ABSTRACT
A display is any means of presenting information directly and it usually makes use of the visual, aural or tactual senses. The purpose of a display in an aircraft is to transfer information about some aspect of the flight accurately and rapidly from its source to the brain of the crew member, where it is then processed. Another characteristic of visual displays is that they need light and visibility to be effective. The purpose may be simply to control a display directly as with the altimeter sub-scale knob. These functional requirements will influence the type of control device which is used. Control-display ratio is the distance of movement of the control related to that of the moving element of the display such as the read-out or the pointer. Direction of movement of the control relative to the display is another aspect requiring Human Factors attention.
