This document discusses considerations for human factors in the design of flight deck displays and controls on commercial aircraft. It notes that modern aircraft have transitioned to glass cockpits with LCD displays rather than analog gauges. When designing displays and controls, human factors should be considered to ensure all crew functions and tasks are supported. Specifically, the document discusses display hardware characteristics like readability in varying light conditions. It also covers control placement and functionality to ensure accessibility, standardization, and usability during operations.

1. Considerations of Human Factors
on Commercial Aircraft
Flight Deck Control Panels
W.M.K.S. Weerasekara

2. Introduction
 Aviation industry has realized that human error, rather than mechanical failure
was the reason most aviation accidents and incidents.
 Modern aircraft’s flight deck is called as glass cockpit. Because most of displays
are large LCD display or touch panels rather than traditional analog dials and
gauges.
 Consideration of human factors issues early on and throughout the design process
will help to ensure that the displays and controls will support all flight crew
functions, tasks, and decisions.
 Mainly Discuss on Display Hardware and Controls

3. Display Hardware
 In the flight deck or the cockpit, display must be in correct readable situation
in any light conditions. Sometimes it was difficult to see and read in bright
light conditions in the cockpit.
 The display quality and its location are significantly affected to the
readability and information that given.
 Discuss on Following Facts
 Visual Display Characteristics
 Display Placement and Installations

4. Visual Display
Characteristics
 The minimum recommended character brightness is 1
cd/m2 (0.3 fL).
 The luminance variability at the edge of the display
should be less than or equal to 50% of the luminance in
the center of the display. The variability in the central
80% of the display should be less than or equal to 20%.
 To prevent flicker, the minimum refresh rate should be
50 – 60 Hz for CRTs, and the minimum frame rate should
be 30 Hz for LCDs.

5.  The delay between the movement of a control and the response to that
movement on the display shall be minimized ( Reposing time should be less
than 3 ms)
 The HUD ( Head Up Display) eye box should be at least 4.5 in wide (11.5 cm),
2.5 in (6.5 cm) high, and 6.0 in (15cm) deep. Markings on the HUD should be
illuminated so that they are not confused with external visual details.
 Reflections may create a “ghost image,” that is, an undesired duplicate
image which may appear as a false image of the object or an out-of-focus
image of a bright light source in the optical field. Anti-reflective coatings may
prevent the “ghosting” effect.

6. Display Placement and Installations
 Visual warnings must be placed in the primary field-of-view. High priority
alarms should be placed in the pilot’s primary field-of-view. If all critical
alerts cannot be placed within 15 degrees, a master warning display is also
appropriate.
 Critical functions and attitude, altitude, airspeed and basic level of
navigation (including heading) should be within the pilot’s primary field-of-
view.
 Current surface trim position indication may be displayed to the pilot in the
secondary field-of-view.
 The nominal viewing distance should be 29 in (737 mm) from the pilot’s
design eye point. Critical displays in the pilot’s field-of-view should have a
minimum viewing distance of 10 in (254 mm); less critical displays may have a
minimum viewing distance of 13 in (330 mm). The maximum viewing distance
should be 40 in (1,016 mm).

7.  Primary Field-of-View - With the normal line-of-sight established at 15
degrees below the horizontal plane, the values for the vertical are +/-15
degrees optimum, with +40 degrees up and -20 degrees down maximum. For
the horizontal visual field (relative to normal line-of sight forward of the
aircraft), the values are +/-15 degrees optimum, and +/- 35 degrees
maximum
 Secondary Field-of-View is based upon the optimum horizontal and vertical
visual fields from the design eye reference point that can be accommodated
with head rotation. These values are +/- 60 degrees horizontal and + 65 and -
35 degrees vertical.

8. Controls
 Conventional aircraft control devices consist of buttons,
knobs, keyboards, and switches, but cursor control devices,
such as a mouse, touchpad, trackball, or joystick are
becoming more frequent.
 Each control device has unique characteristics that may
affect the design of the functions being controlled.
 When designing controls arrangements, accessibility and
functional directions need to be considered

9. Functional Directions
There are standard directions of movements of the controls that it should be
used for the particular functions.

10. Arrangements and Accessibility
 Controls should be designed for nighttime usability (e.g.,
illuminated).
 Ensure that hand-operated controls are operable with a
single hand. The remaining hand will then be free to
operate the primary flight controls.
 Ensure that controls are operable during vibrations.
Vibrations affect not only the ability of pilots to
intentionally activate a control.
 Each cockpit control, other than primary flight controls
and controls whose function is obvious, must be plainly
marked as to its function and method of operation
 Control design and placement should avoid the possibility
that visibility of information could be blocked.

11.  Each control and control system must operate with the ease, smoothness, and
positiveness appropriate to its function.
 A positive indication of control activation should be provided (e.g., by feel,
audible click, or associated light).
 If the system response time is greater than 1.0 second, the system should
provide an indication that it is processing.
Apart from above considerations when designing controls such as push
buttons, rotary controls, Switches, Keyboards and Cursor input devices should
maintain their dimensions and characteristics that are standardize by
regulation bodies.

12. Rotary Controls

13. Push Buttons

14. Thank You !