Work on the Fritz-X proceeded in parallel with work on the Hs-293. Fritz-X was also known as the “FX-1400” or “X-1” by the manufacturer, Ruhrstahl AG, and “PC-1400X” by the German Air Ministry (Reichsluftfahrtministerium / RLM). The Fritz-X was designed by a team under Dr. Max Kramer of the German Aviation Research Institute (Deutsche Versuchsansalt fuer Luftfahrt / DVL), beginning in 1939. Like the Hs-293A, the Fritz-X did not reach operational status until the summer of 1943.
The Fritz-X had some technology in common with the Hs-293, but it had a completely different appearance. The Fritz-X was based on the 1,400 kilogram (3,090 pound) PC1400 hardened armor-piercing bomb. The Fritx-X was 3.26 meters (10 feet 8 inches) long and weighed 1,570 kilograms (3,461 pounds). There were four stubby fixed wings arranged in a cruciform pattern around the bomb’s center of gravity, giving it a wingspan of 1.35 meters (4 feet 5 inches). The Fritz-X had a steeper glide angle and so shorter range than the Hs-293A.
The box-shaped 12-sided tail framed vertical and horizontal fins. The fins had spoilers mounted on them to provide aerodynamic control, with the fins actuated by solenoids to pop them in and out of the airstream at a rate of ten times per second. The bomb was directed by a Kehl-Strassburg system like that used with the Hs-293A, and also had a internal gyro system to keep it from rolling. The Fritz-X did not have a boost motor, but a tracking flare was fitted in the tail.
The Fritz-X was carried by Dornier Do-217 and Heinkel He-177 bombers. A Do-217 could only carry one Fritz-X, in contrast to two Hs-293As. A total of about 2,000 Fritz-X bombs were built, with 200 used in combat. Further work focused on development of a wire-guided version and then a spin-stabilized version, but these efforts were cancelled, since increasing Allied pressure on Germany meant that more emphasis had to be placed on defensive rather than offensive weapons.