Plain English Meaning

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.

Full 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.

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 done before wheels move.