The Zeppelin-Staaken VGO.II was a heavy bomber built in Germany in 1915 and which saw limited service during World War I.Gray & Thetford 1992, p.582 Although only one example was built, it served as a prototype for further ("giant aircraft") by Zeppelin-Staaken. Its "VGO" designation was assigned because the aircraft was constructed by Versuchsbau Gotha-Ost, a division of Gothaer Waggonfabrik. It was developed from the VGO.I that had been purchased by the Imperial German Navy, but the VGO.II was purchased by the Army instead.Szigeti 2007, p.12

Design The VGO.II was a four-bay, equal-span biplane with slightly negative wing stagger.Haddow & Grosz 1988, p.213 Of mostly conventional configuration it diverged most noticeably from the designs of the day not only by its size, but by its biplane horizontal stabilisers, its two fins, and its tricycle undercarriage.Herris 2020, p.15 Its two pilots sat in an open cockpit.Haddow & Grosz 1988, p.212 One engine was mounted in the nose, driving a tractor propeller, and the other two were mounted in nacelles in the interplane gap and drove pusher propellers. These nacelles were large enough to accommodate a mechanic, who could make his way into them in flight (a requirement of the specification). The fuselage included a bomb bay large enough to carry a bomb. As defensive armament, the VGO.II carried two machine guns in the fuselage, one firing upward and the other downward, plus a machine gun in the front of each engine nacelle.Haddow & Grosz 1988, p.221

Development The design and construction of the VGO.II was very similar to that of the VGO.I,Herris 2020, p.44 but incorporated several refinements based on experience gained with test flights of the earlier machine. These modifications included a redesigned tail with a larger gap between the horizontal surfaces, and fewer fins, plus the addition of machine-gun positions in the fronts of the engine nacelles.Herris 2020, p.44–45 These changes were later retrofitted to the VGO.I during its first rebuild.Haddow & Grosz 1988, p.214Herris 2020, p.15

Construction work began in December 1914, and the first flight took place on 25 October 1915. By then, the ongoing problems that the Navy had experienced with the VGO.I very nearly led the Army to cancel the VGO.II, but the aircraft was accepted into Army service on 28 November and given the Idflieg serial number R.9/15.

Operational history In February 1916, the VGO.II was assigned to Rfa 500 (, "giant aeroplane unit") at Auce.Herris 2020, p.45 From there, it undertook test flights before becoming the first R-plane to see combat. Although test pilot Offizierstellvertreter Vinzenz Selmer claimed to have made an attack on Russian targets as early as March, the earliest substantiated raid by the VGO.II was on 13 August against the railway junction at Sloka.Haddow & Grosz 1988, p.222 Successfully missions continued into the autumn. On one of these, it was damaged in a forced landing that tore off its undercarriage and damaged a strut, but it was repaired and returned to service within a few days.Haddow & Grosz 1988, p.222–23

During its service life, the VGO.II was fitted with experimental armament. The first of these was a machine gun fitted to the tip of the tail. However, the flexibility of the fuselage structure meant that this position and the gunner assigned to it were subject to such oscillation as to render the crewmember hopelessly airsick to the point of incapacitation.Haddow & Grosz 1988, p.223 A more promising trial was fitting a downward-firing cannon in the fuselage. Dubbed (, "launching tube"), it was hoped that this installation would be able to achieve greater accuracy than was possible with free-fall bombs, especially against relatively small targets like warships, whose armoured decks it would also be able to penetrate. Ground tests of the cannon installed on a tower began on 25 May, especially to investigate how much recoil it produced. When this proved acceptable, the fuselage of the VGO.II was reinforced, and the cannon installation was again tested on the ground on 6 and 10 October, this time mounted in the aircraft itself. Finally, on 19 October, it was tested in flight. The accuracy proved disappointing, missing the target by from an altitude of , and the cannon was removed.Haddow & Grosz 1988, p.223–24

By the end of 1916, the VGO.II was obsolete, and on 1 January 1917, it was reassigned to Rea (, "giant aeroplane support unit") as a training machine at Döberitz.Haddow & Grosz 1988, p.224 It was eventually damaged beyond repair in a hard landing. The exact date is unknown, but was probably in Summer 1917. No casualty records are associated with the incident.

Operators Imperial German Army Air Service Rfa 500 Rea

Specifications

Notes References

Bibliography