World’s First True Rocket Aircraft: the Heinkel He 176
First Flight of the Heinkel He 176
First All-Liquid Fueled Rocket-Propelled Aircraft
In the late 1930s, the Heinkel concern of Germany began work on the world’s first all-liquid fueled rocket-propelled aircraft. All-liquid fueled rocket motors were a progressively better alternative to the solid-fuel offerings of the time concerning their use in aircraft. Foremost on the mind of Ernst Heinkel was the eclipsing of the then-standing world airspeed record which would bring national pride to Germany and notoriety to Heinkel itself.
Under the direction of Wilhelm Benz and Hans Regner, work began on a private venture design which became the “He 176” reminiscent of the prior Heinkel He 111 Medium Bomber. The aircraft would be powered by a refined Walter HWK-R1 rocket engine outputting 1,373 lbs of thrust. Key to its design would be the smallest possible airframe in an effort to delete all unnecessary aerodynamic-defeating protrusions and save on overall weight. As speeds were projected to be rather intolerable for the feat at hand, the pilot would be given a reclined position to counter the effects of g-forces.
One of the more interesting design features of the He 176 was its pilot escape feature. As the intended airspeeds to be reached were truly monumental and very new territory, the He 176 was given a completely jettisonable cockpit section.
The first He 176 prototype was first flown on July 20th, 1939. However, the aircraft’s performance was such that attending German Reich Air Ministry (RLM) officials were rather underwhelmed by the attempt. This particular rocket-fueled approach was not held in high regard both for its rather noisy execution and inherent dangerous nature concerning the combustible fuel. The He 176 even failed to surpass 435 miles per hour in her first flight attempt.
As such, the He 176 project was not pursued beyond this developmental “peak” despite a second prototype on the drawing board. In the end, the airframe proved too heavy for the intended rocket powerplant, and the wing surface area was deemed too small for the required lift and control at the expected speeds. From then on, the He 176 was sentenced as a museum piece, being sent to Berlin from Heinkel for public display in 1942.