The Central Intelligence Agency and Overhead Reconnaissance; the U-2 and Oxcart Programs, 1954-1974

shoot down a U-2. Before the program started, Richard Bissell had estimated that the U-2 would be able to fly over the Soviet Union with impunity for only about two years. This period was already over, and the Soviets were working frantically to devise a means to stop U-2 overflights. From the very beginning, Soviet air defense units had not only tracked U-2s with radars, but had also made repeated efforts to shoot them down with antiaircraft weapons and interceptor aircraft. In 1956 such attempted interceptions had involved primarily MiG-15s and MiG-17s, which could barely reach 55,000 feet. The advent of MiG-19s and MiG-21s, which could climb even higher, provided a greater threat for U-2 pilots.

Realistic training for pilots learning to intercept the U-2 became possible after the Soviets developed a new high-altitude aircraft, the Mandrake, which was actually an improved version of the Yakovlev-25 all-weather interceptor. The Mandrake used a high-lift, low-drag wing design similar to that employed by the U-2, but its twin engines made it heavier. The Mandrake's operating altitude was 55,000 to 65,000 feet, and its maximum altitude was 69,000, far less than the 75,000 feet reached by the U-2. Like the U-2, the Mandrake's wings would not tolerate great stresses, so it could not be used as an attack aircraft at the high altitudes at which both planes operated. Between 1957 and 1959, Yakovlev built 15 to 20 of these aircraft in two versions: the Mandrake-R or YAK-25RM and the Mandrake-T, sometimes called the YAK-26. These high-altitude aircraft were used to overfly the Middle East, India, China, and Pakistan, as well as border regions of NATO nations in Europe during the late 1950s and early 1960s. It is not believed that Mandrakes ever attempted to overfly the continental United States. $ ^{103} $

Beginning in late 1957, the Mandrake served as a practice target for pilots of high-performance Soviet MiG-19 and MiG-21 interceptors. The Soviet technique that most concerned U-2 pilots was the "snap up" or power dive and zoom climb. In this maneuver, ground-based radar operators would direct the interceptor aircraft along the same flight path as the U-2. When the MiG pilot achieved the same compass heading as the U-2 flying more than 10,000 feet above him, he would put his aircraft into a shallow dive to pick up