[MOC] Schneider Trophy - Supermarine S.5 (Venice 1927)

Hod Carrier · April 12

<-- Macchi M.39 (Hampton Roads 1926)

After coming so close to winning the Schneider Trophy outright, interest in the contest in the United States had begun to wane. The US Navy had already stated that it no longer wished to participate and the Army had yet to declare its intentions. It appeared that there would be no official entry sent to Venice to defend the Trophy.

American interest came only in the form of a private entry from Navy Lt. Alford J. Williams with an aircraft designed by Charles Kirkham. Looking like an enlarged Curtiss R3C, the Kirkham-Williams was to be powered by the 1,250hp Packard X-2775 engine, a 24-cylinder X configuration engine basically comprising the cylinder banks from two Packard V-1500 12-cylinder vee engines stacked one on top of the other on a shared crankcase. Problems with the engine and doubts over its performance relative to the competition meant that the aircraft was withdrawn.

In the meantime, Britain was starting to take the contest much more seriously and had understood that specially trained pilots would be required to get the best out of high-speed aircraft such as those required to win the Schneider Trophy. In the period following the 1925 contest, the Air Ministry had contracted Gloster, Short and Supermarine to produce racing seaplanes and, in 1926, the RAF High Speed Flight was established to provide the pilots who would fly these designs.

The result of these efforts was ten new racing aircraft to three different designs, the most that Britain had ever assembled to contest the Schneider Trophy. Gloster had built three Gloster IV biplanes to individual and slightly different specifications, all using versions of the Napier Lion VII engine. Supermarine had built a similar number of S.5 monoplanes using the same powerplants, while the Short-Bristow Crusader (nicknamed “Curious Ada” by the pilots of the High Speed Flight) ploughed a slightly different furrow in that it used an 860hp Bristol Mercury 9-cylinder radial engine.

With the Kirkham-Williams racer already out of the contest and the Italian team set, the British took as many as six of their potential entries to Venice for final evaluation; two Gloster IVs (IVA and IVB), the Crusader and two or possibly three of the Supermarine S.5s. The Crusader had been troublesome from the start and the selection of a radial engine had resulted in an aircraft with a huge frontal area which made streamlining difficult. In the end, it was withdrawn following a crash on a test flight caused by the aileron control wires having been reversed. In the end, the decision was made to enter two of the S.5s and the Gloster IVB, which would become the last biplane ever to contest the Schneider Trophy.

The design of the Supermarine S.5 incorporated some of the lessons learned the hard way with the S.4. There would be no unbraced cantilever wings and the general layout of the aircraft was changed to improve visibility for the pilot. The Napier Lion VII engine now lived under a very close-fitting cowling to reduce drag and use was made of wing surface radiators for cooling. Engine oil was cooled in corrugations that ran down the fuselage sides.

Given the success of the Macchi M.39, Italy decided to take a slightly more conservative, evolutionary approach. The result would be the Macchi M.52, powered by the 1,000hp FIAT AS.3, the most powerful engine used in the contest at the time. Problems during testing meant that some concerns remained about the reliability of the engine so, to act as an insurance policy, one of the Macchi M.52s would fly with the older 800hp AS.2 powerplant.

Caution regarding engine reliability was clearly well-placed. Just as he crossed the start line, the AS.3 in Capt. Arturo Ferrarin’s M.52 expired and he was out of the race immediately. Maj. Mario de Bernardi, flying the other AS.3 powered M.52, lasted only until the second lap when a connecting rod failed and punched a hole in the crankcase. The hopes of Italy retaining the Schneider Trophy rested on the shoulders of Capt. Frederico Gauzetti in the third of the Macchis, but the technique favoured by the Italian team for taking the almost 180 degree turns on the course was not as efficient as the British technique and he started to fall behind. In the end, his race was ended prematurely when a fuel line broke and sprayed fuel around and into the cockpit forcing his retirement.

Also forced into retiring was Flt Lt. S. Kinkead in the Gloster IVB, which had appeared to lose performance as the race went on. When the aircraft was inspected it was found that the splined propellor shaft had cracked three quarters of the way around its circumference. This just left the two Supermarine S.5s to complete the race, with Flt Lt. S. Webster coming in ahead of Flt Lt. O. Worsley. Webster, who had lost track of how many laps he had flown, flew one additional lap just to make sure of the victory.

An unsuccessful world speed record attempt was made using an S.5 flown by Flt Lt. Kinkead. Diving into the run to gain speed, Kinkead failed to level out and flew the S.5 into the sea, causing his death. It is likely that the conditions (flat calm sea and light mist) meant that he failed to see the horizon and that he could not correctly judge his height and the attitude of the aircraft in order to pull up.