The Aviatik D.I served the Austro-Hungarian Empire as a fighter and reconnaissance escort through the final years of World War 1. The system eventually proved a capable combat aircraft with good speed, climbing ability and service ceiling after the original design was made clear of its inherent deficiencies. The D.I was designed to replace the Hansa-Brandenburg D.I series (a biplane designed by Ernst Heinkel and appearing in 1916 and leaving an ace-making yet fatally accident-prone legacy). Nevertheless, the D.I fought on until the closing bell of World War 1 and was produced in upwards of 700 examples. The Aviatik D.I holds the distinction of becoming the first indigenously-designed fighter to be build in whole in Austria.
The D.I began life in prototype form in August of 1916 with a first flight recorded on January 24th, 1917. The test flight proved fatal, however, and took the life of its test pilot. As such, the initial design was revised to compensate for defects and three more prototypes soon emerged, each charged with a distinct development purpose as well as its 8mm Schwarzlose machine gun fitted to the top wing assembly. After additional testing, production aircraft were ordered and delivered - these with the synchronized (via a propeller interrupter gear) 2 x 7.92mm Schwarzlose forward-firing machine guns along the upper sides of the engine.
Design-wise, the Aviatik D.I was of a conventional single-seat biplane arrangement. Wings were fitted as an upper and lower staggered assembly of equal span with parallel struts and single bays. The engine - an Austro-Daimler water-cooled inline producing 200 horsepower - was fitted to the extreme forward portion of the fuselage and powered a two-blade propeller. The undercarriage was of a fixed arrangement and made up of two main landing wheels and a tail skid. The spacious cockpit was situated aft of the engine at about amidships and offered a relatively good field of vision (as good as vision gets in a biplane). The pilot sat behind the upper wing assembly (which was held relatively close to the top of the engine compartment) behind a simple windscreen in an open-air cockpit. The fuselage tapered into the empennage which featured a single large vertical tail fin and applicable horizontal planes. Performance specifications included a top speed of 115 miles per hour, a service ceiling of approximately 20,100 feet and operational endurance totaling 2 hours, 30 minutes.
Though primary manufacture of the Aviatik D.I was handled by Austrian Aviatik, license-production was also undertaken at multiple facilities during her tenure. These included Lohner, Lloyd, MAG, Thone und Fiala and WKF under various batch series designations and differed mainly in horsepower output of their selected Austro-Daimler engines. In all, roughly 700 of all types were produced from 1917 into 1918. Deliveries began in the Fall of 1917 and continued on into October of 1918.
When in action, early-form D.Is exhibited engine overheating issues and structural weaknesses (namely the fabric tearing away from the understructure or loss of parts and wings while at high speeds). The guns on the original production models were also situated well out of reach of the pilot meaning that a jammed gun stayed jammed until the pilot landed his mount for repairs. As production continued, the structure received attention in areas and was reinforced based on pilot feedback. Likewise, the guns were now moved within reach of the pilot. Engine overheating was solved in-the-field by simply flying without the engine covers on.
The Aviatik D.I also went under the known names of "Berg Fighter" or "Berg D.I" in reference to its designer, Julius von Berg. Austro-Hungarian air elements flew their D.Is in good numbers until the end of the war.
The D.I appeared in a revised form as the D.II with a cantilever low wing assembly. The D.II was produced in limited quantities in two batches beginning in 1918 but arrived too late to see useful delivery to combat units. The D.I was also considered in a few other notable "one-off" prototype forms - mainly the D.III, a high-altitude variant fitting a Hiero engine of 230 horsepower and the Dr.I, a triplane design based on the D.I biplane.