NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The commercial pilot departed on a cross-country flight in the experimental, amateur-built, turboprop airplane. About 3 minutes after takeoff, the pilot initiated a return to the departure airport. About 6.8 nautical miles (nm) from the runway, at an altitude of about 6,500 ft mean sea level, the pilot declared an emergency, stating that he had "lost" the engine. Shortly thereafter, he informed air traffic control that the airplane had experienced a loss of fuel pressure. Witnesses saw the airplane collide with a tree and subsequently impact a pond about 1.2 nm from the runway. They reported no engine sound.
Examination of the airplane revealed no evidence of preimpact failures or malfunctions of the flight controls that would have precluded normal operation. The landing gear and flaps were found retracted. There was no evidence of preimpact failure or malfunction of the engine core. The engine-driven fuel pump showed signs of internal cavitation, while the auxiliary fuel pump, which provided fuel under pressure to the engine-driven fuel pump, flowed nearly 48% less than specified by the manufacturer, and had an inconsistent/intermittent laboring sound during testing. Disassembly revealed an improperly-installed fitting, which resulted in the decreased fuel flow rate, a loss of fuel pressure, and a subsequent engine flame-out. Inspection also revealed that a component of the fuel pump had been replaced after manufacture, but there was no record of this maintenance in the airplane's logbooks.
While it was not known if the pilot attempted to perform an air restart of the engine, a worn ignitor box and ignitor plug may have precluded a successful restart of the engine.
Although the pilot descended the airplane at its published best glide airspeed in his attempt to return to the airport, because the airplane was not equipped with an electrically-operated feathering pump, the propeller blade angle remained where it was set when the engine flame-out occurred, which was likely flat pitch. The flat pitch of the propeller blades significantly decreased the airplane's engine-out glide ratio. Had the pilot promptly feathered the propeller blades to reduce drag following engine flame-out, or had the airplane been equipped with a feathering pump, it is likely the airplane would have been able to reach the intended runway and land uneventfully.
Although an enlarged heart was noted during the autopsy and toxicological testing detected quinine, given that the pilot was actively controlling the airplane just before the accident, there is no evidence that a medical condition or use of quinine contributed to the pilot's inability to fly the airplane.