AEG R.I

Allgemeine Elektricitäts-Gesellschaft (AEG)

Industry	Electrical equipment, aircraft manufacturing
Founded	1883
Headquarters	Germany

The AEG R.I was a prototype biplane heavy bomber (Riesenflugzeug) developed by the Allgemeine Elektricitäts-Gesellschaft (AEG) during the First World War for the Imperial German Army's air arm, the Luftstreitkräfte. Its maiden flight occurred in mid-1918, with only a single unit of the eight ordered reaching completion. This sole finished aircraft suffered catastrophic structural failure in flight, resulting in the loss of all crew shortly before the war's conclusion in November. The remaining incomplete units were dismantled and scrapped.

Design and development

In late 1916, AEG received a commission from the Inspectorate of Flying Troops (Inspektion der Fliegertruppen or Idflieg) to produce two heavy bombers as part of its (Riesenflugzeug) initiative. These bombers featured four engines housed within the fuselage to enable maintenance while airborne. The R.I was powered by 260-horsepower (190 kW) Mercedes D.IVa straight-six engines that transmitted power to the propellers through an intricate arrangement of gearboxes and driveshafts, permitting any engine to drive any propeller. The propellers were installed in nacelles positioned between the wings, each containing its own gearbox. Initially, each engine utilized separate radiators mounted on the fuselage sides; these were later replaced by four radiators affixed to the rear central struts. The engines were clustered within an engine compartment located immediately aft of the nose observer’s station. The fuselage structure employed AEG’s customary cable-braced steel tubing construction. From the nose through to the rear of the engine bay, plywood sheathing was applied, while doped fabric covered the remainder of the fuselage. The three-bay wings consisted of dual steel tube spars combined with duraluminium ribs.

The R.I conducted its inaugural flight on 14 June 1918. Early test flights revealed issues with tail heaviness alongside inadequate engine cooling and insufficient rudder surface area; these deficiencies were promptly addressed before testing resumed. On 3 September 1918, a newly fabricated propeller—insufficiently cured after gluing—failed catastrophically, causing its driveshaft to breach the fuselage and resulting in structural breakup of the aircraft that claimed all seven crew members aboard. Of the seven additional AEG R.I units planned or under construction at war’s end, only one had reached partial assembly; all were subsequently dismantled.

Specifications

File:AEG R.I from rear.jpg

Rear view of the AEG R.I

Bibliography

• Haddow, G.W. and Grosz, Peter M., The German Giants: The German R-Planes 1914-1918, Putnam, London, 3rd edition, 1988, ISBN 0-85177-812-7
• Herris, Jack, A.E.G. Aircraft of WWI: A Centennial Perspective on Great War Airplanes, Aeronaut Books, 2015, ISBN 978-1-935881-28-5, Great War Aviation Centennial Series, vol. 16