| J 23 | |
|---|---|
 | |
| Role | Fighter aircraft |
| National origin | Sweden |
| Manufacturer | Flygcompaniets Verkstäder at Malmen (FVM) |
| Designer | Henry Kjellson and Ivar Malmar |
| First flight | June 1923 |
| Number built | 5 |
The FVM J 23 was a Swedish single seat, single engine, parasol wing fighter aircraft built in the mid-1920s. Five were flown but the type never reached operational status because of structural concerns raised by a fatal accident.
The parasol wing of the J 23 had a thick airfoil section, a straight leading edge and a trailing edge which curved forwards to elliptical tips. In the central region the wing became thinner and the chord decreased in front of the cockpit. [1] [2] It was of wooden, two spar construction [3] and plywood covered apart from the ailerons. [4] These were angled, fabric covered and small but slotted to improve their efficiency. Parallel pairs of airfoil section flying struts ran on each side from the lower fuselage to the wing spars at about one third span. Over the fuselage a pair of N-form cabane struts leaned inwards to meet at the wing's centre. [2]
Like the wing, the fuselage and empennage of the J 23 were wooden structures. The elliptical cross section fuselage consisted of pre-shaped, stress bearing plywood panels around a light framework of frames and stringers. [2] [4] The pilot's open cockpit was just aft of the trailing edge, from where he could see both over the wing and through the narrow gap between wing and fuselage. The six cylinder BMW IIIa engine had a fixed pair of machine gun over it in the forward fuselage and its honeycomb radiator was in the nose, with the propeller shaft set low. [1] This was a high compression engine which could only develop full power at altitude, enabling the J 23 to fly high and fast. [2] [5] Its top speed was claimed to be 220 km/h (137 mph) at 1,000 m (3,280 ft) but 250 km/h (155 mph) at 3,000 m (9,840 ft). [2] The 8 mm (0.3 in) m/22 were synchronized, firing through the propeller. [4] At the rear the ply covered fin was surprisingly [2] small and low, though the fabric covered rudder extended down to the keel. The rudder carried a trim tab. [2] [4] The J 23's cantilever, low aspect ratio, D-shaped, ply covered tailplane was mounted on top of the fuselage, carrying balanced elevators with cut outs for rudder movement. [1]
Its fixed undercarriage had mainwheels on a rigid axle, rubber sprung from the crosspiece between two tall V-form legs mounted on the fuselage at the same points as the interplane struts. [1] [4] The axle and crosspiece were enclosed within an airfoil section fairing, which provided some additional lift. [4]
The J 23 first flew in June 1923 and was tail heavy, a fault rectified by an increase in length [4] (several sources, e.g. [1] put the length at about 6.90 m (22 ft 8 in) but L'Aérophile, a year after the first flight, [3] gives 8.50 m (27 ft 11 in)). By July five examples had been built and all appeared at the Gothenburg International Aero Show [1] late in that month. [2] On 10 August 1923 one set a Swedish altitude record of 8,000 m (26,247 ft). [3] Military testing proceeded until 15 March 1924, when there was a fatal, structural wing failure on one J 23. Though work on the aircraft continued and some modifications like an increase in tail area were made, the J 23 was thereafter seen as too fragile for service use. [1]
Work had also been proceeding on the J 24, similar to the J 23 but with a much more powerful 224 kW (300 hp) Hispano-Suiza 8F V-8 engine. Following the J 23 accident, the sole J 24 was converted into a single bay biplane designated the J 24B. It was flown in 1925 but, overweight, its performance was not good enough to interest the military. [1]
Data from Green and Swanborough p. 235 [1]
Data from Green and Swanborough p.235 [1]
General characteristics
Performance
Armament
The SIAI S.51, Savoia Marchetti S.51 or Savoia S.51 was an Italian racing flying boat built by SIAI for the 1922 Schneider Trophy race.
The Siemens-Schuckert D.VI was a single engine, single seat, parasol wing German fighter aircraft flown in 1919.
The Pfalz D.XV was a German single seat fighter aircraft which was approved for production right at the end of World War I, too late to enter service.
The Wibault 8 or Wib 8 Simoun (Simoon) was a tandem seat, parasol wing fighter aircraft designed and built in France to a 1925 specification which was later withdrawn; only one Wib 8 was completed.
The Wibault 12 Sirocco or Wib 12 Sirocco was a two-seat, parasol wing fighter aircraft designed and built in France in the 1920s. Three fighter prototypes were completed, one for the RAF and two Army co-operation variants. There was no series production.
The Wibault 13C.1 Trombe (Whirlwind), later known as the Wib 130C.1 Trombe was a single seat, parasol wing lightweight fighter aircraft designed and built in France in the 1920s. It was developed into the more powerful Wib 170C.1 Tornade (Tornado) but government interest in lightweight fighters soon waned.
The Letov Š-3 was a single-seat, single-engine parasol wing fighter aircraft designed and built in Czechoslovakia in the early 1920s. Only one was completed and flown, its makers preferring to develop a biplane fighter.
The Hanriot H.26 was a French single seat fighter aircraft prototype completed in 1923. Only one was built.
The LFG Roland D.XV was a World War I German single seat fighter aircraft, ordered as a test-bed for engine comparisons. It was distinguished from earlier Roland biplane designs by the elimination of flying wires. Two later aircraft, also called LFG Roland D.XV, were completely different designs with slab sided fuselages.
The LFG Roland D.XVI, initially designated the LFG Roland E.I, was a single-seat, single-engine, parasol wing German fighter aircraft flown close to the end of World War I. Only two were built.
The LFG Roland D.XVII was a single-seat, single-engine, parasol wing German fighter aircraft flown close to the end of World War I. Only one was built.
The Albatros L.66 was a simple, low powered, two seat sports and training parasol wing monoplane, built in Germany in the mid-1920s.
The Gidroplan Che-22 Korvet is a three-seat, parasol-wing flying boat designed and built in Russia in the 1990s. It can have one or two engines and may be configured as an amphibian. At least eighty have been produced.
The Lioré et Olivier LeO 8, Lioré et Olivier LeO 8-Cau 2 or Lioré et Olivier LeO 8 CAN 2 was a French two seat, parasol wing monoplane night fighter and reconnaissance aircraft, built in 1923.
The Potez 26 was a single seat fighter aircraft designed and flown in France in the mid-1920s. It did not reach production.
The Potez 27 was a French reconnaissance biplane first flown in 1924. 175 were operated by the Polish Air Force, most built in Poland by PWS under licence. Others went to Romania, where they were also used as light bombers.
The Aviméta 88 was an all-metal French two-seat reconnaissance-fighter or heavy fighter tested in 1927.
The Salmson-Béchereau SB-5 was a two-seat fighter aircraft built for a French government programme in 1925. Despite a powerful engine it did not perform well and only one was built.
The Morane-Saulnier MS.300 and MS.301 were French parasol wing introductory trainer aircraft, first flown in 1930. They differed only in engine type. Neither reached production but were developed into two similar trainers, the MS.230 and MS.315, which were made in large numbers.
The Brown 1926 parasol monoplane was a 1920s US, three seat, parasol wing civil aircraft developed from a biplane wartime scout. It was intended for either the private or commercial passenger markets, though one was used as a crop-duster.