Flameout

In aviation a flameout refers to the run-down of a jet engine caused by the extinction of the flame in the combustion chamber. It can be caused by a number of factors, including fuel starvation, compressor stall, insufficient oxygen (at high altitudes), foreign object damage (such as caused by birds, hail or volcanic ash), severe inclement weather, mechanical failure and very cold ambient temperatures.

A flameout is believed to be most likely to occur when flying through certain weather conditions at a low power setting such as flight idle (e.g. during the descent). These conditions include flight through moderate to heavy turbulence, rain, hail or sleet. The potentially hazardous circumstances are highlighted in the flight manual with a requirement to select continuous ignition. Alternatively, the FADEC engine controller will select ignition automatically if it detects specific changes in engine parameters. It will also perform a relight if necessary. A manual re-light attempt is made by following the procedure in the Flight Operations Manual.

Early jet engines were prone to flameout due to disturbances of inlet air, caused from gas ingestion. Fast acceleration or inappropriate throttle settings could also impoverish the fuel/air mixture causing a flameout or an excessive jet pipe temperature. However, if the throttle movements are made smoothly and not too rapidly, there was little or no risk of flame extinction. If this happened at low altitude, it would often lead to the total loss of the aircraft. However, jet engines were developed to be controlled with a governor, a centrifugal feedback valve for controlling the speed of the engine - sometimes referred to as FCU (Fuel Control Unit) or HMU (Hydro-Mechanical Unit) - allowing controlled fuel metering proportional to the engine's rotational speed. Current modern engines are engineered to a higher degree of technical quality controlled by digital electronic systems (FADEC) that constantly fine-tune their performance; thus such flameouts are not as common as they were in the early days of jet-powered aviation.

...
Wikipedia