Definition
The procedure of starting an aircraft engine while in flight, typically following an in-flight shutdown or flameout. Airstarts may be accomplished using the engine's normal starter, by windmilling (allowing airflow through the engine to spin it), or a combination of both, depending on the aircraft type and the published airstart envelope (airspeed and altitude limits).
Plain English
Restarting an engine that has stopped while the aircraft is still flying.
Context Anchor
You may see this term in emergency procedures, engine-failure discussions, and aircraft checklists that describe how to restart an engine in flight.
Derivation
A straightforward compound: 'air' (in flight) plus 'start' (to begin engine operation). The word distinguishes this from a 'ground start,' which is the normal engine start performed on the ramp before flight.
Why Pilots Care
Allows recovery from engine stoppage without immediate forced landing, especially important for turbine and multi-engine aircraft.
Grounding Statement
Picture the airplane already flying with an engine not running, and the pilot trying to get that engine running again before landing.
Intuition Check
Airstart does not mean any engine start that uses air pressure on the ground. Here, it means starting or restarting an engine while the aircraft is flying.
Example Sentence 1
After the flameout, the crew followed the airstart checklist and successfully relit the engine before reaching their decision altitude.
Example Sentence 2
The training syllabus requires each student to demonstrate a successful airstart in the simulator.