Background
The aircraft, a Cessna 421, had been abandoned in the Bahamas for approximately 7 months. A pilot, who had no known flight time in a Cessna 421, flew it to Fort Lauderdale, Florida.
Flight
Except to avoid clouds, the pilot made the flight at a low altitude and airspeed. When asked why, he said he was trying to save the engines. The pilot then departed toward an area of dark clouds and thunderstorms. Radar data showed the aircraft made several heading changes and was returning to the departure airport before it crashed.
Crash and Recovery
The aircraft was found 4 days later where it crashed in a steep nose-down attitude. The forward part of the aircraft was buried in a swamp, but the aft edges of the wings, fuselage, and empennage were visible above water. The propellers showed rotational damage. No preimpact mechanical failure or malfunction was evident.
Examination
Examination of the right engine revealed that its #2 pushrods and rocker arms/shafts/retainers had been removed before flight. Also, a #2 spark plug was stowed with its ignition lead attached. The aircraft owner was not found.
Pilot Background
The pilot's medical certificate was dated May 28, 1985.
Probable Cause
The official findings attribute the accident to three occurrences: first, an in-flight encounter with weather during cruise, with findings including failure to follow procedures/directives, operation with known equipment deficiencies, flight into known adverse weather (thunderstorms, clouds, unfavorable wind); second, loss of control in flight due to airspeed not maintained and inadvertent stall; and third, uncontrolled descent resulting in collision with water. Contributing factors include the pilot's lack of familiarity with the aircraft and lack of total experience in that aircraft type.