The Hawker P.V.4 was a 1930s British biplane aircraft built by Hawker Aircraft in competition for a government order for a general-purpose military aircraft.
The Arado W 2 was a two-seat twin-engine seaplane trainer developed for the DVS in 1928. It was a cantilever monoplane with a fabric-covered steel tube fuselage that accommodated the pilot and instructor in tandem open cockpits. The undercarriage consisted of two pontoons carried on steel struts.
The Beneš-Mráz Be-50 Beta-Minor was a light airplane manufactured in Czechoslovakia shortly before World War II.
The Focke-Wulf S 2 was a trainer aircraft built in Germany in the late 1920s. It was a conventional parasol-wing monoplane with fixed tailskid undercarriage. The pilot and instructor sat side by side in an open cockpit. Only a single example was built.
The Heston JC.6 was a British prototype air observation post aircraft designed and built by the Heston Aircraft Company Limited, who had previously built the Heston Phoenix, the Heston T.1/37 and the Napier-Heston Racer. The JC.6 was also known as the Heston A.2/45 or the Heston AOP.
The Levasseur PL.5 was a carrier-based fighter produced in France in the late 1920s, in response to the 1924 AMBC.2 specification issued by the Service Technique de l'Aéronautique (STAé). It was a conventional, single-bay sesquiplane that carried a crew of two in tandem, open cockpits. Like other Levasseur naval designs of the day, it incorporated several safety features in case of ditching at sea. Apart from small floats attached directly to the undersides of the lower wing, the main units of the fixed, tail-skid undercarriage could be jettisoned in flight, and the underside of the fuselage was given a boat-like shape and made watertight.
The Parnall Scout, unofficially nicknamed the Zeppelin Chaser, was a British fighter prototype of the 1910s. It was the first fighter design from Parnall.
The IMAM Ro.5 was a sport aircraft produced in Italy in the late 1920s. It was a conventional, parasol wing monoplane with fixed tailskid undercarriage and two open cockpits in tandem. It proved popular with private owners and flying clubs, and was built in large numbers. Some Ro.5s were purchased by the Regia Aeronautica for use as trainers and liaison aircraft. A later version, the Ro.5bis, enclosed the cockpits under a long canopy.
The Blackburn T.R.1 Sprat was a British single-engine two-seat biplane trainer, built in 1926 for advanced training, deck-landing and seaplane experience. Just one was built.
The Westland F.7/30 was a British fighter prototype. A single prototype was built in 1934, but the type was not put in production because its performance fell far below the RAF's requirements. The Gloster Gladiator won the F.7/30 competition.
The Parnall Possum was an experimental triplane, with a single, central engine driving wing mounted propellers via shafts and gears. Two of these British aircraft were built in the mid-1920s.
The Parnall Pike was a 2/3-seat biplane reconnaissance aircraft, capable of operating off carrier decks or from water, built to an Air Ministry specification in 1927. Only one was constructed.
The Parnall Pipit was a single-engined, single-seat naval fighter designed to an Air Ministry specification in 1927. Two prototypes were built but both were destroyed by tail flutter.
The PWS 3 was a Polish sport aircraft, developed in 1927 by PWS, which remained a prototype.
The IAR-22 was a single engine basic trainer built in Romania in about 1934. It was a low-wing monoplane with two seats in tandem and a fixed conventional undercarriage.
The CASA III was a 1920s Spanish two-seat monoplane, designed by Luis Sousa Peco and built by Construcciones Aeronáuticas SA (CASA) at Getafe near Madrid.
