CPL » Human Factors » Design of Controls
34.58 Design of Controls
34.58.2 Explain the importance of the following in control design:
Good control design allows the pilot to identify, reach and operate the correct control quickly and accurately, while reducing workload and the risk of error.
(a) Size
Controls should be large enough to:
be easy to locate and operate;
allow accurate movement without excessive effort; and
reduce the risk of accidentally operating a nearby control.
The size of the control should also suit the amount of force and precision required.
(b) Shape/recognition by touch
Different shapes allow controls to be identified by touch without looking at them.
For example, controls may have distinctive knobs, handles or grips so the pilot can recognise them quickly, particularly during:
high workload;
poor lighting; or
emergency situations.
(c) Location
Controls should be positioned where they are:
easy to reach;
within the pilot's normal field of view where necessary; and
located close to the displays or systems they operate.
Frequently used and emergency controls should be especially easy to access.