Reagan Takes Oath As 40th President Washington, Jan. 20 -- Ronald Wilson Reagan of California, promising "an era of national renewal," became the 40th President of the United States today as 52 Americans held hostage in Iran were heading toward freedom. The hostages, whose 14 months of captivity had been a central focus of the Presidential contest last year took off from Teheran in two Boeing 727 airplanes at 12:25 P.M., Eastern standard time, the very moment that Mr. Reagan was concluding his solemn Inaugural Address at the United States Capitol. The new President's speech, however, made no reference at all to the long-awaited release of the hostages, emphasizing instead the need to limit the powers of the Federal Government, and to bring an end to unemployment and inflation. Government Is the Problem Promising to begin immediately to deal with "an economic affliction of great proportions," Mr. Reagan declared: "In this present crisis, government is not the solution to our problem; government is the problem." And in keeping with this statement, the President issued orders for a hiring "freeze" as his first official act. Wearing a charcoal gray club coat, striped trousers and dove gray vest and tie, Mr. Reagan took his oath of office at 11:57 A. M. in the first inaugural ceremony ever enacted on the western front of the United States Capitol. The site was chosen to stress the symbolism of Mr. Reagan's addressing his words to the West, the region that served as his base in his three Presidential campaigns in 1968, 1976, and1980. Oldest to Assume Presidency The ceremony today, filled with patriotic music, the firing of cannons and the pealing of bells, marked the transfer of the Presidency back to the Republicans after the four- year term of Jimmy Carter, a Democrat, as well as the culmination of the remarkable career of a conservative former two-term Governor of California who had started out as a baseball announcer and motion picture star. At the age of 69, Mr. Reagan also became the oldest man to assume the Presidency, and in five months he will become the oldest man to serve in the office. Mr. Carter, looking haggard and worn after spending two largely sleepless nights trying to resolve the hostage crisis as the final chapter of his Presidency, flew from Washington after the inaugural ceremony to Plains, Ga., his hometown. He was scheduled to fly to West Germany early tomorrow to greet the hostages personally at the invitation of the man who defeated him for re-election, Mr. Reagan. Mr. Reagan's briskly delivered speech, lasting 20 minutes, touched on the themes that had characterized his Presidential campaign, particularly its populist invocation of the wisdom of "we, the people," and its stern warning to "the enemies of freedom, those who are potential adversaries," that the United States stood ready to act "to preserve our national security." "Those who say that we are in a time when there are no heroes, they just don't know where to look," Mr. Reagan said, employing an almost conversational style rather than flights of rhetoric. He spoke of "professionals, industrialists, shopkeepers, clerks, cabbies and families who pay taxes to support the Government and whose voluntary gifts support church, charity, culture, art and education." "I have used the words 'they' and 'their' in speaking of these heroes," Mr. Reagan said. "I could say 'you' and 'your' because I am addressing the heroes of whom I speak- you, the citizens of this blessed land. Your dreams, your hopes, your goals are going to be the dreams the hopes and the goals of this Administration, so help me God." At another point, Mr. Reagan said: "We must act today in order to preserve tomorrow. And let there be no misunderstanding -- we are going to begin to act beginning today." The clouds that covered the sky at dawn moved south during the morning, and the winter sun broke through in the inaugural ceremony, sending the temperature to 56 degrees and making it one of the warmest inaugural days on record. With his hand on a family Bible once used by his mother and held by his wife, Nancy, Mr. Reagan repeated the oath of office administered by Warren Earl Burger, Chief Justice of the United States. He said: "I, Ronald Reagan, do solemnly swear that I will faithfully execute the office of the President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States, so help me God." Bush Takes Oath of Office A few minutes earlier, Associate Justice Potter Stewart of the Supreme Court administered an oath to the incoming Vice President, George Herbert Walker Bush, whose hand was placed on a Bible held by his wife, Barbara. Mr. and Mrs. Bush waved briefly to the cheering throngs spread below the speaker's stand, surrounding the reflecting pool and extending back to the tawny-colored Mall. The Washington police, whose helicopters wheeled overhead, estimated that perhaps 10,000 were in attendance on the Capitol grounds for the inaugural ceremony. Mr. Reagan, upon completing his oath, kissed his wife and shook hands with Chief Justice Burger, and then also waved at the applauding, cheering crowd, as Mrs. Reagan, wearing a bright red crepe dress and matching hat and coat, beamed at his side. By all accounts, no one on the speaker's stand knew of the latest developments in Iran. Word quickly spread among the Governors, Congressmen and Reagan friends, family and aides as they left the platform, which had been erected on top of a set of tiered marble and granite steps leading to the freshly painted Capitol. Carter Gives Word on Hostages Mr. Carter informed Mr. Reagan this morning at 8:31 that the release of the hostages was imminent, but the one-time bitter rivals for the Presidency told reporters as they entered the speaker's area separately, to the flourish of trumpets, that the hostages had not yet taken off from Teheran. Only one explicit reference to the hostages took place in the ceremony. The Rev. Donn Moomaw pastor of the Bel Air Presbyterian Church in Los Angeles, where Mr. and Mrs. Reagan worship, said, "We thank you, oh God, for the release of our hostages." But his prayer came before the hostages left Teheran, and Mr. Reagan was apparently following a self-imposed restraint of not saying anything until the Americans had left Iranian air space. The President got his first chance to announce the news at 2:15 P.M. at a luncheon with Congressional leaders in Statuary Hall in the Capitol. "Some 30 minutes ago," he said with a broad smile, "the planes bearing our prisoners left Iranian air space, and they're now free of Iran." His audience burst into applause. The news seemed to turn the inauguration celebration, normally a highly festive occasion, into an event of unbridled joy for Mr. Reagan and his supporters. Tens of thousands of enthusiastic well-wishers lined Pennsylvania Avenue as Mr. and Mrs. Reagan waved and smiled from their open-topped limousine, and the President's aides expressed relief at the resolution of the crisis. "It makes the whole day perfect," Mr. Reagan said, sitting behind his desk this evening at the Oval Office for the first time. Tonight the nation's capital thundered with fireworks, and the Reagans and the Bushes were to spend their time visiting inaugural balls around the city. Another implied reference to the hostages came when Mr. Reagan spoke in his Inaugural Address of improving American preparedness and military strength. "Above all we must realize that no arsenal or no weapon in the arsenals of the world is so formidable as the will and moral courage of free men and women," he said. The speech was aimed by Mr. Reagan at contrasting sharply with what he perceived to be the rhetoric of President Carter four years ago. Whereas Mr. Carter said four years ago today that "even our great nation has its recognized limits" and the United States could not solve all its problems, Mr. Reagan said: "It is time for us to realize that we are too great a nation to limit ourselves to small dreams. We're not, as some would have us believe, doomed to inevitable decline. I do not believe in a fate that will fall on us no matter what we do. I believe in a fate that will fall on us if we do nothing." But Mr. Reagan also took care to turn to Mr. Carter at the outset of his speech to thank him for extending his "gracious cooperation" during the transition, much as Mr. Carter had thanked President Ford in 1977 for helping to heal the country's wounds. "Now, there will be no misunderstanding," Mr. Reagan said, "it's not my intention to do away with government. It is rather to make it work." He said "progress may be slow," but his "first priorities" would be to "get government back within its means, and to lighten out punitive tax burden," a reference to his campaign pledge to balance the Federal budget and cut personal taxes to 30 percent in three years.