On 17 April 1934, the prototype T.S.R II, "K4190", performed its maiden flight, flown by Staniland. In comparison with the previous prototype, K4190 was equipped with a more powerful model of the Pegasus engine, an additional bay within the rear fuselage to counteract spin tendencies, and the upper wing was slightly swept back to account for the increased length of the fuselage; along with other aerodynamic-related tweaks to the rear of the aircraft. During the ensuing flight test programme, K4190 was transferred to Fairey's factory in Hamble-le-Rice, Hampshire, where it received a twin-float undercarriage in place of its original land-only counterpart; on 10 November 1934, the first flight of K4190 in this new configuration was performed. Following successful water-handling trials, K4190 conducted a series of aircraft catapult and recovery tests aboard the battlecruiser HMS "Repulse". K4190 was later restored to its wheeled undercarriage prior to an extensive evaluation process by the Aeroplane and Armament Experimental Establishment at RAF Martlesham Heath.