What is detonation in an aircraft engine?

Detonation in an aircraft engine refers to the occurrence of fuel in the cylinders exploding instead of burning in a controlled manner. In a properly functioning engine, the fuel-air mixture ignites progressively, allowing for a smooth and steady increase in pressure during the power stroke. However, during detonation, the fuel ignites prematurely or too aggressively, leading to a rapid increase in pressure and temperature. This can cause shock waves within the cylinder, resulting in a destructive force that can damage engine components, such as pistons and cylinder heads.

Understanding detonation is crucial for pilots as it can significantly affect engine performance and safety. Factors that can contribute to detonation include low octane fuel, high engine temperatures, high manifold pressure, and excessive engine load. Recognizing the signs of detonation and taking corrective action is essential to ensure safe operation of the aircraft.