Sorry Gareth, I got the information by going to Google, typing "Lord Stansgate" and opening a link "William Wedgwood Benn". The following is the relevant excerpt from the text of that link:

"Although nearly sixty-three at the outbreak of the Second World War, Benn enlisted in the Royal Air Force as a pilot officer. Over the next four years he flew on several operational missions. Given the rank of Air Commodore, Benn worked for a while as Director of Public Relations at the Air Ministry. In 1944 he became a member of the Allied Control Commission that had the responsibility of reconstructing a democratic government in Italy.

In December 1940, Benn was asked by Clement Attlee to become a Labour member of the House of Lords. At that time all peerages were hereditary and meant that on his death, the title would be transferred to his eldest son. He therefore discussed it with Michael, his eldest son, telling him that "If you don't want to go to the House of Lords, I shall turn it down." Michael had already decided he wanted to be an Anglican clergyman and replied that he (his father) could argue for socialism in the House of Lords while Tony, the younger brother, could do the same in the House of Commons. Benn took the title Lord Stansgate.

Michael and Tony Benn both joined the Royal Air Force during the war. Tony successfully served as a pilot officer in South Africa and Rhodesia, but Michael was tragically killed on 23rd June, 1944, when as a result of a faulty air speed indicator, his aircraft crashed at Chichester.

After the 1945 General Election, Clement Attlee appointed Lord Stansgate as his Secretary of State for Air. He held the post until October 1946, but continued to play an active role supporting the Labour Party in the House of Lords until his death on 17th November 1960.