ERA15FA128

A total loss of engine power after takeoff due to fuel starvation as a result of excessive wear of the fuel selector valve. Also causal was the owner/operator and maintenance personnel's inadequate maintenance, and inadequate postmaintenance inspection.

On the day of the accident, the private pilot rented the airplane from a fixed base operator. A witness saw the pilot start the airplane and taxi to the end of the runway, where the pilot performed an engine run-up. Two witnesses reported that the takeoff sounded normal; however, they did not hear the airplane continue around the airport traffic pattern. One of the witnesses then drove to the end of runway where he found the wreckage. Examination of the accident site and airplane revealed that the airplane had descended and impacted trees after departure. There was no evidence of engine power at the time of impact. Examination of the engine revealed no evidence of any preimpact mechanical malfunctions; however, only trace amounts of fuel were found in both the carburetor float bowl and the engine-driven fuel pump. Examination of the fuel system revealed that the fuel strainer and electric fuel pump were both devoid of fuel. The fuel selector was likely original to the airplane, and had not been modified in accordance with mandatory service bulletins issued by the manufacturer to reduce the possibility of pilot mismanagement of the fuel system through inadvertent selection to the "OFF" position. Examination of the fuel selector control revealed that the valve handle was in the right tank position at the time of the accident; however, testing of the valve with air indicated that the valve was closed. Subsequent attempts to manipulate the selector valve revealed that it was stiff to rotate, and positive engagement of the detents could not be consistently obtained. Further attempts to flow air through the valve produced intermittent results, which indicated that the plug cock inside the fuel valve was not functioning properly and could reduce or block the fuel flow, resulting in a partial or complete loss of engine power. Disassembly of the fuel selector valve revealed rotational scoring in the valve body and on the plug cock, which displayed discoloration and heavily-worn detents. Spectroscopy of the debris particles found in the valve body and embedded in the plug cock indicated that the debris was the result of excessive wear of the valve components. Both the owner, who was also the operator and maintenance personnel stated that they checked the fuel selector valve during an annual inspection that was completed about 11 hours prior to the accident. Review of maintenance and operator records revealed several discrepancies, including when the most recent annual inspection had occurred, whether the items required by the inspection were accomplished, and if the annual inspection engine run was performed by an individual unqualified to do so. The condition of the fuel selector valve cast doubt as to whether much of the maintenance had been properly performed, since inspection in accordance with Federal Aviation Administration and manufacturer guidelines would have revealed that the fuel selector valve was not airworthy. Although an autopsy and toxicology testing of the pilot revealed evidence of coronary artery disease and unreported use of antidepressant medication, it is unlikely that these factors impaired the pilot's ability to safely operate the airplane. Given the condition of the airplane's fuel selector valve, it is likely that the engine experienced a total loss of power shortly after takeoff due to fuel starvation, which resulted in the airplane's descent into terrain, leaving the pilot with few options.

