During the Second World War, the importance of Allied strategic bombing of military targets meant that heavy bombers had to be available. The Air Transport Auxiliary (ATA) was a British wartime civilian organization, headquartered at White Waltham Airfield, Berkshire, England that ferried new, repaired and damaged military aircraft between factories, assembly plants, transatlantic delivery points, Maintenance Units (MUs), scrap yards to active service squadrons and airfields. The Royal Air Force (RAF) also created a special unit, the RAF Ferry Command, to meet the needs of delivering aircraft from aircraft factories in North America to RAF operational squadrons in a timely manner.