BMW 003 - Design and Development

Design and Development

The practicality of jet propulsion had been demonstrated in Germany in early 1937 by Hans von Ohain working with the Heinkel company. Recognising the potential of the invention, the Reichsluftfahrtministerium (RLM - Government Air Ministry) encouraged Germany's aero engine manufacturers to begin their own programmes of jet engine development. The BMW 003 began development as a project of the Brandenburgische Motorenwerke (The Brandenburg Motor Works, known as "Bramo ") under the direction of Hermann Östrich and assigned the RLM designation 109-003 (using the RLM's "109-" prefix, common to all jet and rocket engine projects). Bramo was also developing another turbojet, the 109-002. In 1939, BMW bought out Bramo, and in the acquisition, obtained both engine projects. The 109-002 had a very sophisticated contra-rotating compressor design intended to eliminate torque, but was abandoned in favour of the simpler engine, which in the end proved to have enough development problems of its own.

Construction began late in the same year and the engine ran for the first time in August 1940, but produced less than half of the thrust expected, 2.5 kN instead of 6.3 kN. The first flight test took place in mid-1941, mounted underneath a Messerschmitt Bf 110. Problems continued, however, meaning that while the Me 262 (the first aircraft intended to use the engine) was ready for flight-testing, there were no powerplants available for it and it actually began flight tests with a conventional Junkers Jumo 210 piston engine in the nose. It was not until November 1941 that the Me 262 V1 was flown with BMW engines, which both failed during the test, the prototype having to return to the airfield on the power of the piston engine, which was still fitted.

The general usage of the BMW powerplant was abandoned for the Me 262, except for two experimental examples of the plane known as the Me 262 A-1b. The Me 262 A-1a production version used the competing Junkers Jumo 004 whose heavier weight required the wings to be swept back in order to move the center of gravity into the correct position. Work on the 003 continued anyway, and by late 1942 it had been made far more powerful and reliable. The improved engine was flight tested under a Junkers Ju 88 in October 1943 and was finally ready for mass production in August 1944, in time to power the He 162.

The E-version of the BMW 003 was specially designed with ventral mounting points to allow it to be mounted atop the fuselage of an aircraft, and the 003E version was used on the He 162 in this manner.

One late version of the engine added a small rocket motor (BMW 109-718) at the rear and usually just above the exhaust of the engine, which added some 9.8 kN (2,200 lbs/f) of thrust for take off and short dashes. In this configuration, it was known as the BMW-003R and was tested, albeit with some serious reliability problems, on single prototypes for advanced models of the Me 262 (Me 262 C-2b Heimatschützer II), and He 162 (He 162 E). Both prototypes flew under hybrid jet/rocket power during March 1945, though records do not indicate the results of testing with the 162 E.

The BMW-003 was intended for export to Japan, but working examples of the engine were never supplied. Instead, Japanese engineers used drawings and photos of the engine to design an indigenous turbojet, the Ishikawajima Ne-20.