The original Heinkel P.1073 Heinkel was redesigned to fit the RLM's requirements. The BMW 003 was a very troublesome engine when it first appeared and was installed on a Messerschmitt Me 262 prototype. Both engines failed during the test hop, but the plane managed to make it back to the airport powered by a backup piston-engine. The 003 suffered from the same problems as the Jumo 004, but after further development, the engine was finally ready for production. (After the war, the Russians reversed engineered the BMW 003 and developed it as the RD-20. The RD-20 powered the MiG-9, but the engine remained unreliable due to persistent flameouts.) Heinkel redesigned the P.1073 to fit the RLM's needs and the contract was awarded to Heinkel on October 19, 1944. Although Ernst Heinkel named the plane the Spatz for Sparrow, the He 162 was mostly known as the Salamander, because of the creature’s mythical ability to live through fire. The prototype He-162 V1 emerged in 74 days and weighed 6,180 lbs., fully loaded. One third of the weight of the aircraft was wood for the airframe, wings, landing gear doors and nose cone. It had a high mounted wing straight wing with a forward swept trailing edge and a slight dihedral. Twin vertical stabilizers were installed with a high dihedral horizontal stabilizer placed to clear the jet exhaust. The flap system and landing gear were powered hydraulically from an engine-driven pump. 5 The tricycle landing gear retracted into the fuselage (using Bf-109 main landing gear to simplify production) and was then lowered by springs compressed during retraction. 6 . It was also the first aircraft equipped with an ejection-seat as standard equipment. It was powered by an explosive cartridge that allowed the pilot to get clear the engine intake that was just aft of the cockpit. 7 This underground facility was located in Hinterbrühl, Austria and produced 40-50 He 162s per month.