The Pilot, the sole occupant of EI-SBM, was on a flight from Celtic Heliport, Knocksedan, Co Dublin to Weston Airport, Co. Kildare. En route, the Pilot advised Air Traffic Control (ATC) that he was approaching Dunshaughlin. Shortly thereafter, he informed ATC that he had a problem and then, almost immediately, reported that he would have to make an emergency landing and made a “MAYDAY” call. This was the Pilot’s final transmission to ATC.
The helicopter landed heavily on soft ground and rolled over onto its left hand side. The helicopter was substantially damaged and the Pilot suffered serious back injuries. During the initial AAIU Investigation at the accident site, some cleaning cloth material was found entangled on the long tail rotor drive-shaft, between the first and second bearing (first bearing facing FWD).
It was also found that the drive-shaft had completely severed just forward of the second bearing, thus cutting off the vital drive to the tail rotor gearbox. The Investigation concluded that the cloth induced out-of-balance forces on the shaft, causing the drive-shaft to fail. There was no fire.