relationship of the glide slope and
localizer instruments; i.e., flying the symbols to
the center of the instruments rather than flying
to the needles as with the conventional cross-
pointer instrument.

Almost all the subjects thought they would have
benefited from more practice with the PVFD
panel; however, this does not seem to be borne
out by performance data.

When the subjects were asked what particular
instruments or features of the PVFD, if any,
were specifically found advantageous compared
to the conventional display, the following were
specified by the number of subjects listed: air-
speed indicator, 10; glide slope indicator, 6; lay-
out and size of PVFD, 5; localizer indicator, 4;
vertical speed indicator, 4; movement relation-
ship, 3; heading indicator, 1; and sensitivity of
movement, 1.

When the subjects were asked if they thought
they performed as well, better, or worse with
the PVFD compared to their performance with
the conventional panel, the following responses
were given: better, a little better, 7; as well,

about the same, 6; slightly less, not quite as well,
3; worse, 1; don’t know, 1.

When asked if they had confidence in the
quality and reliability of the PVFD, 16 subjects
said yes, 1 said not at first, and 1 said no (one
instrument malfunctioned during one approach
with this subject).

When the subjects were asked their opinion
of the PVFD with respect to its potential and
practicality for use in general aviation aircraft,
18 gave positive responses with and without,
specific exceptions, such as the altimeter. Five
subjects compared the PVFD panel to a con-
ventional flight director system.

IV. Discussion.

Use of the PVFD system resulted in perform-
ance equal to that of the standard display, even
though the pilots had very little experience with
the system. Many of the pilots said that the
instrument approach was simplified. Several
subjects also sai¢ the display was more “natural”
than the conventional display. Upward move-
ment of the airspeed needle (indicating decreas-
ing speed) with upward movement of the air-
craft’s nose was mentioned as an example of
“naturalness.” Lateral movement of the aircraft
symbols during deviation from the localizer cen-
terline, and vertical movement during deviation
from the glide slope centerline, seemed more
natural than flying toward the needles of con-
ventional cross-pointer indicaters.

The instrument evoking the most adverse com-
ments was the digital altimeter; these comments
were directed toward low luminance, poor con-
trast in the high ambient light of the cockpit,
rapid movement of the digits, and lack of a
moving needle for rate information-design details
that could be readily corrected in a second-genera-
tion display.

The vertical speed indicator was judged to be
too sensitive; compression of the scale by a factor
of two would make it comparable to the standard
IVSI.

Combining the functions of the localizer and
heading indicators was suggested as a means of
overcoming some adverse effects of the heading
indicator,

Ease of interpretation of the natural move-
ments of the pointers and symbols (as noted by



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is

Ficure 4. Data acquisition system and signal sampling and conditioning units installed behind pilot’s seat.

The altimeter (G, Figure 1) consisted of a
horizontal case containing electronically acti-
vated Nixie tubes to provide digital information.
The instrument, located directly above the atti-
tude indicator, was placed so that the altimeter
would be in the pilot’s line of sight as he looked
for the runway after breaking out below clouds.
The vertical distance from the top of the altim-
eter to the bottom of the heading indicator was
8 inches.

With the exception of the vertical speed in-
dicator, the rate of movement (sensitivity) of
the pointers and symbols was twice that of most
conventional flight instruments. In other words,
a half-inch movement of the pointer on the
PVFD airspeed indicator was equivalent to a
quarter-inch movement of the needle on a con-
ventional airspeed indicator. The resultant
quickening of movement of the pointers, in com-
bination with high contrast and large pointers,
was designed to cause an increased awareness
through the use of peripheral vision.

Index graduation was used sparingly to avoid
cluttering the instrument faces and to simplify
and quicken pilot interpretation of the readings.
For example, the airspeed indicator had no index
graduations between the numerals, which were
shown in 10-knot increments. Also, pointer
movement was damped to reduce vibration effects
and to prevent overshoot from acceleration. The
heading indicator had graduations only at mid-
points between the 10° increments, The vertical
speed indicator was the only instrument with
conventional graduation between its 500-foot
increments. ;

Conventional (moving horizon) attitude indi-
cators were used in both displays. A 1968 Beech-
craft Bonanza 35A, equipped with dual controls
(Figure 2), was used as the research vehicle.
The experimental PVFD, built by Humphrey,
Inc., of San Diego, California, was installed on
the left (pilot) side of the instrument panel and
the conventional display was moved to the right
section of the panel (Figure 3). A Humphrey,
Inc, data acquisition system with a signal-


