Ruhrstahl X-4

The body of the rocket is cigar-shaped with four small cruciform rudders in the tail and four large wings. The rocket body is made of aluminum alloys, the aerodynamic surfaces are made of bakelite plywood.

The rocket itself was designed in such a way that low-skilled workers could assemble it.

The BMW-Flugmotorenbau 109-548 liquid-propellant liquid engine ( LRE ) provided a rocket with a flight speed of about 900 km / h (according to other sources 1,100 km / h) and was developed by a group of liquid-propellant rocket engines in Munich under the leadership of H. Zborovwski.

Initially, S-Stoff oxidizer (96% nitric acid) and R-Stoff fuel (a mixture of 43% triethylamine and 57% xylidines (weight) were used as fuel components, in some sources Tonka-250, 50-52% triethylamine and 48-50% xylidines (volumetric)), which provided a thrust of the rocket engine of 130 kg, a pulse of 1350 kgf and a run time of 20 seconds.

Subsequently, due to difficulties with the storage of nitric acid, problems with controlling and stabilizing the rocket during the flight phase, it was decided to use solid rocket fuel. Wilhelm Schmidding the youngest from Bodenbach developed a 109-603 solid-fuel rocket engine, with a cast block made of diglycol gunpowder , which allowed the rocket to develop a thrust of 150 kg and an impulse of 1,200 kgf within 8 seconds of flight.

The X-4 missile control commands were transmitted over two thin copper wires that were wound on bobbins (remote control by wire) located at the ends of the wings before launch. The warhead of the rocket was equipped with a non-contact acoustic Doppler fuse Kranich , which issued a command to undermine the fragmentation warhead of the rocket. The mass of the high-explosive fragmentation warhead is 20 kg, the radius of destruction is 8 meters (the Rurshtal X-7 anti-tank missile, developed since 1944, also had a similar design).

The first test launch of the X-4 rocket was carried out on August 11, 1944 with the Fokke-Wulf Fw 190 fighter. Later, the Ju-88 bomber and the Me-262 fighter jet were used for testing.
During the development, it was planned to equip single-seat fighters with a rocket, but in practice it turned out that it was difficult for pilots to control both an airplane and a missile pointing at a target. In addition, there were other design problems, which ultimately led to the conclusion that the X-4 should be launched from multi-seat aircraft, for example, from the Junkers bomber Ju-88.

By the beginning of 1945, more than 1000 units of the X-4 product were assembled at one of the plants in Rurstal ^[1] . On February 6, 1945, as a result of an enemy bombing raid on the BMW Stargard plant for the production of rocket engines, the plant itself and the taxiway to all 1300 missiles, which were already awaiting departure for equipment of the missiles, were destroyed. Based on previously delivered engines, 255 pre-production models were assembled and tested ^[2] .

It cannot be ruled out that some X-4 missiles could be used in the final weeks of World War II, although the missile was not delivered to the Luftwaffe warheads.

After the war, French engineers tried to develop their own version of the X-4 rocket under the designation AA.10 . From 1947 to 1950, a batch of 200 rockets was made. However, the French program was closed due to the difficulties of ensuring safety when refueling a rocket (the combination of nitric acid and Tonka-250 is explosive).

• Purpose: short-range air-to-air missile
• Rocket Length: 2.01 meters
• Case Diameter: 0.22 meters
• Wingspan: 0.726 meters
• Curb weight: 60 kg
• Powerplant: LRE BMW 109-448 (or 109-548 )
  • Thrust - 16 kN
  • Operating time - 20 (33) seconds
• Speed ​​in flight: 893 km / h
• Warhead: high-explosive fragmentation, non-contact detonation
  • Warhead mass: 20 kg (30% of the launch weight of the rocket)
• Range: 3200 m (wire length 4.5 km)
• Guidance system: FuG 510/238 , manual command with visual support, by wire
  • transmitter - Düsseldorf ( German: Düsseldorf )
  • receiver - "Detmold" ( German: Detmold )
• Fuse: Kranich, Acoustic Doppler

At the close of World War II, the Ruhrstahl X-4 was the only air-to-air missile-controlled missile in mass production. At the same time, of all similar projects, it was the most primitive in concept, and probably almost useless for use in aerial combat due to the extreme difficulty of manually pointing a visually tracked missile onto an enemy aircraft. After the end of World War II, manual radio command guidance with visual tracking for the airborne missile defense was universally recognized as a dead end, and was not used in the future.

• Guided missile "Artemis"
• Ruhrstahl X-7
• Hughes JB-3 Tiamat

1. Justo Miranda, Paula Mercado. Secret Wonder Weapons of the Third Reich: German Missiles 1934-1945. - Schiffer Publishing, 2000. - P. 144. - ISBN 0764300865 .

• Anti-tank guided missiles