Dr. Max Otto Kramer (8 September 1903 – June 1986) was a German scientist who worked for the Ruhrstahl AG steel and armaments corporation. He was responsible for the construction of the Fritz X and the Ruhrstahl X-4 missiles (1943-1945), among others. Personal Background Max Otto Kramer was born on 8 September 1903 in Cologne, Germany, earned a degree in electronic engineering at the Technical College of Munich in 1926 and received his doctorate in aeronautics from the Technical College of Aachen in 1931. Already by the late 1930s he was an authority on aerodynamics, working at the German Institute of Aeronautics in Berlin, and holding patents for important innovations related to aircraft, such as landing flaps. His specialty was in the modeling of complex airflows, especially those related to laminar-flow dynamics. Early Research in Germany Kramer had a wide range of interests and his work encompassed automobiles, gliders, propeller noise, acoustic missile and wake tracking, and underwater coatings. However, he is best known for the development of the Ruhrstahl X-1 "Fritz-X" glide bomb, a radio-controlled bomb whose descent could be adjusted. This bomb was deployed a number of times in late 1943 and early 1944, achieving several successes before Allied air superiority and electronic countermeasures rendered it ineffective. Notable amongst its successes were the sinking of the and the infliction of severe damage upon the British battleship , the American light cruiser and the British light cruiser . Kramer continued to evolve the basic Ruhrstahl X-1 design during the war. One direction of research was to improve the ability of this weapon to penetrate the heavy armor of modern battleships of the British and the American classes. The X-2 and X-3 variants of the weapon did so by achieving even higher descent speeds into the transonic range without losing directional stability. The X-5 and substituted greater explosive power for descent speed, with a total weight approaching 2,250 kg. The X-6 attempted to overcome heavy deck armor with a very heavy steel tip and an enhanced explosive charge. None of the variants ever made it into large-scale production or operational use. One of Kramer's most renowned development efforts involved the Ruhrstahl X-4, also known as the Kramer X-4. This was a highly innovative air-to-air missile, designed to be guided by airborne operators into the midst of Allied bomber formations. As such it was a precursor to the air-to-air guided missiles