The Fokker D.XXI fighter was designed in 1935 by Dutch aircraft manufacturer

Fokker Fokker was a Dutch aircraft manufacturer named after its founder, Anthony Fokker. The company operated under several different names. It was founded in 1912 in Berlin, Germany, and became famous for its fighter aircraft in World War I. In 1919 ...

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). The D.XXI was designed as an inexpensive, rugged, and compact fighter aircraft that would possess respectable performance for its era. Entering operational use in the early years of the Second World War, it provided yeoman service for both the '' Luchtvaartafdeling'' (Dutch Army Aviation Group) and the Finnish Air Force. Additionally, a few examples were constructed by the El Carmolí factory before it fell into

rebel A rebel is a participant in a rebellion. Rebel or rebels may also refer to: People * Rebel (given name) * Rebel (surname) * Patriot (American Revolution), during the American Revolution * American Southerners, as a form of self-identification; s ...

hands during the Spanish Civil War. Following the invasion and occupation of the Netherlands in May 1940, several captured Dutch D.XXIs were subsequently placed into service with the Luftwaffe.

Development

Origins

On 14 November 1934, design proposals for a new fighter aircraft were submitted by Fokker to the Luchtvaartafdeling (Dutch Army Aviation Group).Kamphuis 1966, p. 3. Fokker's design team, led by Erich Schatzki, and based at the firm's newly completed plant in the southern district of Amsterdam, had sought to incorporate and combine various new concepts and recent features from successful fighter aircraft, including the previous C.X and D.XVII aircraft. The proposed aircraft was a low-wing monoplane which adopted an entirely enclosed

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

; initial design work had been conducted in cooperation with British engine manufacturer Rolls-Royce, and it had been originally envisaged that the type would be powered by a Rolls-Royce Kestrel IV. Projections of the aircraft's performance included a maximum speed of 420 km/h at an altitude of 4,350 meters, a range of 888 km, and an altitude ceiling of 10,000 meters. The planned armament included

rifle A rifle is a long-barreled firearm designed for accurate shooting, with a barrel that has a helical pattern of grooves ( rifling) cut into the bore wall. In keeping with their focus on accuracy, rifles are typically designed to be held with ...

-calibre machine guns or 20mm cannons, which were to be embedded into the wings and fuselage.

In early 1935, the Luchtvaartafdeling signed a contract for a single prototype of the proposed fighter to be constructed for an evaluation to be performed by the Royal Netherlands East Indies Army. This prototype, designated ''FD-322'', which was powered by a single Bristol Mercury VI-S radial engine which drove a three-blade, two-pitch

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

, performed its maiden flight at Welschap Airfield,

Eindhoven Eindhoven () is a city and municipality in the Netherlands, located in the southern province of North Brabant of which it is its largest. With a population of 238,326 on 1 January 2022,Kamphuis 1966, pp. 3–4. According to aviation author G.H. Kamphuis, the prospects for series production of the new fighter looked doubtful shortly after the first flight was performed due to a high level change in Dutch defence policy; Minister for Foreign Affairs Hendrik Colijn informed the Ministry of War that, in response to the changing international situation, a higher priority would be placed on building up a substantial bomber capability over new fighter aircraft.Kamphuis 1966, p. 4. The change in policy emphasising bombers over fighters was somewhat controversial, in part due to order for new fighters and reconnaissance aircraft being both under consideration at this time, while a requirement for a new training aircraft had also been identified. In addition to the Luchtvaartafdeling's interest in a trainer aircraft, the service had also attached great importance to the concept of a heavily armed 'cruiser' aircraft capable of performing multiple mission types. Further doubts and confusion were added by the emergence of a competing aircraft proposal in the form of the

Koolhoven F.K.58 The Koolhoven F.K.58 was a single engine, interceptor-fighter aircraft designed and mainly manufactured by N V Koolhoven in the Netherlands under contract by France. Intended for ''Armée de l'Air'' use, the F.K.58 saw limited service in the B ...

