ATLANTA, SEPT. 14 -- After 11 years in an Iranian jail, E. David Rabhan, an American businessman, returned to the United States last night and a tearful reunion with his sister, Joan Jacobson, and his longtime friend, former president Jimmy Carter.

"They told me so many times that I was going to be released, I just couldn't get excited. My heart didn't beat fast. After a while I was just numb. Now I feel like I'm going to cry. And I don't want to crack up now," Rabhan said as his Swissair flight from Zurich neared Atlanta.

Rabhan, 64, waited for most of the passengers to get off the plane before he stepped into the jetway. He was immediately embraced by his sister and Carter. There were tears in all their eyes.

"I just put my arms around him and just told him I was glad to see him," Carter said, shortly after greeting Rabhan.

Rabhan's imprisonment never received much attention, and few Americans knew of his plight. Carter had referred to Rabhan as a "hostage" and privately asked the State Department to declare him a hostage. That was never done, and Rabhan said he was bitter that the Reagan and Bush administrations did nothing to help him.

"I think he looks very good," said Carter of Rabhan, who had been the pilot for Carter's first campaign for governor of Georgia in 1970. "Over the course of our lives we have spent hundreds of hours together in conversation. He still has his mental sharpness."

Rabhan was imprisoned in Tehran in September 1979 and charged with breaking Iranian financial laws. He was later charged with spying, but specific charges were never made. There has been speculation that his arrest during Carter's presidency was connected with his past association with the president and was an attempt by the Iranians to punish Carter in a personal way.

Rabhan was released from Evin Prison on Aug. 6, but his departure was delayed several times. This week, when Iranian religious authorities called for a "holy war" Rabhan said, "I thought everything would be off. I was concerned about that."

But early today, Iranian authorities came to the Swiss Embassy in Tehran, where Rabhan was staying, and told him to pack. He said he did not know why he was released or if it had anything to do with an attempt to improve U.S.-Iranian ties.

"The Iranian authorities came to me and told me," said Rabhan, "that they had come to the conclusion that I had been imprisoned on false charges, and that I was guilty of neither violating Iranian financial law or spying."

Rabhan said he was sad to leave behind another American, Jon Pattis, in Evin Prison.

Pattis, 54, is a telecommunication engineer from Aiken, S.C., who was arrested and accused of spying in 1986 after a satellite ground station he was working on in Iran was bombed by Iraq during the war between the two nations.