What happened
While cleared to land and following slower traffic, the pilot reduced airspeed and executed a constant left turn. Upon rolling out on final approach, the pilot opened the throttle in an attempt to arrest the descent rate. However, the engine failed to respond despite remaining operational. To maintain airspeed, the pilot relaxed back pressure on the control yoke and banked slightly to land on a steep incline located short of the runway. This resulted in an increased descent rate and subsequent impact with the terrain.
The investigation
Post-accident examination of the aircraft revealed that the main landing gear had been torn from the fuselage, the firewall was buckled, and the forward portion of the fuselage aft of the firewall showed wrinkling. Investigators noted that a fuel management system had been installed in the airplane one year prior to the accident. This system provides digital indications of total fuel on board, consumption rate, endurance, and remaining fuel via a switch. Prior to the 8-mile flight, the pilot checked the fuel quantity, which indicated 10.1 gallons; following the accident, the reading was 8.0 gallons. While the system is designed to have an error margin of no more than plus or minus 1.0 gallon, recovery crews drained one gallon from all tanks.
Additionally, the pilot reported that a bracket securing the throttle cable to the firewall had broken several months before the accident. Maintenance records showed no entry regarding a repair for this component. Despite the engine being pushed aft and buckling the firewall during the impact, movement of the throttle in the cockpit was still capable of producing movement at the throttle valve.