Air Harbor Airport was owned by Guilford Lake Aviation, LLC, and was located 6 miles north of Greensboro, North Carolina at an elevation of 822 ft mean sea level (msl). It was classified by the FAA as a privately owned, non-towered, public use airport. The airport was equipped with one runway oriented in a 9/27 configuration, which measured 2,460 ft long by 65 ft wide. The pilot rented the airplane from Murphy Aviation, the service provider at the airport that provided fuel, maintenance, parking, tie downs, and airplane rentals. The owner/operator of the airplane was the airport manager and also owned Murphy Aviation. He was listed by the State of North Carolina as the registered agent for Guilford Lakes Aviation LLC, and in the past had also done business at the airport as Air Harbor Airport, Inc. Fuel System Description and Review The airplane was equipped with two 25-gallon fuel tanks, which were secured to the leading edge structure of each wing by screws and nut plates. Each tank had an individual fuel drain at the bottom inboard corner, which was used to check for water or sediment. From the outlet of each tank, fuel lines were routed through the wings to the fuel selector valve located on the left side panel forward of the pilot's seat. From the fuel selector valve, a line led to the fuel strainer bowl, which was mounted on the front of the engine firewall. The fuel line then routed from the strainer bowl to the electric fuel pump, engine driven fuel pump, and carburetor. Examination of the fuel selector control revealed that it was likely original to the airplane. It had four selectable positions: LEFT TANK, RIGHT TANK, OFF, and OFF, indicating that it had not been modified per Piper Service Bulletin No. 840, issued in 1986, or per Piper Service Bulletin No. 840A, which superseded the previous bulletin and was issued in 2013. The modification would have reconfigured the fuel selector so it had a spring-loaded metal stop and only three selectable positions: L TANK, R TANK, and FUEL OFF. Piper Aircraft considered that compliance with these service bulletins was mandatory, which was clearly stated on the service bulletin, to reduce the possibility of pilot mismanagement of the fuel system through inadvertent selection of the "OFF" position, which could result in power interruption or engine stoppage. The electric fuel pump was provided in case the engine-driven fuel pump failed; the electric fuel pump was required to be on for takeoff, landing, and when switching tanks. Examination of the pump indicated that it was functional, and the electric fuel pump switch was found in the "ON" position following the accident. The fuel strainer, which was equipped with a quick drain, was located on the lower left front of the engine firewall and was accessible outside of the nose section. A witness, who saw the airplane taxiing before the accident, observed what he believed was possibly fuel "atomizing" in front of the left wing of the airplane. He advised that it appeared to be coming from the front of the wing root area near the firewall (near where the fuel strainer was located) and dispersing aft over the wing. Examination of the fuel strainer had revealed though, that the quick drain was closed. During further examination of the fuel system for a source of the fuel the witness observed, it was discovered that, fuel staining was seen inside the wings, and the rubber fuel tank vent tube couplers were found age-hardened, split, and leaking. Fuel Valve Inspection Guidance According to the Piper Cherokee Service Manual, the operation of the fuel selector valve was required to be confirmed during inspections. The manual advised that, when the fuel selector handle was not in a positive selector detent position, more than one fuel port would be open at the same time. The manual stated, "It should be ascertained that the fuel selector is positioned in a detent, which can be easily felt when moving the handle through its various positions." According to FAA Advisory Circular (AC) 43.13-1B, Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair, when inspecting fuel crossfeed, firewall shutoff, and tank selector valves, these valves must be inspected for leakage and proper operation. In the case of selector valves, this means the operation of each handle or control needs to be checked to see that it indicates the actual position of the selector valve to the placard location. Movement of the selector handle should be smooth and free of binding, and stops and detents should exhibit positive action and smooth operational feel, as worn or missing detents and stops could cause unreliable positioning of the fuel selector valve. Inaccurate positioning of fuel selector valves could also be caused by worn mechanical linkages between the selector handle and the valve unit. Universal joints, pins, gears, splines, cams, levers, etc., should be checked for wear and excessive clearance, which prevent the valve from positioning accurately or from obtaining fully "off" and "on" positions. An improper fuel valve position setting could seriously reduce engine power by restricting the available fuel flow. High Resolution Photography of Valve Body and Plug Cock Comparison of the fuel selector valve to an exemplar valve removed from another airplane with about 2,206 total hours of operation revealed that the exemplar valve rotated smoothly, and the detents could be felt positively when the valve was selected to each position. High resolution photography of the fuel selector valve revealed the presence of staining, corrosion, and debris, and the plug cock had debris embedded in its surface. None of the noted anomalies observed in the accident airplane's fuel selector valve were observed with the same severity in the exemplar valve. Materials Identification and Spectroscopy Positive material identification was used to determine the materials composition of the valve body, valve stem, and position washer. Spectroscopy of the debris particles found in the valve body and embedded in the plug cock, revealed that the debris particles contained elements like the ones that made up the composition of the valve body, valve shaft, and position washer. Information Provided by the Chief Mechanic The owner/operator's chief mechanic stated that he had assisted the owner in putting the airplane back into service after the owner purchased it. They had replaced all the hoses in the engine compartment, but did not do any work aft of the firewall with the exception of replacing the battery. The chief mechanic also stated that he performed the airplane's last two annual inspections. He advised that entries for the last annual inspection were incorrect, and the annual was actually completed on January 21, 2015. He used Piper guidelines as well as 14 CFR Part 43 during the inspections of the airplane. The fuel selector was "stiff" to turn, but he thought it was not any tighter than any other older Piper he had worked on, and it seemed to work fine. According to the chief mechanic, the owner/operator and the mechanic's helper also assisted with the annual inspection. He and the mechanic's helper had worked separate from the owner/operator and had not performed any work on the fuel selector. He and the mechanic's helper would always "check behind each other." He stated that had performed AD 2010-15-10 regarding inspection of the control wheel shafts, but had not entered it into the maintenance records. He stated that he was not in the airplane when the mechanic's helper performed the engine run-up following completion of the annual inspection, so he did not know if he had "exercised the fuel valve in the airplane." The chief mechanic stated that he did not feel that anything was unairworthy with the airplane, and he was not aware that the owner had not registered the airplane after purchasing it. Information Provided by the