Accident Details
The owner/pilot mechanic reported that during a maintenance test flight for a newly overhauled engine, he began losing engine power at approximately 300 feet of altitude during the initial takeoff climb. He elected to turn left to return to the airport but, not having enough altitude, impacted with swampy terrain on the west side of a lagoon. During the return maneuver, he switched the fuel selector from the left tank to the right tank and then back to the left tank, with no correction to the partial loss of power. He noted the fuel flow indicator dropped from 28 to 17. Prior to the flight, the pilot had performed two ground run-up checks to about 2,200 RPM and noted no discrepancies.
Engine Examination
After recovery, an engine examination was conducted by the owner/pilot mechanic and a representative of New Piper Aircraft, Inc. with FAA oversight. During a fuel flow test, with the electrical fuel pump energized, the fuel outlet line at the fuel servo that supplies fuel to the flow divider was observed spraying fuel, and the B-nut was found loose. The fuel flow test was stopped. The line's B-nut was tightened, and the test resumed. A test of the fuel mixture flow noted a rich mixture flow of approximately 7 gallons per hour, while a lean mixture noted a flow of approximately 4 gallons per hour.
Maintenance Documentation
A review of the accident airplane's maintenance log book documented that the engine installation work was completed per Lycoming Overhaul Manual # 60294-7 (Textron Lycoming, Part number 60294-7, Overhaul Manual for Direct Drive Engine). Textron Lycoming Service Instruction No. 1427B outlines that for an overhauled engine, a ground run check up to full-static recommended power should be performed for a period of no more than 10 seconds. The full-static power for the accident airplane, as per the airplane's flight manual, is 2,700 RPM with the turbocharger control off. After operating the engine at full power, the instructions call for cooling, checking idle mixture, and shutdown. The Piper PA-24-260, Comanche, Service Manual, Section 7A-33, details procedures for engine installation, including cautions and warnings pertaining to fluid leaks on airframe components.