, which had also been designed by Ir. Schatzki. The F.K.58 was somewhat more advanced than the D.XXI, possessing a retractable undercarriage and a higher top speed of 520 kmh. It was decided that the D.XXI and F.K.58 should participate in a series of comparative tests against one another, leading to the D.XXI prototype being dispatched to Soesterberg Air Base, Utrecht, in November 1936. However, head-to-head testing between the two types was delayed by the F.K.58, which did not perform its first flight until September 1938.

Into production

During 1937, the Dutch government gave funding and its approval for a limited expansion of the Army Aviation Group, which resulted in an order being placed for 36 Fokker D.XXI fighters, to be powered by the 830 h.p. Bristol Mercury VII or VIII engines. According to Kamphuis, Dutch interest in the D.XXI had been revived, in part, due to an examination of the first aircraft by an evaluation board, which itself had been conducted due to interest expressed by the Finnish Air Force, which itself would result in export sales being made to Finland. On 20 July 1938, the first Luchtvaartafdeling D.XXI conducted its first flight, after which it participated in test flights prior to deliver to Soesterberg. On 8 September 1939, the final aircraft of the first batch of 36 was delivered. Even as the domestic demand for the D.XXI was being questioned, the type had attracted the attention of a number of foreign governments.Kamphuis 1966, pp. 4, 6. In 1937, the Finnish government decided to place an order for an initial batch of seven aircraft, further negotiations were also conducted towards the acquisition of a manufacturing license, under which Finland proceeded to domestically produce further aircraft as well. Between 1939 and 1944, the State Aircraft Factory (Valtion Lentokonetehdas) at Tampere manufactured a total of 93 aircraft.Kamphuis 1966, p. 6. Throughout 1940 and 1941, the Finnish State Aircraft Factory set about reconditioning the aircraft that had been used in the Winter War for continued service; an additional 50 D.XXIs were ordered in 1941, which were powered by the

Pratt & Whitney R-1535 Twin Wasp Junior The Pratt & Whitney R-1535 Twin Wasp Junior was an engine used in American aircraft in the 1930s. The engine was introduced in 1932 as a 14-cylinder version of the 9-cylinder R-985. It was a two-row, air-cooled radial design. Displacement was ; ...

engine, acquired via Sweden.Kamphuis 1966, p. 9. These can be identified by their longer cockpit glazing, smooth cowl, and large ventral air intake under the cowl. The two fuselage-mounted machine guns on these D.XXIs were relocated in the wings and the vertical tail surface was increased in size to offset the new engine. Owing to the increased loaded weight, the R-1535-powered D.XXI had a slightly reduced performance and was not as maneuverable as the Mercury-powered versions. In 1944, five additional Finnish D.XXIs were assembled from spares.Kamphuis 1966, p. 10. The

Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish ance ...

government ordered a pair of D.XXI fighters along with arrangements for its own manufacturing license. The Danish D.XXI fighters were powered by a 645 h.p. Bristol Mercury VI-S radial and carried a

Madsen 20 mm cannon The 20 mm AA Machine Cannon M/38 was a 20 mm rapid fire autocannon produced by the Danish company Dansk Industri Syndikat (DISA). The gun, which could be adapted to several tactical uses, was a primary weapon of the military of Denmark. ...

under each wing. Ten aircraft were completed by the Royal Army Aircraft Factory in Copenhagen prior to the German invasion of Denmark in April 1940. The Second Spanish Republic also acquired a manufacturing license for the D.XXI. Reportedly, a total of 50 fuselages were manufactured on the Spanish production line; however, the Spanish plant in which the fighter was being produced was overrun by Nationalist forces before any of the Spanish-built aircraft were completed. Some sources say that a single Spanish D.XXI managed to escape capture after the production facility was captured.

