What causes detonation at high power settings?

Detonation in an aircraft engine refers to an uncontrolled, explosive combustion of the air-fuel mixture within the cylinders, which can cause significant engine damage if it occurs regularly. At high power settings, the engine experiences higher pressures and temperatures, making it more susceptible to this condition.

The correct option reflects how detonation is characterized by the rapid and uncontrolled increase in pressure and temperature that leads to the fuel mixture exploding rather than burning smoothly and progressively. In a properly functioning engine, the combustion should occur in a controlled manner, allowing for efficient conversion of fuel into power. However, when detonation occurs, it disrupts this controlled burn, leading to spikes in pressure that can damage engine components.

Understanding the nature of detonation is important for pilots and instructors, as it emphasizes the need for careful monitoring of engine settings and mixture management, especially during high power settings, to prevent potential damage and enhance engine performance.