MIA99LA122

While descending to land at the destination airport, the engine lost power. The pilot was able to maintain some engine power by moving the throttle in and out. While attempting a forced landing on a road, the flight encountered a truck and had to pull up. The right wing collided with power lines, the airplane crashed onto the road, slid off the road, and collided with trees. The pilot estimated there was 10 gallons of fuel remaining after the accident. Examination of the carburetor after the accident showed the inlet fuel screen was blocked about 50 percent with fiberglass debris, however there was no evidence of precrash mechanical failure or malfunction of the carburetor. The engine was operated to full power after the accident using the accident carburetor and with the carburetor fuel inlet screen blocked 50 percent. There was no evidence of failure or malfunction of the engine.

On April 11, 1999, about 1414 central daylight time, a Glenn H. Harris Vari-Eze, N250GH, registered to an individual, crashed while attempting a forced landing following loss of engine power, near Eufaula, Alabama, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was destroyed and the private-rated pilot received serious injuries. The passenger received minor injuries. The flight originated from Covington, Tennessee, the same day, about 1230.

The pilot stated that while in descent for landing at the Eufaula Airport, the engine lost power. He was able to maintain some engine power by moving the throttle control back and forth. He could not make the airport and decided to land while he still had some engine power. While attempting a forced landing on a road, they encountered a truck. They attempted to climb over the truck, at which time the right wing collided with power lines and the winglet separated. The aircraft then crashed back on the road, went off the road, and collided with trees, where the right wing separated and the aircraft came to rest. At the time of the accident he estimated he had more than 10 gallons of fuel remaining.

After the accident the carburetor was removed from the engine and taken to a overhaul facility by an FAA inspector. The inlet strainer screen was found to be partially blocked with a foreign substance. No evidence of precrash mechanical failure of the carburetor was noted. (See Consolidated Fuel Systems, Inc. Report.)

Examination of the carburetor inlet strainer screen and the foreign substance in it was performed by the NTSB Materials Laboratory, Washington, D.C. About 1/2 of the inlet screen was blocked by a white deposit. The deposit consisted of a mixture of very fine white particles and long translucent fibers. The fibers had characteristic peaks for silicon, calcium, aluminum, and oxygen, consistent with glass fibers. Several clumps of fibers were found embedded in the white material consistent with a fiberglass composite. (See Materials Laboratory Factual Report.)

After the accident the engine was installed on a engine test stand in the presence of an FAA inspector. Another carburetor was installed and the engine was operated using an electric fuel boost pump. No evidence of mechanical failure or malfunction was noted. The engine was operated a second time with only gravity fuel feed. The engine again operated normally. The mechanic who conducted the engine run for FAA also examined the fuel strainer bowl from the aircraft at the request of NTSB. A very small amount of fiberglass debris was found in the strainer. (See FAA inspector statement and Mechanic statement.)

Under NTSB supervision, the carburetor installed on the engine at the time of the accident was reassembled using another top portion to replace the top portion damaged in the accident, and an unobstructed fuel inlet screen. This carburetor was installed on the engine along with a wooden propeller from a Long-Eze aircraft. The engine was started and operated to 2,500 rpm, using a gravity feed fuel system, with no evidence of failure or malfunction. A fuel inlet screen with a 50 percent blockage was installed in the carburetor. The engine was again started and operated to 2,500 rpm, using the gravity feed fuel system, with no evidence of failure or malfunction. Examination of the aircraft's fuel system by NTSB showed no fuel pickup, fuel line, or fuel vent line obstructions.