Ruhrstahl/kramer X-4 missile
Development work on the X-4 wire-guided air-to-air missile began in July 1943 and it was intended for use by both the Fw 190 and the Me 262. It was powered by a BMW 109-548 liquid-fuelled rocket engine and had wooden fins which had fairings at their tips containing 8.5km of fine wire on bobbins for the guidance system. The 20kg fragmentation warhead was effective to about 8m or 26ft. The first tests, using converted F-8 Fw 190 V69,WNR. 582072, took place on August 11, 1944, at E-stelle Tarnewitz on the Baltic coast. An X-4 was fitted beneath each wing on an ETC 71 rack. Four more Fw 190s were also used in tests – V70 and a trio of F-8s. When the missile was launched, the pilot had to manually guide it to its target using a special joystick mounted on the instrument panel.this proved to be extremely difficult however, and development moved on to aircraft with two or more crew such as the Ju 88. In the end, although 1000-1300 X-4s were built, their engines were destroyed when BMW’S factory at Stargard was bombed.
The wire-guided X-4 air-to-air missile was intended for use by high-performance fighters such as the Fw 190 and Me 262 but although more than 1000 were made, all of the rocket engines intended for the type were destroyed in a bombing raid before they could be delivered. A close up of the X-4 missile attached to the wing of a Fw 190. One of its guidance wires can be seen trailing from the streamlined pod on its wingtip. Once it was launched, the X-4 had to be manually guided on to its target using a joystick – almost an impossible task for a pilot simultaneously trying to keep his own aircraft aloft. Left: The RZ 65 rocket launcher tubes fitted into the wing structure of Fw 190 V69 appear as three holes in the leading edge of each wing. The SG 113 weapons system was carried vertically within each wing of the Fw 190. It was fired downwards automatically when passing over a tank.the attacking pilot had to be flying low for it to work but so low that the blast resulting from the tank being blown up stood a good chance of destroying the aircraft too.