SEA98LA014

On November 15, 1997, about 1435 Pacific standard time, N1668P, a Piper PA-18-150, operated by the owner/pilot, collided with trees during a forced landing and was substantially damaged near Battle Ground, Washington. The forced landing was precipitated by a loss of engine power during initial climb after takeoff. The private pilot was seriously injured and his passenger received minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight was conducted under 14 CFR 91.

According to interviews of the pilot that were conducted by the Safety Board (records of interview attached), the pilot stated that on the day of the accident, he departed from his private grass airstrip in Battle Ground and flew to Evergreen Field in Vancouver, Washington, to refuel. He stated that he shut down the airplane when he reached the fuel pump, and he "topped off" both wing fuel tanks himself. He then started the engine without difficulty, and departed from Evergreen Field without performing an engine "run-up." He stated that he then landed back at his grass airstrip, taxied to the end of the strip, and shut down the engine.

The pilot stated that he then boarded his passenger and started the engine after using the engine fuel primer once or twice. He stated that he could remember locking the primer in place after using it. After the engine was started, he took off. As he was climbing about 300 feet per minute, "the fire went out" and the engine "stopped dead." He stated that it did not sputter or cough, it just "went dead."

The pilot stated that he did not attempt to restart the engine, other than moving the fuel selector valve. He stated that he immediately moved the control stick forward to get the nose down. He also remembered that he moved the fuel selector valve from what he thought was the left tank position to the right tank position. He was shown a diagram during the interview of the fuel selector, and indicated that the pointer was the small triangular-shaped pointer opposite of the longer handle (which is the correct indication for the fuel selector).

The pilot further stated that he did not attempt to perform a 180-degree turn, and instead headed toward a clearing in the trees. The airplane struck a tree and this was the last thing that he remembered.

According to a Federal Aviation Administration (FAA) aviation safety inspector from Hillsboro, Oregon, the airplane impacted trees and terrain about 3,000 feet northwest of the departure airstrip. The surrounding terrain was rolling and heavily wooded. The right wing was substantially damaged. Both fuel tanks were about three-quarters full. No evidence of fire was noted. No baggage was found aboard the airplane.

According to the Clark County Sheriff's Office report of the accident (attached), the pilot, who was seated in the front seat, was wearing a four-point seat restraint system at the time of the accident. The passenger, seated in the rear, was wearing a lap belt. The rear seat was not equipped with a shoulder harness. The fuel selector valve was placed in the off position during rescue. The wreckage was removed under the direction of the Safety Board for future examination.

On November 25, 1997, the wreckage underwent additional examination by the Safety Board. The examination revealed substantial impact damage to both wings, all lift struts, cabin area, firewall, engine, and propeller. No evidence of a preimpact flight control system malfunction was found. The flaps were found in the retracted position. Pieces of evergreen branches were imbedded into the right wing tip. The airplane had been modified with the installation of a Lycoming O-360-A3A 180-horsepower engine, tundra tires, and an extended baggage compartment.

Examination of the cockpit instruments revealed that the tachometer time read 1,642.47 hours. The engine fuel primer was found about halfway in the open position and was not locked. The throttle and mixture controls were in the full forward position, and the carburetor heat was in the off position.

The engine remained attached to the airframe by its mounts. The fixed pitch propeller remained attached to the crankshaft and exhibited aft bending and leading edge scoring on one of its two blades. The other blade did not exhibit any notable deformation. Crankshaft and camshaft continuity to the rear engine-driven accessories and all valves was confirmed by manually rotating the propeller. The crankshaft rotated freely and valve action was observed on all valves. Both magnetos remained attached to the rear engine mounting location and did not appear damaged. The left magneto was tested and found to produce a spark on all four leads when manually rotated. The right magneto could not be accessed for testing; it was crushed aft into the firewall. All top spark plugs were removed and examined; they were all gray in color and exhibited oval shaped electrodes. The carburetor bowl was found to contain a liquid that was similar in color, texture, and odor to 100 low lead aviation gasoline. No preimpact mechanical malfunctions were found during the examination of the engine.

The Safety Board removed the airplane's ignition switch and sent it to Teledyne Continental Motors in Atlanta, Georgia, for examination and testing. The examination and testing occurred on December 3, 1997, under Safety Board supervision (report attached). No malfunctions or anomalies were found.

Examination and functional testing of the fuel selector valve in-situ revealed that it was installed 90 degrees counter-clockwise form the correct position of the valve stem. With the fuel selector handle in this position, it was determined through the application of airflow into the fuel lines that the fuel selector was actually feeding from the right tank when the pointer was reading LEFT. When the pointer was selected such that it indicated the OFF position, the selector was feeding from the left tank. When the pointer was selected to such that it indicated the RIGHT position, the valve was actually in the off position. When the selector handle was rotated during the testing, no detents could be felt as the selector was changed from one position to another (Diagrams of correct versus in-situ fuel selector valve operation are attached).

The selector valve was then removed for further examination by the Safety Board. The valve itself was undamaged and remained intact. Functional testing with the use of air into each port of the valve revealed similar results to the in-situ findings that verified an incorrectly installed handle assembly. The valve stem was noted to be square in shape and did not exhibit the D-shape found on the back side of the handle.

The valve itself was then disassembled one piece at a time. The disassembly revealed that the spring retaining washer was incorrectly installed upside down, which prevented the spring from applying pressure onto the slotted detent washer. With the valve assembled in this fashion, the detent feature of the valve was eliminated.

Examination of the airframe records (excerpts attached) revealed an entry, dated January 15, 1997, that indicated a new O-ring was installed in the fuel selector valve. This is the most recent entry of work being performed on the valve that would have required some disassembly of it. The entry also cited compliance with FAA Airworthiness Directive 60-10-08 (excerpt attached) which pertains to checking the detent function and correct rigging of the valve such that the pointer is properly aligned to the placarded fuel tank locations. The entry further states that the detents in the valve were "OK."

The records indicate that the airplane and engine received an annual inspection on the same date of the fuel selector O-ring change. The entry indicated that the tachometer time read 1,611.40 hours (31.07 hours before the