R. Nicklas,‘ bears special mention. This vividly
interesting documentation of aircraft instrument
development contains a bibliography of 384
papers, articles, and reports. Nicklas states: “In
a series of tests covering the period 1903-1906,
the Wright brothers employed a Richard ane-
mometer, not primarily to determine airspeed as
in later years, but to measure the length of their
flights. For a number of years to come, most
pilots depended on the force of the wind in their
faces to determine airspeed.” He also states that
the first real instrument in an aircraft is re-
ported to have been an oil pressure gauge, to
warn against impending engine malfunction.

Although most early instruments were round
faced, some instruments with vertical scales were
tried as early as 1923 in a DeHavilland P-302
airplane. Because of insufficient length of the
fixed scales, they were soon abandoned.

In the late 1920’s Lt. James H. Doolittle, sup-
ported by the Guggenheim Fund, endeavored to
simplify the instrument panel by having the
pointers of the round-faced directional indicators
form a vertical line when the aircraft was fly-
ing straight and level and all pointers affected
by pitch form a horizontal line in normal flight
attitude. Doolittle’s main objective was simplifi-
cation. He sought to relieve the pilot of all
unnecessary interpretations,

At the end of his report, Nicklas points out
that during the years covered by his study, too
little time had been spent exploring integration
of the variables in the cockpit, and he suggests
that even a modest effort in this direction would
be well worthwhile.

It was felt that a new instrument display,
designed to reduce the time needed for instru-
ment scan by utilizing the pilot’s peripheral
vision, would enhance safety by reducing the
potential for work overload. The effect of such
a display should be to decrease the pilot’s anxiety
during an instrument approach. This lowered
anxiety should cause a reduction of sympathetic
excitation, which in turn should be directly re-
flected in the pilot’s heart rate. The heart rate,
in this sense, is used as an indicator of short-
term stress and should contribute insight into
a pilot’s perception of the progress of an instru-
ment approach. A study was therefore designed

to measure, quantitatively, pilot performance and
heart rate during ILS approaches made under
two conditions: (1) with a conventional instru-
ment display and (2) with a new peripheral
vision flight display (PVFD) panel, which was
first conceived by Hasbrook in the late 1960's.

II. Methodology.

The experimental PVFD panel was designed
to provide early visual indications of changes
from desired values of certain flight parameters.
These parameters were airspeed, vertical speed,
glidepath and localizer deviation, heading, and
altitude.

High contrast is important for seeing changes
in the relative positions of objects, particularly
those in the peripheral visual field; therefore,
large moving black pointers and aircraft symbols
were used against large white backgrounds. It
is of interest that many early aircraft instru-
ments also had white dials with black numerals
and pointers.? This contrast scheme was reversed
when fluorescent paint was introduced to help
pilots see the instruments during night flight.

Since control of the aircraft’s pitch and roll
attitude is obtained primarily by reference to
the attitude indicator, this instrument was made
the focal point of the panel (A, Figure 1); it
was placed directly in front of the pilot and as
high on the panel as practicable. The airspeed,
glidepath, and vertical speed indicators were
placed on either side of the attitude indicator
so that pitch changes would produce vertical
movement of the pointers in these instruments.
The localizer and heading indicators were placed
immediately below the attitude indicator so that
lateral flight deviations would be shown by
lateral movement of the pointers.

The airspeed indicator (B, Figure 1) was made
in a vertical format with a movable tape so that.
the pilot could manually place the desired air-
speed at the midpoint of the instrument scale;
the moving pointer responded to changes in air-
craft velocity and moved upward to indicate
reduced airspeed and downward for increased
airspeed. When the black pointer was at the
midpoint of the instrument, the pilot was assured
of being at the selected airspeed without the
necessity of reading the numerals on the instru-


PILOT PERFORMANCE AND HEART RATE DURING IN-FLIGHT USE
OF A COMPACT INSTRUMENT DISPLAY

I. Introduction.

The complexity and number of instruments
placed in instrument panels present a consi-
derable problem to pilots in scanning these
instruments in increasingly complicated flight
situations. Instrument landing approaches are
particularly vulnerable to delays in pilot response
because of the relatively low altitudes and the
minimal time available for decision making.
During an instrument landing system (ILS)
approach, for example, the average general avia-
tion jet aircraft is only 15 to 20 seconds from the
runway threshold when the pilot “breaks out”
under a 200-foot ceiling at the middle marker.
With an approach speed of about 200 feet per
second, the pilot who spends 1 or 2 seconds read-
ing each instrument has little time or altitude
to correct errors that may have developed during
the approach.

