Airfix 1/72 617 Squadron Dambusters 80th Anniversary set A50191As the first of 20 modified Avro Lancasters arrived at RAF Scampton on 8th April 1943, the specially assembled volunteer crews of specialist 'Squadron X' (later allocated the RAF squadron number 617) from within 5 Group Bomber Command must have been intrigued. The new aircraft were B. III (Specials), referred to at Avro's Woodford factory as Lancaster Type 464 Provisioning and each one had been modified with equipment to deliver the Vickers Type 464