Fokker D.VII - Fokker's Triumph

  Fokker had struggled since the eclipse of his Eindeckers, and his famous Triplane was only a partial success. Limited to the same engines and weapons his competitors used, Fokker needed a significant breakthrough to build a dramatically better airplane, and he finally achieved it in the Fokker D.VII with its wing of innovative structural and aerodynamic design.
  Although sharing its engine and armament with the Albatros, Pfalz, and other German designs, the Fokker D.VII introduced important structural and aerodynamic innovations that greatly improved its effectiveness. By far the most important was its thick wooden wing built around a box spar. The thick wing, with its rounded leading edge, offered high lift and exceptional stalling characteristics, making the D.VII maneuverable and easy to fly and enabling it to ‘hang on its prop’ without stalling. These exceptional handling qualities made good pilots out of average ones and made aces out of good pilots. Other designers used thin airfoils because they had somewhat less drag than the thick Fokker wing. However, the strong Fokker wing eliminated the need for the extensive system of bracing wires that thin airfoils required. The combined drag of thin airfoils with their bracing wires was significantly more than the drag of the thick Fokker wing which needed no external bracing wires, and this was the secret to the Fokker’s improved speed and climb with the same power.
  Due to relatively stagnant engine development, upon its introduction to service the Fokker D.VII was powered by the same basic Mercedes engine used in the Albatros scouts in August 1916! It was not until the new BMW engine finally arrived in June/July that the Fokker D.VII fulfilled its full potential and became the premier fighter of the war. The BMW engine was similar to the familiar 160 hp Mercedes D.III engine but developed its 185 hp at 2,000 meters altitude because it was over-compressed. That meant it could not be run at full throttle until reaching the thinner air at 2,000 meters without detonation and engine damage. This design gave it more power at high altitude for increased speed and exceptional climb.
  Mercedes countered with the over-compressed 180/200 hp D.IIIau and finally the 200/220 hp D.IIIavu, the latter having greater bore. The Mercedes 180/200 hp D.IIIau was installed in most D.VIIs, and the 200/220 hp D.IIIavu was installed in a few late examples. The D.IIIavu gave performance equivalent to the BMW.
  Although the BMW-powered Fokker D.VII became a legend in its own time, there were never enough of them to win the air war for Germany. Only about 1/6 of D.VIIs at the Front were powered by the BMW engine.
  Two items were key to Fokker fighter evolution, the engine and the wing design. The above table shows the differences in specifications between types. The D.II(MAG) was a reinforced development of the Fokker D.IV that differed mainly in its use of the more powerful 185 hp Daimler, which gave the aircraft more speed and better climb rate than the D.IV. Unsurprisingly, the Fokker D.VII powered by the 185 hp BMW had better speed and much better climb than the D.VII powered by the 170 hp Mercedes. The D.VII was much stronger than the D.IV.
  All the types were similar in their use of steel-tube fuselage and tail structure, 6-cylinder water-cooled engines, and two machine guns. The D.VII’s use of a nose radiator reduced cooling drag compared to the bulky side radiators of the D.IV and D.II(MAG), an incremental improvement of the design.
  However, the key difference was the wing design.The thick airfoil, cantilever wing of the D.VII was a fundamental advantage in several respects. For one, although it was similar in weight to the thin wing, it was significantly stronger, which made the D.VII much safer and more robust than the earlier D.IV, which was relegated to training due to fragility. In addition, the cantilever wing allowed elimination of most of the drag-producing bracing wires, contributing to the better speed and climb enjoyed by the D.VII. Finally, the rounded wing leading edge gave the D.VII much better stall characteristics.
  The excellent stall characteristics of the D.VII wing gave it important advantages that may not be obvious to readers who are not pilots. First, the air flow separation from the thick, rounded wing is gradual as the angle of attack increases; the resulting turbulence gives the pilot advance warning of the approaching stall. This enables the pilot to either avoid the stall by reducing the angle of attack, or to knowingly enter the stall if that gave a tactical advantage. Also, the wing can fly at higher angles of attack, giving greater lift and another tactical advantage. The behavior during the stall was also more benign and stall recovery was straightforward.
