1 fatality

2007-01-09: Cessna 207 Skywagon/Stationair (N9941M) — Air Supply Alaska — Cook Inlet, United States of America

Cook Inlet, United States of AmericaFlight

On January 9, 2007, a Cessna 207 Skywagon/Stationair (registration N9941M) operated by Air Supply Alaska was involved in an aviation accident near Cook Inlet, United States of America in flight. One person was killed. Investigators recorded the probable cause as: The total loss of engine power during cruise flight due to the disintegration of engine bearings and the fracture of a connecting rod, which resulted in a ditching into ice covered ocean water. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781198364Data APIEditorial standards

A commercial pilot ditched a wheel-equipped airplane in ice-covered ocean waters after total engine power loss due to bearing disintegration and connecting rod fracture. The pilot was not recovered.

Accident Details

The commercial certificated pilot prepared for a VFR cross-country nonscheduled cargo flight under 14 CFR Part 135. He preflighted the wheel-equipped airplane, which had been parked overnight with an electric engine heater and engine cover, then started the engine. After start, he contacted the company owner and reported that engine oil pressure appeared low but within operating range. They discussed possible reasons, including cold ambient temperatures of about -20°F. The pilot departed and reported to his company that engine pressure was good. About 10 minutes later, he declared an emergency and stated he was ditching in the water about 18 miles west of the departure airport.

Retrieved track data from the pilot's GPS showed the airplane's maximum altitude was 1,439 feet msl while crossing ocean waters in an area about 22 miles wide. A review of the manufacturer's maximum glide distance chart indicated that from about 1,500 feet, the airplane could glide approximately 2.1 nautical miles.

Engine Examination

The airplane was located about two hours after the accident, floating nose down next to a segment of pan ice, about 8.8 miles from the initial accident location. The pilot was not recovered, and subsequent searches did not locate him. Following recovery, examination of the engine revealed an 8x5-inch hole in the top of the case adjacent to the number 2 cylinder. The number 2 connecting rod was broken from its crankshaft journal and from the bottom of the piston. The number 1 connecting rod bearing was missing from its normal position, and the rod showed evidence of high heat. Evidence of oil starvation and high heat signatures to several crankshaft and connecting rod bearings was found throughout the engine, along with fragmented bearing material.

Survival Factors

The pilot was not wearing any personal flotation equipment. The expected survival time in the 29°F ocean water was about 30 minutes. The company's operations manual did not contain a written policy requiring pilots to maintain sufficient altitude to reach shore when crossing ocean waters.

Probable cause

The total loss of engine power during cruise flight due to the disintegration of engine bearings and the fracture of a connecting rod, which resulted in a ditching into ice covered ocean water. Factors contributing to the survivability of the accident were the pilot's improper decision to fly over frigid water without sufficient altitude to reach a suitable landing area, the lack of written policy and procedures by the operator requiring sufficient altitude to reach shore when crossing ocean waters, temperature extremes consisting of sub-zero air and below freezing water temperatures, and the lack of personal flotation/survival equipment.