| D.XXI | |
|---|---|
 | |
| Role | Fighter |
| Manufacturer | Fokker |
| Designed by | Erich Schatzki |
| First flight | 27 March 1936 |
| Primary users | Finnish Air Force Dutch Air Force Danish Air Force |
Contents
|
Design and development
The Fokker D.XXI was a low wing monoplane with a steel tube fuselage covered in large part by fabric. Following some of the standard Fokker design practice, it had wooden wings and a fixed spatted undercarriage. Power was provided by a Bristol Mercury radial driving a three-blade two-pitch airscrew. When it entered service in 1938 it was a quantum leap forward for the Dutch Army Aviation Group though. Until then its fighter force had consisted of aging biplanes with open cockpits. The new Fokker proved to be an extremely sturdy aircraft capable of attaining a speed of 700 km/h in a dive.
Operational history
In 1936 a few Fokker D.XXIs were used by the Spanish Republic. Although the order by the ML-KNIL was cancelled, the Luchtvaartafdeeling (Dutch Army Air Force before World War II) placed an order of 36 aircraft, which were all delivered in time to participate in the war against the Germans in May 1940. The Fokker D.XXI, although much slower and more lightly armed than the Bf 109, performed surprisingly well in dogfights, due to its maneuverability. It was also one of the few aircraft that could follow a Stuka bomber into its dive. Nonetheless, the numerical inferiority of the Luchtvaartafdeeling compared to the Luftwaffe resulted in the destruction of most Dutch Fokker D.XXI fighters during the campaign. Some were captured during and after 15 May, but their fates, apart from their capture, are unknown.[2]The Fokker D.XXI performed better and for much longer in the Finnish Air Force, which had acquired a number of licence-built fighters prior to the start of the Winter War. Against the aircraft of the Soviet Air Force, the Fokker was more evenly matched, and its rugged design with a radial engine and fixed undercarriage made it very suitable for Finnish conditions. Later in the war, as newer models of Soviet fighters appeared, the Fokker D.XXI was underpowered and too lightly armed (with only four 7.92 mm/.312 in machine guns) to compete. Plans to arm the Fokkers with 20 mm cannons were dropped and only one fighter was armed as such (two 20 mm cannons and two 7.92 mm/.312 in machine guns). Another fighter was equipped with retractable landing gear, but due to less than anticipated performance improvement, wasn't continued in the series. During the Continuation War (1941–44) the Finnish State Aircraft Factory (Valtion Lentokonetehdas, VL) also built some 50 D.XXIs with the Swedish-built Pratt & Whitney R-1535 Twin Wasp Junior as the Bristol Mercury was in short supply. These can be identified by their longer cockpit glazing, smooth cowl, and large ventral air intake under the cowl. The fixed undercarriage lent itself to both unimproved runways and conversion to skis for winter use, both of which were advantages in the Finnish theater.
Several Finnish Air Force pilots became fighter aces on Fokker D.XXI, top scoring Fokker ace being Jorma Sarvanto with 12 5/6 victories. Many other aces scored at least one victory on Fokker. The highest scoring airframe is FK-110, with 10 victories, which survived the war, and is on display at Central Finland Aviation Museum.
Variants
- D.XXI-1 : First production aircraft, they were delivered to Denmark. Number built: 2
- D.XXI-2 : 36 were delivered to the RNLAF. Number built: 53
- D.XXI-3 : Finnish license-built D.XXI-2s. Number built: 38
- D.XXI-4 : Upgraded D.XXI-3, powered by R-1535-SB4C-G Twin Wasp Junior engine 825 hp (615 kW). Number built: 50
- D.XXI-5 : Upgraded D.XXI-4, powered by Bristol Pegasus radial engine 920 hp (686 kW). Number built: 5
- Project 150 : Proposed version powered by a Bristol Hercules radial piston engine. Not built.
- Project 151 : Proposed version powered by a Rolls-Royce Merlin piston engine. Not built.
- Project 152 : Proposed version powered by a Daimler-Benz DB.600H engine. Not built.
Operators
- Danish Army Air Corps received 7 aircraft and built 15 on license.
- Finnish Air Force received 7 aircraft and built 90 on license.
- Luftwaffe operated an unknown number of captured Dutch aircraft.
- Dutch Army Aviation Group received 36 aircraft.
Popular culture
A converted North American Harvard trainer masqueraded as a Fokker D.XXI for the Paul Verhoeven movie Soldier of Orange (1977).Specifications (D.XXI)
Data from Lentäjän Näkökulma & Thulinista Hornetiin
General characteristics- Crew: One, pilot
- Length: 8.20 m (26 ft 11 in)
- Wingspan: 11.00 m (36 ft 1 in)
- Height: 2.95 m (9 ft 8 in)
- Empty weight: 1,594 kg (3,511 lb)
- Max takeoff weight: 1,970 kg (4,399 lb)
- Powerplant: 1× Bristol Mercury VIII air-cooled, 9-cylinder, radial, 618.76 kW (830 hp)
- Never exceed speed: 700 km/h (434 mph)
- Maximum speed: 460 km/h (285 mph)
- Cruise speed: 429 km/h (267 mph)
- Range: 930 km (502 nmi, 574 mi)
- Service ceiling: 11,350 m (36.089 ft)
- Rate of climb: 6,000 m in 7 min 30 sec (19,680 ft)
- Power/mass: 405 hp/t ()
- 4 × 7.92 mm (.312 in) FN Browning M36 machine guns
No comments:
Post a Comment