The Consolidated PBY Catalina, also known as the Canso in Canadian service, is an American flying boat, and later an amphibious aircraft of the 1930s and 1940s produced by Consolidated Aircraft. It was one of the most widely used seaplanes of World War II. Catalinas served with every branch of the United States Armed Forces and in the air forces and navies of many other nations.
During World War II, PBYs were used in anti-submarine warfare, patrol bombing, convoy escort, search and rescue missions (especially air-sea rescue), and cargo transport. The PBY was the most numerous aircraft of its kind, and the last military PBYs served until the 1980s. As of 2014, nearly 80 years after its first flight, the aircraft continues to fly as a waterbomber (or airtanker) in aerial firefighting operations in some parts of the world.
The designation "PBY" was determined in accordance with the U.S. Navy aircraft designation system of 1922; PB representing "Patrol Bomber" and Y being the code assigned to Consolidated Aircraft as its manufacturer. Catalinas built by other manufacturers for the U.S. Navy were designated according to different manufacturer codes, thus Canadian Vickers-built examples were designated PBV, Boeing Canada examples PB2B (there already being a Boeing PBB) and Naval Aircraft Factory examples were designated PBN. In accordance with contemporary British naming practice of naming seaplanes after coastal port towns, Royal Canadian Air Force examples were named Canso, for the town of that name in Nova Scotia. The Royal Air Force used the name Catalina and the U.S. Navy adopted this name in 1942. The United States Army Air Forces and later the United States Air Force used the designation OA-10. U.S. Navy Catalinas used in the Pacific against the Japanese for night operations were painted black overall; as a result these aircraft were sometimes referred to locally as "Black Cats".
The PBY was originally designed to be a patrol bomber, an aircraft with a long operational range intended to locate and attack enemy transport ships at sea in order to disrupt enemy supply lines. With a mind to a potential conflict in the Pacific Ocean, where troops would require resupply over great distances, the U.S. Navy in the 1930s invested millions of dollars in developing long-range flying boats for this purpose. Flying boats had the advantage of not requiring runways, in effect having the entire ocean available. Several different flying boats were adopted by the Navy, but the PBY was the most widely used and produced.
Although slow and ungainly, Catalinas distinguished themselves in World War II. Allied forces used them successfully in a wide variety of roles for which the aircraft was never intended. PBYs are remembered for their rescue role, in which they saved the lives of thousands of aircrew downed over water. Catalina airmen called their aircraft the "Cat" on combat missions and "Dumbo" in air-sea rescue service.
As American dominance in the Pacific Ocean began to face competition from Japan in the 1930s, the U.S. Navy contracted Consolidated, Martin and Douglas in October 1933 to build competing prototypes for a patrol flying boat. Naval doctrine of the 1930s and 1940s used flying boats in a wide variety of roles that today are handled by multiple special-purpose aircraft. The U.S. Navy had adopted the Consolidated P2Y and Martin P3M models for this role in 1931, but both aircraft were underpowered and hampered by inadequate range and limited payloads.
Consolidated and Douglas both delivered single prototypes of their new designs, the XP3Y-1 and XP3D-1, respectively. Consolidated's XP3Y-1 was an evolution of the XPY-1 design that had originally competed unsuccessfully for the P3M contract two years earlier and of the XP2Y design that the Navy had authorized for a limited production run. Although the Douglas aircraft was a good design, the Navy opted for Consolidated's because the projected cost was only $90,000 per aircraft.
Consolidated's XP3Y-1 design (company Model 28) had a parasol wing with external bracing struts, mounted on a pylon over the fuselage. Wingtip stabilizing floats were retractable in flight to form streamlined wingtips and had been licensed from the Saunders-Roe company. The two-step hull design was similar to that of the P2Y, but the Model 28 had a cantilever cruciform tail unit instead of a strut-braced twin tail. Cleaner aerodynamics gave the Model 28 better performance than earlier designs. Construction is all-metal, stressed-skin, of aluminum sheet, except the ailerons and wing trailing edge, which are fabric covered.
The prototype was powered by two 825 hp (615 kW) Pratt & Whitney R-1830-54 Twin Wasp radial engines mounted on the wing's leading edges. Armament comprised four .30 in (7.6 mm) Browning AN/M2 machine guns and up to 2,000 lb (910 kg) of bombs.
The XP3Y-1 had its maiden flight on 28 March 1935, after which it was transferred to the U.S. Navy for service trials. The XP3Y-1 was a significant performance improvement over previous patrol flying boats. The Navy requested further development in order to bring the aircraft into the category of patrol bomber, and in October 1935, the prototype was returned to Consolidated for further work, including installation of 900 hp (670 kW) R-1830-64 engines. For the redesignated XPBY-1, Consolidated introduced redesigned vertical tail surfaces which resolved a problem with the tail becoming submerged on takeoff, which had made lift-off impossible under some conditions. The XPBY-1 had its maiden flight on 19 May 1936, during which a record non-stop distance flight of 3,443 mi (2,992 nmi; 5,541 km) was achieved.
The XPBY-1 was delivered to VP-11F in October 1936. The second squadron to be equipped was VP-12, which received the first of its aircraft in early 1937. The second production order was placed on 25 July 1936. Over the next three years, the design was gradually developed further and successive models introduced.
The aircraft eventually bore the name Catalina after Santa Catalina Island, California; the name was coined in November 1941, as Great Britain ordered their first 30 aircraft.
An estimated 4,051 Catalinas, Cansos, and GSTs of all versions were produced between June 1937 and May 1945 for the U.S. Navy, the United States Army Air Forces, the United States Coast Guard, Allied nations, and civilian customers.
The Naval Aircraft Factory made significant modifications to the PBY design, many of which would have significantly interrupted deliveries had they been incorporated on the Consolidated production lines. The new aircraft, officially known as the PBN-1 Nomad, had several differences from the basic PBY. The most obvious upgrades were to the bow, which was sharpened and extended by two feet, and to the tail, which was enlarged and featured a new shape. Other improvements included larger fuel tanks, increasing range by 50%, and stronger wings permitting a 2,000 lb (908 kg) increase in gross takeoff weight. An auxiliary power unit was installed, along with an improved electrical system, and the weapons were upgraded with continuous-feed mechanisms.
138 of the 156 PBN-1s produced served with the Soviet Navy. The remaining 18 were assigned to training units at NAS Whidbey Island and the Naval Air Facility in Newport, Rhode Island. Later, improvements found in the PBN such as the larger tail were incorporated into the amphibious PBY-6A.