Generally, pilots handle the exacting require-
ments of an instrument approach extremely well;
however, there have been enough approach and
landing accidents to suggest that instrument
panel design should be reevaluated with a view
toward simplifying flight-data displays.

Most aircraft. instruments require the use of
central (foveal) vision for acquisition of precise
information. The angular range of central vi-
sion is limited to less than one-half degree of
subtended angle Beyond this angle, visual
acuity diminishes rapidly; at 40° to the side,
acuity is reduced by about 95 percent. Thus,
the pilot’s reading (foveal) vision covers an area
of about 1 square inch at a distance of 28 inches
—the average distance between the pilot’s eyes
and his instrument panel. Because of this ocular
limitation, the pilot must look directly at each
instrument to obtain needed information.

Milton, Jones, and Fitts? measured eye move-
ments of pilots during instrument approaches
and found that the time of visual fixation on an
instrument varied from 0.86 second to 0.34
second, depending on the information required.
Interestingly, 41 percent of the pilot’s visual fixa-
tion time (including transfer of his gaze from
some other fixation point) was spent on the ILS
eross-pointer while only 15 percent was devoted
to the attitude indicator, 25 percent to the head-
ing indicator, 10 percent to the airspeed indi-
cator, and only 2 percent each to the altimeter
and vertical speed indicator.

The reasons for these differences in fixation
time are unknown; it is possible that difficulty
in interpreting the readings of the instruments
may be a factor, or perhaps the priority assigned
to instruments for a given phase of flight is
responsible. However, this latter possibility does
not equate well with the little time (2 percent)
given to the altimeter during flight near the
ground in the latter part of an instrument
approach,

Obviously, time for scanning the instrument
panel is an important factor during an instru-
ment approach. Also, additional equipment in-
creases the area and number of indicators to be
scanned. Accordingly, it was thought that re-
ducing the size of certain instruments, changing
their shapes, making them more readable, and
utilizing the pilot’s peripheral as well as his
central vision for acquisition of information®
would alleviate these problems, and that com-
pressing these instruments into a small area
would also reduce the time needed to scan the
instruments.

A review of past efforts in the field of instru-
ment design brings out some interesting informa-
tion. One document, “A History of Aircraft
Cockpit Instrumentation, 1903-1946” by Douglas





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np

»

cs

References

|. Wulfeck, Joseph W., et al.; Vision in Military Avia- _ 8. Hasbrook, A. Howard: Peripheral Vision: A Factor
tion. Wright-Patterson AFB, Ohio, WADC Technical for Improved Instrument Design, Proceedings of the
Report 58-399, November 1958. Eleventh Annual SAFE Symposium, Phoenix, Arizona,
. Milton, John L., Richard E. Jones, and Paul M. Fitts: October 1973.
Eye Fixations of Aircraft Pilots. IL. Frequency, Dura- 4. Nicklas, Douglas R.: A History of Aircraft Cockpit
tion, and Sequence of Fixations When Flying the Instrumentation, 1903-1946, Wright-Patterson AFB,
USAF Instrument Low Approach System (ILAS). Ohio, WADC Technical Report 57-801, April 1958.
Wright-Patterson AFB, Ohio, AF Technical Report
No, 5839, October 1949,
Bibliography
. Anonymous: Guidance and Control Displays, AD-739- Aircraft Instruments. Report of the Aeromedical
779, A compendium of papers presented at the 18th Laboratory, JASDF, 14(2) :57-68, September 1973.
meeting of the Guidance and Control Panel of  , Harris, William, Robert R. Mackie, and Clark L.
AGARD, Paris, France, October 19-21, 1971. Wilson: Performance Under Stress: A Review and
Bauer, Robert W., e¢ al.: Panel Layout for Recti- Critique of Recent Studies, AD No. 108779, July 1956.
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Pa

. Hagihara, H., S. Aramaki, T. Ito, and Y. Nagasawa:

Consideration of Investigation on Reading Error of

11

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