Born: 1923, Ipswich.
Died: 31st August 1943; age: 20; KiA on air operations.
Rank: Sergeant/Flight Engineer; Service Number: 1615700.
Regiment: Royal Air Force Volunteer Reserve, 15 Squadron.
Relatives Notified & Address: Son of Herbert Stephen & Gladys Brock, of Ipswich.
Father: Herbert Stephen Brock, born October 1892, Norwich, Norfolk.
Mother: Gladys Brock (nee Manwaring), born 1891, Norwich, Norfolk.
Derek was a member of the 10th Ipswich Scout Group.
31st August 1943
Aircraft: Stirling III; Serial Number: EE954; Code: LS-J; Based: Mildenhall, Suffolk. Derek was the Flight Engineer to Flight Sergeant Norman Lindsay Thomas and his crew on the Stirling. They were on the homeward journey, after a bombing mission on the city of München-Gladbach, North Rhine-Westphalia, Germany. A German night fighter made a firing pass at the whole length of the Stirling with canon and machine gun fire. The attack by the enemy machine was made from below and the crew had no intimation of it until cannon shells exploded in the forward portion of the fuselage causing extensive damage, Derek was killed, and the aircraft caught fire.
Despite the smoke and the damaged state of his aircraft Flight Sergeant Thomas retained control and organised his crew to combat the flames. It was through his skill in handling his aircraft and crew in a very difficult situation that a badly damaged aircraft was brought safely home to England. He has always shown himself to be a very reliable Captain of his aircraft and the most determined in pressing home his attack. He is recommended for the award of the Distinguished Flying Medal.