Amateur-built AVENTURA II N727TK accident near Deland, Florida

Probable cause

Improper installation of the electric-driven fuel pump inlet hoses, which resulted in a hose failure and subsequent loss of engine power due to fuel starvation.

NTSB analysis

The pilot reported the engine lost partial power about 300 ft above ground level during takeoff on a maintenance test flight. He applied full throttle and turned on the electric fuel pumps, but the engine did not regain power. The pilot initiated a forced landing; however, due to the low altitude at the time of the power loss, the airplane impacted trees. The airplane came to rest in a nose-down attitude in a residential area. The airplane sustained substantial damage to the fuselage and wings.

Postaccident examination of the wreckage revealed multiple anomalies within the fuel supply system. Functional testing of the electrically-driven fuel pumps with the hoses installed revealed a significant vacuum leak on the inlet manifold side of one of the pumps. The leak prevented the fuel pumps from pulling fuel from the tank. The hose was found to be loose and could be pulled off by hand. The internal diameter of the hose was too large for the pump’s attach fitting, and a worm clamp had been over-tightened to attach it, which may have contributed to the line cracking. The opposite end of the same hose was too small for the brass fitting it was installed on, and the hose had been damaged and deformed when pressed onto the fitting, creating a significant blockage through the line. It is unknown how much of a reduced fuel-flow this blockage may have caused. The fuel pumps functioned properly when tested with new hoses installed, and several engine test runs in this configuration was successfully performed.

Recorded data showed recovered from onboard avionics recorded a drop in fuel pressure on takeoff for the accident flight. Based on this data, as well as the postaccident examination findings, it is likely that this loss of fuel pressure resulted in fuel starvation and the loss of engine power during takeoff. It is also likely that the improperly sized and installed fuel lines directly resulted in the loss of fuel pressure.

Text from the NTSB. Open the NTSB docket for ERA24LA279 for the full record.