The memorials, at the Upwood, Warboys and Mepal bases, formed part of an ambitious project by the Airfields of Britain Conservation Trust (ABCT) to mark every known disused airfield site in Britain. It has already installed more than 100 memorials and expects to have more than 200 in place by the end of the year. The charity unveiled the Upwood and Warboys memorials on July 27 and the one at Mepal the following day, after a long period of planning and co-operation between itself and local stakeholders. A spokesman for ABCT said: "Upwood remains a most famous airfield which dates back to the First World War when it was originally known as Bury. Heavily used by many famous bomber aircraft types and their units between the late 1930s and the early 1960s, Upwood then gave excellent RAF service as primarily a ground station before being taken over by the United States Air Force in the 1980s." Much of the airfield site is now derelict. Nearby Warboys was originally a satellite airfield for Upwood but became an independent base in its own right. The spokesman added: "It played a major part in RAF Bomber Command's Pathfinder Force operations, seeing Avro Lancaster and De Havilland Mosquito squadrons. "One of Britain's most famous bomber pilots, 'Hamish' Mahaddie, served as station commander and his son will be attending the memorial unveiling." Mepal, near Ely, housed Short Stirlings and Avro Lancasters which played a major part of the RAF's bombing offensive until the end of the war. The ABCT spokesman said: "As with Upwood and Warboys, Mepal continues to be an evocative and highly relevant place, also epitomising the sheer timelessness that is a striking feature of Britain's airfields." Further information is at www.abct.org.uk.