The Blackburn B-20 was an experimental aircraft, first flying in 1940, that attempted to drastically increase the performance of flying boat designs. Blackburn Aircraft undertook an independent design study based on a patent filed by their chief designer, J. D. Rennie.[1]
The B-20 was an attempt to combine the best features of both the flying boat and the floatplane. While on the water, the B-20 was essentially a floatplane, using a large float under the fuselage for buoyancy, and two smaller floats near the wing tips for stability. In flight, the main float retracted towards the fuselage, fitting into a "notch" to become streamlined as a part of the fuselage. The wing floats folded outward to become the wing tips.[2]
Blackburn along with Supermarine and Saunders-Roe tendered craft for Air Ministry Specification R1/36. What would enter service as the Saunders Roe Lerwick was the chosen aircraft but the Ministry was interested enough to authorise prototype of the B-20, serial number V8914. The prototype would fly for the first time on March 26, 1940
