Incident Overview
On a ferry flight from Oakland, California, to Honolulu, Hawaii, the pilot declared a low fuel emergency and altered course toward Hilo, Hawaii. About 2.5 hours later, the aircraft was ditched in the Pacific Ocean. The pilot evacuated the aircraft before it sank and was subsequently rescued by the U.S. Coast Guard.
Flight Details
The pilot stated that, under flight planned conditions, the aircraft departed Oakland with sufficient fuel to reach the intended destination with a 2-hour reserve. However, winds at flight altitude, which had been reported as light and variable during the preflight weather briefing, developed into a significant headwind during the flight. At a point 7 hours and 10 minutes into the flight, the pilot calculated that fuel remaining was 8 hours and 40 minutes, with 7 hours and 40 minutes remaining to destination. Three hours later, the pilot determined that the 2-hour reserve was depleted. He declared an emergency and diverted to the nearest airport, Hilo. Prior to fuel system exhaustion, the pilot elected to ditch the aircraft while the engines were still producing power.
Rescue
After ditching, the pilot evacuated the aircraft before it sank. He was rescued by the U.S. Coast Guard.
Probable Cause
The official probable cause is the pilot's inadequate en route fuel consumption calculations, which led to his failure to recognize a deteriorating fuel duration versus time-to-go situation in a more timely way.