The Vickers-Supermarine Spiteful. Meant to be the successor to the Spitfire, it was essentially a Spitfire Mk.XIV with new laminar-flow wings and a new armament of four 20mm Hispano cannons along with an inwards-retracting undercarriage. Testing began in June 1944 and the first example was delivered in March 1945 and the last example being delivered in 1947. However, the laminar flow wing actually made handling more difficult, especially towards the stall and at low speeds (as P-51 pilots could easily tell you) made it dangerous for pilots. Additionally, newer Spitfire variants such as the F.20, F.21 and F.22 were in the works thus the project was scrapped with only a few Spitefuls and Seafangs (navalised Spitfefuls for use by the Fleet Air Arm) being built with the type being declared obsolete in 1947.