N613HHWright William V AVID FLYER

On April 1, 2011, about 1045 mountain daylight time, a William Wright Avid Flyer, N613HH, collided with trees during an off airport forced landing following a loss of engine power on takeoff from a strip near Cedar City, Utah. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot was not injured; the airplane sustained substantial damage to the wings from impact forces. The local personal flight was departing with a planned destination of Cedar City. Visual meteorological conditions prevailed, and no flight plan had been filed.

The pilot stated that he departed Cedar City on a local test flight after restoring the airplane. He flew for approximately 1 hour, performing both maneuvers and touch-and-go takeoffs and landings. He returned to the airport, and picked up another pilot for a familiarization flight.

About 1/2 hour into the second flight, the engine sputtered and lost power. The pilot made an emergency landing on a landing strip for radio remote controlled airplanes. He performed some troubleshooting, and determined that fuel was not getting from the header tank to the engine. He was successful in getting the fuel flowing again. He ran the engine for about 30 minutes on the ground, and performed a successful run up. The pilot decided to leave his passenger at the strip, and fly home alone. He planned to return by car to pick up the passenger.

The pilot departed the strip, and reported that the engine ran well until about 200 feet above ground level (agl). The engine then lost all power, and he glided the airplane into 15-foot-tall trees. He was wearing a three-point harness; the full extent of his injuries included bruises along the strap lines.

On April 19, 2011, inspectors from the Federal Aviation Administration (FAA) supervised examination of the airplane by personnel from Rotech Flight Safety, Inc., who were technical advisers to the Austrian accredited representative per International Civil Aviation Organization Annex 13. The complete Rotech report is part of the public docket; pertinent parts of the report follow.

During the visual inspection, the investigators noted modifications to the exhaust system for incorporation of cabin heat by shrouding the exhaust muffler, and ducting into the cabin. They also observed that the exhaust gas temperature (EGT) probes had been relocated from the factory recommended positions, and the previous holes plugged with pop rivets. The installation manual noted that EGT would give the most rapid response in the event of improper mixture, pre-ignition, or detonation.

The investigators observed an aftermarket mixture control installed on the engine, which also included modifications to the fuel and air intake systems. The Rotax installation manual stated that no modification should be made to the carburetor and air intake system without consulting Rotax. The system installed did not have their approval.

The engine had dual carburetors installed. Both carburetors had jets that were different from the stock jets with leaner fuel to air ratios than the stock jets. Both jets were different from each other. According to the Rotech representative, in order for the engine to run properly, both carburetors must be synchronized to each other, and are required to have the exact same jetting.

The fuel filters were installed in the incorrect location on the fuel system. The installation manual called for the filters to be between the fuel pump and the carburetors. On the accident engine, they were installed between the fuel pump and the fuel tank.

The carburetor vent lines were improperly installed.

The fuel pump was installed improperly to the top of the engine. The installation manual stated to mount it in a cool place, not on the engine itself.

The spark plugs were nonstandard. The electrodes were excessively black and sooty, which the investigators noted was consistent with a rich fuel/air mixture. Examination of the ignition wires revealed that exposed bare wires had been spliced and soldered together, which had the potential of shorting. Solder was not an acceptable repair method, and the wire was in poor shape.

Improper gear oil had been used to lubricate the Rotary and water pump drive shaft rather than 2-stroke injection oil as specified by the manufacturer.

According to FAA Advisory Circular AC 20-27F, Certification and Operation of Amateur-Built Aircraft, "Amateur builders are free to develop their own designs or build from existing designs. We do not approve these designs and it would be impractical to develop design standards for the wide variety of design configurations, created by designers, kit manufacturers, and amateur builders."