The engine of a helicopter involved in a fatal crash in Co Clare last month would have stopped within seconds after part of it disintegrated, according to a preliminary air-accident report yesterday.
The helicopter was conducting a routine gas-pipeline inspection on July 12th when it crashed into a field near the village of Ballynacally, about 10 miles from Ennis.
The observer on board, Frederick Balcombe (69), from Townsparks, in Skerries, Co Dublin, was killed and the pilot seriously injured.
In his preliminary report, air-accident investigator Leo Murray said the cause of the failure of part of the engine was still being investigated.
In an interim safety recommendation, he says that, because of the increased hazards associated with low-level aerial work, the Irish Aviation Authority should review the suitability of permits for single-engine helicopters.
The wreckage of the Aerospatiale helicopter was brought to the air-accident investigation unit facility at Gormanston, Co Meath, for examination.
Mr Murray said the engine was sent to the manufacturers' facility at Tarnos, France, for detailed examination.
"Opening of the transmission shaft and accessory gearbox revealed that the bevel gear of the accessory drive train had disintegrated. The cause of this failure has yet to be determined.
"The direct effect of this failure was to stop the fuel supply, causing stoppage of the engine within seconds," the report said.
The investigation is continuing, and a final report will be published later.