  In comparison, the thin wing with sharper leading edge used by the D.IV and all competing Allied fighters stalled abruptly with little warning for the pilot, and aircraft behavior during the stall was generally dramatic compared to the gentle behavior of the D.VII. For all but expert pilots, the result was that pilots avoided approaching the stall and were not able to fly their aircraft to their limits to get the most performance and maneuverability out of them. This explains the saying that the D.VII made good pilots out of average pilots; they were able to fly the D.VII to its limits and their opponents generally were not. After being re-equipped with the D.VII, German pilots doubled their rate of scoring victories. In January 1917 Fokker received an order for 200 AEG C.IV (240-439/17) two-seaters for use as trainers. This occurred because Fokker had no original designs suitable for production and Idflieg wanted to utilize Fokker’s unused production capacity. In July 1917 Fokker received a second order for 200 AEG C.IV (6500-6699/17) two-seaters.
  Upon the D.VII winning the First Fighter Competition, Fokker needed that production capacity. He asked for cancellation of the AEG C.IV contract for the remaining part of the C.IV contract and Idflieg agreed. The contract for AEG C.IVs 6600-6699/17 were cancelled and the work numbers were not reused.
  Production of the BMW IIIa engine was only sufficient to power about 1/3 of Fokker-built D.VII fighters; the others had to rely on the Mercedes D.IIIa. Far fewer BMW engines went to Albatros and OAW, so perhaps 1/6 of all D.VIIs at the front had the BMW. In July 1918 the new 185 hp Mana Ill was installed in D.VII 4292/18, and post-armistice in 10347/18 and 10348/18. The Mercedes 180/200 hp D.IIIau was installed in most D.VIIs, and the 200/220 hp D.IIIavu was installed in a few late examples.


Fokker D.VII Specifications
Engine: 185 hp BMW IIIa
Wing: Span 8.90 m
Area 20.2 m2
General: Length 6.954 m
Height 2.945 m
Empty Weight 688 kg
Loaded Weight 906 kg
Maximum Speed: 200 km/h
Climb: 1000m 1.8 min
2000m 4.0 min
3000m 7.0 min
4000m 10.2 min
5000m 14.0 min
6000m 18.7 min


Fokker Fighter Evolution
Fokker Type D.IV D.II(MAG) D.VII D.VII
Engine 160 hp Mercedes D.III 185 hp Daimler(MAG) 170 hp Mercedes D.IIIa 185 hp BMW IIIa
Wing Span, m 9.7 10.2/9.70 8.90 8.90
Wing Chord, m 1.25 1.23 1.60/1.20 1.60/1.20
Wing Gap, m 1.32 1.30 — —
Wing Area, m2 22.5 21.4 20.2 20.2
Length, m 6.3 6.70 6.954 6.954
Height, m 2.45 2.55 2.945 2.945
Empty Weight, kg 606 645 654 688
Loaded Weight, kg 841 865 844 906
Max Speed, km/h 160 175 190 200
Climb to: 1,000 m 3 3.1 3.0 1.8
2,000 m — — 6.5 4.0
3,000 m 12 11.0 11.0 7.0
4,000 m 30 — 17.3 10.2
5,000 m — 34.9 22.5 14.0
6,000 m — — — 18.7
Note: Climb times in minutes.


Fokker D.VII Production Orders
Date Quantity Ordered
   Fokker Albatros & OAW
Feb. 1918 300 400
March 1918 — 200
June 1918 100 200
July 1918 200 300
Aug.1918 - 300
Aug. 1918 - 300
Sept. 1918 200 -
Oct. 1918 200 300
Nov. 1918 - 200
Total 1,000 2,200
Note: The above are German orders. 630 Austro-Hungarian-built D.VIIs were ordered in August 1918 as follows: Fokker - 225, MAG - 150, Aviatik - 255. Few were completed.


