Zeppelin-Staaken VGO.II
The Zeppelin-Staaken VGO.II was a heavy bomber built in Germany in 1915 and which saw limited service during World War I. Although only one example was built, it served as a prototype for further 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.
Design
The VGO.II was a four-bay, equal-span biplane with slightly negative wing stagger. 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. Its two pilots sat in an open cockpit. 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. 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.Development
The design and construction of the VGO.II was very similar to that of the VGO.I, 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. These changes were later retrofitted to the VGO.I during its first rebuild.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 at Auce. 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. 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.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. A more promising trial was fitting a downward-firing cannon in the fuselage. Dubbed, 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.
By the end of 1916, the VGO.II was obsolete, and on 1 January 1917, it was reassigned to Rea as a training machine at Döberitz. 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.