Design

The Fokker D.XXI was a low-wing monoplane fighter aircraft. Following standard Fokker design practice of the period, it featured a welded steel tube fuselage that was largely covered by fabric, including the flight control surfaces; element 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

rib In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...

s made of

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

. The aircraft was outfitted with a fixed spatted undercarriage with cantilever legs; 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, and was entirely jettisonable in an emergency situation to enable pilots to

bail out A bailout is the provision of financial help to a corporation or country which otherwise would be on the brink of bankruptcy. A bailout differs from the term ''bail-in'' (coined in 2010) under which the bondholders or depositors of global sy ...

. 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 tank located aft of the engine, wing-mounted auxiliary fuel tanks could also be installed. The main armament consisted of two pairs of 7.92mm M36 FN-Browning machine guns, one pair housed within the wings, carrying 300 rounds of ammunition each, and the other pair within the forward fuselage and shooting through the propeller blades, carrying 500 rounds each. Upon its entry to service in 1938, the D.XXI represented a significant leap forward for the Dutch Army Aviation Group, whose fighter force had until that time consisted of aging biplanes with open cockpits. The new Fokker quickly proved to be an extremely sturdy aircraft, being capable of attaining a speed of 700 km/h in a dive. During the early production of the D.XXI, Fokker's design office considered a number of developments to the basic design, including a wing re-design. A number of alternative engines were considered, including such power plants as the Rolls-Royce Kestrel V and the Pratt and Whitney Twin Wasp Junior. During 1938, work on three extensively modified versions known as the 150, 151 and 152 were initiated. These aircraft were to be powered by the

Bristol Hercules The Bristol Hercules is a 14-cylinder two-row radial aircraft engine designed by Sir Roy Fedden and produced by the Bristol Engine Company starting in 1939. It was the most numerous of their single sleeve valve ( Burt-McCollum, or Argyll, typ ...

, the Rolls-Royce Merlin and the Daimler-Benz DB 600H. Retractable landing gear was incorporated into these redesigns.

Operational history

The Fokker D.XXI was first used in combat by the Finnish Air Force during the 1939–1940 Winter War between the Soviet Union and Finland.Kamphuis 1966, p. 8. Upon the war's outbreak, a total of 41 aircraft were in Finnish service, all powered by the Mercury VIII engine. On 1 December 1939, the D.XXI achieved its first victory with the shooting down of a Soviet Tupolev SB. The Fokker was evenly matched against the aircraft of the Soviet Air Force, and its rugged design with a radial engine and fixed

undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...

made it well suited for Finnish conditions. The performance of the Finnish D.XXI allegedly won the admiration of many Soviet pilots. As the Winter War continued and newer models of Soviet fighters appeared, the Fokker D.XXI proved to be increasingly 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 with 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 was not continued in the series. 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. A total of 12 D.XXI aircraft were lost during the conflict, six being lost to accidents rather than enemy action.Kamphuis 1966, pp. 8–9. The conflict between Finland and the Soviet Union was resumed in the Continuation War (1941–1944), the D.XXI was again a key element of the Finnish Air Force. During the first air battle, six Mercury-engined D.XXIs shot down a pair of Soviet

Ilyushin DB-3 The Ilyushin DB-3, where "DB" stands for ''Dalniy Bombardirovschik'' (Russian: Дальний бомбардировщик) meaning "long-range bomber", was a Soviet bomber aircraft of World War II. It was a twin-engined, low-wing monoplane that f ...

bombers. Several Finnish Air Force pilots became

fighter aces A flying ace, fighter ace or air ace is a military aviator credited with shooting down five or more enemy aircraft during aerial combat. The exact number of aerial victories required to officially qualify as an ace is varied, but is usually co ...

with the Fokker D.XXI. The top scoring Fokker ace,

Jorma Sarvanto Jorma Kalevi Sarvanto (22 August 1912 – 16 October 1963) was a Finnish Air Force pilot and the foremost Finnish fighter ace of the Winter War. Early life Sarvanto was born and raised in Turku, Finland. He attended high school in Turku and g ...

