Zeppelin-Staaken VGO.II

Versuchsbau Gotha-Ost (VGO)

Company type	Subdivision of Gothaer Waggonfabrik
Industry	Aircraft manufacturing
Founded	1914
Headquarters	Gotha , Germany

The Zeppelin-Staaken VGO.II was a heavy bomber constructed in Germany during 1915, which saw limited operational use in the First World War. Although only a single unit was produced, it served as the foundational prototype for subsequent Zeppelin-Staaken Riesenflugzeuge ("giant aircraft"). The "VGO" designation originates from its manufacturer, Versuchsbau Gotha-Ost, a subdivision of Gothaer Waggonfabrik. This model evolved from the earlier VGO.I, initially acquired by the Imperial German Navy, whereas the VGO.II was procured by the Imperial German Army.

Design

The VGO.II featured a four-bay biplane layout with equal wingspans and a slight negative stagger between the wings. While its overall design adhered largely to conventional norms of the era, it stood out due to its considerable size and distinctive elements such as biplane horizontal stabilisers, dual vertical fins, and a tricycle undercarriage configuration. The crew consisted of two pilots seated in an open cockpit. Propulsion was provided by three engines: one positioned at the nose driving a tractor propeller, and two others housed within nacelles located in the interplane gap, each powering pusher propellers. These nacelles were spacious enough to accommodate an onboard mechanic who could access them during flight, fulfilling a key requirement for Riesenflugzeuge. The fuselage incorporated a bomb bay capable of carrying a single bomb weighing up to 1,000-kilogram (2,200 lb). Defensive weaponry included two machine guns mounted within the fuselage—one firing upward and another downward—as well as a machine gun at the front of each engine nacelle.

Development

The VGO.II's design and build closely followed that of the VGO.I, but incorporated multiple improvements derived from insights gained during test flights of its predecessor. Among these enhancements were a reconfigured tail featuring a wider gap between the horizontal stabilizers, a reduction in the number of fins, and the addition of forward-facing machine gun mounts on the engine nacelles. These upgrades were subsequently applied retroactively to the VGO.I during its initial overhaul.

Construction commenced in December 1914, with the maiden flight occurring on 25 October 1915. By this point, persistent issues experienced by the Navy with the VGO.I nearly prompted the Army to abandon the VGO.II project, yet it was ultimately accepted into Army service on 28 November and assigned the Idflieg serial number R.9/15.

Operational history

In February 1916, the VGO.II was allocated to Rfa 500 (Riesenflugzeugabteilung, "giant aeroplane unit") stationed at Auce. It initially conducted test flights before becoming the first R-plane deployed in combat operations. Although test pilot Offizierstellvertreter Vinzenz Selmer claimed an attack on Russian targets as early as March, the earliest verified offensive by the VGO.II occurred on 13 August, targeting the railway junction at Sloka. Successful sorties persisted into the autumn months. During one mission, it sustained damage from a forced landing that resulted in loss of its undercarriage and damage to a strut; repairs were completed within days, allowing it to return to active duty.

Throughout its operational tenure, the VGO.II underwent trials with experimental weaponry. Initially, a machine gun was mounted at the tail tip; however, due to fuselage flexing causing severe oscillations, the gunner stationed there suffered extreme airsickness rendering them ineffective. A more promising experiment involved installing a downward-firing 130-millimetre (5+1⁄8 in) cannon within the fuselage. Known as (Aussstossrohn, "launching tube"), this arrangement aimed to improve accuracy over free-fall bombs against relatively small targets such as warships and penetrate their armored decks. Ground trials of the cannon mounted on a tower commenced on 25 May to assess recoil effects. Once recoil was deemed manageable, reinforcements were added to the VGO.II’s fuselage, followed by further ground testing on 6 and 10 October with the cannon installed onboard. The weapon was finally tested in flight on 19 October; however, accuracy was unsatisfactory, missing by approximately 40–45 metres (131–148 ft) from an altitude of 800 metres (2,600 ft). Consequently, the cannon was removed.

By late 1916, the VGO.II had become outdated and was reassigned on 1 January 1917 to Rea (Riesenflugzeugersatzabteilung, "giant aeroplane support unit") for use as a training aircraft at Döberitz. It ultimately suffered irreparable damage following a hard landing; although the precise date remains unknown, it likely occurred during Summer 1917. No records indicate any casualties resulting from this incident.

Operators

Imperial German Army Air Service

Rfa 500

Rea