Eastern Airlines was at the edge of bankruptcy, unable to keep its costs in line with the new market of deregulation. Faced with strike deadlines, loan defaults and the refusal of one union to grant concessions deemed necessary for survival, Eastern agreed to be taken over by the very competition that deregulation can and has produced: Texas Air Corp., with its lower-cost- per-mile operation, which put it in position to look for airline acquisitions that already include Continental Airlines and New York Air. With Eastern's considerable Atlantic seaboard and Caribbean routes added to Texas Air's western holdings, Texas Air would ensure itself a commanding position in the industry. What that control of the eastern corridor will do for -- or to -- the shuttle riders of the future is not nearly so clear.

There is the considerable matter of slots, the finite number of landing and takeoff rights at four leading airports -- including National and LaGuardia. If the Eastern sale holds, Texas Air's combination of holdings will give it 31 percent of the slots at National, as well as control of the shuttle lane from Boston to New York to Washington. Does this mean more low-cost, low-fare flights along this corridor -- or, because of this controlling position, fewer low- fare flights? After all, Texas Air would be searching for some way to cut down on or cover the labor and other costs that Eastern could not handle any longer. At the same time, new arrangements for allocating and transferring those slots -- the administration is proposing a "buy-sell" market at whatever prices the slots bring -- could bring new competition from other rivals of Texas Air.

What concessions, if any, might Texas Air exact from the unions that Eastern has been dealing with? It was the refusal of the International Association of Machinists to consider cost relief for Eastern unless there was a change in the airline's top management that led to the takeover agreement. But who's to say how friendly IAM President Charles Bryan will be to this new management? Like the principals in these financial arrangements, the public will be waiting to see what the free market will do to air travel in this country and around the world.