Port Victoria P.V.5

The Port Victoria P.V.5 was a British single-engined floatplane fighter aircraft of the First World War. A single example was built and flown at the Royal Naval Air Service's Port Victoria Marine Experimental Aircraft Depot on the Isle of Grain in 1917. Despite demonstrating good manoeuvrability and handling, no production followed, with the Royal Naval Air Service instead using landplanes for the fighter role.

Design and development
In 1916, the Air Department of the British Admiralty issued a requirement for a single-seater fighter floatplane. The specification demanded a speed of 85 kn at 6500 ft, an endurance of four hours and an armament of a single machine gun and two 65 lb (30 kg) bombs. The use of a 150 hp Smith Static radial engine as powerplant was requested.

The Port Victoria Marine Experimental Aircraft Depot prepared two designs to meet the requirement. One, the Port Victoria P.V.5, was a development of its earlier P.V.2 sesquiplane, while the other, the P.V.5A was a more conventional biplane.

Both the P.V.5 and P.V.5A were nearing completion in late 1916, but the absence of their intended engines delayed testing. The Smith Static was an experimental ten-cylinder single-row radial engine developed by the American John W. Smith, which had attracted the attention of the Admiralty because of its light weight and promised low fuel and oil consumption, but proved to be a failure, with only a few engines ever completed. When it was realised at Grain that the Smith Static (which was to be used by the P.V.4 and P.V.5A as well as the P.V.5) would not be forthcoming, a 150 hp Hispano-Suiza 8 V8 engine was obtained, and it was decided to modify the P.V.5 to use it. Soon after, in January, overall control for the supply of aircraft was transferred to the Ministry of Munitions, who subjected the operations of Port Victoria to increased scrutiny, and while it was decided to continue work on the P.V.5, development of the P.V.5A was suspended.

The P.V.5's wing bracing struts also carried the aircraft's floats, forming a "W" shape when viewed from the front, with no bracing wires used, while a high-lift wing section, developed by the National Physical Laboratory and used on the Port Victoria P.V.1 and P.V.2 was again employed. Armament was the specified single synchronised Vickers machine gun, with the two 65 lb bombs carried internally. The Hispano-Suiza engine was enclosed in an annular cowling and drove a two-bladed propeller. Flat-bottomed pontoon-type floats were fitted, which were angled outwards to divert spray away from the engine and propeller.

The P.V.5, serial number N53, finally flew in July 1917, but capsized when it alighted at the end of its first flight due to a float failing. The aircraft proved to be manoeuvrable and pleasant to fly, with a good view from the cockpit, but performance was less than required by the specification, this being blamed by Port Victoria on the aircraft's propeller being poorly matched to the aircraft, and the Hispano-Suiza engine being heavier than the Smith Static that the aircraft was originally designed for. No production followed, with the fighter requirements of the Royal Naval Air Service eventually being met by landplanes such as the Sopwith Pup and Camel