Definition
A type of gas turbine engine starter that uses a high-pressure jet of air directed onto the turbine blades to spin the engine up to starting speed. The air is supplied from an external source, an onboard auxiliary power unit, or another running engine, and is aimed (impinged) directly onto the turbine wheel rather than driving a separate starter motor.
Plain English
A way of starting a jet engine by blasting air straight onto the turbine blades to make them spin, instead of using an electric or mechanical starter motor.
Context Anchor
Seen in turbine engine starting-system descriptions and maintenance discussions of air-start equipment.
Derivation
From the Latin 'impingere,' meaning 'to strike against.' The name describes exactly what happens: a stream of air strikes the turbine blades to get them turning.
Why Pilots Care
Provides a lightweight, reliable method to start large turbine engines without heavy electric motors or dedicated gearboxes.
Analogy
It is like blowing air onto a small fan to make it spin. The starter uses controlled, high-pressure air instead of breath, but the basic idea is the same.
Intuition Check
Do not assume “starter” means an electric motor here. In an impingement starter, the starting force comes from air striking blades.
Example Sentence 1
The small turbojet uses an impingement starter, so a high-pressure air cart must be connected before engine start.
Example Sentence 2
Maintenance confirmed the impingement starter air supply lines were free of moisture before the next flight.