O.Thetford, P.Gray German Aircraft of the First World War (Putnam)
Albatros D IV
The Albatros D IV was something of a hybrid, having a partial D II wing cellule and a D Va fuselage. It was powered with an experimental, specially geared, version of the standard 160 h.p. Mercedes D III, which enabled the engine to be completely buried in the nose. No guns were fitted and as there was no significant increase in performance the D IV remained no more than a prototype mainly due to difficulties with the motor. Span, 9.05 m. (29 ft. 8 3/4 in.). Length, 7.33 m. (24 ft. 0 5/8 in.). Speed, 165 km.hr. (103.12 m.p.h.). Climb, 5,000 m. (16,400 ft.) in 32 min. Range, 350 km.
W.Green, G.Swanborough The Complete Book of Fighters
ALBATROS D IV Germany
The DIV was developed essentially to test the geared version of the 160 hp Mercedes engine (this having reduced the 1,400 rpm of the engine crankshaft to 900 rpm at the propeller). It was based on the D II cellule, but substantially enlarged, and three D IVs were ordered in November 1916. It is believed that only one of these was completed and flown. It was tested with two-, three- and four-bladed propellers until April 1918, but excessive vibration led to the discontinuation of the programme.
Max speed, 103 mph (165 km/h).
Endurance, 2.2 hrs.
Span, 29 ft 8 in (9,04 m).
Length, 24 ft 0 5/8 in (7,33 m).
Wing area, 220.66 sq ft (20,50 m2).
J.Herris Albatros Aircraft of WWI. Vol.4: Fighters (A Centennial Perspective on Great War Airplanes 27)
Albatros D.IV
The Albatros D.IV was designed strictly as an experimental test bed for a version of the Mercedes D.III engine using a reduction gear and was never intended as a production fighter. Based on the D.II, the D.IV prototype - likely only one of the three ordered was built - was unarmed. A small headrest similar to the one fitted to early production D.V fighters was fitted, and the engine could be fully enclosed for superior streamlining due to the raised thrust line provided by the reduction gear.
The geared engine drove the propeller at slower rotation speed than the ungeared engine, requiring a larger diameter propeller and a taller undercarriage to keep the propeller from striking the ground. Ground tests with the large, two-blade propeller had to be stopped due to severe engine vibration and the D.IV could not be flown with this propeller. Eventually experimental three and four-bladed propellers were tried and some tests flights were made with these propellers. These flights revealed mediocre performance, although the only detail available was a climb to 5,000 feet took 32 minutes, a climb rate far below the production Albatros fighters. Engine and propeller vibration remained excessive and trials were stopped in April 1918.
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J.Herris - Albatros Aircraft of WWI. Volume 4: Fighters /Centennial Perspective/ (27)
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| Albatros D.IV prototype
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J.Herris - Albatros Aircraft of WWI. Volume 4: Fighters /Centennial Perspective/ (27)
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| The Albatros D.IV was never intended as a production fighter. Instead, it was designed solely as a flying testbed for the 160 hp Mercedes D.III engine with experimental reduction gear. The completely enclosed engine made the aircraft very streamlined for its time. However, the experimental reduction gear was a constant source of problems. Vibration with the large diameter, two-blade propeller shown here was so extreme the aircraft could not be flown. Fitting experimental 3-blade and 4-blade propellers enabled the aircraft to be flown, but vibration was still excessive and performance was worse than production Albatros fighters with the standard engine.
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J.Herris - Albatros Aircraft of WWI. Volume 4: Fighters /Centennial Perspective/ (27)
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| The story of the Albatros D IV is a tale of the one that got away. Following upon the operational success of their D II and D III fighters, Albatros came up with the extremely logical idea of using the robust wing of the D II, married to a new elliptical sectioned fuselage, later to be adopted for their D V. This hybrid machine was the Albatros D IV of which only one was built. Up to now, Albatros's thinking had been flawless, particularly as the reversion to the D II's wing promised to prevent the occasional catastrophic high speed wing shedding being experienced with their 'V' strutted D III sesquiplanes. Where Albatros's thinking went awry was in choosing to fit the prototype with an experimental geared variant of the 160hp Mercedes D III. This engine, which appears never to have worked satisfactorily, managed to delay D IV flight testing to the point where officialdom simply lost interest. With another engine, the D IV might have helped bridge the gap between the Albatros D III and the Fokker DVII, something the Albatros D V never quite did.
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J.Herris - Albatros Aircraft of WWI. Volume 4: Fighters /Centennial Perspective/ (27)
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| Albatros D.IV
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J.Herris - Albatros Aircraft of WWI. Volume 4: Fighters /Centennial Perspective/ (27)
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| Albatros D.IV
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