The intelligence picture was complicated further when the best source of information on Soviet military activity in Cuba -- high-level aerial reconnaissance -- was curtailed at a crucial time for diplomatic reasons. In mid-September the Kennedy Administration placed restrictions on US Air Force U-2 flights over Cuba after the Communist Chinese shot down a U-2 over the mainland and the Soviets protested an accidental U-2 overflight of Sakhalin Island.
The restrictions limited aerial reconnaissance over Cuba to a few peripheral and in-and-out flights by CIA-piloted U-2s. Other intelligence -- such as refugee and agent reports, intercepted communications, and shipping information -- could not fill the gap. Unbeknownst to anyone in Washington, the first Soviet Medium Range Ballistic Missiles (MRBMs) arrived at the port of Mariel on Sept. 15, 1962.
In early October, the National Security Council's Special Group relaxed the restrictions on U-2 flights after receiving more reliable HUMINT reports about suspicious Soviet activities in western Cuba. Bad weather and bureaucratic delay kept the first Air Force-piloted U-2 mission under the new reconnaissance schedule from being flown until Oct. 14.On 11:30 PM (Pacific) on October 13, Major Richard Heyser took off in a U-2 from Edwards Air Force Base in California. At the Council on Foreign Relations, James M. Lindsay picks up the story:
The flight to Cuba took Heyser five hours. At 7:30 a.m., he began his reconnaissance run, approaching the island from the south. He was flying fourteen miles high, twice the altitude of commercial jet traffic. The weather over Cuba was picture perfect. As the U-2 entered Cuban airspace he switched on the plane’s camera. His job now was to fly a straight and steady course, which meant not lettinghis eyes stray far from the circular airspeed indicator. He was flying at an altitude known to U-2 pilots as “coffin corner,” where the air was so thin it could barely support the weight of the plane, and the difference between maximum and minimum speeds was a scant six knots (seven mph). If he flew too fast, the fragile black bird would fall apart. If he flew too slow, the engine would stall, and he would nose-dive.
Analysts at the National Photographic Interpretation Center would soon conclude that were three medium-range ballistic missile (MRBM) launch sites near San Cristobal. The Cuban Missile Crisis was under way.He scanned the sky for telltale wisps of smoke from Soviet surface-to-air missiles recently deployed on the island. If he saw a contrail heading in his direction, he was trained to steer an S-pattern, into the missile path and then away from it, so that the missile would zip past him, lacking sufficient power to adjust its course.But no wisps of smoke appeared. It was an uneventful reconnaissance run. After six minutes and 928 photos, Heyser exited Cuban airspace. He adjusted course and headed for his final destination, McCoy Air Force Base near Orlando, Florida.