Engine start system is powered by what?

Engine start system is powered by what?

• A. Electrical Power
• B. Mechanical Power
• C. Hydraulic Power
• D. Pneumatic Power

Answer: (D)

The engine start system on the A320 is driven by pneumatic power. It uses an air turbine starter that is powered by bleed air supplied from the aircraft’s bleed system (from the APU or an external ground source). When you start, the air start valve opens and delivers high‑pressure bleed air to the starter, converting that pneumatic energy into rotational mechanical energy to spin the engine’s high‑pressure spool until it reaches self‑sustaining speed. At that point, fuel and ignition are introduced and the engine comes up to idle. Electrical power supplies the control and ignition systems, but the actual turning energy to start the engine comes from air. Hydraulic power isn’t used to drive the engine start in this aircraft, and a mechanical prime mover isn’t what initiates the start sequence.

The engine start system on the A320 is driven by pneumatic power. It uses an air turbine starter that is powered by bleed air supplied from the aircraft’s bleed system (from the APU or an external ground source). When you start, the air start valve opens and delivers high‑pressure bleed air to the starter, converting that pneumatic energy into rotational mechanical energy to spin the engine’s high‑pressure spool until it reaches self‑sustaining speed. At that point, fuel and ignition are introduced and the engine comes up to idle.

Electrical power supplies the control and ignition systems, but the actual turning energy to start the engine comes from air. Hydraulic power isn’t used to drive the engine start in this aircraft, and a mechanical prime mover isn’t what initiates the start sequence.