Flameout refers to which engine condition?

• A. A condition in the operation of a gas turbine engine in which the fire in the engine goes out due to too much or too little fuel sprayed into the combustors.
• B. A visual flame on the engine nacelle.
• C. A combustion instability phenomenon.
• D. A flameout occurs when the fuel supply is perfectly balanced.

Answer: (A)

Flameout is when the combustor flame in a gas turbine engine goes out because the fuel-air mixture is outside the flame's allowable range. If the fuel is sprayed in either too much (rich) or too little (lean), the flame can no longer be sustained, causing a loss of combustion and thrust. It’s not about a flame on the nacelle, nor about a general combustion instability. And a perfectly balanced fuel supply would normally keep the flame burning, not extinguish it.