Simon Glancey has submitted the following:
Sgt. Dadswell was killed when Avro Lancaster III ED606 JO-E of 463 (R.A.A.F.) Squadron collided with another Lancaster, ND637 CF-L of 625 Squadron while preparing to land at R.A.F. Waddington after a mission to Stuttgart. The Lancasters collided near Branston, 4 miles south east of Lincoln, and crashed with the loss of all fourteen crew members from both aircraft.
Royal Air Force Bomber Command Losses of the Second World War: 1944; W.R. Chorley; 1997; Midland Counties Publications; ISBN 0 904597 91 1, pages 115 and 116
Also killed in the same incident were Sgt. J.G.B. Jameson, Sgt. A.W. Aiston and Sgt. J.A. Coates
John Douglas Dadswell is remembered at Westoe in W101.08 page 24, and in the RAF Book of Remembrance, page 29.