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Description

Link: www.flickr.com/photos/dizzyfug…

Some background:
The Fokker D.XX fighter was designed in 1935 by Dutch aircraft manufacturer Fokker as a conservative export alternative to the D.XXI monoplane. The latter had been developed in response to requirements laid out by the Royal Netherlands East Indies Army Air Force (Militaire Luchtvaart van het Koninklijk Nederlands-Indisch Leger, ML-KNIL), but Fokker saw a good deal of market potential for the aircraft in Europe, too, but was afraid that many smaller European air forces still preferred conservative biplane designs.

As a consequence, the D.XX was developed in parallel to the D.XXI and both aircraft shared many components, primarily the fuselage and the tail section. Like its D.XXI stablemate the D.XX biplane was designed as an inexpensive, rugged, and compact fighter aircraft that would possess respectable performance for its era.

Following standard Fokker design practice of the period, the D.XX featured a welded steel tube fuselage that was largely covered by fabric, including the flight control surfaces, but elements forward of the trailing edges of the wings were covered by detachable aluminum panels instead. The wings were of a wooden construction, being composed of two box spars attached to ribs made of plywood, and covered by fabric, too. The aircraft was outfitted with a fixed, spatted undercarriage with cantilever legs, and braking was provided by independently-operated pedals using compressed air.

The cockpit of the D.XXI was fully enclosed by a plexiglas hood featuring large sliding sections. The canopy was entirely jettisonable in an emergency situation to enable pilots to bail out. Pilots were protected against turnover injuries by means of a pylon built into the structure of the aircraft set behind the seat. Fuel was housed in a 77-gallon tank located aft of the engine, and an auxiliary fuel tank could also be installed behind the pilot seat.

Main armament consisted of two pairs of 7.92mm M36 FN-Browning machine guns, two being housed within the forward fuselage above the engine, requiring the latter to be synchronized in order to shoot through the propeller blades, and another pair was carried in fairings under the lower wings, outside of the propeller arc.

Initially, the Fokker D.XX was powered by the 830 h.p. Bristol Mercury VII or VIII engines, but for export customers a number of alternative engines were considered, too. These included such power plants as the 650 h.p. Rolls-Royce Kestrel V and the 750 h.p. Pratt and Whitney Twin Wasp Junior. There were even plans to mount the 1,050 h.p. Rolls-Royce Merlin and the 1,090 h.p. Daimler-Benz DB 600H, both coupled with a radiator installation under the fuselage.

However, interest in the Fokker D.XX was low, since the monoplane promised much superior performance and future development potential. Compared with the Fokker D.XXI, the D.XX lacked top speed and acceleration, but it had, thanks to its much bigger wing area, a better rate of climb and was the superior dogfight aircraft.

Anyway, with the D.XXI as direct in-house competitor and very similar aircraft like the Gloster Gladiator on the market, Fokker's last biplane aircraft was not a success. A major contract with Sweden for an initial batch of 30 aircraft and rights for further license production did not materialize. Other prospects, e. g. Lithuania, Latvia, Greece, Egypt and Yugoslavia, settled upon aircraft of British production, and in the end only Norway and Denmark bought the biplane fighter.
Total production, including two prototypes and three pre-production aircraft, only reached a mere 46 machines, and none of them survived the first months of the 2nd World War.

General characteristics (Danish version):
Crew: one
Length: 8.2 m (26 ft 11 in)
Wingspan: 10.6 m (34 ft 8 ½ in)
Height: 2.92 m (9 ft 7 in)
Wing area: 28m² (300 sq ft)
Empty weight: 1,594 kg (3,514 lb)
Loaded weight: 4,594 lb (2,088 kg)

Powerplant:
1 × Bristol Mercury VIII 9-cyl. air-cooled radial piston engine, 620 kW (830 hp)

Performance:
Maximum speed: 253 mph (220 knots, 407 km/h) at 14,500 ft (4,400 m)
Cruise speed: 338 km/h (210 mph; 186 kn)
Stall speed: 85 km/h (53 mph; 46 knots)
Range: 930 km (578 mi; 502 nmi)
Endurance: 2 hours
Service ceiling: 11,350 m (37,240 ft)
Rate of climb: 11.7 m/s (2,300 ft/min)
Climb to 10,000 ft (3,050 m): 4.75 min
Power/mass: 0.309 kW/kg (0.188 hp/lb)

Armament:
4× 8 mm (0.315 in) machine guns with 500 RPG in the fuselage and 300 RPG under the lower wings

Description

Link: www.flickr.com/photos/dizzyfug…

Some background:
The Fokker D.XX fighter was designed in 1935 by Dutch aircraft manufacturer Fokker as a conservative export alternative to the D.XXI monoplane. The latter had been developed in response to requirements laid out by the Royal Netherlands East Indies Army Air Force (Militaire Luchtvaart van het Koninklijk Nederlands-Indisch Leger, ML-KNIL), but Fokker saw a good deal of market potential for the aircraft in Europe, too, but was afraid that many smaller European air forces still preferred conservative biplane designs.

