The Albatros D.V is a fighter aircraft built by the Albatros Flugzeugwerke and used by the Luftstreitkräfte (Imperial German Air Service) during World War I. The D.V was the final development of the Albatros D.I family and the last Albatros fighter to see operational service. Despite its well-known shortcomings and general obsolescence, approximately 900 D.V and 1,612 D.Va aircraft were built before production halted in April 1918. The D.Va continued in operational service until the end of the war.
Design and development
In April 1917, Albatros received an order from () for an improved version of the D.III. The resulting D.V prototype flew later that month. The D.V closely resembled the D.III and used the same 127 kW (170 hp) Mercedes D.IIIa engine. The most notable difference was a new, fully elliptical cross-section fuselage which was lighter than the partially flat-sided fuselage of the earlier D.I to D.III designs. The new elliptical cross-section required an additional longeron on each side of the fuselage and the fin, rudder and tailplane initially remained unchanged from the D.III. The prototype D.V retained the standard rudder of the Johannisthal-built D.III but production examples used the enlarged rudder featured on D.IIIs built by the (OAW), in what was known as the independent city of Schneidemühl. The D.V also featured a larger spinner and ventral fin.
Compared to the D.III, the upper wing of the D.V was closer to the fuselage, while the lower wings attached to the fuselage without a fairing. The D.V wings were almost identical to those of the standard D.III, which had adopted a sesquiplane wing arrangement broadly similar to the French Nieuport 11. The only significant difference between wings of the D.III and D.V was a revised routing of the aileron cables that placed them entirely within the upper wing, conducted structural tests on the fuselage, but not the wings, of the D.V.
Early examples of the D.V featured a large headrest, usually removed in service, because it interfered with the pilot's field of view. The headrest was deleted from the second production batch. Aircraft deployed in Palestine used two wing radiators, to cope with the warmer climate. issued production contracts for 200 D.V aircraft in April 1917, followed by additional orders of 400 in May and 300 in July. Initial production of the D.V was exclusively undertaken by the Johannisthal factory, while the Schneidemühl factory produced the D.III through the remainder of 1917.
Operational history
The D.V entered service in May 1917 and structural failures of the lower wing immediately occurred. In 2009, Guttman wrote that "Within the month was doing belated stress testing and concluding, to its dismay, that the D.V’s sesquiplane wing layout was even more vulnerable than that of its predecessor". The outboard sections of the D.V upper wing also suffered failures, requiring additional wire bracing and the fuselage sometimes cracked during rough landings. Against these problems, the D.V offered very little improvement in performance. Front line pilots were considerably dismayed and many preferred the older D.III; Manfred von Richthofen was critical of the new aircraft. In a July 1917 letter, he described the D.V as "so obsolete and so ridiculously inferior to the English that one can't do anything with this aircraft". British tests of a captured D.V revealed that the aircraft was slow to manoeuvre, heavy on the controls and tiring to fly.
Albatros responded with the D.Va, which featured stronger wing spars, heavier wing ribs and a reinforced fuselage. The modified D.Va was heavier than the D.III but the structural problems were not entirely cured. Use of the high-compression 130 kW (180 hp) Mercedes D.IIIaü engine offset the increased weight of the D.Va. The D.Va also reverted to the D.III aileron cable linkage, running outwards through the lower wing, then upwards to the ailerons - much the same as the earlier Albatros B.I unarmed two-seater had used before 1914 - to provide a more positive control response. The wings of the D.III and D.Va were interchangeable. To further strengthen the wing, the D.Va added a small diagonal brace connecting the forward interplane strut to the leading edge of the lower wing; the brace was also retrofitted to some D.Vs.