Definition
The phase of activity before a flight in which the pilot inspects the aircraft, reviews weather and route information, checks documents and weight and balance, and confirms that the airplane, the pilot, and the conditions are ready for the planned flight.
Plain English
Everything the pilot checks and prepares before getting in and starting the engine, to make sure the airplane and the flight are ready to go.
Context Anchor
Used in checklists, flight planning, instructor briefings, and risk-management discussions before engine start, taxi, or takeoff.
Derivation
Pre- means 'before' (from Latin prae). So preflight literally means 'before the flight' — the work done before wheels move.
Why Pilots Care
Identifies mechanical issues, weather problems, or pilot readiness gaps on the ground before they become in-flight hazards.
Intuition Check
Preflight does not mean only walking around the airplane. In this context, it also includes planning, personal readiness, passenger considerations, and other decisions made before departure.
Example Sentence 1
During preflight, she noticed a small amount of water in the fuel sample and drained it before starting the engine.
Example Sentence 2
During preflight the pilot noticed low fuel and decided to top off the tanks.