Fuel Exhaustion & Starvation · NTSB ERA15FA128

PIPER PA28 — Greensboro, NC

1 fatal
DateFebruary 11, 2015
LocationGreensboro, NC
AircraftPIPER PA28
Purpose of flightPersonal
ConditionsDay · Visual Meteorological Cond
Phase / occurrencePrior to flight Aircraft maintenance event
Pilot age74
Pilot total time359 hrs · Building experience
Time in type63 hrs
Fatalities1

Probable cause

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.

NTSB findings

  • Aircraft-Aircraft systems-Fuel system-Fuel selector/shutoff valve-Inadequate inspection - C
  • Aircraft-Aircraft systems-Fuel system-Fuel selector/shutoff valve-Fatigue/wear/corrosion - C
  • Personnel issues-Task performance-Maintenance-Scheduled/routine maintenance-Maintenance personnel - C
  • Personnel issues-Task performance-Maintenance-Scheduled/routine maintenance-Owner/builder - C
  • Personnel issues-Task performance-Inspection-Post maintenance inspection-Maintenance personnel - C
  • Personnel issues-Task performance-Inspection-Post maintenance inspection-Owner/builder - C
  • Organizational issues-Support/oversight/monitoring-Oversight-Oversight of maintenance-Operator

What happened

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.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.

View the official NTSB docket →