Transportation Secretary Drew Lewis yesterday handed the Air Line Pilots Association (ALPA) a major victory with the announcement that a presidential commission will determine whether the airplanes of the future can be operated as safely with two-man crews as with three-man crews.

The ALPA board of directors then withdrew the threat of a nationwide pilots' strike March 2, saying the secretary's action makes "the suspension of service unnecessary at this time."

Lewis said that ALPA President J. J. O'Donnell "has pledged that ALPA will abide by the recommendations of the task force," although the board's resolution made no such promise.

The commission will have an immediate effect on the future of two new Boeing airplanes, the 757 and 767. Surprisingly, Lewis said, it also will reopen the question of crew size for the McDonnell Douglas DC9-Super 80, an airplane the Federal Aviation Administration certified last summer with a two-member cockpit. "If the issue is right, then the fact a decision has been made is secondary to that," a spokesman for Lewis said.

When ALPA first raised the crew-size issue last summer, it sought to argue that three-man crews were safer, but that didn't wash statistically, as O'Donnell admitted in a recent interview. McDonnell Douglas DC9s, Boeing 737s and British Aerospace BAC 111s have been flying for years with just two people in the cockpit, and their safety record is indistinguishable from that of airplanes with three-member crews.

The new ALPA argument is that the workload of the future, in more crowded skies, will be too much for two pilots, even will all the automation in new cockpits. Lewis said his goal is "a climate of confidence between ALPA and the FAA rooted in a common desire for the safest air system possible.

Boeing, with about $4 billion in development costs on the line, has been worried that a major restudy of the old issue would interfere with its production schedule. The first 767 is to be delivered in August 1982; the first 757 in January 1983. Before that can happen, however, the new planes must be certified as airworthy by the Federal Aviation Administration. A long squabble over crew complement could delay that process.

Lewis promised the commission, to consist of three technically qualified people, would make its recommendations to the president within 120 days of appointment.

A spokesman for Boeing said, "Until the role of the commission is more clearly defined, we are unable to assess what impact it will have on the certification process of our new airplanes."

McDonnell Douglas said in a statement it was confident "any well-informed and impartial advisory group" will arrive at the same conclusion the FAA reached last summer and affirm the DC9-Super 80 as a two-member airplane.

The announcements yesterday remove one of the two major labor problems the new secretary had on his platter. The other is with the Professional Air Traffic Controllers Organization, whose contract with Lewis' Federal Aviation Administration expires March 15. Negotiations begin today.

Lewis' announcement came late in the day after he met with the ALPA board of directors at the Embassy Row Hotel. It was learned that Lewis consulted with airline and airframe manufacturers late last week.

ALPA President O'Donnell had been threatening a nationwide walkout for weeks unless the FAA modified its position on several safety issues, but it was always clear that the size of the crew was the central concern.