SR.N1

The SR.N1 participated in the test programme for four years prior to its retirement, by which point it had served its purpose in successfully validating the concept and further hovercraft had been developed.

In less than four years following the SR.N1's maiden flight, multiple hovercraft were being designed and produced by several companies in the United Kingdom, as well as in France by Jean Bertin and Japan by Mitsubishi Shipbuilding & Engineering under a license given by Westland Aircraft.

[4] Also during this time, British engineer and inventor Christopher Cockerell had been exploring his own concepts on how to produce more efficient fast-moving watercraft, involving multiple technologies such as inflatable air cushions, pump-jets and centrifugal fans; these would effectively emerge as a single new form of amphibious vehicle, later known as the hovercraft.

[5] Having tested and found substance to his theories during the early 1950s, Cockerell proceeded to approach various aircraft companies and shipbuilders, but had difficulty gaining their backing, in part due to a lack of understanding of the technologies involved.

These reports confirmed the validity of Cockerell's theories and data in addition to noting the considerable potential of the hovercraft concept; Saunders-Roe was keen to be awarded a further contract to continue its research.

[13] In 1959, a specialised subsidiary of the NDRC, named Hovercraft Development Limited (HDL), for which Cockerell was appointed as technical director to handle the contract with Sauders-Roe and built up a patent portfolio.

[14] Saunders-Roe determined that, in addition to more theoretical work, a test programme involving a large-scale radio-controlled model would be necessary to provide sufficient data to make progress, and produced a proposal to this effect on 4 September 1958.

It was controlled from a small cab placed just forward of the cylindrical centre piece set into the middle of the deck which contained the craft's engine and horizontally mounted fan.

Forward and backward thrust was provided via a set of longitudinal ducts which were fixed to either side of the craft's deck and supplied with air from the engine housed within the cylindrical centre piece to which they were attached.

[14] The supporting research for the acquisition of such patents had been typically performed by HDL, who conducted extensive experiments and built full-scale test beds as part of their activities.

[23] This engine run was aborted when telemetry from onboard accelerometers had indicated high stress levels which threatened the craft's structural stability in the long term; these stresses had been generated as the result of an integral shroud that had been placed around the plane of the fan to increase aerodynamic efficiency, and was quickly resolved by its removal, providing greater clearance for the tips of the fan blades.

[24] More extensive test runs of the engine revealed a few minor issues, such as a level of instability within the valves of the thrust control system, which were modified accordingly ahead of the scheduled first flight.

While the demonstration was only intended to involve land-based motion, in response to pressure from enthusiastic journalists, the company decided to proceed with the first water-based flight on that day as well.

[28] The demonstration received considerable press coverage, the majority of which being largely positive; reportedly, the craft was dubbed by some in the media as "the flying saucer".