, obtained 12 5/6 victories with the type; many other future aces also scored at least one victory with the Fokker. The highest scoring airframe was FR-110, achieving 10 victories; this aircraft survived the war and is on display at the Central Finland Aviation Museum. Finland continued to operate their D.XXIs until 1949, and classified them as surplus to requirements in 1952.

Although the order by the ML-KNIL was cancelled, the '' Luchtvaartafdeling'' (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. On 10 May 1940, the day that Germany launched its invasion of the Netherlands, 28 D.XXIs were serviceable and ready for operations. That first day, six D.XXIs escorted a formation of

Fokker T.V The Fokker T.V was a twin-engine bomber, described as an "aerial cruiser", built by Fokker for the Netherlands Air Force. Modern for its time, by the Battle of the Netherlands, German invasion of 1940 it was outclassed by the airplanes of the '' ...

bombers to attack the Meuse bridges to hinder the German advance; they were intercepted by nine German

Messerschmitt Bf 109 The Messerschmitt Bf 109 is a German World War II fighter aircraft that was, along with the Focke-Wulf Fw 190, the backbone of the Luftwaffe's fighter force. The Bf 109 first saw operational service in 1937 during the Spanish Civil War an ...

s, and during the ensuing dogfight, one Bf 109 was shot down and two more damaged for the loss of one D.XXI and two T.Vs. That same day, a flight of D.XXIs intercepted and shot down 37 out of 55 inbound

Junkers Ju 52 The Junkers Ju 52/3m (nicknamed ''Tante Ju'' ("Aunt Ju") and ''Iron Annie'') is a transport aircraft that was designed and manufactured by German aviation company Junkers. Development of the Ju 52 commenced during 1930, headed by German Aeros ...

troop transports which had crossed the border during the early morning. Due to many aircraft becoming unserviceable as a result of battle damage after the first day, it was decided to regroup at

Buiksloot Buiksloot is a former village in the Dutch province of North Holland. It is now a neighbourhood of Amsterdam-Noord. Buiksloot was a separate municipality from 1811 until 1921, when it was merged with Amsterdam. From 1888 to 1956, Buiksloot had ...

, north of Amsterdam, on 11 May. For the following four days, missions out of Buiksloot were flown by D.XXIs flying in both solo and small formations to escort friendly units as well as in the search-and-destroy role. On 11 May, at least two Bf 109s were recorded as having been shot down by D.XXI fighters. Sorties against the numerically superior German forces continued until the middle of 14 May, at which point news of the Dutch capitulation reached Buiksloot, upon which both the remaining aircraft and the airstrip were destroyed to prevent their use by the Germans. Out of the original force of 28 D.XXI aircraft, eight fighters had remained airworthy.Kamphuis 1966, p. 12. The D.XXI, although much slower and more lightly armed than the Bf 109, performed surprisingly well in combat due to its manoeuvrability. It was also one of the few aircraft that could follow a ''

Stuka The Junkers Ju 87 or Stuka (from ''Sturzkampfflugzeug'', "dive bomber") was a German dive bomber and ground-attack aircraft. Designed by Hermann Pohlmann, it first flew in 1935. The Ju 87 made its combat debut in 1937 with the Luftwaffe's Cond ...

'' bomber into its dive. Nonetheless, the numerical superiority of the '' Luftwaffe'' led to the destruction of most ''Luchtvaartafdeling'' D.XXI fighters during the campaign. Some were captured during and after 15 May, but their later fates are unknown. The LVA (Netherlands Air Force) scored a total of 38 victories against the Luftwaffe during their struggle against the German juggernaut. 16 of those went to Fokker D.XXI pilots, with highest scoring being Gerben Sonderman of the 3 Ja.V.A. with 4 victories.