Fokker D.VII Serial Numbers
Manufacturer Serial Numbers
Fokker 227-526/18
Albatros 527-926/18
OAW 2000-2199/18
OAW 4000-4199/18
Fokker 4250-4449/18
OAW 4450-4649/18
Fokker 5050-5149/18
Albatros 5200-5599/18
OAW 6300-6649/18
Albatros 6650-6899/18
Fokker 7604-7805/18*
OAW 8300-8649/18
Albatros 10050-10100/18**
Fokker 10347-10399/18***
Notes: * Includes two experimental aircraft
** Only two aircraft identified
*** 37 built in this range.

Fokker E.V/D.VIII

  During the Second Fighter competition, held at Berlin - Adlershof in May-June 1918, Fokker entered two new Oberursel UR.II-powered monoplane prototypes with cantilever wings, the V25 and the V28.
  An airframe offering even better overall performance than the Fokker D.VI was required, and it was to be compatible with both the 110 hp UR.II engine as well as the more powerful UR.III eleven-cylinder engine, which was expected to replace it on the Oberursel production line soon.
  Other companies also entered similarly-powered prototypes, such as Pfalz with their D.VI and Kondor with their D.II. But the Fokker designs stole the show, especially these two monoplanes.
  Of all the rotary-powered prototypes evaluated at this competition, the Fokker V.28 was decided to have the best overall performance. Fokkers other entry in the category, the low-wing V25, was rejected due to the limited downward visibility, in spite of its excellent performance. Oddly, the mid- and low-wing layout of the early Fokker E-types caused no reservations three years earlier.
  The V28 was flown with both the nine-cylinder UR.II, which later powered most production examples, as well as eleven-cylinder UR.III. Tests were also conducted with the Goebel Goe.III and Siemens-Halske Sh.III engines.
  Very quickly the V.28 was ordered into production under the official designation Fokker E.V after the mandatory type-tests were successfully passed in early July 1918. Interestingly, the first five examples of the type were accepted as early as 3 July, before frontline pilots at the competition came to the decision that the type should be put into production. The E.V had impressed pilots at the competition so much that half of the production order that had been placed for the Fokker D.VI was cancelled in order to free manufacturing capacity for the new monoplane fighter. The E.V not only had much better performance, it was also easier to build, and the plywood-covered wing saved linen fabric that was needed to cover the airframes of almost all aircraft then in production in Germany.
  Unlike the D.VI, the Fokker E.V was obviously intended right from the start to serve at the most active sectors at the front with some of the most prolific fighter units. The component unit of choice in Jagdgeschwader I was Jagdstaffel 6. The Staffel received nine or ten examples on 5 August. Jagdstaffel 19 (JG II) was selected to receive the E.V in early August as well, and in Jagdgeschwader III the component unit of choice was Jagdstaffel 36. It is worth noting that these three units had all operated the Fokker Dr.I until fairly recently. In fact, Jagdstaffel 36 was still operating a few Triplanes as late as August, Jasta 19 flew them until mid-June, and Jasta 6 until mid-May. Consequently, many of the pilots in these Jastas were still accustomed to the rotary engine, as were the ground crews. And all three Staffeln mentioned had operated the Fokker D.VII before they received the E.V. This fact is clear evidence that the overall performance of the new monoplane was not considered to be inferior to the D.VII in any way.
  Further examples of the E.V were delivered to the Marine Feld Jagdstaffeln, as well as to some of the component Jastas of Jagdgruppe 1 and Jagdgruppe 12. Considering that, a large number of the new fighters were delivered within a few weeks, it is likely that single examples found their way to other Jagdstaffeln as well.
  The Fokker “Parasol”, as it was quickly dubbed by the Jasta pilots, left a lasting impression on those flew them and encountered them in combat.
