What happened
During a long-distance cross-country flight, the pilot of a newly acquired aircraft was performing his first 700 nm journey in the plane. Approximately two hours after reaching a cruising altitude of 21,000 feet, the pilot notified air traffic control of an intention to divert. During the subsequent descent, the pilot reported that one engine was sputtering due to fuel issues. Shortly after, an emergency was declared as both engines began to sputter, with the pilot reporting only 15 total gallons of fuel remaining in the tanks.
A witness observed the aircraft traveling southbound with a noticeable side-to-side wing rocking motion before the plane rolled to the right and struck a citrus grove. This flight represented the pilot's first operation in this specific aircraft above 13,000 feet and was likely his longest intended flight since the purchase of the plane.
Findings
Investigations into the airframe found no evidence of any flight control or system component failures prior to the impact. Similarly, the power plant examination showed no mechanical failures in the engine's rotating or reciprocating components before the crash.
Evidence suggests that the aircraft was refueled while parked on a slope, with the left wing tip estimated to be 12 to 14 inches lower than the right. According to the Pilot's Operating Handbook and the FAA Type Certificate Data Sheet, the usable fuel capacity is dependent on the aircraft being level; the wing tanks are highly sensitive to attitude, and an unlevel state prevents the tanks from being filled to their full usable capacity. The improperly leveled refueling likely resulted in an inaccurate fuel calculation.