U.S. Army AC-1/CV-2A Caribous
The Army ordered 159 Caribou aircraft from DeHavilland starting in 1960. They were given the designation AC-1. The first aircraft (60-3762) was delivered in January, 1961. The production Caribou differed from the 5 prototypes in several ways (although none were significantly altered the Caribou's basic airframe).
The prototype's three-section main landing gear doors were changed to a two gear door on the AC-1 and the right cabin door was made jettison able. The auxiliary power unit (APU) was relocated from the left engine nacelle to the left fuselage side. An oxygen system was installed and web seats were installed in the cabin replacing the earlier solid seats. A total of 56 AC-1s were built by June of 1961. these aircraft were redesignated in 1962 to CV-2A. (Thanks to Wayne Mutza for this information)
U.S. Army AC-1A/CV-2B Caribous
To meet U.S. Department of Transportation requirements, the AC-1 was modified with a number of internal structural improvements to the airframe so that the caribou could operate at a gross weight of 28,500 pounds. These changes were significant and the Army designated all Caribous produced after July 11, 1961 as AC-1As with deliveries of the new variant starting during 1963. Before deliveries began, the Army redesignated the AC-1A to CV-2B in 1962.
The primary external difference between the CV-2A and CV-2B was the installation of an AN/APN-158 weather avoidance radar in the nose mounted radome. This radar installation was later refitted to the CV-2As and the five prototypes YAC-1s. A total of 103 CV-2Bs were built for the Army. When the Caribous were transferred to the U.S. Air Force in 1967 they were redesignated as C-7As. (Thanks to Wayne Mutza for this information)