Accident Overview
On May 22, 2014, at about 1130 mountain standard time, a Beech H35 (registration N4689D) sustained substantial damage following a forced landing on rough terrain near the Avi Suquilla Airport (P20), Parker, Arizona. The flight, conducted under 14 CFR Part 91, originated from Quail Mesa Ranch Airport (15AZ) about 1115 with a planned destination of P20. Both occupants—the pilot-rated owner and a flight instructor—were not injured.
Pilot Report
The pilot-rated owner, who could not act as pilot in command due to medical reasons, reported to the NTSB that approximately 5 miles from the destination, the engine lost power. Manipulation of engine and fuel controls failed to restore power, leading to a forced landing. He stated that about 15 to 20 gallons of fuel were onboard at departure.
Aircraft Damage
During the landing roll, the nose landing gear collapsed, and the right wing sustained substantial damage. Post-accident examination revealed buckling of the fuselage from the firewall to the aft fuselage, impact damage to the nose gear and supporting structure, and a buckled right wing aft spar near the main landing gear area. The instrument panel was undamaged; radios had been removed prior to the flight.
Fuel System Examination
The fuel tank quantity gauge indicated zero. Engine control cable continuity was intact. The fuel selector was in the "left tank" position. Fuel from the fuel selector drain was clear. The fuel selector inlet screen was found installed inverted on the lower side of the retention spring, with a small amount of fibrous debris present. Header tanks were attached to each wing tank inlet line; fuel flow from each line appeared normal with no anomalies noted. The fuel selector had proper detents in all positions.
Engine Examination
The engine showed no impact damage. The propeller assembly remained attached but had impact damage. Spark plugs had light grey deposits and normal wear. Fuel injectors were clear. The fuel manifold valve contained a yellow residue below the screen; no debris in the screen. The fuel control valve inlet screen was clean. Fuel found at components was consistent with 100LL.
Engine Test Run
The engine was set up for a test run using a header tank and tie-downs. New spark plugs, injectors, and screens were reinstalled. The engine started readily and ran normally with the boost pump on. Approximately one minute after startup, switching the boost pump off caused the engine to shut down. Multiple runs produced the same result.
Post-Run Findings
Examination after the test run revealed a loose fuel return line at the engine-driven fuel pump connection. The b-nut ferrule was cracked, and the flare in the rigid line was irregular. Threads on the b-nut and pump fitting were damaged. The fuel pump itself operated normally when tested by hand and with an electric drill submerged in water; disassembly showed no anomalies.
Manufacturer Testing
The fuel pump, fuel control assembly, fuel manifold valve, injectors, and associated lines were sent to the manufacturer. The fuel pump and fuel control assembly functioned normally on the test bench. However, the fuel manifold valve and nozzles exhibited abnormal flow versus pressure indications, and a leak was observed at the vent port, indicating a compromised diaphragm.