About 1,200 union jobs have been eliminated since Northwest Airlines employees walked off the job three days ago. Northwest has closed 29 of 32 maintenance bases at airports across the country except Detroit , Minneapolis and Milwaukee . The cuts have eliminated or replaced about 400 mechanics and 800 plane cleaners, who are among the 4,400 members of the Aircraft Mechanics Fraternal Association walking picket lines. "In flush times, skilled workers feel they're better off going it alone," said Steve Babson, who teaches labor relations at Wayne State University . "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."