Changes at airport after helicopters crash during take-off
Incident in May highlighted safety issues at Cumbernauld Airport.
A helipad has been extended at a small Scottish airport after a collision between two helicopters during a take-off.
No-one was injured when the pilot of a Robinson R44 helicopter (G-CTFL) reversed into another of the same model (G-HYND) at Cumbernauld Airport in May but safety instructions have been revised.
The pilot, who was carrying two passengers, was taking off for a lesson but was unaware another helicopter, with three passengers, had landed behind him and was shutting down after a sightseeing trip.
The AAIB said the pilot of G-CTFL was not alerted that G-HYND had parked on grass behind him and felt he was restricted by other aircraft on the field, including an R22 helicopter.
AAIB report said: "After lifting to hover, the pilot decided to more rearwards and then taxi behind the R22.
"He did not turn his helicopter to check that the area to his rear was clear before reversing, because of the proximity of the R22 on his right and because he did not wish to turn his tail left towards the building, where some spectators had assembled.
"The main rotor blades of G-HYND were still turning slowly and, as G-CTFL approached, one of the m struck the engine housing of the hovering helicopter."
After the collision the tail of the G-CTFL helicopter struck the ground.
Since the incident, the helipad has been extended as has a parking area for helicopters.
A mirror has been installed on a hangar to assist pilots checking behind them and the operator has banded pilots from reversing from the helipad.
The AAIB said: "It is likely that the pilot of G-CTFL was startled by the unexpected collision with the other helicopter.
"The 'startle effect' is likely to have impaired his ability to comprehend the situation and also his psychomotor skills, leading to his loss of control.
"When the helicopter operator's employees responded to the accident they did not take any fire fighting equipment to the scene, so it was fortuitous that there was no outbreak of fire before all the helicopters' occupants escaped.
"As a result, emergency response procedures have been changed, but this accident highlights the need to regularly review such procedures."