A preliminary report into a helicopter crash in Co Kildare last month in which a flight instructor and a trainee pilot were killed has expressed concern over the time taken to raise the alarm.
The light two-seater helicopter, which was on an instructional flight from Weston airport, Co Kildare, struck overhead power lines and crashed in a remote part of the Bog of Allen on April 1st.
The helicopter's pilot Colm Clancy (34) from Co Donegal and his student Dermot Sheridan (24) from Co Clare, who was studying for his private pilot's licence, were killed.
The Air Accident Investigation Unit's preliminary report into the crash, published today, said the flight left Weston airport at 4.01pm for a 90-minute lesson.
The last known radio contact with the aircraft was made less than 12 minutes later at 4.12pm.
About 35 minutes later, the Schweizer 300CBi helicopter hit electrical lines, which were unpowered at the time, and crashed in bog land, six kilometres from the village of Carbury.
Investigators calculated the time of the crash from a watch retrieved from one of the men which showed the battery had gone dead at 4.47pm, presumably on the point of impact.
The air traffic control at Weston closed shortly after 7.30pm on the day of the crash and a search for the helicopter and its occupants did not begin until the following day when a concerned family member contacted the airfield.
A search for the aircraft only commenced at 10.38am the following day, some 17 hours after the aircraft crashed.
The wreckage was located shortly before 11.30am in bog land near Kilshanchoe, on the Kildare-Meath border, by a Coast Guard rescue helicopter which had followed the missing helicopter's known flight path.
The AAIU said it was "concerned over the amount of time that had elapsed before the helicopter was notified as missing".
As a consequence, the investigation was examining the flight planning process and requirements associated with the accident flight.
The report said investigators did not believe the weather played a factor in the accident.
It said the investigation was also examining "engineering and operational aspects of the flight, including what exercise was being carried out at the time of the accident".
Mr Clancy had over two years experience as a pilot and Mr Sheridan had been in the air on several previous occasions.
The European Helicopter Academy, which is based in Weston airport and operated the helicopter, said an annual maintenance check on the three-year-old aircraft had been carried out only a few days before the crash.
The Schweizer 300CBi helicopter is one of the most frequently used aircraft for helicopter training in the world.
The full report into the accident by the AAIU is due to be completed later in the year.
