The AGO S.I was a German prototype ground-attack aircraft built in October 1918 but possibly never flown before the end of World War I. It was a single-seat biplane armed with a downwards-firing 20 mm cannon.
The Albatros Dr.II was a German prototype single-seat fighter triplane, the sole example of which flew in the spring of 1918. It was similar in many respects to the D.X biplane, employing amongst other features the same 145 kW (195 hp) Benz Bz.IIIbo V-8 liquid cooled piston engine and twin 0.312 in (7.92 mm) machine guns.
The three pairs of wings were sharply staggered, braced by broad I-struts and shared parallel chords. All three pairs were equipped with ailerons, linked by hinged struts.
After the success both the Sopwith Triplane and the Fokker Dr.1, many manufacturers in Germany turned their eye towards the design their own version of the triplane format. These experiments were an attempt to improve climb performance. Albatros Flugzeugwerke failed in their first attempt in September of 1917, when they designed the flawed Albatros Dr.1 which was built on the DVa airframe and powerplant. The Albatros Dr.II was their last attempt to create a viable triplane.
Albatros D.IX was a German prototype single-seat fighter built by Albatros Flugzeugwerke in early 1918. During this time Germany had its back to the wall, resources were becoming in short supply and simple cost effective aircrft were needed. The design of the D.IX was meant to streamline manufacturing. It differed from previous Albatros fighter designs by using a simplified fuselage with a flat bottom and slab sides. The wings and tail were similar to those of the unsuccessful Albatros D.VII.
Power was provided by a Mercedes D.IIIa in-line water cooled engine producing 180 hp (130 kW). The D.IX was armed with twin synchronised 0.312 in (7.92 mm) LMG 08/15 machine guns. The test flight of the prototype revealed the performance of the aircraft to be disappointing. Because of the performance report the project was quickly discontinued without any more examples being built.
The Albatros D.X was a German prototype single-seat fighter biplane developed in 1918 in parallel with the D.IX. It used the same slab-sided, flat-bottomed fuselage (a departure from previous Albatros designs) but was powered by a 195 hp (145 kW) Benz Bz.IIIbo water-cooled v-8 engine in place of the D.IX's Mercedes D.IIIa straight-six.
The D.X participated in the second D-type contest at Adlershof in June 1918, but development ceased at the prototype stage. The D.X airframe was use in the design of the Albatros Dr.II triplane.
The Albatros D.XI was a German single-seat fighter biplane; and the only Albatros fighter to be powered by rotary engine (the 60hp Siemens-Halske Sh.III). The Albatros D.XI presented a departure from customary wire braced Albatros designs by using struts instead of cables to brace the wing cellule.
The wings had unequal spans with the upper planes having greater span than the lower ones, and were braced by I-struts with an aerofoil cross-section, additional rigidity being provided by twinned diagonal struts from the base of these to the top of the fuselage, located where the "landing wires" of a normal wire-braced biplane would be. The use of a rotary engine requireded a large-diameter propeller and a correspondingly tall undercarriage. The D.XI was armed with the same twin 0.312 in (7.92 mm) Spandau LMG 08/15 machine guns employed on other Albatros fighters.
Two prototype aircraft were ordered and built (2208/18 and 2209/18). Construction of the first prototype, 2209/18, was completed in March 1918 but engine supply problems meant the aircraft did not begin flight testing until May 1918. D.XI 2209/18 participated in the in the Second Fighter Competition (used to allow front line pilots to provide input into future fighter selections) in June 1918, and put up an unexceptional performance before crashing on landing due to its high undercarriage and short fuselage. This contributed to Idflieg (German Flying Inspectorate) eliminating the D.XI from production consideration, especially considering other aircraft entering production had priority for the Sh.III engine.
Albatros continued development work, and the second prototype, 2208/18, which had larger ailerons, a four bladed prop and a shorter undercarriage to assist landing, participated in the Third Fighter Competition. Even with these modifications, the control response was too docile, although other flight characteristics were good. Again the D.XI was not selected for production, and the last of the prototype airframes was destroyed by the allies in early 1920.
The last Albatros fighter of World War I actually completed and flown, the D.XII featured the slab-sided plywood- covered fuselage introduced by the D.X, and the first of two prototypes was flown in March 1918 with a 180 hp Daimler D IlIa engine. The second prototype, fitted with a Bohme undercarriage embodying compressed- air shock absorbers, and unbalanced ailerons of inverse taper in place of the balanced parallel-chord ailerons of the first prototype, followed in April 1918, and was later fitted with a 185 hp BMW IlIa engine for participation in the third D-type contest of October.
The D.XII was difficult to land without digging its large prop into the ground. Preformance Reports stated the aircraft had a high rate of climb. The wing loading of 7.8 lb/ft² indicated that the D.XII must have been very agile. Ernst Udet called it the best fighter of the war. Further production of the Albatros D.XII ended with the Armistace.