Variants

;D.XXI: Prototype serial no FD-322 ;D.XXI-1: Pattern aircraft supplied to Denmark, three built, powered by Bristol Mercury VIS engines. Armed with 2x machine guns and 2x

Madsen cannon The 20 mm AA Machine Cannon M/38 was a 20 mm rapid fire autocannon produced by the Danish company Dansk Industri Syndikat (DISA). The gun, which could be adapted to several tactical uses, was a primary weapon of the military of Denmark. ...

;D.XXI-1:Production aircraft built at the Royal Army Aircraft Factory, ten built powered by

Bristol Mercury VIII The Bristol Mercury is a British nine-cylinder, air-cooled, single-row, piston radial engine. Designed by Roy Fedden of the Bristol Aeroplane Company it was used to power both civil and military aircraft of the 1930s and 1940s. Developed from ...

engines. ;D.XXI-2: 53 Built, of which 36 were delivered to the

RNLAF , colours = , colours_label = , march = ''Parade March of the Royal Netherlands Air Force'' , mascot = , anniversaries = , equipment ...

. ;D.XXI-3: Finnish license-built D.XXI-2s, fitted with additional cannons in 1940. Number built: 35 ;D.XXI-4: Upgraded D.XXI-3, powered by Pratt & Whitney R-1535-SB4C-G Twin Wasp Junior engines. Number built: 55 ;Project 150: Proposed version powered by a

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

; * Hærens Flyvertropper (Danish Army Aviation Troops) – Received three aircraft and built ten on license. Locally designated as "IIIJ" ("third fighter aircraft").Salamander Books, Ltd. 1974. .London, United Kingdom: Salamander Books, Ltd., 1988. .Schrøder, Hans (1991). "Royal Danish Airforce". Ed. Kay S. Nielsen. Tøjhusmuseet, 1991, p. 1–64. . ** Jydske Flyverafdeling – two. Eskadrille ; * Finnish Air Force – Received seven aircraft and built 90 on license. **

No. 10 Squadron, Finnish Air Force No. 10 Squadron ( fi, Lentolaivue 10 or ) was a divebomber squadron of the Finnish Air Force in World War II. The squadron was part of Flying Regiment 1. Organization Winter War *1st Flight (''1. Lentue'') *2nd Flight (''2. Lentue'') *3rd Fligh ...

No. 12 Squadron, Finnish Air Force No. 12 Squadron ( fi, Lentolaivue 12 or ''LLv.12'', from 3 May 1942 ''Le.Lv.12''), renamed No. 12 Reconnaissance Squadron (Finnish: ''Tiedustelulentolaivue 12'' or ''TLe.Lv.12'' on 14 February 1944) was a reconnaissance squadron of the Finnish Air ...

No. 14 Squadron, Finnish Air Force No. 14 Squadron ( fi, Lentolaivue 14 or ''LLv.14'', from 3 May 1942 ''Le.Lv.14''), later renamed No. 14 Reconnaissance Squadron (Finnish: ''Tiedustelulentolaivue 14'' or ''TLe.Lv.14'' on 14 February 1944), was a reconnaissance squadron of the Finn ...

No. 24 Squadron, Finnish Air Force No. 24 Squadron ( fi, Lentolaivue 24 or ''LLv.24'', from 3 May 1942 ''Le. Lv.24''), renamed No. 24 Fighter Squadron (Finnish: ''Hävittäjälentolaivue 24'' or ''HLe.Lv.24'' on 14 February 1944) was a fighter squadron of the Finnish Air Force dur ...

No. 26 Squadron, Finnish Air Force No. 26 Squadron ( fi, Lentolaivue 26 or ''LLv.26'', from 3 May 1942 ''Le.Lv.26''), renamed No. 26 Fighter Squadron (Finnish: ''Hävittäjälentolaivue 26'' or ''HLe.Lv.26'' on 14 February 1944) was a fighter squadron of the Finnish Air Force durin ...

