The Wikipedia entry about it says,
The operation encountered many obstacles and was eventually aborted. Eight helicopters were sent to the first staging area, Desert One, but only five arrived in operational condition. One encountered hydraulic problems, another got caught in a cloud of very fine sand, and the last one showed signs of a cracked rotor blade. During planning it was decided that the mission would be aborted if fewer than six helicopters remained, despite only four being absolutely necessary. In a move that is still discussed in military circles, the field commanders advised mission abort, which President Carter accepted and confirmed.
As the U.S. force prepared to leave, one of the helicopters crashed into a transport aircraft which contained both servicemen and jet fuel. The resulting fire destroyed both aircraft and killed eight servicemen. Operation Eagle Claw was one of Delta Force's first missions.[Note 1]
It also says,
While en route, Bluebeard 6 was grounded and abandoned in the desert when its pilots interpreted a sensor indication as a cracked rotor blade. Its crew was picked up by Bluebeard 8. The remaining helicopters ran into an unexpected weather phenomenon known as a haboob (fine particles of sand suspended to a milky consistency in the air following dissipation of a thunderstorm). Bluebeard 5 flew into the haboob, but abandoned the mission and returned to the Nimitz when erratic flight instrumentation (altitude indicator) made flying without visual reference points impossible.
Why did Bluebeard 6's rotor crack? Was it caused by bad weather or unknown mechanical failure or something else?
Did the haboob cause any failures of the helicopters?