  It is not known for sure which Jasta was the first to receive the new fighter. The aircraft delivered to Jasta 6 are well documented, and it is known that many of the E.Vs delivered to the unit on 3 or 5 August were accepted at Schwerin between 13 and 19 July. However, 14 examples were accepted between 3 and 12 July, and logic would imply that these were delivered a bit earlier to other units than Jasta 6. One of the five aircraft accepted on 3 July was 107/18, which crashed at Jasta 19, indicating that this unit may have been the first recipient of the E.V. Details reporting on the frontline use of the aircraft at Jasta 19 are unfortunately not available. It is known that Lt. Hans Pippart crashed to his death on 11 August 1918 flying a Fokker D.VII, following a balloon attack. But the new Parasol would probably not have been the first choice for such a mission beyond enemy lines at the time. So it is possible, though unconfirmed, that the two victories that Ulrich Neckel was credited with on 13 and 14 August may have been claimed while flying the E.V.
  Fortunately, Lt. Richard Wenzl left some interesting insight into the use of the plane at Jasta 6 in August 1918. According to him, the new aircraft were picked up on 5 August from the Park at Clermont, while the Jasta 6 war diary notes that they arrived on 3 August. Wenzl noted that the performance of the type powered by the 110 hp Oberursel engine was exceptional, although it was designed for the 140 hp engine. Being the technical officer of Jasta 6, Wenzl was fairly well informed about the higher-horsepower engine, and he may have gotten this information from one of the JG I members who attended the Second Fighter Competition at Adlershof just recently.
  He goes on to report that the ground forces were not informed about the new type of aircraft and greeted them with a hail of ground fire during initial trial flights along the front. Again, according to the Jasta 6 war diary, Lt. Paul Wenzl came under heavy fire from all German positions during a test flight of the E.V on 3 August, even though all German units in the area had been informed about the fact that JG I was to operate the parasol now. This is more evidence that the information about the drastically new-looking fighter was not properly distributed to everybody pulling a trigger on the German side.
  Familiarization visits to neighboring units soon followed, and thanks to these a surprisingly large number of photographs of Jasta 6 Fokker E.Vs is now available to us. At the outbreak of the British offensive on 8 August, Jasta 6 pilots initially kept flying their Fokker D.VIIs rather than the new type for understandable reasons.
  After the unit moved to Bernes on 12 August, they finally brought over their E.Vs from Chambry, and worked them up for combat use.
  Unfortunately, the old Fokker illness of shoddy workmanship had its final wartime outbreak with the E.V. On 16 August, Lt. Riedel, Jasta 19, demonstrated the recently-arrived E.V 107/18 to several of his comrades on the ground by putting the plane through some extreme low-level aerobatics. A simplified eye-witness report by Jasta 12 pilot Lt. Hans Besser reported that “suddenly a wing came off”, indicating that a large section of the wing broke off in flight. Riedel reportedly tried to bail out, but he was flying at too low an altitude to escape. He was killed in the ensuing crash.
  Just three days later, a very similar accident occurred at Jasta 6. Lt. Emil Rolff, who had scored the first victory on the E.V at Jasta 6 on the day of Riedel's fatal crash, fell victim to an identical form of wing failure. At 9:50 a.m., while conducting a test flight, the wing failed at low altitude, variously reported as being at 300 or 800 meters. Like Riedel before him, Rolff could not escape from the plunging aircraft in time and lost his life.
  At just the same time, other pilots of Jasta 6 were engaged in a fierce fight against Sopwith Camels at the front, flying their new “Parasols”. Lt. Richard Wenzl reported that he had forced one of their opponents from 5500 meters down to 200 meters when engine failure forced him to break off pursuit. He only just made a safe landing with a standing propeller. During the same combat, Lt. Matzdorf was credited with a Sopwith Camel at the time of Rolff's crash, and this may have been the second victory scored by Jasta 6 pilots on the “1918-monoplane”.
  If that was the case, it was also the last one, since the acting commander of JG I, Ernst Udet, took immediate action and grounded the type in the Geschwader. The news of the second fatal crash quickly made the rounds, and as a consequence the order to ground the type in all units was issued quickly. On 24 August production and acceptances at Schwerin were halted until the cause(s) for the fatal accidents had been identified and rectified.