No. 30 Squadron, Finnish Air Force No. 30 Squadron ( fi, Lentolaivue 30 or ''LLv.30'', from 3 May 1942 ''Le.Lv.30''), renamed No. 30 Fighter Squadron (Finnish: ''Hävittäjälentolaivue 30'' or ''HLe.Lv.30'' on 14 February 1944) was a fighter squadron of the Finnish Air Force durin ...

No. 32 Squadron, Finnish Air Force No. 32 Squadron ( fi, Lentolaivue 32 or ''LLv.32'', from 3 May 1942 ''Le.Lv.32''), renamed No. 32 Fighter Squadron (Finnish: ''Hävittäjälentolaivue 32'' or ''HLe.Lv.32'' on 14 February 1944) was a fighter squadron of the Finnish Air Force durin ...

; * '' Luftwaffe'' – Operated an unknown number of captured Dutch aircraft. ; * Dutch Army Aviation Group – Received 36 aircraft. ;

Spanish Republic The Spanish Republic (), commonly known as the Second Spanish Republic (), was the form of government in Spain from 1931 to 1939. The Republic was proclaimed on 14 April 1931, after the deposition of King Alfonso XIII, and was dissolved on 1 A ...

Spanish Republican Air Force The Spanish Republican Air Force was the air arm of the Armed Forces of the Second Spanish Republic, the legally established government of Spain between 1931 and 1939. Initially divided into two branches: Military Aeronautics ('' Aeronáutica M ...

– May have completed one aircraft.

Aircraft on display

Aviation Museum of Central Finland The Finnish Air Force Museum ( fi, Suomen Ilmavoimamuseo), formerly the Aviation Museum of Central Finland ( fi, Keski-Suomen ilmailumuseo), is an aviation museum located near Jyväskylä Airport in Tikkakoski, Jyväskylä, Finland. The museum ...

has FR-110 on display having been restored with additional parts from FR-81 and FR-137. This plane was the personal mount of Lt. Viktor Pyötsiä in the Winter War and gained the highest number of aerial victories of all D.XXI airframes, 10 in total. Pyötsiä's score in the Winter War, 7 kills, is displayed on the vertical stabilizer. Lt. Pyötsiä scored a total of 19.5 victories. *In 2022 a flyable replica was completed at Vliegveld Hoogeveen by veteran aircraft restorer Jack van Egmond. A number of original parts was used and the plane was built according to original Fokker build specifications as Jack van Egmond is in possession of 397 out of 416 Fokker blueprints. It made its first flight on May 23rd 2022.{{cite web , url=https://www.facebook.com/watch/?v=1063523271211403 , title=First Flight Fokker D.21 229 (PH-XXI) *

Militaire Luchtvaart Museum The Militaire Luchtvaart Museum was located at Camp Zeist near the former Soesterberg Air Base. It was the official museum of the Royal Netherlands Air Force. In 2006 the Ministry of Defence decided to merge three military museums in the Netherl ...

has a replica painted in KLu markings. It was built by Fokker in 1987-1988.
Crash Foundation

Specifications (D.XXI – Finland – Mercury)

{{Aircraft specs , ref={{cite book, last=Heinonen, first=Timo, title=Thulinista Hornetiin : 75 vuotta Suomen ilmavoimien lentokoneita, year=1992, publisher=Keski-Suomen Ilmailumuseo, location=Tikkakoski, isbn=951-95688-2-4{{cite book, last=Raunio, first=Jukka, title=Lentäjän Näkökulma II., year=1993, publisher=Jukka Raunio, location=Forssa, isbn=951-96866-0-6 , prime units?=met , genhide= , crew=one , capacity= , length m=8.2 , length ft= , length in= , length note= , span m=11 , span ft= , span in= , span note= , upper span m= , upper span ft= , upper span in= , upper span note= , mid span m= , mid span ft= , mid span in= , mid span note= , lower span m= , lower span ft= , lower span in= , lower span note= , swept m= , swept ft= , swept in= , swept note= , dia m= , dia ft= , dia in= , dia note= , width m= , width ft= , width in= , width note= , height m=2.92 , height ft= , height in= , height note= , wing area sqm=16.2 , wing area sqft= , wing area note= , swept area sqm= , swept area sqft= , swept area note= , volume m3= , volume ft3= , volume note= , aspect ratio= , airfoil= , empty weight kg=1,594 , empty weight lb= , empty weight note= , gross weight kg=1,970 , gross weight lb= , gross weight note= , max takeoff weight kg= , max takeoff weight lb= , max takeoff weight note= , fuel capacity= , lift kg= , lift lb= , lift note= , more general= , eng1 number=1 , eng1 name=

