History of Flight
On September 28, 2015, about 1320 Pacific daylight time, a Cessna 150F, registration N8529G, sustained substantial damage after an emergency landing and collision with terrain following a loss of engine power during initial climb. The airplane was departing Jefferson County International Airport (0S9) in Port Townsend, Washington, runway 27, about 1315, en route to Skagit Regional Airport (BVS) in Burlington, Washington. The commercial pilot and sole passenger were seriously injured. Visual meteorological conditions prevailed for the personal flight conducted under 14 CFR Part 91; no flight plan was filed.
The pilot reported that shortly after takeoff, reaching an altitude of about 600 feet above ground level, the engine emitted a loud popping noise and ceased operating. Attempts to restart the engine by priming were unsuccessful; the pilot had no further memory after the restart attempt.
Three witnesses provided statements. One observed the airplane climbing with normal engine sound, then the engine cut followed by a backfire and two crash sounds. A second witness heard engine trouble, a backfire, then silence, with a crash about two minutes later. A third witness saw the airplane flying low, listing left, with no engine noise, then heard a loud crash. At the scene, both occupants were conscious, and the pilot expressed confusion about the event.
The airplane came to rest in trees about 20 feet north of the 17th hole tee box at Discovery Bay Golf Course, approximately 1.15 nautical miles northwest of the departure end of runway 27. Impact damage was sustained to both wings, the engine and propeller, and the cabin/cockpit areas.
Personnel Information
The pilot, age 69, held a commercial pilot certificate with single-engine land, multiengine land, single-engine sea, and instrument airplane ratings. He reported 3,000 total flight hours, with 2,000 hours in the same make and model as the accident airplane, and 20 hours of multiengine time. In the preceding 90 and 30 days, he had flown 20 and 1 hour respectively. His most recent flight review was on September 8, 2014. A third-class FAA medical certificate was issued on August 11, 2015, with the limitation: "Must have available glasses for near vision."
Aircraft Information
The accident airplane was a Cessna 150F, serial number 15062629, a two-place, single-engine, high-wing aircraft with fixed tricycle landing gear. It was powered by a 100-horsepower Continental Motors O-200-A engine, serial number 62418-5-A. The airplane received a standard airworthiness certificate in the utility category in December 1965.
Maintenance records showed the most recent annual inspection was completed on January 9, 2015, at an airframe total time of 2,383.4 hours and tachometer time of 51.4 hours. The engine had been overhauled at a tachometer time of 49.0 hours; the logbook entry included a handwritten date of 9-5-13 and tachometer time of 28.0 hours, with total time 2,332.0 hours. The pilot reported 41.4 hours on the engine since overhaul.
Engine Examination
Postaccident examination revealed that four crankshaft gear bolts had sheared, and the accompanying gear's dowel pin had failed due to a fatigue fracture. The airframe and powerplant mechanic who performed the overhaul stated he used a calibrated torque wrench and the Continental O-200 Overhaul Manual (dated January 1984). He opined that the bolt failure resulted from sudden engine stoppage upon tree impact and was not the cause of the accident; he suggested carburetor ice as a possible cause for the power loss, noting the pilot had waited about 30 minutes for fog to clear.
Detailed inspection of the engine disclosed no preimpact anomalies except the sheared bolts and dowel pin. The carburetor needle valve occasionally stuck in the full up position. The oil screen contained significant metallic debris and a black substance. Cylinder attachment nuts lacked torque seal; black sealant was found in oil galleys. Of the four crankshaft gear bolts, two exhibited fatigue fractures, while two showed overstress fractures.
Meteorological Information
At 1315, the weather at Oak Harbor Airport (OKH), about 14 nautical miles northeast of the accident site, reported wind from 340° at 8 knots, visibility 10 miles, sky clear, temperature 17°C, dew point 9°C, and altimeter 30.05 inches of mercury. According to the carburetor icing-probability chart, moderate icing could be expected at cruise power and serious icing at descent power under those conditions.
Wreckage and Impact
The airplane's wings struck trees at the 40-foot level on a heading of north. The propeller and engine then impacted head-on with a 28-inch-diameter tree at the same height. The airplane rotated about 90 degrees left and fell vertically to the ground, coming to rest upright in a densely wooded area. The forward fuselage and both wings were substantially damaged; the aft fuselage and empennage sustained minor damage. No postcrash fire occurred. Control continuity was confirmed, and flaps were in the up position.
Probable Cause
The official investigation did not state a probable cause.