ROBERT GATES appears to be home free.If there was any possibility that information might come out to damage Mr. Gates's chances of becoming the next director of central intelligence, it was most likely to emerge in the testimony of Alan Fiers, former head of the CIA's Central American task force during the Iran-contra scandal. In his appearance before the Senate Select Committee on Intelligence last Thursday, Mr. Fiers did provide fresh evidence that suggested then-deputy CIA director Gates had been told earlier than he has said he was about Iran-contra events. But Fiers also testified that he was sure Gates did not know the details of the scheme to rearm the Nicaraguan contra rebels. Fiers described his belief that "a broad array" of people "had an understanding" that a private network was supporting the contras. "I think, in my own mind - and this is speculation - that Bob Gates was in that broad universe, and I don't think that necessarily is a pejorative, because there were a lot of people in that universe," said Fiers, who pleaded guilty in July to lying to Congress about the affair. Fiers went on to say that he believed Gates's intent was to avoid knowledge of the setup, "to stay away from the shoals that were there." If Gates is guilty of a sin of omission, it appears not to have persuaded most of the members of the Senate intelligence committee that he is unfit to head the nation's intelligence community. The tone and demeanor of the senators questioning the nominee suggests that, on balance, the committee is favorably disposed toward the career CIA analyst. Almost five years have passed since Iran-contra - the sale of arms to Iran in exchange for hostages and the diversion of the profits to the contras - was exposed, and the public seems tired of it. Opinion polls show that most of the public has no opinion on Gates. In short, there's not much in it for a senator to expend a lot of political capital in fighting the Gates nomination. One senator who has sharply questioned Gates's record is Bill Bradley (D) of New Jersey. On more than one occasion, he has focused on Gates's role in a mid-1980s US arrangement to share intelligence with Iraq in exchange for information about Iran. Senator Bradley has suggested that the US also aimed to influence Iraq politically or militarily, and that Gates participated in this arrangement without the necessary permission from the president to go ahead with the covert operation. Gates has defended himself by saying that the law on this was vague.