What happened
During a multi-engine certification check flight, the left engine was shut down and feathered. The designated pilot examiner instructed the applicant to restart the engine; however, the restart attempt failed. Following the unsuccessful restart, the examiner took control of the aircraft and initiated a return to the originating airport.
The applicant attempted manual gear extension procedures, but the position of the landing gear could not be verified. On final approach, the landing gear was not in the down and locked position. The examiner subsequently executed a go-around, but the airplane was unable to maintain its altitude. During the descent during the go-around, the aircraft impacted trees and terrain. A post-impact fire occurred, which destroyed the aircraft.
The investigation
Investigators found the landing gear in the retracted position and the left propeller in a feathered position. A metallurgical examination of the starter cable revealed areas of electrical arcing in the section passing through the wing root. When the left engine starter was energized using an exemplary cable, the starter successfully rotated the engine crankshaft.
Calculations determined the density altitude at 3,100 feet. According to the aircraft manufacturer, the single-engine climb capability for this aircraft type is -7 feet per minute when the landing gear is extended.