On June 15, 1992, an Aerospatiale AS-355-F (registration N365DU) operated by Omniflight Helicopters was involved in an aviation accident near Fort Bragg, NC. Investigators recorded the probable cause as: THE TOTAL BLOCKAGE OF THE OIL SUPPLY LINE FOR THE REAR MAIN BEARING IN ENGINE MODULE THREE WHICH RESULTED IN THE FAILURE OF THE BEARING, AND THE SUBSEQUENT LEAK FROM THE ENGINE START DRAIN VALVE. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 3 related events involving the same aircraft type or operator are linked below.
An air ambulance helicopter en route to pick up a patient experienced an engine fire warning and smoke in the cabin, prompting an emergency landing at Simmons Army Airfield. Examination revealed blocked oil supply, bearing failure, and a fuel leak caused by vibration.
Incident Overview
An air ambulance helicopter was en route to pick up a patient when the pilot observed the engine fire light illuminate. Shortly thereafter, smoke entered the cabin area. The flight crew executed an emergency landing at the nearby Simmons Army Airfield at Fort Bragg, North Carolina.
Examination Findings
Following the incident, an examination of the helicopter revealed multiple issues. The oil supply line for the bearing was blocked with carbon, and the rear bearing in the number three module had failed. Additionally, the engine start fuel valve began leaking fuel as a result of loss of torque on connecting bolts due to engine vibration. The start fuel valve was located directly above the engine starter/generator. An extensive fire had occurred in the number one engine compartment, originating in the area of the starter/generator.