PBY Catalina was the United States Navy designation for an American and Canadian-built flying boat of the 1930s and 1940s. PB stands for Patrol Bomber, with Y being Consolidated Aircraft’s manufacturer identification. It could be equipped with depth charges, bombs, torpedoes, and .50 caliber machine guns and was one of the most widely used multi-role aircraft of World War II. Catalinas served with every branch of the US military and in the air forces and navies of many other nations. In the United States Army Air Forces and later in the USAF their designation was the OA-10, while Canadian-built PBYs were known by the nickname Canso.