The more established carriers are therefore trying to wring more savings from labor, their biggest expense.

But analysts who follow established carriers say it is the other way around - the success of low-cost airlines depends on that map being redrawn.

A recession could hurt Eastern, with its big losses and small reserves, more than an established carrier.

The accident also raised questions about the safety of the buses compared with more established carriers.

Since airline deregulation, dozens of established and new carriers have gone bankrupt.

Many fledgling airlines, in fact, have fleets that are much younger, on average, than some of the more established carriers.

This is a major constraint on profitability for established carriers, which tend to have a higher cost base.

Since the drop in air travel after the Sept. 11 attacks, nearly all the established carriers have sought bankruptcy protection.

Other statistics may suggest, however, that such fledgling airlines have had more frequent but less-serious safety problems than some established carriers.

As a result, the established carriers are reducing their fares to meet this competition.