50-Hour Fuel Nozzle Inspection Neglected To Lock Wire Placement

A probable cause report issued by the National Transportation Safety Board says a 2006 helicopter accident in Patterson, LA that killed two people was due to a missing piece of wire.

A Bell 206L helicopter took off from the Perry Flying Service in Patterson on March 14, 2006 on an air taxi, cross country flight with three passengers. Shortly after takeoff, "the helicopter had a loss of engine power while in cruise flight," according to the NTSB report.

The pilot was forced to make a "hard landing" in a marshy area after which two of the three passengers were able to exit the aircraft. The helo then caught fire before the pilot and a third passenger could extricate themselves.

"An examination of the engine at the accident site revealed that the fuel line to fuel nozzle "B" nut could be turned by hand, and did not contain a lock wire as required. All other fittings and nuts on the engine were found to be secure," said the report.

The fire caused a marsh fire that burned for several weeks, according to KLFY-10.

The evening before the accident, a mechanic performed a 50-hour fuel nozzle inspection. This required the removal, disassembly, cleaning, inspection, reassembly, and reinstallation of the fuel nozzle According to the report, the mechanic apparently then failed to secure it with a lock wire.

When NTSB investigators re-enacted the sequence of events, "The test revealed that the engine would experience a substantial loss of power that could conclude in a flame out. Testing further revealed that conditions would have been conducive for an in-flight fire."

The probable cause is listed as, "The improper installation of an engine fuel line fitting by other maintenance personnel, which resulted in a loose fitting and a loss of engine power during cruise flight. Factors associated with the accident are a tailwind, and the lack of a suitable site for a forced landing."

FMI: Read The Full Probable Cause Report