Introduction
On November 22, 2021, at approximately 1140 mountain standard time, an experimental amateur-built Vans RV-10, registration N54CT, was involved in an accident near the Grassy Meadows/Sky Ranch Airport in Hurricane, Utah. The airplane sustained substantial damage, and the pilot reported minor injuries. The flight was operated under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Flight Details
The pilot reported that before takeoff, he performed an engine runup with the fuel selector set to the left fuel tank. After the runup, he switched to the right fuel tank and back taxied on runway 17 for departure. During the takeoff, he intended a downwind departure to the north. While on the downwind leg, he reduced power and decreased the rate of climb because the engine operating temperatures were rising. Shortly afterward, the engine experienced a complete loss of power. The pilot advanced the propeller control to full rpm, switched the fuel selector valve to the left fuel tank, and turned on the fuel boost pump. Unable to restore power, he executed a 360° turn to lose altitude before landing. However, after turning onto final approach for runway 17, he realized he did not have sufficient altitude to reach the runway and initiated a forced landing to an open field. The airplane landed hard and impacted terrain, coming to rest in a nose-low attitude.
Postaccident Examination
Examination of the airplane by the pilot revealed substantial damage to the fuselage and left wing. The wreckage was recovered for further examination. Data downloaded from the avionics recorded various engine parameters. The data indicated that at 1140:27 unit time, power was advanced for takeoff, and fuel flow increased to 22 gallons per hour (gph). About 51 seconds later, fuel flow began to decrease, while fuel pressure remained around 26 psi. When fuel flow dropped below 9.7 gph, engine rpm started to decrease from approximately 2,500 rpm.
Examination of the recovered airframe and engine found that the fuel line from the fuel servo outlet port to the fuel flow transducer inlet port was loose at the fuel servo fitting. An external fuel source was attached to the left-wing fuel inlet line, and the No. 1 cylinder fuel injector line was removed for testing. When power was applied to the airframe and the boost pump was turned on with the throttle and mixture levers at full forward, fuel was observed expelling from the loose fuel line fitting, and no fuel flowed from the fuel injector line.
Additionally, damage to the firewall appeared to restrict fuel flow from both left- and right-wing fuel inlet lines. An external electric fuel boost pump was attached inline from an external fuel source to the inlet line of the engine-driven fuel pump, and the loose fitting at the fuel servo was tightened about 3.5 turns. With the fuel boost pump on and throttle and mixture at full forward, fuel expelled from the cylinder No. 1 fuel injector line. Then, the fuel outlet line at the fuel servo was loosened about 3.5 turns, causing fuel to leak from the fitting, and no fuel expelled from the No. 1 fuel injector line.
Findings
The investigation identified a loose fuel line fitting at the fuel servo and firewall damage that restricted fuel flow. The engine power loss was consistent with fuel starvation due to these issues.