What steps should be taken if detonation or preignition is detected?

When detonation or preignition is detected in an aircraft's engine, the most prudent course of action is to land as soon as practical. Detonation, which occurs when fuel-air mixture in the cylinder detonates uncontrollably, and preignition, which happens when the fuel-air mixture ignites before the spark plug fires, can lead to severe engine damage if not addressed.

Prompt action is necessary because these conditions could lead to engine failure, posing a significant safety risk to the flight. Continuing to fly while monitoring engine performance is not advisable, as it does not resolve the underlying problem and risks further engine damage or failure.

Increasing altitude to cool the engine may not address the root causes of detonation and preignition, especially since altitude changes can affect engine performance due to reduced air density. Switching to a higher grade of fuel could mitigate the issue, but such a change is not an immediate solution in-flight and cannot be accomplished without landing the aircraft first.

Thus, prioritizing a safe landing ensures that the pilot can address the problem properly and prevent potential hazards related to engine performance.