In the late summer of 1942, Alexander Lippisch was working on the P.11 twin-jet fast bomber. When the Horten Ho IX was chosen instead, work was stopped on the P.11. One year later, the RLM then issued an official contract to develop a “Very Fast Bomber” that was based on Lippisch’s earlier research. The project was renamed “Delta VI” upon completion of design work on an unpowered glider, which was to serve as the initial prototype.
The RLM bestowed the highest priority on producing a fighter version. The LFA (Aviation Research Institute) constructed models, mock-ups and carried out windtunnel research and made ready for production. By Febuary 1944, design work for the proposed fighter, fighter-bomber and heavy fighter was nearly complete. The wing was swept back at 37 degrees, and the low wing loading promised a good climb capability and excellent maneuverability. Armament was to be two MK 103 30mm cannon mounted in the wings, with a provision for an additional two MK 103 30mm cannon or one BK 7.5 75mm cannon in an external pack.
Dr. Lippisch hoped to commence flight tests with the unpowered glider by April 1944, with the two Jumo 004B turbojet powered version to be flying by July 1944. The center section of the of the unpowered glider Delta VI was captured by American troops at Salzburg, this being the only part of the aircraft to be completed.