What happened
While cruising at 2,000 feet in instrument meteorological conditions, the pilot reported a failure of the artificial horizon. Approximately five minutes after this transmission, air traffic control lost both radar tracking and radio communication with the aircraft. A witness positioned roughly one mile north of the crash site reported hearing a continuous, loud engine noise originating from the water for approximately 30 seconds, which was immediately followed by a sound resembling an explosive impact. Due to heavy fog, the witness was unable to visually confirm the source of the noise.
Search efforts later located the wreckage in water approximately 25 feet deep. The debris field spanned an area between 150 and 200 feet. Recovered components included both engines, portions of the fuselage, the empennage, seats, interior elements, and parts of the left wing. Notably, the aircraft's attitude indicator was not among the recovered items.
Findings
Investigation of the recovered components showed that the left and right vacuum pumps were functioning correctly and showed no signs of mechanical failure. However, a physical impression on the vertical speed indicator needle suggested a descent rate between -2,500 and -3,000 feet per minute. The loss of the artificial horizon was the primary reported issue prior to the loss of contact.