[Illustration: 66. X-4.]
The fin-stabilized X-4 air-to-air missile was guided to its target by
means of electrical impulses which passed through two wires connecting
the rocket to the launch aircraft until detonation. Once the missile was
on its way to the target bomber, the fighter pilot directed its course
with a separate small control stick in his cockpit. Because the control
wires streamed out ahead of the launching aircraft, the pilot was
prevented from evasive maneuvering.
Launched from German fighter aircraft, usually a FW-190, the X-4 was
powered by either a solid-propellant engine or a bi-propellant
liquid-rocket engine. It carried a 20-kilogram (44-pound) warhead.