Definition
A heading value chosen and set into the heading bug or autopilot heading selector before it is needed, so that the aircraft can be flown to or rolled out on that heading accurately and without delay.
Plain English
A heading the pilot dials in ahead of time so the aircraft can be turned to it smoothly when the moment comes.
Context Anchor
Seen in instrument flying when maintaining straight-and-level flight, correcting heading errors, or turning to an assigned heading.
Derivation
From 'pre-' (before) and 'select' (to choose). The word literally means 'chosen in advance,' which is exactly its operational use here — the heading is picked and set before it is flown.
Why Pilots Care
Setting the heading before the turn frees attention for scan, altitude, and airspeed during the maneuver. Forgetting to preselect, or setting the wrong value, is a common cause of overshooting or undershooting an assigned heading.
Intuition Check
Do not assume a preselected heading is the same as the airplane’s exact path over the ground. It is the chosen direction to point the nose; wind can make the actual ground path different.
Example Sentence 1
After being cleared to turn left to 270, the pilot moved the heading bug to the preselected heading and began the turn.
Example Sentence 2
Failure to establish a preselected heading often results in gradual unintended turns during long instrument legs.