Northwest has closed 29 of 32 maintenance bases at airports across the country -- all except Detroit, Minneapolis and Milwaukee. Spokesman Kurt Ebenhoch said independent companies, with less expensive nonunion workers, have been hired to fix planes at those airports and to clean its planes at every airport.

That eliminates the jobs of about 400 mechanics and 800 plane cleaners, who are among the 4,400 members of the Aircraft Mechanics Fraternal Association walking picket lines.

Ebenhoch said the airline is considering the legally thorny question of whether to make the 1,200 replacement mechanics it hired to keep flying through the strike into permanent employees.

While that could trigger legal challenges, it also could mean fewer AMFA strikers return to work once a settlement is reached.

George Larko of Taylor, who has worked 19 years as a Northwest mechanic, expressed no regrets about the strike as he picketed at Detroit Metro Airport on Monday. But he understands how difficult it will be for AMFA to negotiate a contract that reverses those changes.

"I don't think we will get our jobs back," Larko said. "I think there's going to come a point where we'll have to move on with our lives and the company will have to move on. But the company and the union have to sit down and work this out."

The first few days of the Northwest strike has at least some labor activists worried that it could become as disastrous as the breaking of PATCO, the air traffic controllers union, in the early '80s.

Then-President Ronald Reagan hired replacement controllers after PATCO struck, a move that emboldened antiunion employers and marked one of organized labor's historic failures.

Jonathan Tasini, a pro-union activist and president of the Economic Future Group, wrote in his online newsletter Monday that auto manufacturers, telecommunications firms, and other companies may adopt Northwest's aggressive strategy of using replacement workers from the onset of a strike.

"We will see if the airline can sustain its operation for very long," Tasini said. "But, if it can, this will be a very bad precedent: Companies inside and outside the industry will come to the conclusion that the Northwest plan is a blueprint for the future."

Northwest is facing bankruptcy this fall if it keeps losing $4 million a day because of high labor costs, soaring fuel bills and tough competition that limits how much it can charge for tickets.

Before the strike, Northwest told AMFA it must reduce the cost of cleaning and fixing its planes by $176 million a year. Hiring outside contractors to do much more of that work is a big part of the airline's plan to do that. A 25% pay cut for all AMFA workers is another.

If the union has a better way to do that, spokesman Bill Mellon says Northwest would consider it.

"We're flexible in the methods that the unions would use to come up with the target numbers," Mellon said. "They could come back with different variables to reach that number."

When asked if AMFA ultimately will win the strike and get a contract, Bob Rose, president of the local at Detroit Metro, says, "Absolutely."

But there were no negotiations Monday and none are scheduled.

Many critics say AMFA is having a difficult time winning a new contract because it has long been a renegade union determined to go it alone, raiding other unions for members and disdaining membership in the AFL-CIO labor coalition.

AMFA, for example, has represented Northwest's mechanics only for the past several years, after wresting control of the unit away from a much larger union, the International Association of Machinists.

Its aggressive policy has been part of AMFA's historic character. Its national director, O.V. Delle-Femine, who still runs AMFA, founded the union in 1961 on a premise that airline mechanics were part of an aristocracy of labor, more akin to pilots than to baggage handlers, and that their skills deserved much better compensation.

Then, as now, many airline mechanics were represented by larger unions such as the Machinists that often included ticket agents and even bus drivers and other groups. Delle-Femine's message that mechanics' needs often were overlooked became a key recruiting point for AMFA.

So, too, did AMFA's highly democratic organization. The union has no paid organizers, relying solely on volunteers, and Delle-Femine accepted no salary for several years when the union had no workers to represent. During years of organizing travels, he sometimes slept in airports when he had no money for a hotel.

Just a few years ago, AMFA seemed to triumph. AMFA bested the Machinists in its fight to represent Northwest's mechanics, and then Northwest agreed to new contract terms in 2001 that made the airline's mechanics among the highest paid in the industry.

It was a heady time. With major airlines adding new routes and planes year by year, the Federal Aviation Administration predicted an acute shortage of mechanics by 2010.

The Sept. 11, 2001, terrorist attacks changed everything. Major airlines saw their business plummet; financial losses mounted into the billions of dollars, and a shortage of mechanics became a glut practically overnight.

At Northwest, AMFA represented more than 9,000 workers before 9/11, more than twice the number employed just before the strike.

Indeed many, if not most, of the replacement mechanics hired by Northwest appear to be former workers at major airlines who were laid off after 9/11. Some, AMFA says it believes, were even Northwest workers.

In this new climate, Northwest's mechanics may be paying a penalty for their go-it-alone strategy.

Other Northwest unions, including those representing pilots, flight attendants, ramp workers and ticket agents, all have decided not to honor AMFA's picket lines.

"In flush times, skilled workers feel they're better off going it alone," Steve Babson, who teaches labor relations at Wayne State University, said Sunday. "In times like today, they may be better off with a more broadly defined union to present a broader front and backed by more financial resources."

But Rose of Local 5 said members stand by AMFA's long-term approach.

"It was the right way to go. We have no regrets on it," he said. Then, referring to the recent departure of several unions from the AFL-CIO, he added, "We have no regrets about not joining the AFL-CIO, as some of their party obviously had because they just left it."