O.Thetford, P.Gray German Aircraft of the First World War (Putnam)
Albatros D XII (with Bohme undercarriage)
At least two D XII prototypes were built. D 2210/18 was first flown in March 1918 and participated in the second D types Competition. A modified machine fitted with a Bohme undercarriage which featured compressed-air shock absorbers flew in April 1918. This undercarriage necessitated an additional strut, which may just be observed running vertically above the wheel in the above photograph. The D XIIs again featured the slab-sided ply-covered fuselage introduced with the D X. There was again a variation in the ailerons, the Bohme undercarriage machine having unbalanced ailerons of inverse taper, and D 2211/18 having overhung balanced ailerons of parallel chord. Engine, 160 h.p. Mercedes D III. Span, 8.2 m. (26 ft. 10 7/8 in.). Length, 5.785 m. (18 ft. 11 3/4 in.). Height, 2.8 m. (9 ft. 2 1/4 in.). Area, 19.84 sq.m. (214 sq.ft.). Weights: Empty, 580 kg. (1.276 lb.). Loaded, 760 kg. (1,672 lb.). Speed, 180 km.hr. (112.5 m.p.h.). Climb, 8,000 m. (26,240 ft.) in 54 min. Duration, 1 hr. Armament, twin Spandau machineguns.
The second D XII (2211/18) was fitted with B.M.W. IIIa engine of some 185 h.p. and participated in the third D types Competition in October 1918.
W.Green, G.Swanborough The Complete Book of Fighters
ALBATROS D XII Germany
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 IIIa 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 IIIa engine for participation in the third D-type contest of October.
Max speed (D IIIa), 112 mph (180 km/h).
Endurance, 1 hr.
Empty weight, 1,279 lb (580 kg).
Loaded weight, 1,675 lb (760 kg).
Span, 26 ft 10 3/4 in (8,20 m).
Length. 18 ft 11 1/2 in (5,78 m).
Wing area, 213.55 sq ft (19,84 m2).
J.Herris Albatros Aircraft of WWI. Vol.4: Fighters (A Centennial Perspective on Great War Airplanes 27)
Albatros developed the D.XII using a modified D.IX fuselage with new wing cellule. Although busy producing the Fokker D.VII in large quantities, Albatros still wanted to develop their own design to replace the Albatros D.Va in production.
The D.XII prototype 2210/18 first flew in May 1918 but was too late to participate in the manufacturers' flight demonstrations and climb trails at the Second Fighter Competition. Albatros hurried to complete the D.XII's static load tests to have the aircraft ready for the competitive evaluations by front-line fighter pilots in July. These tests were completed by June 22, and after strengthening a few components, including landing gear struts and fuel tank support, Idflieg approved the D.XII for the flight trials by front-line pilots that started June 28.
During the comparative flight trials the Albatros D.XII fared better than previous Albatros fighters. At the July 6 fighter-pilot debriefing session Oblt. z. See Gotthard Sachsenberg advocated the Albatros D.XII in the Mercedes-powered category, claiming
it was faster and more maneuverable than the Pfalz D.XII despite the Pfalz being 'acknowledged to have a higher safety factor' (able to withstand higher 'G' loading). In contrast, Ltn. Theodor Mallinckrodt pointed out the Albatros D.XII exhibited considerable wing bending in flight, which the Pfalz D.XII did not, and predicted 'very many landing crashes', perhaps due to the tall landing gear coupled with the short fuselage. As a result, the pilots requested a fly-off between the two types the following week.
During the second fighter-pilot debriefing on July 14 the front-line pilots unanimously recommended continued production of the Fokker D.VII and were nearly unanimous about the Pfalz D.XII. Again, one ace, Ltn.z.See Theo Osterkamp preferred the Albatros D.XII over the Pfalz due to its lighter controls and better field of view. However, Ltn. Dieter Collin preferred the flying characteristics of the Pfalz, which was already in production. With the Pfalz narrowly preferred by nearly all the pilots, Idflieg returned the Albatros D.XII to the company for improvement.
The first prototype, 2210/18, was modified with a 185 hp BMW. The second prototype, 2211/18, also powered by a BMW, was lengthened and given wings of increased span with aerodynamically balanced ailerons. The final D.XII configuration, probably the modified 2210/18, participated at the Third Fighter Competition.
Surprisingly, the flight characteristics of the modified Albatros D.XII were now judged as superior to those of the Fokker D.VII, an outcome that is difficult to reconcile with the superiority of the Fokkers wing. However, the Albatros D.XII was slower than the Rumpler D.I and slightly inferior to the Fokker V29 and V36. Moreover, despite extensive wire bracing, the airframe was not as robust as the competing Fokker D.VII and V36; during tight turns and power dives the wings flexed and the control surfaces vibrated. With the sturdy D.VII in full production and widespread and successful service, and also being faster than the D.XII, Albatros again was frustrated in securing a production order for its new fighter.
Albatros Fighter Specifications
D.XI D.XII/1 D.XII/2 D.XIII D.XIV
Engine 205 hp Sh.III 170 hp Mercedes D.IIIa 185 hp BMW.IIIa 170 hp Mercedes D.IIIa 185 hp BMW.IIIa
Span (Upper) 8.00 m 8.20 m 8.85 m 9.50 m 8.80 m
Span (Lower) 6.60 m 7.46 m 7.42 m - -
Chord (Upper) 1.5 m 1.4 m 1.4 m 1.65 m 1.7m
Chord (Lower) 1.0 m 1.4 m 1.4 m 1.10m 1.10 m
Gap 1.43 m 1.45 m 1.45 m 1.32 m 1.37 m
Stagger 0.43 m 0.28 m 0.28 m 0.75 m 0.70 m
Wing Area 18.5 m2 19.84 m2 20.01 m2 20.6 m2 20.64 m2
Length 5.58 m 6.62 m - 5.85 m 6.20 m
Height 2.87 m 2.68 m - 2.75 m 2.82 m
Empty Weight 494 kg 619 kg 621 kg 639 kg 640 kg
Useful Load 195 kg 180 kg 180 kg 181 kg 180 kg
Loaded Weight 689 kg 799 kg 801 kg 820 kg 820 kg
Wing Loading 37.2 kg/m2 40.3 kg/m2 40.0 kg/m2 39.8 kg/m2 39.7 kg/m2
Power Loading 3.36 kg/hp 4.70 kg/hp 4.33 kg/hp 4.82 kg/hp 4.43 kg/hp
Max. Speed 180 km/h 180 km/h 180 km/h 185 km/h 185 km/h
Climb, 1,000 m 1.8 minutes - 1.9 minutes 2 minutes 2 minutes
Climb, 2,000 m 4.3 minutes - 4.1 minutes - -
Climb, 3,000 m 6.3 minutes - 6.8 minutes - -
Climb, 4,000 m 9.3 minutes - 10.4 minutes - -
Climb, 5,000 m 12.8 minutes - 16.7 minutes 23 minutes 23 minutes
Climb, 6,000 m 17.8 minutes - - - -
Notes: All were armed with two machine guns. D.XIII track 1.75 m; D.XIV track 1.76 m.