A Royal Air Force Merlin HC3A helicopter is pictured during a training flight over Oxfordshire, Buckinghamshire The HC3 and HC3a are operated by No.28 (AC) Squadron and 78 Squadron at RAF Benson.No.78 Squadron was re-formed on 3 Dec 07 to allow for the increase in aircraft after the purchase of the 6 Danish Merlin HC3a earlier in 2007.The Merlin is the first of a new generation of advanced, medium support helicopters for the RAF. It is an all weather, day and night, multi-role helicopter used in both tactical and strategic operational roles.