Saunders-Roe A.33 Flying Boat
The Saunders-Roe A.33 was a four-engined flying-boat designed for the Royal Air Force in the late 1930s. It had a parasol wing and sponsons instead of wingtip floats. The sponsons also held fuel in addition to providing stability.
Prototype K4773 first flew on 14 October 1938, however only 11 days later during high speed taxi trials, it suffered a major wing failure. Further development was abandoned and a contract for 11 additional aircraft was cancelled.