Rare 1944 or 1945 flight footage from Alexander Lippisch's archives of a German prototype P13a supersonic coal fuelled Ramjet Delta wing interceptor gliding in for landing. The craft in the film has features shown in the design drawings for the production fighter version of the P13a and not the simplified DM1 glider. The footage is not necessarily an operational supersonic fighter and may be a large glider or model prototype to test the proposed production version configuration. What is clear is that the design was capable of stable flight. Something to be expected from an aeronautical engineer of Dr Lippisch's calibre. A glider only prototype known as the DM1 was built by others as Dr Lippisch elsewhere concentrated on more secret developments. The Coal dust fueled ramjets were tested successfully by Professor Eugene Sänger on a Dornier 17. The Ramjets starting at approx 250km'hr and accelerating the unstreamlined bomber to 150km'hr faster than it's usual maximum speed. Contrary to popular Myth, Ramjets can start and generate useful power at subsonic speeds. The French Leduc fighter powered solely by ramjet was able to start at around 250km'hr and accelerate in a climb to mach 0.85 The Lippisch P13a configuration was tested in the German supersonic wind tunnels during the war and found to be stable and controllable up to Mach 2.5 The production version was to be fitted with twin 30mm canon, and taking off from a dropable wheeled sled, accelerated to ramjet starting speed ...
