Primary finding
Probable cause
The loss of engine power in one engine for undetermined reasons. A factor in the accident was the aircraft's diminished single engine performance during the early portion of the overweight ferry flight.
Investigator assessment
Analysis narrative
The aircraft was being operated on a trans-Pacific ferry flight. A special flight permit authorized a gross weight increase and ferry fuel tanks had been installed along with long range communication and navigation radios. The pilot reported that when 85 miles from the departure airport, the right engine failed and he was unable to restart it. Power from the remaining engine was insufficient to maintain level flight at the overweight condition and the pilot permitted the aircraft to drift down until it was necessary to ditch in the ocean 28 miles offshore. The pilot had departed and returned to Hawaii twice previously. The first time he returned due to an oil leak on the left engine, and the second time because of a loose window. A mechanic who repaired the window reported that the left engine appeared to still be leaking oil. Both pilots told the FAA inspector that the oil leak had been repaired.
Source record
Factual narrative
On April 10, 1997, at 0706 hours Hawaiian standard time, a Piper PA-31-350, N27659, was destroyed when it ditched in the Pacific ocean, 30 miles northeast of Hilo, Hawaii, following loss of power in one engine. The aircraft departed Hilo on a VFR flight plan at 0546. The ferry flight was destined for Hayward, California, and visual meteorological conditions prevailed. Both of the airline transport pilots were not injured. The aircraft was being operated on a special (ferry) flight permit which authorized a gross weight increase to 9,500 pounds. Ferry fuel tanks had been installed, along with long range communication and navigation radios. The pilot reported that when 85 miles northeast of Hilo, the right engine failed in a slow, gradual loss of power, and he was unable to restart it. He feathered the propeller, declared an emergency, and reversed course. Power from the remaining engine was insufficient to maintain level flight at the overweight condition, and he permitted the aircraft to drift down until he ditched in the ocean 28 miles offshore. He and the other pilot evacuated the aircraft into life rafts, the aircraft sank, and they were rescued by Coast Guard helicopters about 2 hours later. The location of the ditching was latitude 20 degrees 05.34 minutes north, and 154 degrees 40.04 minutes west. According to inspectors from the FAA Honolulu Flight Standards District Office, the pilot had departed and returned to Hawaii twice previously. The first time he returned due to an oil leak on the left engine, and the second time because the pilot's openable window was "coming off". A mechanic who repaired the window reported that the left engine appeared to still be leaking oil. Both pilots told the FAA inspector that the oil leak had been repaired. -