Casualties unknown

1998-02-08: Mooney M20J (N4120H) — Davis, WV

Davis, WV, US

On February 8, 1998, a Mooney M20J (registration N4120H) was involved in an aviation accident near Davis, WV. Investigators recorded the probable cause as: A loss of power due to blockage of the fuel screen and one of the four fuel injector nozzles. A contributing factor was snow covered terrain. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During takeoff at about 100 feet above ground level, an airplane experienced engine roughness and power loss. It touched down in a snow-covered field, nosed over, and came to rest inverted. Subsequent testing revealed a blocked fuel nozzle and a plugged inlet screen.

Event Description

During the takeoff roll and climb, as the airplane reached approximately 100 feet above ground level (AGL), the engine began to run rough and subsequently lost power. The pilot performed a forced landing, touching down on a snow-covered field. During the landing, the airplane nosed over and came to rest inverted.

Post-Accident Examination

Following the accident, the engine was tested on the ground. The fuel flow was observed to fluctuate during the test. The fuel injector servo system was then examined, and several discrepancies were identified. The safety wire attached to the plug used for adjusting the diaphragms inside the fuel servo was missing its lead seal. Additionally, one of the four fuel injector nozzles was found to be blocked. Individual injector nozzles were tested, revealing debris blocking the flow in one nozzle, while the remaining nozzles produced an acceptable fuel stream.

A representative from Aircraft Fuel Specialists, Ltd., who conducted the testing, provided further insight. He stated that the adjustment to the diaphragms would not have caused the loss of power as described to him. Instead, he noted that the blockage of the inlet screen, which was completely plugged, and the single blocked nozzle were more likely contributors to the power loss.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X09558. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.