Adolf Georgievich Tolkachev Адольф Георгиевич Толкачёв (1927, Aktyubinsk, Kazakhstan – September 24, 1986) was a Soviet Union electronics engineer who provided key documents to the U.S. Central Intelligence Agency (CIA) over the years between 1979 and 1985. Working at the Soviet radar design house Phazotron as one of the chief designers, Tolkachev gave the CIA complete information about such projects as the R-23, R-24, R-33, R-27, and R-60, S-300; fighter-interceptor aircraft radars used on the MiG-29, MiG-31, and Su-27; and other avionics. The United States considered the most advanced airborne radar among the systems Tolkachev compromised was the passive phased array radar used by the MiG-31 Foxhound fighter. He was executed as a spy in 1986.
His distrust of the communist government seemed to spring from persecution his wife's parents had suffered under Joseph Stalin. He told the CIA he was inspired by Aleksandr Solzhenitsyn and Andrei Sakharov.
Tolkachev attempted five times from January 1977 to February 1978 to approach cars with U.S. diplomatic license plates in Moscow, coincidentally approaching the CIA Moscow bureau chief at a gas station, but the CIA was wary of counterintelligence operations by the KGB. On his fifth attempt the CIA assigned a Russian-speaking officer named John I. Guilsher to make contact with him. Eventually Tolkachev established his bona fides with intelligence data that proved to be of "incalculable" usefulness to US experts. The U.S. Air Force completely reversed direction on a $70 million dollar electronics package for the F-15 Eagle as a result of Tolkachev's intelligence.
Because Tolkachev resisted the use of traditional CIA methods including dead drops, preferring personal meetings; he was able to transfer a much larger volume of classified data, much of it collected using various matchbox-sized cameras. The need for these meetings necessitated several innovations in CIA tradecraft such as signals and concealment. Although he demanded money for his cooperation, he seemed to insist that he only wanted payment as proof of the value of his effort and risk. He was eventually paid a salary "equivalent" to the U.S. President, at the time $200,000 annually, most of which was to be held in escrow until he defected.
At some point in 1985, Tolkachev was compromised. While attempting to meet him, a CIA officer was arrested and questioned at the Lubyanka KGB headquarters and prison, and incriminating materials including spy equipment such as cameras was seized from him, but he was soon released into US custody and later ejected from the USSR. The source of the exposure is believed to have been Edward Lee Howard, an ex-CIA officer who fled to Moscow to avoid treason charges. Aldrich Ames apparently also passed his name to the Soviets.
Though Tolkachev was executed, he had carefully compartmentalized his spy work and his family, so they were not punished. His son Oleg Tolkachev is now a prominent architect. https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/csi-studies/studies/vol47no3/article02.html
The case was discussed at a 1999 post-war intelligence conference. KGB General Oleg Kalugin said that Tolkachev's wife worked with him and was put in prison, but later released under Gorbachev or Yeltsin. When she tried to contact a US embassy, Kalugin says she was ignored. Panelist Paul Redmond doubted this story, and said that the CIA had gone to "incredible lengths to find the son, to get money to him and help him out." 
- Schudel, Matt. "Cold War Spy Tale Came to Life on the Streets of Moscow". The Washington Post. Retrieved 2010-04-23.
- Bearden, Milton; James Risen. The Main Enemy: The CIA's battle with the Soviet Union. Century. ISBN 0-7126-8151-5.
- Spycraft, Robert Wallace and H. Keith Melton, Dutton, 2008
- from http://foia.cia.gov and CIA's Center for the Student of Intelligence page US Intelligence and the End of the Cold War Conference in Texas Henry R. Appelbaum and John H. Hedley Bush School of Government and Public Service at Texas A&M University in College Station, Texas, 18-20 November 1999. Panel III, Espionage and Counterintelligence, James Olsen, Chair; Oleg Kalugin, Paul Redmond, and Allen Weinstein