What happened
Prior to departing on a scheduled ferry flight, both previously damaged propellers on the aircraft were removed and replaced. During this process, an incorrect propeller was installed on the left position by an individual whose mechanic's certificate had been revoked. The aircraft departed with full fuel tanks, all gears braced down, and no radios onboard.
While flying in formation with another airplane after takeoff, the pilot used hand signals to indicate a need to land. The pilot executed a landing in a field without using flaps. After rolling approximately 300 feet, the airplane became airborne and subsequently collided with several trees.
The investigation
Post-accident examination of the aircraft revealed that the right propeller was in the feathered position. An inspection of the fuel vent system showed that all recovered fuel vents were blocked; specifically, an insect resembling a wasp was discovered within a section of the left fuel vent line.
An examination of the engines, propellers, and flight controls showed no evidence of mechanical malfunction or failure prior to the impact. However, the No. 1 top spark plug of the left engine was found to be missing. Additionally, the permanent maintenance records lacked an entry confirming that the airplane had been inspected and deemed safe for the intended ferry flight.
Findings
- The pilot's airman certificate had previously been suspended for 180 days in February 1996 due to operating an aircraft with incorrect propellers installed.
- An incorrect propeller was installed on the left side of the engine by a person with a revoked mechanic's certificate.