AEG D.I

Allgemeine Elektricitäts-Gesellschaft (AEG)

Industry	Electrical equipment, aircraft manufacturing
Founded	1883
Headquarters	Germany

Template:Infobox aircraft

The AEG D.I was a prototype biplane fighter aircraft developed by the Allgemeine Elektricitäts-Gesellschaft (AEG) during World War I for use by the Imperial German Army (Deutsches Heer) and its air branch, the Luftstreitkräfte. In 1917, three prototypes were commissioned, but following fatal accidents involving the first two, the project was discontinued. A triplane iteration, known as the AEG Dr.I, was also produced.

Development

In early 1917, AEG initiated the design of a single-seat fighter prototype designated D.I. The fuselage featured the company's characteristic steel tube construction, while the wings were single-bay with a steel tube spar. Originally, wooden ribs were used in the wing structure but were later replaced with steel ribs to enhance durability. The incorporation of steel tubing in the wings allowed for a reduction in drag by minimizing wire bracing and limiting interplane struts to a single I-strut on each side. Propulsion came from a water-cooled 160-horsepower (120 kW) Mercedes D.III straight-six engine equipped with a front-mounted radiator. Armament consisted of two synchronized forward-firing 7.92-millimeter (0.312 in) LMG 08/15 machine guns.

The initial prototype was finalized in May 1917. During flight trials, it achieved a top speed of 225 kilometres per hour (140 mph) and exhibited climb performance comparable to the contemporary Albatros D.V. At that time, it was the fastest German fighter available. Consequently, the Inspectorate of Flying Troops (Inspektion der Fliegertruppen or Idflieg) commissioned three additional units for further evaluation. In July, an order for 20 pre-production models was placed, contingent upon successful static load testing conducted between June 28 and July 3. While the wings passed these tests, the fuselage initially failed; however, after AEG reinforced the fuselage, it passed on August 4. Around this period, modifications were made to lengthen the second prototype’s fuselage to enhance lateral stability and improve landing behavior.

Subsequently, Idflieg authorized operational flight assessments by military pilots. On August 21, one D.I crashed under unexplained circumstances; nevertheless, testing continued with another aircraft until August 25. Only minor adjustments were required before clearance for combat deployment could be granted. Unfortunately, on September 5, renowned fighter ace Walter Höhndorf lost control in a spin and crashed due to unknown reasons. Following these incidents and after several pre-production units had been completed, Idflieg terminated the program.

Variants

AEG D.I

A 1917 experimental single-seat biplane fighter prototype.

AEG Dr.I

A 1917 experimental single-seat triplane fighter prototype.

Specifications (AEG D.I)

Second version of the AEG D.I

Bibliography

• Gray, Peter and Owen Thetford. German Aircraft of the First World War, 2nd edition, London: Putnam, 1987. ISBN 0-85177-809-7.
• Green, William and Gordon Swanborough. The Complete Book of Fighters: An Illustrated Encyclopedia of Every Fighter Built and Flown, Revised and Updated edition, London: Salamander Books, 2001. ISBN 1-84065-269-1.
• Herris, Jack. A.E.G. Aircraft of WWI: A Centennial Perspective on Great War Airplanes, Aeronaut Books, 2015. ISBN 978-1-935881-28-5.