Frederick Mockridge was the son of Frederick and Elizabeth Mockridge of Derby, qualifying as an Air Gunner on 30 July 1943 and posted to 58 Squadron, which was then part of Coastal Command. His first operational sortie was in a Halifax patrol of the Bay of Biscay on 13 Nov 1943, joining the crew of W/O. Clive Desmond Young a week later. Switching from anti-submarine duties to anti-shipping patrols in the English Channel, Mockridge's crew attacked shipping near Granville on 20 July 1944 and attacked a U-Boat on 30 July 1944.
In Sep 1944, Mackridge was taking part in patrols in the North Atlantic and off the Norweigan coast. On 16 Oct 1944, Young was piloting Halifax II HX178 when crashing into the sea, killing all crew including Mockridge and his New Zealander colleague, Douglas James Edmiston. Mockridge is remembered on the Runnymede Memorial. A letter from 58 Squadron's Commanding Officer to Mrs Mockridge details:
"The aircraft in which he was flying as air gunner crashed into the sea at about 2110hrs on 16 Oct after carrying out a training exercise. A naval vessel saw the crash and located the wreckage at once, but found no survivors. Several ships and aircraft joined in the search and the body of the pilot was found during the morning. We are unable to discover the cause of the accident, as the weather was good, the pilot was extremely competent and had my complete confidence. Frederick was a skilful and resolute member of a very good crew, and we shall all miss him."