The Air Line Pilots Association is kicking off a nationwide campaign for better air safety that appears to have as its primary goal the guaranteed employment of at least three pilots on jetliners.

ALPA President, J. J. O'Donnell has threatened a nationwide pilots' strike in March over safety issues and has employed a Washington public relations firm to assist it in attacking the credibility of the Federal Aviation Administration.

At the same time there is some risk for O'Donnell, according to sources within the union, because his pilots are not united in their support of three-man crews, as well as for the Boeing Corporation, which is seeking certification of two new jetliners with two-member crews and is anxious for economic reasons to avoid delay.

The crew size issue is only one of several the public will be hearing about, and that tactic is one O'Donnell's critics admire."I have a lot of problems with the FAA on these other issues," said another pilot, "and J. J. is smart. He's tying crew size into all these other things."

In recent weeks, ALPA has stressed its unhappiness with the FAA on such matters as a slow-moving research and development program for an electronic system that would prevent collisions in the air, inadequacies in air traffic control, and lack of sufficiently expert FAA employes to examine and certify new airplanes. All of these issues have been cited by outside experts as potential problems in aviation safety.

Despite support on those matters, "I think J. J.s going to fall flat on this one if he really calls a nationwide strike because a lot of pilots will not go out over the [crew] issue," one union leader said when guaranteed anonymity. "Hell, the barn isn't even there any more, much less the door."

MANY OF ALPA's 33,000 members fly two-man jetliners -- the DC9, the British Serospace BAC111 and one version of the Boeing 737 -- and like their jobs. O'Donnell himself was a pilot on the two-man DC9 for years.

The crew issue received substantial attention last summer as McDonnell Douglas was winning FAA certification of its new DC9-Super 80 with a two-man crew. Although several issues surrounded the delay in the Super 80 certification, the noise ALPA made on crew size clearly contributed to the delay in the Super 80's certification and to the continuing economic problems at Douglas Aircraft.

Boeing is worried that the new Reagan administration FAA will be stamped into another long look at the crew-size issue. "If ALPA can in any way bring pressure on us to slow down that delivery process, we're going to have a helluva time meeting our contractual commitments," said Tom Riedinger of Boeing.

Boeing has run away with the new-airplane contest by developing and marketing two jetliners -- the 757 and the 767 -- at the same time. Boeing is seeking to certify both planes with both two-man and three-man cockpits, then let the airlines choose which one to order.

If either new jet is delayed in receiving its certification of airworthiness from the FAA, the financial peril for Boeing could be enormous. Boeing has spent about $4 billion in developmental costs for the two planes. "If we can't get out 300 units in five years the recovery rate is zero," Riedinger said. Boeing has a total of 264 orders for the new planes. Delivery of the first 767 is scheduled for August 1982; the first 757 is scheduled for January 1983.

Thus O'Donnell's campaign strikes at the heart of the old question of whether there exists an irreconcilable conflict of interest in the Federal Aviation Administration's charter both to regulate aviation safety and look out for the welfare of the industry. If the FAA moves on Boeing's schedule for certifying the 757 and 767, is it properly protecting the flying public or properly protecting Boeing's economic health?

The safety issue itself is nothing but a statistician's exercise. Both the FAA and the neutral National Transportation Safety Board have concluded, based on years of accident records, that there is no safety benefit with a third man in the cockpit.

In an interview yesterday, FAA Administrator Langhorne M. Bond said that "people overlook this: The safety board has never made a finding of probable cause or contributing factor [in a airliner accident] relating to crew size. How big can the problem be when it has never been implicated as the cause of a crash?"

An example of how large an issue it is with O'Donnell, however, can be found in ALPA's new contract with Republic Airlines. That contract, signed last week, deferred for the future the crewsize question for Republic's new Super 80s, which will be delivered this summer.

The ALPA bylaws specifically prohibit ALPA crews from agreeing to two-man crews without approval of two-thirds of the ALPA board. That board is dominated by pilots from major trunk carriers such as United, where pilots have negotiated three-man crews on 737s. The United contingent walked out of the ALPA convention last month when an amendment to the three-man crew requirement was proposed. United prevailed.

O'Donnell reiterated yesterday his call for an indepedent comparison of the workload imposed on two- and three-man crews. "If it showed that the workload was such that [a two-man crew] didn't impair safety -- we think it does -- we would live with the results," O'Donnell said. "We think the [TEXT OMITTED FROM SOURCE]