Detonation
What is detonation?
Detonation is the sudden, explosive (rather than smooth, controlled) burning of the fuel-air mixture inside an engine cylinder, occurring when that mixture reaches its critical pressure and temperature. It produces very high cylinder head temperatures and a loss of engine performance, and is most likely at high power settings—commonly caused by using a fuel grade lower than specified, high manifold pressure paired with low engine rpm, or generally excessive power. Think of it as the fuel "exploding" all at once instead of burning evenly—like engine "knock" in your car.
Also known as: knock, engine knock
Studying for an FAA written test?
Terms like detonation show up on the FAA knowledge test. Study them in context with ACS-aligned practice questions, AI explanations, and the cited FAA handbook reference behind every answer — free to start.
Learn more in the library
Related terms
- decompression sickness
- delamination
- density altitude
- departure procedure
- dew point
- differential ailerons
- dihedral
- direct entry