Some Northwest Airlines planes could be back in the air by midweek if leaders of the striking pilots union approve a tentative contract agreement Saturday.

But it probably will be a few days longer if the proposal is put to a rank-and-file vote, as expected, to ensure pilots are fully behind the pact. The company, meanwhile, announced Friday that the walkout would lead to its first money-losing quarter since 1993.The airline has been grounded since Aug. 28, but labor problems disrupted travel before the strike and Northwest expects a lengthy post-strike recovery.