The Consolidated OA-10 was the USAAF’s designation for the Catalina flying boat, used by the air force for air-sea rescue duties in the vast expanses of the Pacific. The majority of these aircraft were produced by Vickers of Canada between December 1943 and May 1945, as the OA-10A-VC, with the remaining aircraft produced by Consolidated. The AAF received 336 (or 335) PBY-5As, giving them the designation OA-10 and OA-10A, and 75 (or 76) PBY-6As with the designation OA-10B. OA was the AAF designation for Observation, Amphibian, a category that included fifteen aircraft, most if not all also used by the US Navy.
The designation OA-10-CO was given to 49 PBY-5As produced by Consolidated at San Diego between October 1941 and December 1943, and given four blocks of consecutive serial numbers.
They were followed into USAAF service by 56 OA-10A-COs (also PBY-5As) obtained individually and given non-sequential serial numbers.
The designation OA-10A-VI was given to 230 aircraft produced by Canadian Vickers for the USAAF. These aircraft had originally been designated as PBV-1As by the US Navy. These aircraft were develivered between December 1943 and May 1945.
Finally, in May-September 1945 the USAAF received 75 OA-10B-CNs, produced by Consolidated at New Orleans as part of a block of 114 PBY-6As of which another 30 went to the Soviet Union.