Definition
An action by a pilot that results in a violation of a Federal Aviation Regulation or a North American Aerospace Defense Command Air Defense Identification Zone tolerance. Pilot deviations include airborne events such as deviating from an assigned altitude, heading, or clearance, as well as surface events such as entering a runway or taxiway without authorization.
Plain English
A pilot deviation is when a pilot does something that breaks an aviation rule or goes against an air traffic control instruction — either in the air or on the airport surface.
Context Anchor
Seen in FAA safety discussions, air traffic control reports, airspace procedures, altitude assignments, and runway operations.
Derivation
‘Deviation’ comes from the Latin ‘deviare,’ meaning to turn off the road. In aviation, it carries that same idea — the pilot has departed from the path the rules or controllers laid out.
Why Pilots Care
Pilot deviations can trigger FAA investigations, enforcement actions, certificate suspension, or safety risks.
Intuition Check
Do not read “deviation” here as any small difference from perfect flying. In this FAA use, a pilot deviation means the pilot failed to follow a rule, instruction, or clearance.
Example Sentence 1
Crossing the hold-short line without a clearance is a pilot deviation and will likely result in a phone number to call after landing.
Example Sentence 2
During preflight planning, the instructor emphasized checking all altitudes to prevent a pilot deviation on the IFR flight.