Accident Details
On April 15, 2009, about 1945 Pacific daylight time, a Raytheon Aircraft Company A36 single-engine airplane, registration N464TJ, was substantially damaged during a forced landing after a loss of engine power near Lopez Island, Washington. The airplane was operated by the private pilot under 14 CFR Part 91 for a personal cross-country flight. The pilot and three passengers were not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Snohomish County Airport (PAE), Everett, Washington, about 30 minutes prior to the accident, with an intended destination of Friday Harbor, Washington.
Flight and Engine Issues
According to the pilot's written statement, during preflight inspection he verified the fuel level and noted that the oil filler cap, when twisted off, showed mineral oil of different color and viscosity than normal. The oil level was one quart below the full mark. During the uneventful takeoff, the pilot remained briefly in the traffic pattern before proceeding. At 6,500 feet msl with propeller rpm set to 2,300 rpm, the pilot observed the rpm increase to 2,500 rpm and slowly rise to 2,600 rpm. He readjusted to 2,300 rpm, but the rpm again rose. He pulled the rpm lever fully back, but rpm continued to climb. He then pulled the throttle back, and both rpm and manifold pressure dropped.
The pilot turned toward Lopez Island and checked engine oil pressure and temperature. Subsequently, he heard a loud bang followed by a significant trail of white smoke over the windscreen and a loss of engine power. He initiated a forced landing to a nearby road with no traffic observed. During descent through about 50 feet agl, a vehicle turned onto the road traveling opposite his flight path. The pilot extended his approach, cleared the vehicle, and landed on the road. Due to telephone poles on the right, he aligned slightly left of center. During the landing roll, the left wing struck a street sign and then two or three large wooden fence posts hidden in blackberry brambles, spinning the airplane 270 degrees. The airplane came to rest upright on the road.
Post-Accident Examination
Examination by an FAA inspector revealed structural damage to both wings. The empennage was twisted and displaced to the right. The engine oil filler cap was unsecured from the oil filler neck; about one quart of oil remained in the sump. A hole was observed above the number four cylinder. The wreckage was recovered for further examination.
On May 27, 2009, an examination under NTSB supervision found three of four engine mounts separated. Two holes were observed in the crankcase above the number two and four cylinders. The left and right magnetos, vacuum pump, fuel pump, throttle body fuel control unit, and fuel manifold valve remained attached. The propeller governor remained attached but its two aft nuts were found loose, with multiple threads visible between nuts and governor. Oil residue was on the aft side of the propeller governor mount pad and seal, and around the number six push rod housings. The oil filler neck and cap were intact and undamaged. The oil pump was intact with metallic debris in the cavity and scratches on walls. The oil filter exhibited metallic debris internally.
The number five and six cylinders were removed, revealing extensive mechanical damage inside the crankcase and on skirts of cylinders one through five. Disassembly showed connecting rods for cylinders one and six intact; number five rod had thermal discoloration and mechanical damage; and rods for cylinders two, three, and four were separated from the crankshaft. Airframe examination located oil residue on the left engine cowling door, lower left engine cowling, left fuselage, and engine compartment.
Maintenance History
Engine maintenance logbooks showed the engine was disassembled and inspected due to a propeller strike on March 25, 2009, at an engine total time of 1,237.1 hours. An annual inspection was completed on April 7, 2009, at airframe total time 1,237.1 hours. A company work order dated April 7, 2009, stated in part: "Remove propeller and engine following prop strike on tow bar...reinstall engine, propeller, and governor following service..." at 1,237.1 hours. Using the HOBBS meter reading of 1,237.6 hours, the airplane had accumulated 0.5 hours total flight time since the engine installation and annual inspection. The pilot reported that the accident flight was the first flight following the annual and propeller strike inspections.