Fritz X was the most common name for a German guided anti-ship glide bomb used during World War II. Fritz X was a nickname used both by Allied and Luftwaffe personnel. Alternate names include Ruhrstahl SD 1400 X, Kramer X-1, PC 140 or FX 1400 (the latter is also the origin for the name "Fritz X". Along with the USAAF's similar Azon weapon of the same period in World War II, it is one of the precursors of today's anti-ship missiles and precision-guided weapons.

t] HistoryThe Fritz X was a further development of the high-explosive bomb SD 1400 (Splitterbombe, dickwandig 1400; German for "fragmentation bomb, thick-walled, 1400 kg". It was given a more aerodynamic nose, four stub wings, and a box shaped tail unit. The Luftwaffe recognized the difficulty of hitting moving ships during the Spanish Civil War.[1] Dipl. engineer Max Kramer, who worked at the DVL, had been experimenting since 1938 with remote-controlled free-falling 250 kg bombs, and in 1939 fitted radio-controlled spoilers.[2] In 1940, Ruhrstahl was invited to join the development, since they already had experience in the development and production of unguided bombs.

The dual-axis joystick-equipped Kehl series of radio-control transmitter sets onboard the deploying aircraft were used to send the control signals to the Fritz-X, with the ordnance itself picking up the signals through a Straßburg receiver within it to send the signals on to the movable surfaces in the Fritz-X's tail fin structure