, eng1 type=9-cyl. air-cooled radial piston engine , eng1 kw= , eng1 hp=830 , eng1 shp= , eng1 kn= , eng1 lbf= , eng1 note= , power original= , thrust original= , eng1 kn-ab= , eng1 lbf-ab= , eng2 number= , eng2 name= , eng2 type= , eng2 kw= , eng2 hp= , eng2 shp= , eng2 kn= , eng2 lbf= , eng2 note= , eng2 kn-ab= , eng2 lbf-ab= , eng3 number= , eng3 name= , eng3 type= , eng3 kw= , eng3 hp= , eng3 shp= , eng3 kn= , eng3 lbf= , eng3 note= , eng3 kn-ab= , eng3 lbf-ab= , more power= , prop blade number= , prop name= , prop dia m= , prop dia ft= , prop dia in= , prop dia note= , rot number= , rot dia m= , rot dia ft= , rot dia in= , rot area sqm= , rot area sqft= , rot area note= , perfhide= , max speed kmh=460 , max speed mph= , max speed kts= , max speed note= , max speed mach= , cruise speed kmh=429 , cruise speed mph= , cruise speed kts= , cruise speed note= , stall speed kmh= , stall speed mph= , stall speed kts= , stall speed note= , never exceed speed kmh=700 , never exceed speed mph= , never exceed speed kts= , never exceed speed note= , minimum control speed kmh= , minimum control speed mph= , minimum control speed kts= , minimum control speed note= , range km=930 , range miles= , range nmi= , range note= , combat range km= , combat range miles= , combat range nmi= , combat range note= , ferry range km= , ferry range miles= , ferry range nmi= , ferry range note= , endurance= , ceiling m=11,350 , ceiling ft= , ceiling note= service ceiling , g limits= , roll rate= , glide ratio= , climb rate ms= , climb rate ftmin= , climb rate note= , time to altitude={{convert, 6,000, m, ftin, abbr=on, 0 in 7 min 30 sec , sink rate ms= , sink rate ftmin= , sink rate note= , lift to drag= , wing loading kg/m2= , wing loading lb/sqft= , wing loading note= , disk loading kg/m2= , disk loading lb/sqft= , disk loading note= , fuel consumption kg/km= , fuel consumption lb/mi= , power/mass=0.309 kW/kg (0.188 hp/lb) , thrust/weight= , more performance= , armament=* 4 × {{convert, 7.7, mm, in, abbr=on, 3 Vickers machine guns , guns= , bombs= , rockets= , missiles= , hardpoints= , hardpoint capacity= , hardpoint rockets= , hardpoint missiles= , hardpoint bombs= , hardpoint other= , avionics=