As a consequence, the D.XX was developed in parallel to the D.XXI and both aircraft shared many components, primarily the fuselage and the tail section. Like its D.XXI stablemate the D.XX biplane was designed as an inexpensive, rugged, and compact fighter aircraft that would possess respectable performance for its era.

Following standard Fokker design practice of the period, the D.XX featured a welded steel tube fuselage that was largely covered by fabric, including the flight control surfaces, but elements forward of the trailing edges of the wings were covered by detachable aluminum panels instead. The wings were of a wooden construction, being composed of two box spars attached to ribs made of plywood, and covered by fabric, too. The aircraft was outfitted with a fixed, spatted undercarriage with cantilever legs, and braking was provided by independently-operated pedals using compressed air.

The cockpit of the D.XXI was fully enclosed by a plexiglas hood featuring large sliding sections. The canopy was entirely jettisonable in an emergency situation to enable pilots to bail out. Pilots were protected against turnover injuries by means of a pylon built into the structure of the aircraft set behind the seat. Fuel was housed in a 77-gallon tank located aft of the engine, and an auxiliary fuel tank could also be installed behind the pilot seat.

Main armament consisted of two pairs of 7.92mm M36 FN-Browning machine guns, two being housed within the forward fuselage above the engine, requiring the latter to be synchronized in order to shoot through the propeller blades, and another pair was carried in fairings under the lower wings, outside of the propeller arc.

Initially, the Fokker D.XX was powered by the 830 h.p. Bristol Mercury VII or VIII engines, but for export customers a number of alternative engines were considered, too. These included such power plants as the 650 h.p. Rolls-Royce Kestrel V and the 750 h.p. Pratt and Whitney Twin Wasp Junior. There were even plans to mount the 1,050 h.p. Rolls-Royce Merlin and the 1,090 h.p. Daimler-Benz DB 600H, both coupled with a radiator installation under the fuselage.

However, interest in the Fokker D.XX was low, since the monoplane promised much superior performance and future development potential. Compared with the Fokker D.XXI, the D.XX lacked top speed and acceleration, but it had, thanks to its much bigger wing area, a better rate of climb and was the superior dogfight aircraft.

Anyway, with the D.XXI as direct in-house competitor and very similar aircraft like the Gloster Gladiator on the market, Fokker's last biplane aircraft was not a success. A major contract with Sweden for an initial batch of 30 aircraft and rights for further license production did not materialize. Other prospects, e. g. Lithuania, Latvia, Greece, Egypt and Yugoslavia, settled upon aircraft of British production, and in the end only Norway and Denmark bought the biplane fighter.
Total production, including two prototypes and three pre-production aircraft, only reached a mere 46 machines, and none of them survived the first months of the 2nd World War.

General characteristics (Danish version):
Crew: one
Length: 8.2 m (26 ft 11 in)
Wingspan: 10.6 m (34 ft 8 ½ in)
Height: 2.92 m (9 ft 7 in)
Wing area: 28m² (300 sq ft)
Empty weight: 1,594 kg (3,514 lb)
Loaded weight: 4,594 lb (2,088 kg)

Powerplant:
1 × Bristol Mercury VIII 9-cyl. air-cooled radial piston engine, 620 kW (830 hp)

Performance:
Maximum speed: 253 mph (220 knots, 407 km/h) at 14,500 ft (4,400 m)
Cruise speed: 338 km/h (210 mph; 186 kn)
Stall speed: 85 km/h (53 mph; 46 knots)
Range: 930 km (578 mi; 502 nmi)
Endurance: 2 hours
Service ceiling: 11,350 m (37,240 ft)
Rate of climb: 11.7 m/s (2,300 ft/min)
Climb to 10,000 ft (3,050 m): 4.75 min
Power/mass: 0.309 kW/kg (0.188 hp/lb)

Armament:
4× 8 mm (0.315 in) machine guns with 500 RPG in the fuselage and 300 RPG under the lower wings