At approximately 3:00 am local time on April 25, 1980, U.S. Marine Corps Major Jim Schaefer lifted off in Bluebeard 3, the Navy RH-53D Sea Stallion helicopter he was piloting. The helicopter’s massive rotors kicked up a dense cloud of sand at Desert One, a small patch of Iranian territory that had, in the last hour, been transformed into an American airbase of sorts.
Minutes earlier, their mission, rescuing the 52 Americans held hostage at the United States embassy in Tehran, had been aborted. Eight helicopters had launched for the task; two aborted en route, leaving six that made it to the first waypoint, Desert One, where they would refuel before heading onto the forward staging area deeper inside the country.
Soon after arrival, however, a third helicopter aborted due to problems with its second-stage hydraulic system that provided functionality for its flight controls. This left five helicopters, which was not enough to carry on with a mission that required 120 men to ultimately arrive safely in Tehran to affect the rescue.
Delta Force commander U.S. Army Colonel Charlie Beckwith, in charge of the mission’s ground element, called for the abort. The message was transmitted all the way up to the chain of command to the White House, where President Jimmy Carter deferred to the judgment of the men on the ground.
The mission was over. The hostages were not going to be rescued, at least not during the remaining days of April 1980.
Warning, very, very long article at the link.