What happened
While operating under instrument meteorological conditions, the aircraft was tracked by radar performing a series of climbing and descending turns. During this sequence, the aircraft executed a final descending turn, after which it was no longer detectable on radar. The wreckage was located approximately 0.09 miles from the point of the last radar contact, at which time the aircraft was at an altitude of 2,000 feet above ground level.
Physical evidence at the crash site indicated that the aircraft struck the terrain while in a nearly 90-degree nose-down attitude.
Findings
An investigation into the wreckage, including the engines, propellers, flight controls, and various onboard systems, revealed no signs of mechanical malfunction or structural failure prior to the impact. The investigation found no evidence of pre-crash failure within the airplane's systems or components.