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AEG D.I Biplane Fighter Prototype

The AEG D.I biplane fighter program was marred by crashes of two of the three prototypes - as such the 20-strong pre-series order was cancelled.

 Entry last updated on 8/7/2017; Authored by Staff Writer; Content ¬©

  AEG D.I  
Picture of AEG D.I Biplane Fighter Prototype


Service Year: 1917
Type: Biplane Fighter Prototype
National Origin: Imperial Germany
Manufacturer(s): Allgemeine Elektricitats-Gesellschaft AG (AEG) - Imperial Germany
Total Units Built: 3

Allgemeine Elektricitats-Gesellschaft AG (AEG) served the German Empire in World War 1 (1914-1918) as an aircraft maker. Among their contributions was the short-lived AEG D.I biplane fighter. This design managed only three prototypes for its time and a first-flight was held during May 1917. The AEG Dr.I was an off-shoot of the series, developed along the lines of a triplane fighter. It was no more successful with just one example constructed.

The D.I marked the first fighter to be developed by the company and it incorporated traditional biplane qualities - an over-under wing arrangement, fixed wheeled undercarriage (tail-dragger), and open-air cockpit. The wings were slightly unequal span with a single bay each and single struts reinforced the members outboard of the fuselage. The pilot sat in an open-air cockpit under and aft of the upper wing assembly. The engine was fitted forward of the pilot in a streamlined housing and drove a two-bladed propeller at the nose. Internally there was a steel-tubed understructure and fabric skinning was used along the wing surfaces. Proposed armament was 2 x 7.92mm LMG 08/15 machine guns set over the nose and synchronized to fire through the spinning propeller blades. Power was from a Daimler D.IIIa 6-cylinder liquid-cooled inline piston engine of 160 horsepower.

As tested, the D.I managed a top speed of 127 miles per hour and ranged out to 300 miles. Its service ceiling was 16,000 feet and initial rate-of-climb reached 1,313 feet per minute.

A total of three prototypes were eventually completed by AEG with the first arriving in May of 1917. Between August and September of that year, the aircraft saw a lengthening of its fuselage to improve stability. The radiators were changed in the second and third prototypes.

Despite a prototype having crashed during testing, some twenty pre-production forms were ordered by the German Air Service for active evaluations. Following the crash of a second prototype on September 5, 1917, this commitment was abandoned and the D.I fell to history - proving to be unstable and a handful at the controls.

Structural (Crew, Dimensions, Weights)

Operating Crew (Typical): 1
Overall Length: 20.01 feet (6.1 meters)
Overall Width: 27.89 feet (8.50 meters)
Overall Height: 8.69 feet (2.65 meters)

Weight (Empty): 1,510 lb (685 kg)
Weight (MTOW): 2,072 lb (940 kg)

Power / Performance (Engine Type, Top Speed)

Engine Type: 1 x Daimler D.IIIa 6-cylinder liquid-cooled inline piston engine developing 160 horsepower and driving a two-bladed propeller at the nose.

Top Speed: 111 knots (127 mph; 205 kph)
Maximum Range: 251 nautical miles (289 miles; 465 km)
Service Ceiling: 16,404 feet (5,000 meters; 3.11 miles)
Rate-of-Climb: 1,313 feet-per-minute (400 m/min)

Armament / Mission Payload

2 x 7.92mm LMG 08/15 machine guns synchronized to fire through the spinning propeller blades.

Global Operators (Customers, Users)

Imperial Germany (cancelled)

AEG D.I Variants

D.I - Base Series Designation; three prototypes completed.
Dr.I - Triplane variant of 1917 based on the D.I design.

AEG D.I Images