Synopsis
On 13 October 2006, a Eurocopter EC120B, registration N526AG, and a Hughes OH-6A, registration N239MY, were involved in an accident at Tougher Business Park, County Kildare. The EC120B was landing after a short flight from Carlow, while the OH-6A was parked on the ground with its main rotor nearly stopped. The EC120B's rotor downwash caused the OH-6A's main rotor to strike its tailboom, resulting in damage. No injuries occurred.
History of the Flight
The Eurocopter EC120B departed from a site in Carlow for a 20-minute flight to a private landing site at Tougher Business Park near Newbridge. The pilot, the sole occupant, was familiar with the site, having visited it several times in the preceding two months. The landing site was a level grass field at an elevation of approximately 350 feet above mean sea level. The pilot brought the helicopter to a hover in an open area east of the intended landing site, where he observed a helicopter on the ground with its main rotor almost stopped. He then approached from the hover position, passed to the left of the parked helicopter, and landed some distance beyond.
Damage
The Hughes OH-6A, which had landed minutes earlier, was parked with its pilot outside. As the EC120B passed in close proximity, its rotor downwash caused the OH-6A's main rotor blade to strike the tailboom. The OH-6A sustained damage to the tailboom, a main rotor blade, and the associated rotor damper. The EC120B was undamaged.
Licensing
Both helicopters were registered in the United States and operated in Ireland. The pilot of the OH-6A held a US Commercial Pilot's Licence (Helicopter) issued by the FAA. The pilot of the EC120B held a JAA Private Pilot's Licence (Helicopter) issued by the UK CAA, a current Medical Certificate Class II issued by the Irish Aviation Authority, and was rated on the Eurocopter EC120 and Robinson R44 types. Federal Aviation Regulations and Irish Aviation Authority licensing orders permitted the pilot of N526AG to operate a US-registered aircraft in Ireland with his UK licence.
Ownership
The Eurocopter EC120B was registered to Southern Aircraft Consultancy, a trustee in the United Kingdom, and operated in Ireland by the beneficial owner. This arrangement is common for non-US citizens to own US-registered general aviation aircraft.
Discussion
The main rotor of a helicopter produces significant downwash, which can affect nearby objects. A parked helicopter with stationary or low-rpm rotor blades is susceptible to damage from downwash, as the blades may flap downward and strike the tailboom or cockpit canopy. In this case, the proximity of the maneuvering helicopter was sufficient to cause damage to the parked helicopter.