09/30/2011. Remarks by Johan Visschedijk: "The Seagull was originally designed to the 1940 Air Ministry Specification S12/40 for an advanced fleet reconnaissance amphibian, capable of ship stowage. Three prototypes were ordered under contract Air/4562/CB.20(b) of April 9, 1943, Air Ministry serials assigned were PA143, PA147 and PA152. Research and shifting operational requirements led to the changed Specification S.14/44 issued November 27, 1944 that covered an air-sea rescue and reconnaissance flying boat.
Powered by an 1,815 hp Rolls-Royce Griffon 29 twelve-cylinder liquid-cooled V-engine, the first prototype, PA143, made its first flight on July 14, 1948 from the water at Itchen with Lt.Cdr. Mike Lithgow at the controls. A number of modifications were made during flight testing, the most significant one was the adding of a central fin to improve directional stability.
The second prototype PA147 was first flown, also by Lithgow, on September 2, 1949, and in October made 44 landings at the carrier HMS Illustrious, and on July 22, 1950 gained the World's Speed Record for amphibians with 241.9 mph (389.3 kmh). Experiments and flight testing continued, but they, with the only partly completed third prototype PA152, were eventually sold as scrap in 1952."