ANC03LA123

The private pilot reported the airplane was in cruise flight when he intentionally let the left fuel tank run dry, and the engine lost power. He said he allowed the tank to run until empty because he was attempting to determine the airplane's fuel endurance. After the engine stopped, he switched to the full right tank and restarted the engine. The engine ran without mishap for approximately 10 minutes, and then began to lose power. The pilot said he was unable to completely restore power, and ultimately the engine lost all power. He made a forced landing in trees, and the airplane received structural damage to the wings and fuselage. The airplane has not been recovered from the accident site due to its remote location. The pilot, who is also a certificated aviation mechanic, indicated he did not know why the engine lost power.

On September 23, 2003, about 1930 Alaska daylight time, a wheel-equipped Piper PA-18 airplane, N330T, received substantial damage when it collided with trees during an emergency landing following a loss of engine power while in cruise flight. The accident site was approximately 20 miles southwest of Nenana, Alaska. The solo private pilot/operator was not injured. The Title 14, CFR Part 91 personal flight operated in day visual meteorological conditions, and a VFR flight plan was in effect. The flight departed a remote site near Lake Minchumina, Alaska, about 1800, and was en route to Fairbanks, Alaska.

During a telephone conversation with the National Transportation Safety Board investigator-in-charge (IIC) on September 24, the pilot related that the airplane was in cruise flight at 5,500 feet, when the engine lost power due to fuel starvation. The pilot said he had deliberately allowed the left wing fuel tank to run dry to determine the airplane's fuel endurance. He said he immediately switched to the right tank, which was full, and the engine started again. He continued to fly for approximately 10 minutes without mishap, but shortly thereafter, the engine began to lose power. He said he initially thought he had carburetor ice, but the application of carburetor heat did not restore full power. The engine subsequently lost all power, but he was able to restore full power for a short duration by pumping the engine throttle. The engine lost power again, and he was able restore partial power by pumping the throttle. The pilot indicated the engine went through several sessions of power loss, and then restoration, by pumping the throttle, until the engine finally lost all power about 1,000 feet above the ground. He made an emergency descent in search of a suitable landing site, but was unable to find an area clear of trees. The airplane struck between two large trees, and collided with smaller trees during the descent, receiving structural damage to the wings and fuselage.

The IIC spoke with the pilot again on October 30. He said that the airplane has not been recovered from the accident site, nor inspected, due to its remote location. He said he is employed as a certificated aviation mechanic, but without further inspection of the airplane, he was unsure of why the engine lost power.