Definition
A cockpit avionics function that allows the pilot to dial in a target altitude in advance, so that the autopilot and altitude alerting system can capture and hold that altitude when the aircraft reaches it. It typically provides visual and aural alerts as the aircraft approaches, reaches, and deviates from the selected altitude.
Plain English
A control where the pilot sets the altitude they plan to climb or descend to. The aircraft's systems then warn the pilot as that altitude approaches and help level off there automatically.
Context Anchor
Seen in instrument flying, especially when using an autopilot, altitude alerting system, or a clearance that assigns a specific altitude.
Derivation
Pre-select means to choose ahead of time. The name describes exactly what the pilot does: pick the altitude before reaching it, so the aircraft's systems are ready when the moment arrives.
Why Pilots Care
It reduces workload and helps prevent altitude deviations by automating the level-off point.
Intuition Check
Do not assume the altitude pre-selector gives you permission to climb or descend. It only sets a target in the aircraft equipment; your clearance or flight plan still determines what altitude you may use.
Example Sentence 1
After being cleared to climb to 8,000 feet, the pilot dialed 8,000 into the altitude pre-selector before pushing the throttle forward.
Example Sentence 2
Once armed, the altitude pre-selector caused the autopilot to capture the assigned altitude smoothly.