NTSB Factual Report

HISTORY OF FLIGHT

On July 23, 2009, at 1915 Pacific daylight time, a Cessna 150H, N22278, impacted trees and terrain shortly after takeoff from a private airstrip approximately 7 miles east of Washougal, Washington. The private pilot, the sole occupant and owner of the airplane, sustained serious injuries. The airplane sustained substantial damage to the wings, tail and fuselage during the impact sequence. The flight was operated as a personal flight under the provisions of 14 Code of Federal Regulations (CFR) Part 91. Visual meteorological conditions (VMC) prevailed and no flight plan was filed. The local flight departed from the pilot's private airstrip shortly before the accident.

The pilot reported to first responders at the accident site that the airplane's engine developed a problem during the initial climb after takeoff. He was unclear as to the nature of the problem. In a subsequent written statement to NTSB, the pilot stated that "immediately" after takeoff the engine lost power. The airplane's left wing then struck a large tree and subsequently crashed into wooded terrain.

Several witnesses adjacent to the accident site reported seeing the airplane during its initial climb and subsequent collision with trees and terrain. One witness stated the airplane was flying "too low" and clipped several branches followed by a "pop" sound. Another witness stated the airplane banked left after colliding with the tree and descended into a wooded area. A third witness stated the airplane struck the trees in a "weed whacker fashion" and the propeller sound changed noticeably after colliding with the tree. The witness stated the engine noise increased just before the airplane banked and pitched over.

PERSONNEL INFORMATION

The pilot, age 78, held a private pilot certificate for airplane single-engine land and a Federal Aviation Administration (FAA) third-class airman medical certificate issued on May 21, 2008. The pilot reported 2,500 total flight hours with 600 hours in the accident model airplane.

AIRCRAFT INFORMATION

The two-seat, high-wing, fixed-gear airplane was manufactured in 1968 and powered by a Continental O-200 engine. Review of copies of maintenance logbook records showed an annual inspection was completed in March 2008. At the time of the accident, the airframe total time was 13,051 hours, the engine total time was 9,629 hours; 954 hours since major overhaul.

TESTS AND RESEARCH

On August 31, 2009, the airplane wreckage and engine were examined at the pilot's hangar facility.

The engine and mounting assembly was removed from the main wreckage and suspended from a hoist. Impact related damage was noted to the exhaust system, ignition leads and cylinder numbers 1 and 3. The alternator, both magnetos, vacuum pump, and starter remained attached to the engine and were undamaged.

The top ignition leads and spark plugs were removed. The electrode areas were oil soaked and extensive wear was noted to the ground and center electrodes. When compared to the Champion Check-A-Plug comparison card, all top spark plugs exhibited "worn out – severe" operating signatures.

The cylinder rocker arm covers were removed; the overhead components were lubricated and undamaged. The cylinders were examined internally utilizing a lighted borescope. Light grey combustion deposits and residual oil was observed in all of the cylinder combustion chambers. The engine crankshaft was rotated manually and valve train continuity was noted to all cylinders and gears, and both magnetos produced spark to all ignition lead ends. Cylinder compression was obtained for number 1, 2 and 3 cylinders. It was noted that the number 4 cylinder exhaust valve was stuck in the open position when the engine crankshaft was rotated. The cylinder was removed and examined. The valve remained stuck in the open position and was removed utilizing a punch and heavy hammer. A dark brown material and smearing was noted along the exhaust valve neck. Comparable material and smearing was observed along the interior surface of the exhaust valve guide.

The carburetor was undamaged and removed from the engine. The fuel inlet screen was clear and no debris was noted. The carburetor was disassembled; the floats and internal components were undamaged and no mechanical anomalies were noted. No fuel was observed in the carburetor float bowl and associated fuel lines.

Examination of the airframe revealed that the fuel primer was not latched and was observed in the unlocked position with its shaft extended beyond the locking collar. The fuel selector handle and valve were found in the “ON” position. No additional mechanical anomalies were noted with the airframe.

An unknown quantity of fuel was found in the right fuel tank at the time of the examination. First responders reported that there was a strong odor of aviation gasoline at the accident site when they arrived. Extensive impact related damage was noted to both wings and associated fuel system.

NTSB Probable Cause

A loss of engine power during initial climb due to a stuck exhaust valve.