AEG DJ.I

Allgemeine Elektricitäts-Gesellschaft (AEG)

Industry	Electrical equipment, aircraft manufacturing
Founded	1883
Headquarters	Germany

The AEG DJ.I was a prototype biplane fighter developed by the Allgemeine Elektricitäts-Gesellschaft (AEG) during First World War service for the Imperial German Army's (Deutsches Heer) Imperial German Air Service (Luftstreitkräfte). It evolved from the unsuccessful AEG PE triplane fighter, retaining the same armoured fuselage configuration, weaponry, and powerplant. Although three prototypes were commissioned, only two were completed prior to the war's conclusion in November 1918.

Development

In 1917, AEG was tasked with creating a single-seat fighter specialized in engaging enemy ground-attack aircraft. Given that these missions required flying at very low altitudes, the aircraft itself needed to be armoured. The earlier PE prototype had been rejected by the Inspectorate of Flying Troops (Inspektion der Fliegertruppen (Idflieg)) due to unsatisfactory flight characteristics. AEG believed that converting the design into a biplane could enhance performance by reducing drag through the removal of one wing, thereby increasing speed. The company retained the fuselage design incorporating integral armour protecting the pilot, engine, and fuel tank, but introduced newly designed two-bay wings featuring broad I-shaped interplane struts instead of traditional bracing wires to minimize susceptibility to anti-aircraft damage. The first prototype was powered by an experimental water-cooled 195-horsepower (145 kW) Benz Bz.IIIb V8 engine, while the second employed a water-cooled 245 hp (183 kW) Maybach Mb.IVa straight-six engine. Both models were equipped with two 7.92-millimetre (0.312 in) leMG 08/15 machine guns and carried four small bombs.

Construction on the initial prototype commenced in March 1918 and was finished by May; however, flight testing under Idflieg did not start until August. The reason for this delay remains unclear but may be linked to engine availability issues with the Benz powerplant. The second prototype was built between May and July, with records indicating its Maybach engine required replacement in September, potentially due to flight testing activities. A third prototype was reportedly under construction during that same month, though no further details are available. No production orders were finalized before hostilities ceased in November 1918.

Bibliography

• Gray, Peter & Thetford, Owen. German Aircraft of the First World War. Putnam, London, 1987 (2nd edition).
• Herris, Jack. A.E.G. Aircraft of WWI: A Centennial Perspective on Great War Airplanes. Aeronaut Books, 2015.