December 24, 1983

J. Lynn Helms, the Administrator of the Federal Aviation Administration, submitted his resignation today, saying he wanted to resume his business consulting work. President Reagan accepted the resignation expressing regret and thanked Mr. Helms for a ''job well done.'' Mr. Helms's handling of the 1981 air traffic controller's strike was, as President Reagan said in his brief letter of acceptance today, his best-known accomplishment. Mr. Helms, with the backing of the President, dismissed 11,400 strikers of the Professional Air Traffic Controllers Organization and kept the nation's airports open, though at a reduced level. The exchange of letters between Mr. Helms and President Reagan made no mention of reports that Mr. Helms's private business dealings had been under investigation.

The State Department has recommended that President Reagan file notice that the United States will withdraw from Unesco in 1985 unless the United Nations agency curtails what the Administration regards as questionable political activities. The recommendation has been sent to the White House, according to a State Department official, with the President facing a deadline of Dec. 31 for deciding whether to send formal notice of withdrawal. If he does so, according to Administration advocates of the recommendation, he would then have a year to continue American participation in the agency while applying leverage for changes.

After years of hand-wringing over the ''holiday blues,'' a form of depression once thought to afflict vast numbers of Americans, mental health experts now stress that Christmas actually intensifies most major emotions of everyday life, joyous or sad. Christmas is a time, they say, when lovers rejoice more than ever while the lonely may sink into despair; when close-knit families bind together while warring households shatter; when most workers relax and enjoy themselves while workaholics fret and feel guilty, and when the mentally well may feel better while the mentally ill may feel worse. Christmas is also a time, they say, when dimly remembered roles are resumed with new intensity as far-flung families reunite. Sibling rivals who live a continent apart may return home to compete again for a favorable nod from their parents, and powerful professionals who command respect and awe in the community may find themselves reduced to whining children under the disapproving glance of a dictatorial mother. For Most, No Despair But for most people Christmas is not a time of depression and despair, according to the handful of researchers who have studied the psychological impact of the season.

Lance Cpl. Russell Biffle, from Mississippi, watched today as Bob Hope told jokes, Brooke Shields burst into song and Cathy Lee Crosby cavorted in a slinky red dress. It was, he thought, like getting at least a little bit of America in the tormented country of Lebanon. ''It's not home,'' Corporal Biffle said after the Hope Christmas concert aboard this 18,500-ton helicopter assault ship, 10 miles off Lebanon, ''but it's as close to home as we'll get.''

President Sandro Pertini said Italy should withdraw its military contingent from Beirut. Page 4. WASHINGTON, Dec. 23 - The Defense Department today postponed publication of a report on the truck bombing of the Marine compound in Beirut amid indications that the Reagan Administration is divided over how to deal with the document. A Pentagon spokesman, announcing the delay 30 minutes before copies of the report were scheduled to be given to reporters, said Secretary of Defense Caspar W. Weinberger needed more time to review the document and prepare recommendations for President Reagan.