The Austro-Hungarian Empire managed its own aero-industry apart from that of Germany's during World War 1 (1914-1918) and several homegrown designs emerged during the fighting. One of these offerings arrived from the work completed by Professor Richard Knoller - this becoming the Knoller "70". The single-seat, single-engine biplane debuted during 1917 and was tested into 1918. This led to an order for ten pre-series aircraft for additional evaluation but the Austro-Hungarian surrender ended any future the biplane fighter would have had.
The Knoller 70.01 was the first of two prototypes completed. Physical work began in 1917 by K.u.k. Fliegerarsenal Fischamend. The aircraft's general arrangement was traditional for the period as it sat its pilot in an open-air cockpit aft of the engine installation at the nose and under / behind the upper wing assembly. The wings were of a biplane arrangement, unstaggered and featuring single bays - one of the more interesting design elements of these members was an inherent ability to "flex" on-the-fly as the aircraft gained speed, thus reducing drag. Struts and cabling braced the members to the fuselage both under and above the aircraft. The fuselage was aerodynamically refined with a large spinner added to the nose and the empennage tapering smoothly. The tail itself was made up of a single vertical fin with mid-set horizontal planes. The undercarriage was of a tail-dragger arrangement, wheeled and fixed in place.
Dimensions of the aircraft included a wingspan of 26.2 feet, a length of 20.9 feet and a height of 9.4 feet.
Power was derived from a single Hiero 6-cylinder, water-cooled engine outputting 230 horsepower and driving a two-bladed propeller at the nose. As tested, the 70.01 was estimated to hold a maximum speed of 149 miles per hour.
Proposed armament was made up of 2 x 8mm Schwarzlose machine guns, these set over the nose and synchronized to fire through the spinning propeller blades.
Prototype 70.01, achieved a first-flight on November 23rd, 1917. However, a few days into its test phase it was damaged while on the ground. During the repair period, ailerons were installed at the upper wing members for improved controlling but more damage was suffered during a landing action in the spring of 1918. Prototype 70.02 was made available during September of 1918 but the end of the war in November of 1918 meant the end of the Knoller fighter project.