Definition
A human-factors design flaw in which the movement of a cockpit control does not match the corresponding movement shown on its associated display, causing the pilot to react in the wrong direction or with the wrong input. The mismatch may be in direction, sense, scale, or expected response, and it increases the risk of error, especially under workload or stress.
Plain English
When a control and the screen or instrument it works with don't move the same way as each other, so what the pilot does with the control doesn't match what they see, and they end up doing the wrong thing.
Context Anchor
Seen in cockpit design, instrument interpretation, simulator training, and human-error discussions after an incident or accident.
Derivation
From 'control' (the lever, switch, or knob the pilot moves) and 'display' (the instrument or screen showing the result). 'Incompatibility' here means the two don't agree with each other — the control says one thing, the display shows another.
Why Pilots Care
It can produce incorrect control inputs, especially in instrument conditions or high workload, raising the chance of spatial disorientation or procedural error.
Analogy
It is like a computer mouse set so that moving it right makes the pointer move left. The equipment may still work, but it fights the way your mind expects it to respond.
Grounding Statement
If the pilot’s hand movement and the visible result do not match in an expected way, the design can create confusion at the exact moment the pilot needs quick, correct action.
Intuition Check
Do not read this as a failed control or a broken display. It means the control and display relationship is confusing or unnatural, even if both parts are functioning.
Example Sentence 1
The accident report cited control-display incompatibility, noting that the trim wheel rotated opposite to the direction shown on the trim indicator.
Example Sentence 2
During certification testing the engineers corrected the control-display incompatibility on the heading selector so the display matched the pilot's natural expectation.