NTSB

Probable cause: The reciprocating engine’s exhaust valve being stuck in the “open” position, which resulted in a partial loss of engine power during initial climb.

Probable cause: Maintenance personnel’s failure to properly secure the vacuum pump, which resulted in a loss of engine oil and the subsequent total loss of engine power due to oil starvation.

Probable cause: The pilot’s loss of airplane control while conducting aerobatic flight maneuvers with insufficient altitude to recover.

Probable cause: The student pilot’s improper landing flare in gusting crosswind conditions, which resulted in a hard landing.

Probable cause: A partial loss of engine power due to fuel contamination from an undetermined source.

Probable cause: The loss of engine power for reasons that could not be determined because postaccident examination and testing of the engine did not reveal any anomalies that would have precluded normal operation.

Probable cause: The non-instrument-rated pilot’s improper decisions to begin and to continue a flight under visual flight rules into instrument meteorological conditions, which resulted in controlled flight into terrain.

Probable cause: The pilot’s improper in-flight fuel management and his failure to switch the fuel selector to the “both” position in accordance with the Before Landing checklist, which resulted in a loss of engine power due to fuel starvation.

Probable cause: The pilot’s decision to taxi the airplane from the road and his subsequent failure to maintain clearance from signs and a fence after a successful emergency landing following a total loss of engine power.