The revolutionary Junkers D.1 all metal monoplane fighter entered service in late 1918 and can trace it"s lineage back to Professor Hugo Junkers" 1912 patent for a thick cantilever wing design intended to increase lift and reduce drag. This cantilever wing design was utilized on Junkers" experimental 0.1-0.2mm ferro-magnetic steel skinned two seat J 1 monoplane completed in November 1915. Successful flight testing was rewarded with an order for 6 single seat J 2 fighters in January 1916. Skinned in sheet steel like the J 1, the J 2 proved to be too heavy for use as a front line fighter. Thereafter Junkers was able to use corrugated duralumin (an aluminium alloy) for his private venture J 3 in the middle of 1916 which was abandoned when work began on the armour plated two-seat ground attack J 4 biplane in late 1916. The J 4 successfully went into production in 1917 with the military designation Junkers J.1. The success of the J 4/J.1 led to a contract to develop 3 new monoplane fighter designs in December 1916. The J 5 had the engine positioned behind the pilot and didn"t make it off the drawing board. The J 6 had a parasol wing and some work was carried out during 1918 although it was never completed. In late 1917 work began on the single seat J 7 and two seat J 8 (the J 8 prototype was developed into the J 10 which was put into production in March 1918 as the Junkers Cl.1). The J 7 was constructed from duralumin tubes and frames covered with 0.35mm corrugated duralumin sheets fixed with aluminium rivets. Wing spar joints etc had steel collars fixed with iron rivets. When the 160hp Daimler-Mercedes D.III powered J 7 first flew in September 1917 it featured unusual pivoting wing tips instead of ailerons but these were replaced with more conventional items in time for additional testing in mid October. Numerous improvements were made over the following months before it was demonstrated at the first fighter competition in January 1918. The speed and climb performance were excellent but it was felt that it lacked maneuverability and downward visibility. Perhaps understandably the revolutionary design was viewed with suspicion by many pilots more accustomed to traditionally constructed biplanes (a suspicion not really overcome well into the 1930s).
The qualified success of the J 7 prototype encouraged Junkers to develop a production version known as the J 9 which featured numerous changes, the most obvious of which was a lengthened fuselage, wider wingspan and elimination of the “head rest” fairing. Pre-production prototype J 9/I took to the air on 12 May 1918 and performed well with it"s 160hp Daimler-Mercedes D.III engine although this was replaced with a 200hp D.IIIaü in time for the 2nd fighter competition in June 1918. The 2nd pre-production prototype J 9/II was powered by an experimental 195ps Benz Bz.IIIb V8 engine which never performed reliably enough to take part in the 2nd fighter competition. A 3rd J 9/III(?) was modified with a shortened fuselage & wings and was fully camouflaged and designated “Junk D I” when photographed on 8 July 1918. A factory photograph taken on 8 August 1918 shows at least 5 completed J 9 airframes including J 9/I and J 9/II along with another 2 similarly unpainted long fuselage airframes, the modified shortened J 9/III(?) “Junk D I” and another short fuselage aircraft still under construction. Following type testing of long fuselage J 9/I (now painted in camouflage and designated “Junk.D.I. 5180/18”) and J9/II in early September 1918 it appears that production was hurriedly converted to the short fuselage configuration. When at least 4 Junkers D.1 were dispatched to the front on 2 October 1918 they all appeared to have short fuselages and no image showing a long fuselage D.1 in service is known to us. How much action the Junkers D.1 saw before the Armistice is unconfirmed but they were used to great effect during the fighting between German Freikorps and Bolshevik (and other) forces in the Baltic during 1919. Ultimately just 40 Junkers D.1 were completed by Junkers & Co (Jko) and Junkers-Fokker (Jfa) with the majority being delivered after the Armistice. Any history of this important aircraft here is of necessity very brief so we encourage you to seek out any, or all, of the references listed below, but we do so with the caution that a reasonable amount of confusion exists about this aircraft and much of what you may have read in some books and online about the development and specifications of the Junkers D.1 is now understood to be incorrect.
WW1 colour schemes are contentious at the best of times and we have done our best to provide what we consider to be accurate painting information for this model and, while we have been as meticulous as we could be, I’m sure some will not find our choices to their liking. The Air Ministry report on Junkers D.1 5183/18 found abandoned at Evere, Belgium in January 1919 notes that “The wings are painted a pale green, with irregular patches of light mauve on top, and white underneath”. Close examination of photographic evidence shows that the “light mauve” and “white” were not sprayed on but applied with a brush or perhaps by sponge etc. The fuselage of 5183/18 had been overpainted ...“a chocolate-brown colour, except underneath, where a white pigment has been applied”. It also noted that “pale green” could be seen where the brown paint had come off. Interior duralumin surfaces and frames were left unpainted on the prototype J 7 and may have remained unpainted on the first few aircraft but a photo on page 12 of Datafile 33 shows the interior painted in a reasonably dark colour that was probably grey-green. Interior steel brackets and collars riveted with iron rivets appear to have been painted black or possibly with red-brown primer unless overpainted with grey-green. Junkers aircraft serving with Kampfgeschwader Sachsenberg in the Baltic were overpainted in the middle of 1919 with an irregularly applied translucent dull camouflage colour thought to be a grey-green.