This was an Allied operation against U-boats transiting the Bay of Biscay (September 1943).
Typical of the operations in this important theatre was the sinking on 27 September of Kapitänleutnant Hans-Hartwig Trojer’s outward-bound U-221 by the depth-charge attack of a Handley Page Halifax long-range patrol bomber of the RAF’s No. 58 Squadron. The U-boat shot down the aeroplane before sinking, but six of the aeroplane’s eight-man crew were recovered, after 11 days at sea, by the destroyer Mahratta.
Before its loss with all 50 of its crew, U-221 had sunk 11 ships totalling 69,589 tons, as well as 10 landing craft totalling 759 tons and being carried by a transport ship, and also damaged one 7,179-ton ship.