Simon Glancey has submitted the following:
Corporal Brennen was one of five crew members killed when Douglas C-47A Dakota FZ674 of 575 Squadron crashed in zero visibility at airfield B.14 (Ambile), Northern France. The Dakota was taking part in a freight and casualty evacuation mission, and was on the outbound leg from R.A.F. Broadwell when it struck the ground in heavy fog.
Though without Anger: Losses of Transport and Special Duties Aircraft and Assault Gliders 1940 to 1945. C. Cummings, 2009, Nimbus Publishing, ISBN 978-0952661962, page 346
William Edward Brennen is remembered at Annitsford on A25.05 and A25.06