  Engine failure was also a common problem for the pilots of Jasta 6, just as before on the Fokker Triplane. Wenzl reported that 30 forced landings occurred over a period of ten days of use of the E.V, but not one of them resulted in a crash. Rightfully, he and his men were proud of this accomplishment, and it also speaks highly of the handling qualities of the aircraft in unpowered flight.
  Jasta 35 commanding officer Rudolf Stark was another witness of the E.V, albeit under somewhat unusual circumstances, directly related to the above mentioned events. He left an interesting recollection of the plane in his book “Die Jagdstaffel Unsere Heimat” (published in English under the title “Wings of War”).
  By late August 1918, Jasta 35 was one of the few remaining Jagdstaffeln to be fully equipped with worn-out and outdated Albatros D.Va, Pfalz D.IIIa, and Roland D.VI fighters. On 24 August, the long-awaited call from the local Armee Flug Park came in, informing Stark that six new Fokker D.VII were ready to be picked up by Jasta 35 pilots. The six pilots that had seen the longest service with the Staffel were selected to receive these treasures, and in exchange the six worst performing aircraft (three Rolands, two Albatros, and one Pfalz) were returned to the Park.
  After the pilots had processed the paperwork that came along with picking up the new aircraft they still had some time left to tour the Park. There they came across a new type of fighter which immediately caught their attention. Stark wrote: “Amongst the single-seaters are a few new machines we don't know yet: Fokker monoplanes with rotary engines. Strikingly beautiful things. The latest Fokker has brought out. Jagdgeschwader I was scheduled to receive them, but currently the type is still banned since a few improvements have to be implemented.
  Those are great prospects for the future. Fokker stays Fokker. Each new type by him is a major improvement. The other companies are bringing out new types as well, but usually they have only changed their appearance somewhat, the flight- and combat performance has not improved much.”
  This statement is highly interesting in more than one way. To begin with, the fighters were not scheduled to be delivered to JG I, they had been returned by JG I, Jasta 6 to be exact. And Stark and his men must have seen the unit markings that were applied to these monoplanes, denoting previous frontline service. But the exact reason for the aircraft being stored at the AFP, the recent wing failures, are not mentioned by Stark. Either he was not informed about this by the AFP staff in order not to tarnish the reputation of the new type, or Stark wanted to withhold the information from the reader. The admiration he expresses for the new aircraft in his writings suggests the former theory.
  Secondly, apparently the pilots of Jasta 35b had not been informed about the arrival of the new type at the front, around three or four weeks after it was first introduced. This does not speak well for the required circulation of such crucial information amongst the Jagdstaffeln in the summer of 1918.
  Immediately after the plane was grounded, Anthony Fokker himself travelled to the front and visited both Jasta 19 and Jasta 6 in order to learn more about the accidents. And no doubt this trip was also intended to dispel any kind of mistrust against his company at an early stage.
  The exact date of his arrival is unclear, but Jasta 19 still had their examples of the E.V on hand, and Fokker lost no time to demonstrate his faith in the strength of his design. He managed to convince two dozen members of JG II to climb onto the wing of an E.V and even took motion picture footage of this “human load test”. Several photographs were also taken at the event. When he visited Jasta 6 around the same time, he found that their E.Vs had already been returned to the AFP, where Stark then saw these planes. At Jasta 6, Fokker then had himself photographed next to the replacement planes that were delivered to this unit - which were O.A.W.-built examples of the Fokker D.VII. Very likely these were originally intended for Jasta 35b, which, being considered more of a “secondary” unit, now had to make do with just six D.VII (O.A.W.) for the time being.
  Faulty assembly procedures at the Perzina factory, which manufactured wings for Fokker, as well as improper dimensions of some of the wing spars, were found to be the main reasons for the wing failures. Moisture entering the plywood wing structure through breathing holes further added to the problem, and the combination of these factors caused the wing failures.
