Design & Development

Work on the design started under the aegis of the Deutsche Forschungsanstalt für Segelflug (DFS)—the German Institute for the Study of sailplane flight. Their first design was a conversion of the earlier Lippisch Delta IV known as the DFS 39 and used purely as a glider testbed of the airframe. A larger follow-on version with a small propeller engine started as the DFS 194. This version used wingtip-mounted rudders, which Lippisch felt would cause problems at high speed. Lippisch changed the system of vertical stabilization for the DFS 194's airframe from the earlier DFS 39's wingtip rudders, to a conventional vertical stabilizer at the rear of the aircraft. The design included a number of features from its origins as a glider, notably a skid used for landings, which could be retracted into the aircraft's keel in flight. For takeoff, a pair of wheels, each mounted onto the ends of a specially designed cross-axle, were needed due to the weight of the fuel, but the wheels, forming a takeoff "dolly" under the landing skid, were released shortly after takeoff.

The designers planned to use the forthcoming Walter R-1-203 cold engine of 400 kg (880 lb) thrust, which used a monopropellant consisting of stabilized HTP known by the name T-Stoff. Heinkel had also been working with Hellmuth Walter on his rocket engines, mounting them in the He 112's tail for testing, and later in the first purpose-designed, liquid-fueled rocket aircraft, the He 176. Heinkel had also been selected to produce the fuselage for the DFS 194 when it entered production, as it was felt that the highly volatile monopropellant "fuel's" reactivity with organic matter would be too dangerous in a wooden fuselage structure. Work continued under the code name Projekt X.

The division of work between DFS and Heinkel led to problems, notably that DFS seemed incapable of building even a prototype fuselage. Lippisch eventually asked to leave DFS and join Messerschmitt instead. On 2 January 1939, he moved with his team and the partly completed DFS 194 to the Messerschmitt works at Augsburg. The delays caused by this move allowed the engine development to "catch up". Once at Messerschmitt, the team decided to abandon the propeller-powered version and move directly to rocket-power. The airframe was completed in Augsburg and in early 1940 was shipped to receive its engine at Peenemünde-West, one of the quartet of Erprobungsstelle-designated military aviation test facilities of the Reich. Although the engine proved to be extremely unreliable, the aircraft had excellent performance, reaching a speed of 550 km/h (340 mph) in one test.

In the Me 163B and -C subtypes, a windmill generator on the extreme nose of the fuselage, and the backup lead-acid battery inside the fuselage that it charged, provided the electrical power for the radio, the Revi16B, -C, or -D reflector gunsight, the direction finder, the compass, the firing circuits of the cannons, and some of the lighting in the cockpit instrumentation.

There was an onboard lead/acid battery, but its capacity was limited, as was its endurance, no more than 10 minutes, hence the fitted generator.

The airspeed indicator averaged readings from two sources: the pitot tube on the leading edge of the port wing, and a small pitot inlet in the nose, just above the top edge of the underskid channel. There was a further tapping-off of pressure-ducted air from the pitot tube which also provided the rate of climb indicator with its source.