Poor maintenance leads to fuel exhaustion

This March 2010 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.

Aircraft: Cirrus SR22. Injuries: 1 Fatal, 1 Serious. Location: Morton, Wash. Aircraft damage: Destroyed.

What reportedly happened: According to the passenger, she and the pilot were returning from a business trip. They refueled the airplane at an airport in the San Francisco Bay area, then began the flight home. While the airplane was in cruise flight, the pilot suddenly placed his hands on the controls, told her the engine had lost power, and they were going to land at a nearby airport.

He entered a steep right turn toward the airport. She said the pilot remained calm throughout the approach to the airport and reassured the passenger during the descent that they would land safely. The pilot also declared a MAYDAY message and spoke on the radio. The passenger sent a text message to a friend indicating that they were not going to make it to the airport. She did not recall anything after this point. The airplane crashed in trees approximately 2.5 miles short of the runway.

The passenger indicated that the pilot had discussed the Cirrus Airframe Parachute System with her prior to the trip and showed her how to activate it in the event of an emergency. The passenger reported that the pilot did not attempt to activate the CAPS during the flight.

Examination of the airframe and engine revealed no evidence of pre-impact mechanical anomalies except for the fitting cap on the throttle and metering assembly inlet, which was not installed. The cap was found resting on the cylinder baffle, and there was light blue staining on the crankcase indicating fuel leakage. During a post-accident engine run, the engine operated normally with a substitute cap installed finger tight.

It was determined that during the airplane’s annual inspection was completed about 11 flight hours prior to the accident, three engine cylinders were replaced. Following the cylinder replacement, the fuel system pressures were checked with instrumentation that was plumbed into the system at the throttle and metering assembly. Following the pressure tests, the line where the instrumentation was connected should have been secured with the fitting cap that was found not installed. The manufacturer’s maintenance procedure requires that after the pressure tests are completed the cap be torqued and that a leak check be performed.

Metallurgical examination of the cap showed that if it had been properly torqued it would have remained secure. Therefore, it is likely that the cap was installed finger tight and was not properly torqued when it was reinstalled. During the accident flight, the cap loosened and came off, resulting in a loss of engine power due to fuel starvation. There was no logbook entry for the most recent annual inspection, nor had the final items on the annual inspection checklist been completed. The Director of Maintenance for the facility had signed off the work order and returned the airplane to service. The assigned mechanic with inspection authorization indicated that he had not completed the annual inspection on the airplane and that the last maintenance he performed was that noted on the work order and annual inspection checklist. If the final checks had been completed, it is likely that the improperly secured cap would have been found because the fuel leakage would have been evident.

Probable cause: The failure of maintenance personnel to properly secure a fitting cap on the throttle and metering assembly inlet after conducting a fuel system pressure check, which resulted in a loss of engine power due to fuel starvation. Contributing to the accident was the decision by the Director of Maintenance to return the airplane to service without verifying with the assigned inspector that all annual inspection items had been completed.

For more information: NTSB.gov. NTSB Identification: WPR10FA163


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