BMW 003

The BMW 003, (full RLM designation BMW 109-003), was an early axial-flow turbojet engine produced by BMW AG in Germany during World War II. The 003 and the Junkers Jumo 004 were the only German turbojet engines to reach production during World War II.

Work had begun on the design of the BMW 003 before its contemporary, the Jumo 004, but prolonged developmental problems meant that the BMW 003 entered production much later, and the aircraft projects that had been designed with it in mind were re-engined with the Jumo powerplant instead. The most famous case of this was the Messerschmitt Me 262, which used the 003 in two of the V-series prototypes and in the two experimental A-1b aircraft. The only production aircraft to use the BMW 003 were the Heinkel He 162 and late, four-engined versions of the Arado Ar 234.

Some 500 BMW 003 engines were built in Germany, but very few were ever installed in aircraft. The engine also formed the basis for turbojet development in Japan during the war, and in France and the Soviet Union following the war.

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 Reich Air Ministry (German: Reichsluftfahrtministerium, abbreviated RLM) 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,^[1] 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, so delaying the program that while the Me 262 (the first aircraft intended to use the engine) was ready for flight-testing, there were no power plants 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 aircraft had 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 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.

The only production aircraft to use the 003 was the Heinkel He 162, which fitted a modified "E" version of the engine. This version was modified with ventral mounting points to allow it to be mounted atop the fuselage of an aircraft.

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.^{[citation needed]}

Post-war use

Following the war, two captured BMW-003s powered the prototype of the first Soviet jet, the Mikoyan-Gurevich MiG-9. Blueprints for BMW engines had been seized by Soviet forces from the Basdorf-Zühlsdorf plant near Berlin and from the Central Works near Nordhausen. Production of the BMW 003 was set up at the "Red October" GAZ 466 (Gorkovsky Avtomobilny Zavod, or "Gorky Automobile Plant") in Leningrad, where the engine was mass-produced from 1947 under the designation RD-20 (reactivnyi dvigatel, or "jet drive").^[2]

After the Allied occupation of Germany, Marcel Dassault assisted Hermann Östrich in moving from the American Zone of occupied Germany into the French Zone. Within a couple of years, he was working for Voisin, a division of SNECMA, France's state-owned aircraft engine company. Using the basic design of the 003, he produced the larger Atar jet engine that powered Dassault's Ouragan, Dassault Mirage III and Mystère fighters.^[3]

Variants

Data from:Aircraft Engines of the world 1946^[4]

BMW 003 A1 (TL 109-003)

Prototype, 5.87 kN (1,320 lbf) / 8,000 rpm / sea level.

BMW 003 A2 (TL 109-003)

Initial production variant, 7.83 kN (1,760 lbf) / 9,500 rpm / sea level.

BMW 003 C (TL 109-003)

Improved design, reduced weight A2, 8.81 kN (1,980 lbf) / 9,500 rpm / sea level

BMW 003 D (TL 109-003)

Improved design C, 8.81 kN (1,980 lbf) / 9,500 rpm / sea level.

BMW 003 E

With ventral mounting points for use on the Heinkel He 162 and Henschel Hs 132.

BMW 003 R (TLR 109-003)

An A2 with a BMW 718 (RLM powerplant number 109-718) liquid-fuel rocket fixed permanently above the jet exhaust nozzle, running on R-stoff (a.k.a. Tonka or TONKA-250, 50% triethylamine and 50% xylidine) for fuel and SV-Stoff (aka RFNA: 94% HNO₃, 6% N₂O₄) oxidizer. The R delivered a combined thrust of 20.06 kN (4,510 lbf) for 3 minutes.

Applications

• Arado Ar 234
• Heinkel He 162
• Messerschmitt Me 262 (A-1b test version, and Heimatschützer II experimental interceptor only)

Specifications (BMW 003A-2)

Data from Aircraft Engines of the world 1946^[4]

General characteristics

• Type: Axial flow turbojet
• Length: 3,632.2 mm (143 in)
• Diameter: 690.9 mm (27.2 in)
• Dry weight: 623.7 kg (1,375 lb)

Components

• Compressor: 7-stage axial compressor
• Combustors: 1 annular combustion chamber
• Turbine: Single-stage axial
• Fuel type: J-2 diesel fuel or gasoline
• Oil system: Pressure feed at 586 kPa (85 psi), dry sump with 4 scavenge pumps with annular tank and cooler, using oil grade 163 S.U. secs (35 cs) (D.T.D 44D) at 38 °C (100 °F)

Performance

• Maximum thrust: 7.83 kN (1,760 lbf) at 9,500 rpm at sea level for take-off
• Overall pressure ratio: 3.1:1
• Turbine inlet temperature: 770 °C (1,418 °F)
• Specific fuel consumption: 142.694 kg/kN/hr (1.4 lb/lbf/hr)
• Thrust-to-weight ratio: 0.0125 kN/kg (1.282 lbf/lb)
• Normal, static: 6.89 kN (1,550 lbf) / 9,000 rpm / sea level
• Military flight: 6.23 kN (1,400 lbf) / 9.500 rpm / 2,500 m (8,202 ft) / 900 km/h (559 mph; 486 kn)
• Normal, flight: 2.85 kN (640 lbf) / 11,500 rpm / 11,000 m (36,089 ft) / 900 km/h (559 mph; 486 kn)

See also

Related development

• SNECMA Atar

Comparable engines

• Junkers Jumo 004
• Ishikawajima Ne-20
• Heinkel HeS 011
• Metrovick F.2

Related lists

• List of aircraft engines

References

Notes

Bibliography

External links

Wikimedia Commons has media related to BMW 003.