Flameout

Flameout is a term used in combustion systems to describe the cessation of a sustained flame in a combustor. In aviation, it most often refers to a jet or turbine engine losing continuous combustion, causing a reduction or loss of thrust.

Common causes include fuel delivery problems (for example, fuel starvation due to low pressure or a fault in the fuel control unit), contamination or icing of fuel, and faults in ignition or protection systems. Severe disturbances in the airflow, such as compressor surges or stalls, can also destabilize the flame. In multi-engine aircraft, flameout may occur on one engine while another continues to operate normally.

Detection and response: engine parameters such as exhaust gas temperature, rotational speed, and fuel flow indicate flameout. Pilots follow established restart procedures, attempting to reignite the flame by restoring fuel flow and enabling ignition, or, if ignition cannot be restored, by continuing flight with an engine-out procedure and preparing for a possible landing.

Prevention and consequences: flameout increases the risk of loss of aircraft performance and controllability, especially at low altitude or in critical phases of flight. Preventive measures include robust fuel systems and control logic, proper fuel management, avoidance of conditions that promote flame instability, and routine maintenance and testing of ignition and fuel systems.

Other usages: flameout is also used in rocketry and industrial combustion to describe loss of flame in a chamber due to fuel-oxidizer starvation or other destabilizing factors; restarting typically requires restoring the proper mixture and initiating ignition.