Modern-Aviation

The first order placed was for a total of 300 aircraft. Their serial numbers were from KB700 through KB999. These Lancasters were delivered between September 1943 and March 1945. The Lancasters with serial numbers KB700 through KB774 were fitted with Merlin 38 engines. All subsequent aircraft were fitted with Merlin 224's.

Major changes were made beginning with KB-855. The U.S. built, electrically powered Martin mid-upper turret with two .50 calibre machine guns replaced the Fraser-Nash mid-uppers. As well, "4000 pound" bomb bay doors replaced the "8000 pound" doors that were on earlier aircraft. These had enabled the aircraft to carry larger bombs and gave the Lancaster a somewhat pregnant appearance. The possibility of having a mid-under gun turret was eliminated and H2S radar was installed below the fuselage. The changes to accommodate the Martin turret were extensive as the location of the turret had to be moved forward necessitating changes to the rear centre section structure, the capacity of the electrical system had to be increased, the ammunition supply system had to be changed, and the former mid-upper turret hydraulic system eliminated.

The second order placed was for a total of 200 aircraft although only 130 were built. Their serial numbers were from FM100 through FM229. They were delivered between April 1945 and August 1945.

None of the 430 aircraft were lost while being tested at Malton. Almost all of the Lancaster Mk. X's were ferried to England and none were lost in transit.Following the end of the war in Europe, the Lancaster Mk. X's in service were flown to Canada by their crews. Many were to be used as part of "Tiger Force" that was to be the Commonwealth's contribution to the bombing war in the Pacific. Following the end of the war with Japan, almost all of the Mk. X Lancasters were put into storage. Western Canada, and in particular southern Alberta, was a preferred location because of the dry climate and the abundance of former BCATP facilities. Beginning in 1946 many of the Mk. X Lancasters were taken out of storage and modified to a variety of configurations for various duties with the RCAF.