Lancaster LM101 took off from RAF Waddington at 2329 hours on the night of 20/21st July 1944 to bomb railway yards at Coutrai, Belgium. Bomb load 11 x 1000lb and 4 x 500lb bombs. Nothing was heard from the aircraft after take-off and it did not return to base. Fourteen aircraft from the Squadron took part in the raid and two of these including LM101 failed to return.
Post war it was established that the aircraft crashed near Marke (West Vlaanderen) in the south west outskirts of Coutrai, and all the crew were killed. FO Jeffery is buried in the Kortrijk (Coutrai) (St Jan) Communal Cemetery, Belgium, while the other six crew members are buried in the Parish Cemetery Wevelgem, Belgium, which is located 22kms east of the Ieper (Ypres) town centre.