References

Citations

{{Reflist

Bibliography

* De Jong, Peter. ''Le Fokker D.21 (Collection Profils Avions 9)'' (in French). Outreau, France: Éditions Lela Presse, 2005. {{ISBN, 2-914017-26-X. * Eberspacher, Warren. ''Fokker D-XXI, Volume 1: Dutch and Danish Aircraft (International Squadron Monograph No.1)''. St. Paul, MN: Phalanx Publishing Co. Ltd., 1994. {{ISBN, 1-883809-05-3. * Gerdessen, Frits. ''Nederlandse Militaire Luchtvaartt VI: Fokker D-XXI (deel 2)'' (in Dutch). Spijkenisse, the Netherlands: Stichting Vrienden van het Militaire Luchtvaart Museum/Afdeling Luchtvaartkennis KNVvL, 1991. No ISBN. * Gerdessen, Frits and Luuk Boerman. ''Fokker D.XXI: History, Camouflage and Markings – Operations of the LVA/ML Fokker D.XXI (Dutch Profile 5)'' (bilingual Dutch/English). Zwammerdam, the Netherlands: Dutch Decal, 2007. No ISBN. * Green, William. "D-XXI: Ancestor of Alliance". ''RAF Flying Review'' Vol. XVII, No. 12. * Green, William. "Four Guns and a Canopy". ''RAF Flying Review'', Vol. 19, No. 2. * Green, William. "The 'Halfway-House' Fokker". ''Air Enthusiast'', August 1971. * Green, William. "The Last of the Fighting Fokkers". ''RAF Flying Review''. * Heinonen, Timo. ''Thulinista Hornetiin – 75 vuotta Suomen ilmavoimien lentokoneita'' (in Finnish). Tikkakoski, Keski-Suomi, Finland : Keski-Suomen ilmailumuseo, 1992, {{ISBN, 951-95688-2-4. * Hooftman, Hugo. ''Fokker D-XXI (Nederlandse Vliegtuig Encyclopedie 5)'' (in Dutch). Bennekom, the Netherlands: Cockpit-Uitgeverij, 1978. * Kamphuis, G.H. ''The Fokker D.XXI (Aircraft in Profile number 63)''. Leatherhead, Surrey, UK: Profile Publications Ltd., 1966. * Keskinen, Kalevi, Kari Stenman and Klaus Niska. ''Fokker D.XXI (Suomen Ilmavoimien Historia 3)'' (in Finnish, with English summary) . Espoo, Finland: Tietoteos, 1974 (2nd edition 1977). {{ISBN, 951-9035-15-X. **4th improved edition republished in two parts as: ***Keskinen, Kalevi and Kari Stenman. ''Fokker D.XXI ercury(Suomen Ilmavoimien Historia 3a)'' (in Finnish). Helsinki, Finland: Hobby Kustannus Oy, 2000. {{ISBN, 952-5334-02-3. ***Keskinen, Kalevi and Kari Stenman. ''Fokker D.XXI

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(Suomen Ilmavoimien Historia 3b)'' (in Finnish). Helsinki, Finland: Hobby Kustannus Oy, 2000. {{ISBN, 952-5334-03-1. * Ledwoch, Janusz. ''Fokker D.XXI (Wydawnictwo Militaria 5)'' (in Polish). Warsawa, Poland: Wydawnictwo Militaria, 1995. {{ISBN, 83-86209-34-8. * Raunio, Jukka. ''Lentäjän näkökulma 2'' (in Finnish). Forssa, Finland, 1993. {{ISBN, 951-96866-0-6. * Skulski, Przemysław. ''Fokker D.21 (Seria "Pod Lupą" 10)'' (in Polish, with English summary). Wrocław, Poland: Ace Publication, 1999. {{ISBN, 83-86153-79-2. * Taylor, John W.R. "Fokker D.XXI" ''Combat Aircraft of the World from 1909 to the present''. New York: G.P. Putnam's Sons, 1969. {{ISBN, 0-425-03633-2. * Toll, Karl. "The Last of the Fighting Fokkers". ''Airpower'', January 1982.

External links

{{Commons category, Fokker D.XXI
Fokker D.XXIs to Finland
{{Webarchive, url=https://web.archive.org/web/20060925152812/http://www.sci.fi/~fta/fr-fin-1.htm , date=2006-09-25

Rebuild Fokker Holland
{{Fokker aircraft {{Authority control D 21 1930s Dutch fighter aircraft Single-engined tractor aircraft Low-wing aircraft Aircraft first flown in 1936 World War II aircraft of Finland