Simon Glancey has submitted the following:
Pilot Officer Hetherington was the Navigator aboard Avro Lancaster X KB749 NA-A of 428 (R.C.A.F.) Squadron, which was lost on a mission to bomb the Luftwaffe airfield at Soesterberg. The Lancaster exploded in mid-air, killing five of the seven crew, including P/O Hetherington. The Pilot and Flight Engineer were thrown clear by the explosion, and survived to become Prisoners of War.
Royal Air Force Bomber Command Losses of the Second World War: 1944; W.R. Chorley; 1997; Midland Counties Publications; ISBN 0 904597 91 1, page 385
He is remembered in Ashington on A17.43