The D.VII, which was intended to participate in the third D-type Contest of October 1918, was essentially similar to the D.VI apart from having completely redesigned vertical and horizontal tail surfaces. Like its predecessor it was powered by a geared Benz Bz Illbm eight-cylinder Vee engine driving a four-bladed propeller. Armament comprised the standard twin 7.92mm synchronised machine guns, and only one prototype was completed.
Another 195 h.p. Benz-powered prototype, the D V of 1918 reverted to a slab-sided ply-covered fuselage. Most singular feature was the juxtapositioning of the wing surfaces, the lower one being of much broader chord, and the main lifting surface. The narrow-chord upper-wing panels pivoted differentially outboard of the centre-section, the entire surface of both wings acting as "ailerons" to provide lateral manoeuvre.
In this L.V.G. the streamlining embraces both the interplane and plane-cum-fuselage connectiong twin-struts, of more or less V structure. The inner set is provided with a round cutting in the streamlining. The steepness, though not markedly whale type, camouflaged body of the L.V.G. may be result of the employment of a powerful stationary motor. The chord of the lower plane of the L.V.G. looks large for a scout; the rudder asks for comment. Considering the large impulses on a scout rudder from hard work the unsupported position seems daring. The hinged fixed plane and elevator position of the L.V.G. Scout is that of the Brandenburg seaplane faschion.
This experimental two-seat seaplane was designed By Claude Dornier at Luftschiffbau Zeppelin GmbH. Construction began in 1918. It was of all-metal construction except for the fabric-covered wing and cruciform tail surfaces. Ailerons were fitted with Flettner-type servos.
Armament conststed of 2 × forward-firing 0.312 in (7.92 mm) "Spandau" LMG 08/15 machine guns controled by the pilot, and 1 × 0.312 in (7.92 mm) trainable Parabellum MG14 machine gun for observer. The machine was fitted with an Benz Bz IIIbo 8 cylinder liquid cooled V engine, 195 hp (145 kW). The top speed of the Zeppelin-Lindau CS.I was 93.75 mph (150 kmh) Both nose and side radiator installations were tested.
The Zeppelin-Lindau D.I is better known as the Dornier D.I. It was an all-metal fighter and a milestone in aeronautical technology that would come to define modern aircraft. It was designed by Claude Dornier in early 1918 while he was working as an aeronautical engineer at Luftschiffbau Zeppelin company at Lindau-Reutin on the Bodensee.
A wooden mockup was inspected by Idflieg (Inspektion der Fliegertruppen, Inspectorate of Flying Troops) on February 11, 1918. Subsequently six aircraft were ordered (allotted s/n D.1750/18 to D.1755/18) Three of them were powered by a 160 hp Mercedes D.III, the other three by a BMW IIIa engine.
The D.I's layout was very advanced for its time. It featured an all-metal construction with stressed fuselage skinning and cantilever wings of torsion-box construction, and carrying a jettisonable fuel tank beneath the fuselage. The type incorporated many features well ahead of the contemporary state of the art. The upper wing was mounted on the fuselage with four wide, profiled struts, without any wires. The aircraft was full-metal, with smooth duralumin covering The D.I would have carried twin synchronized 0.312 in (7.92 mm) machine guns.
The maiden flight of the D.I happened on June 4th, 1918 by Dornier test pilot Vizefeldwebel Heinz Ruppert who flew D.1752/18 successfully. The profile shows D.1751/18 with its BMW engine. During the second fighter competition, held at Berlin between May 27 and mid-July, while flown by Hauptmann Wilhelm Reinhard (commander of Jagdgeschwader I), the D.1751/18 crashed when it shed the upper wing on July 3, 1918, killing the pilot. Just before the aircraft had been flown by Oberst-Leutnant Herman Göring (commander of Jasta 27), Hauptman Curt Schwarzenberger and Leutnant Constantin Krefft. The accident notwithstanding, other fighter pilots universally agreed that the D.I was "on average" superior to the other Mercedes engined fighters.
For the totally destroyed D.1751/18 a replacement aircraft was built with strengthened wing bracing and attachments. It received the s/n D.1751/18 (Ersatz) and participated in the third fighter competition, held October 10 to November 2, 1918. This resulted in an order for 50 aircraft, allotted the s/n D.1900/18 to D.1949/18.
Early 1919, when work was halted on the aircraft production upon enactment of the Armistice agreements, 50 % of the aircraft were ready and were hidden from the Inter-Allied Armistice Commission (IAAC).
In 1921, two aircraft were sold to the USA, one was evaluated by the USN, BuNo. A-6058, the other one received the USAAS s/n 68546 and was evaluated at McCook Field under the Project Number P-241, it was transferred to the McCook Field museum on May 14, 1923, however, it was surveyed on September 8, 1926. Another D-I was in Dornier factory museum and was destroyed by the Allies bombs during WW2. The Dornier D-I was an example that modern layout of an aircraft isnít a guarantee for success.