There has been loads of speculation as to the cause of the "downing"
I saw that and it was apparently a Sukhoi of some sort, firing head on and obviously UP
The official story is an SA-2 was the cause. See US Government history at
Cia And The U-2 Program, 1954-1974 ... - Google Book Search
page 176. Wiki at
1960 U-2 incident - Wikipedia, the free encyclopedia provides the following
For 36 years, the official story of the U-2 incident was that the spy plane had been shot down by one of a salvo of fourteen Soviet SA-2 rockets. This story originated with Oleg Penkovsky a GRU agent who spied for the CIA. In recent years, however, new information emerged which differed substantially from the official version.
In 1996, Soviet pilot Captain Igor Mentyukov revealed that, at 65,000 feet (19,812 meters) altitude, under orders to ram the intruder, he had managed to catch the U-2 in the slipstream of his unarmed Sukhoi Su-9, causing the U-2 to flip over and break its wings. The salvo of rockets had indeed scored a hit, downing a pursuing MiG-19, not the U-2. Mentyukov said that if a rocket had hit the U-2, its pilot would not have lived.
Though the normal Su-9 service ceiling was 55,000 feet (16,760 meters), Mentyukov's aircraft had been modified to achieve higher altitudes, having its weapons removed. With no weapons, the only attack option open to him was ramming.
In 2000, Sergei Khrushchev wrote about the experience of his father, Nikita Khrushchev, in the incident. He described how Mentyukov attempted but missed intercepting the U-2, failing even to gain visual contact. Major Mikhail Voronov, in control of a battery of anti-aircraft missiles, fired three SA-2s at the radar contact but only one ignited. It quickly rose toward the target and exploded in the air behind the U-2 but near enough to violently shake the aircraft, tearing off its long wings. At a lower altitude, Powers climbed out of the falling fuselage and parachuted to the ground. Uncertainty about the initial shootdown success resulted in thirteen further anti-aircraft missiles being fired by neighboring batteries, but the later rockets only hit a pursuing MiG-19 piloted by Sr. Lt. Sergei Safronov, mortally wounding him. Sergei Safronov was posthumously awarded the Order of the Red Banner