NTSB

Probable cause: An impact with terrain for reasons that could not be determined based on the available information.

Probable cause: Maintenance personnel’s improper installation of the muffler attachment hardware, which resulted in the muffler separating in flight, thermal damage that interrupted the magnetos’ function, and the subsequent total loss of engine power.

Probable cause: The inability of the pilot of the Piper and the student pilot and flight instructor of the Diamond to see and avoid the other airplane. Contributing to the collision was the Piper pilot’s failure to use the correct common traffic advisory frequency to announce his airplane’s position.

Probable cause: Fatigue failure of the No. 1 cylinder intake valve, which resulted in the loss of engine power.

Probable cause: The accumulation of carburetor ice before takeoff, which resulted in a partial loss of engine power on initial climb and a forced landing on unsuitable terrain.

Probable cause: The total loss of engine power for reasons that could not be determined based on the available evidence.

Probable cause: A fuel leak from the carburetor float bowl due to a missing plug, which resulted in excessive fuel consumption and a total loss of engine power due to fuel exhaustion. Contributing to the accident was the pilot’s decision to depart on the accident flight leg after noting the airplane’s unexpectedly high fuel consumption during the previous leg.

Probable cause: The pilot’s improper hand propping procedure, which resulted in a runaway airplane and subsequent impact with a hangar.

Probable cause: The pilot’s improper fuel management, which resulted in a total loss of right engine power due to fuel starvation; the pilot’s inadequate flight planning; the pilot’s failure to secure the right engine following the loss of power; and his failure to properly configure the airplane for the go-around, which resulted in the airplane’s failure to climb, an exceedance of the critical angle of attack, and an aerodynamic stall.