The prestigious DFC that was awarded to a member of the famous 617 "Dam Busters" squadron Group Captain Ivan Whittaker which is to be auctioned at Spinks in Bloomsbury, London, it was announced. 30/04/2004: Distinguished Flying Cross awarded to Dam Buster Ivan Whittaker who retired from the RAF as a group captain in 1974, but died five years later and remains the only flight engineer to be twice awarded the Distinguished Flying Cross. His first award, received in November 1943, was for taking part in daring and hazardous operations - including the attack on dams along the Ruhr. He received a second a year later after landing a plane with badly wounded legs following a raid over France.