First Overflights of Eastern Europe
The CIA initiated U-2 flights over hostile territory even before the President granted final approval for overflights of the Soviet Union. After consulting with the Commander of US Air Force Europe, Richard Bissell used existing Presidential permission for Air Force overflights of the Soviet Union’s East European satellites as his authority to plan a mission over Poland and East Germany. Bissell had informed the President of his intention to conduct such missions in the "ACQUTONE Operational Plan" submitted 31 May.
The first operational use of a U-2 took place on Wednesday, 20 June 1956. CIA pilot Carl Overstreet flew a U-2 (mission 2003) equipped with an A-2 camera from Wiesbaden embarking over Warsaw, the Prague and a bit of East Germany. It appeared that the Soviets had not tracked the U-2. At the end of the mission, Detachment A immediately rushed the exposed film to the United States for processing. The developed film arrived at the Photo-Intelligence Division (PID) on 22 June 1956. PID personnel considered the pictures obtained by mission 2003 to be of good quality.
Following the success of this first mission, Bissell was eager to begin overflights of the Soviet Union. But even after the President granted his approval on 21 June, such missions could not yet take place for two reasons. First, President Eisenhower had agreed with a CIA and State Department recommendation that West German Chancellor Konrad Adenauer be informed in advance of US plans to overfly the Soviet Union from bases in Germany (in keeping with existing policies. Adenauer was not informed about overflights of Eastern Europe). Second, Soviet party chief Nikita Khrushchev had invited representatives of the US Air Force to the Moscow Air Show which opened on 23 June 1956. Led by Air Force Chief of Staff Nathan F Twining, the delegation would be in the Soviet Union for a week, and General Twining requested that no overflights of the Soviet Union be staged until the Air Force delegation had left.
Both of these restrictions on overflights of the Soviet Union were cleared up by the end of June.
A few days later the Air Force delegation returned from Moscow, but now unfavorable weather prevented the start of operations against the Soviet Union.
While awaiting for the clouds over the Soviet Union to clear, Detachment A carried out two more overflights of Eastern Europe on 2 July, 1956: mission 2009 over Czechoslovakia, Hungary, and Bulgaria; and mission 2010 over East Germany, Poland, Hungary and Romania. That afternoon Bissell and DDC Cabell gave President Eisenhower a detailed briefing on the first U-2 overflight, which the President found "very interesting, very positive". Eisenhower was anxious to know, however, whether radars had tracked the aircraft. Bissell replied that. Although East European radars had picked up the 20 June flight, radar operators had misread the altitude as only 42,000 feet. He added that the Agency was awaiting reports on that morning’s flights to see if they, too, had been detected. Noting that the U-2 detachment had four aircraft working and could average up to two flights per day, Bissell told the President that the crews were "ready and eager to go in beyond the satellites" and overfly the center of the Soviet Union.
Eisenhower replied that he thought it "urgent" to know whether the recent flights had been tracked by hostile radars. The President was obviously concerned that CIA estimates that the U-2 could fly virtually undetected were proving false. One of the reasons why he had approved the overflight program was the CIA’s assurance that the Soviet Union would remain unaware of the flights or – at the very worst – receive only occasional, vague indications.
