Profit and Loss and the Balance Sheet are different animals. They can pay down debt if they have cash in their Balance Sheet, even if the P&L shows a loss.

One of the big differences is the P&L statement has the depreciation taken as an expense. It can be the difference between showing a profit and showing a loss. The cash when you buy a plane is shown as a debt on the Balance Sheet. It is not shown as a loss. Only the depreciation each year reduces the profit for that year.