20180501004409A

Experimental amateur-built, Thunder Mustang sustained substantial damage during a forced landing. The airplane was taking part in an in-flight photography mission with another Thunder Mustang, with the photographs being taken from a Beechcraft bonanza. After about one hour of flight, which included multiple north-south passes north of the airport, the group agreed to end the mission and return to Reno. As the airplane's approached within about 2 miles of the airport from the north, the accident pilot transmitted a "mayday" call over the common traffic advisory frequency. The pilot of the other Thunder Mustang replied, asking for a confirmation, and the pilot responded again with a mayday call adding that he intended to land on runway 14. The other pilot watched as the accident airplane began to descend towards the airport. He observed it overshoot the runway 14 centerline to the south, and then begin a sweeping 180 left turn followed by a right turn to rejoin the centerline. By this time the airplane was midfield and low over the runway, flying at what he judged to be a high speed. He could not tell if the airplane had touched down or was still floating, and as it approached the end of the runway, it veered off the right side and nosed over. The airplane came to rest inverted in a gravel area about 20 ft right of the runway edge, and 80 ft short of the runways paved end. The runway surface exhibited a 1,200-FT-long series of intermittent black rubber transfer marks, and propeller blade gouges leading from the runway centerline to the airplane. A runway construction crew, along with the other pilots from the photography mission, all arrived at the accident site within about 3 minutes, followed a few minutes later by the local fire department. They observed that the vertical stabilizer had folded right against the horizontal stabilizer, and that the canopy was shattered by ground impact. The pilot remained in his seat within the airplane and his helmet appeared to be impinged against the gravel surface. After multiple attempts to move and lift the airplane, he was extracted about 45 minutes later. The airplane was equipped with a liquid-cooled, fuel injected, 12-cylinder engine manufactured by ryan falconer racing engines, and a three-blade constant-speed propeller manufactured by hartzell propellers. The engine's fuel pump, water pump, propeller governor, auxiliary alternator, and both the scavenge and pressure oil pumps, were driven by the engine crankshaft via pulleys and two parallel serpentine belts. Post-accident examination revealed that the water pump pulley had separated from the pump drive flange. The pulley mounting bolt heads had detached, leaving their threaded stud ends still in the flange. Both serpentine belts had also detached, along with the top of the engine coolant outlet hose, which was adjacent to the pulley. No other mechanical anomalies were noted, and the pump assembly was retained by the NTSB for further examination.