  These problems could be rectified fairly quickly by ensuring a more careful assembly of strengthened, correctly dimensioned, and fully varnished wooden wing components. Successful load tests of the wing were conducted on 7 September, permission to resume production of the fighter was granted on 24 September and acceptances continued on 8 October. Since Fokker was to blame for the problem, he was required to supply replacement wings for the 139 Fokker E.Vs that were delivered with the faulty wings at his expense. The official designation of the fighter was also changed, probably as a measure to restore faith in the “Parasol”. The “E” designation was dropped and the re-born fighter was baptized Fokker D.VIII.
  In October, a total 61 of the “new” fighters were accepted at Schwerin, but likely a maximum of around 40 of these were accepted in time to be delivered to the front before the armistice. To date, no evidence of delivery of any of these aircraft to a Jagdstaffel in the remaining weeks of the war has been confirmed. But unearthing this kind of information for the last few weeks of the war is very difficult indeed. Several were photographed in the immediate post-war period in Entente hands, but some of these certainly still carried the “E.V” designation, while on others no designation can be made out at all.
  Use of the Fokker E.V at Jasta 36 is also recorded, and available information paints a somewhat mysterious picture here. Photographs indicate that the E.Vs were still on hand at the unit as late as mid-September, well after the type had been officially grounded. Possibly the Staffel was hoping for a quick remedy to the wing problem and kept the planes for that reason. It seems highly unlikely that operational flights were continued after the flight ban, since this would have been in direct disregard of an official order. In any case, this kind of behavior is unusual. Eventually, replacements in form of the unloved Pfalz D.XII arrived at Jasta 36 - someone had to take these - and no record of preferential shipment of the Fokker D.VIII to the unit late in the war has been found.
  It should be pointed out that one Fokker E.V, 113/18, was shipped to Austro-Hungaria for evaluation purposes in early July. It was powered by a 150 hp Steyr rotary engine, and evaluation began on 26 July. The following month, the aircraft was damaged beyond repair as the result of a landing accident.
  While it has been stated that the prospects for the production of the Fokker D.VIII beyond the 335 examples ordered (out of which 289 were completed in Germany) were not good, an important fact should be pointed out. By the end of the war, full-scale production of the Oberursel Ur.III was finally underway, and the engine was fitted to many late-production examples of the D.VIII. At the end of the war, no other German manufacturer had a suitable airframe for the use of this engine in production. It would have been a completely logical choice to continue manufacture of the D.VIII to absorb these engines until a better airframe was available. But the end of the war intervened, and no fifth batch of the D.VIII was ordered by the German authorities.
  Several Fokker D.VIIIs were operated by the German post-war units until the Versailles treaty brought an end to these kinds of activities.
  Besides this, examples of the “Parasol" were flown in Belgium, Italy, the Netherlands, and Poland in the post-war period. Further information concerning the use of the aircraft by these countries can be found in “Fokker Aircraft of WWI, Volume 7”.


Fokker E.V / D.VIII Specifications
Engine: 110 hp Oberursel UR.II
Wing: Span 8.34 m
Area 10.7 m2
General: Length 5.865 m
Height 2.82 m
Empty Weight 405 kg
Loaded Weight 605 kg
Maximum Speed: 200 km/h
Climb: 1000 m 2.0 min.
2000 m 4.5 min.
3000 m 7.5 min.
4000 m 10.8 min.
5000 m 15.0 min.
6000 m 19.5 min.


Fokker E.V/D.VIII Production Orders
Quantity Ordered Quantity Delivered Engine Serials Works Numbers First Acceptance of a Production Aircraft
10 10 110 hp Ur.II 100-109/18 2741-2750 July 3, 1918
200 129 110 hp Ur.II 110-309/18 2751-2950 July 3, 1918
65 62 110 hp Ur.II 500-564/18 3255-3319 October 24, 1918
60 26 145 hp Ur.III 670-729/18 2672-2731(1) October 8, 1918
Note 1: The low works numbers for the last batch of D.VIII fighters ordered is because these numbers were re-assigned to the D.VIII from 60 D.VI biplanes ordered earlier that were cancelled. These aircraft were fitted with the 145 hp Ur.III, which finally achieved production.