Definition
Pilot deviations that occur while the aircraft is in flight, in which the pilot fails to comply with an Air Traffic Control clearance or instruction, or violates a Federal Aviation Regulation. Common examples include entering controlled or restricted airspace without a clearance, deviating from an assigned altitude or heading, and failing to follow published procedures.
Plain English
Mistakes a pilot makes while flying that break a rule or go against what air traffic control told them to do.
Context Anchor
Seen in FAA discussions of pilot deviations, especially when separating mistakes made in flight from mistakes made during taxi or other ground operations.
Derivation
‘Deviation’ comes from the Latin deviare, meaning ‘to turn off the road.’ In aviation it carries that same idea — the pilot has stepped off the path that regulations or ATC laid out.
Why Pilots Care
These events can cause loss of separation from other aircraft and trigger safety or enforcement actions.
Intuition Check
Do not read “deviation” as just a small change or harmless variation. In this FAA context, an airborne deviation means the pilot or aircraft did not comply with a required rule, clearance, instruction, or procedure while in flight.
Example Sentence 1
Busting an assigned altitude by 400 feet is one of the most common airborne deviations reported by ATC.
Example Sentence 2
Controllers watch closely for airborne deviations to keep aircraft safely separated.