Airports nationwide reported few flight delays yesterday as airline crew members joined passengers in passing through X-ray security checkpoints.

Except for grumbling by flight crews, little seemed changed at the nation's 500 airports as a Federal Aviation Administration order took effect.

As of yesterday, flight crews boarding jets through terminal areas must pass through security checkpoints. Previously, they had been waved through after showing an identification badge.

"I think it's a pain," said Libby McCall, an American Airlines flight attendant as she placed a a blue traveling bag on the X-ray conveyor belt at National Airport. But, she added, "I'm glad we all have to go through security. I don't think you can be too safe in our skies today."

The FAA issued the order last week in response to the Dec. 7 crash of Pacific Southwest Airlines (PSA) Flight 1771, which investigators have said they believe was caused by a disgruntled airline employe with a handgun. All 43 persons on board were killed.

Federal investigators said they believe that David A. Burke, fired by USAir, used an old employe badge to bypass security at Los Angeles International Airport and boarded Flight 1771 with a .44-caliber pistol to seek revenge against his former boss.

Investigators said Burke is thought to have entered the cockpit and shot the crew. The gun and a note were found in crash rubble.

PSA spokesman Bill Hastings denounced as "irresponsible" comments by Rep. Cardiss Collins (D-Ill.) suggesting that the crash could have been prevented if PSA had heeded FAA warnings of failures in the airline's security system at Los Angeles.

The airline has been notified six times in three years of security lapses, Hastings said. He said PSA corrected the problems and had passed an unannounced FAA security check on the morning of the crash.

Employes most affected by the new FAA directive were station agents who move often between concourses and ticket counters.

"If they let us go first, it's not a problem," said Jennifer Freese, a customer-service agent for Braniff Airlines at Dulles International Airport.

"I've been through three or four times today," she said.

The Airline Pilots Association called the new order an overreaction to a single, bizarre event and predicted flight delays at airports while pilots and flight attendants and their bags went through the security check.

But airport spokesmen at Los Angeles, New York, Chicago and Atlanta said operations went smoothly. Flight crews at many airports bypassed passenger checkpoints and entered airline operations centers through other secured doors.

"It only bothers me if it will slow down my getting to work on time," said Gary Wozolek, a Continental Air Lines pilot waiting at Dulles. "I don't mind people looking through my bags. But it's a pain to have to wait in line."

At National, three Eastern Airlines pilots who were waiting to take a Boeing 727 to Atlanta on a morning flight, expressed the full range of opinions voiced by flight crews. Each asked not to be named, expressing concern that he would be fired if found to have consented to an interview. One pilot said he did not mind the new order, the second called the move a "typical government reaction" and predicted that the new rule will not be permanent.

"We're used to abuse," said the third, referring to Eastern pilots' labor dispute with the airline's management. "This is minor."