Having reached a preliminary agreement on the Japanese role in its new wide- bodied 777 jetliner, Boeing Co. says it's on the verge of committing to a 777 feature distinct from past planes: wings that will fold up in crowded


Alan R. Mulally, vice president of engineering at Boeing's New Airplane Division, said airlines interested in buying the plane want the folding wings to avoid the huge expense of modifying airport gates worldwide for the 350- passenger aircraft.Demand for folding wings is so strong that Boeing already is testing components for a proposed design that would allow the outer 25 feet of each wing to fold, he said.

"The airlines are concluding that folding wing capability is going to be very valuable to them," he said. "We've been reviewing the military experience with folding wings and we're very close to choosing a design concept."

Airlines buying replacements for DC-10s or L-1011s want a plane that can move more passengers, but still use the same gates as those previous models.

''Airlines are encouraging us to tailor our design (for the 777) so they will have no changes in airport infrastructure, and it looks like a plane with folding wings will fit very well," he said.

U.S. airport executives said they recognize that folding wings are needed to solve the kind of problem they are having with some gates being spaced too close together to allow two 747-400s to park side-by-side, but added that they also will result in greater terminal congestion.

Lee Nichols, chief spokesman for Los Angeles International Airport, said Tuesday that planes with folding wings might provide additional flexibility at some terminals where congestion occurs often enough that the airport has to use remote parking sites more and more often.

He added, however, that larger planes also might result in more congestion inside terminals, particularly at peak periods. But he said he expects Los Angeles International, which handles more than 46 million passengers a year, will be able to deal with the extra load.

Executives at John F. Kennedy International Airport in New York said they were unsure how aircraft with folding wings would affect their operations, but said facilities managers are monitoring Boeing's plans.

At Seattle-Tacoma International Airport, spokeswoman Rachael Garson said the new planes aren't expected to be a problem because Seattle's terminals have a capacity of 20 million passengers a year, but currently move about 15 million.

Mr. Mulally made his comments about the folding wings as Boeing unveiled details for eventual development of a family of up to five models of 777s.

The kickoff model would carry 353 passengers up to 5,300 statute miles on routes such as those between the West Coast and Hawaii, the East Coast to the West Coast or Australia to Hong Kong.

A second model would cut the number of passengers to 280, provide space for a business class and increase the range to 7,600 miles. A third model would stretch the plane to carry 404 passengers, again with a range of about 7,600 miles. A fifth model would carry the same 353 passengers as the first, but extend the range to almost 8,000 miles.

Boeing executives had announced last week that they had signed a memorandum of understanding with three Japanese aerospace companies - Mitsubishi Heavy Industries Ltd., Kawasaki Heavy Industries Ltd. and Fuji Heavy Industries Ltd. - to take part in development of the 777.

Negotiations on a final agreement are expected to continue for the next three months, but the memo spelled out the general outlines for Japanese participation.