FAA Aviation Mechanic Powerplant (AMP)Turbine EnginesMedium
During climb, a turbojet engine experiences a compressor stall accompanied by loud banging noises, vibration, and a rise in exhaust gas temperature. What is the correct immediate corrective action by the pilot?
- ARetard the throttle to reduce fuel flow and unload the compressor
- BAdvance the throttle further to increase airflow through the compressor
- CIncrease the aircraft's angle of attack to increase inlet ram air
- DShut off the bleed air system only and maintain power
Show answer & explanationAnswer & explanation
Correct answer: A. Retard the throttle to reduce fuel flow and unload the compressor
A compressor stall occurs when airflow through the compressor is disrupted, often due to excess fuel flow relative to airflow. Retarding the throttle reduces fuel flow and restores a proper fuel-to-air ratio, relieving the stall condition.
Why the other options are wrong
- B. Advancing the throttle increases fuel flow and can worsen the stall.
- C. Increasing angle of attack does not directly resolve internal compressor airflow disruption.
- D. Bleed air alone is not the primary corrective action for an active stall.
Compressor Stall
A disruption of smooth airflow through the compressor, causing pressure surges, loud banging, vibration, and increased EGT, often due to distorted inlet airflow or excess fuel flow.
- Caused by FOD, damaged blades, or rapid throttle movement
- Symptoms include bangs, vibration, and EGT rise
- Corrected by reducing throttle/fuel flow
Memory trick: 'Stall? Pull it back!' - reduce throttle to fix a stall