This March 2009 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Piper Cherokee. Injuries: None. Location: Sanford, Fla. Aircraft damage: Destroyed.
What reportedly happened: The student pilot, who was flying with a CFI, intended to make a stop-and-go landing. He used maximum wheel and aerodynamic braking to stop the airplane. After coming to a stop, both pilots realized that the engine had stopped running. After calling tower personnel and advising them of the situation, the instructor made four attempts to re-start the engine. After the final attempt, the pilots noticed smoke and flames coming from the engine compartment. The instructor moved the mixture control to idle cut-off, and exited the airplane.
There was fire damage to the engine and airframe, including firewall deformation. The fire appeared to originate in the induction system air box. Damage to the air box was consistent with a fuel-air explosion. During the course of the investigation the source of the original loss of power was not identified, nor was it definitively proven how the air box was damaged. However, flooding of the engine during repeated attempts to start the engine could have played a role in the accident. The operator’s maintenance personnel reported that the airplane did not have a history of engine problems.
Probable cause: An engine air induction explosion for an undetermined reason during repeated engine start attempts.
For more information: NTSB.gov