19990731017589A

(.19) On July 31, 1999, about 1630 Alaska daylight time, a wheel equipped avid flyer, an experimental, homebuilt airplane, N511AF, sustained substantial damage during a forced landing about 10 miles north of Anchorage, Alaska. The airplane was being operated as a visual flight rules (VFR) local personal flight when the accident occurred. The solo commercial pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight departed the lake hood airstrip, Anchorage, about 1400. During a telephone conversation with the national transportation safety board investigator-in-charge on August 1, the pilot reported that after departure from the lake hood airstrip, he completed a series of touch-and-go landings at two local area airstrips. He said that while returning to the lake hood airstrip, the engine began to run rough, and lose power. He said that for a short time, he was able to restore partial engine power by actuating the engine fuel primer. The pilot reported that while he was attempting to land on a small, private airstrip, all engine power was lost. He said that during the approach, the airplane landed short of the airstrip, and collided with a stand of trees. The main landing gear collapsed, and the airplane sustained substantial damage to fuselage. (-23) on July 31, 1999 at about 1630 hours adt wheel equipped avid flyer N511AF was involved in an emergency landing accident on an airstrip known as sleeper strip (put). The commercial pilot stated he could not maintain power on the engine. The aircraft received substantial damage on landing. (.4) the solo commercial pilot reported that during cruise flight the engine began to run rough, and lose power. He noted that for a short time, he was able to restore partial engine power by actuating the engine fuel primer. While attempting to land on a small, private airstrip, all engine power was lost, and the airplane collided with a stand of trees. An examination of the interior of the fiberglass fuel tanks revealed delamination of the resin material within the tank, and both main fuel tank outlets were blocked with a brown, plastic-like material. Examination of both in-line wing fuel filters revealed the presence of the same material found in the main fuel tanks. The pilot/owner stated that in the past, he had operated the airplane f or about 40 hours using an alcohol based fuel. Avid aircraft service letter number 03, dated 5/91, covering all avid flyer models, stipulates that a placard be placed near the filler neck stating, in part: 'no alcohol blended fuels. These fuels may cause deterioration of the fiberglass tanks or carburetor parts.' The pilot/owner stated that since he has owned the airplane, he has not received any warnings or directives concerning the use of alcohol based fuels directly from the manufacture of the airplane kit, avid aircraft, inc.