The 757 is the only type of aircraft presently used by all six U.S. "legacy" airlines.

That travel now mostly goes through other cities which serve as hubs for international legacy airlines.

Aer Lingus adopted a "some frills" strategic approach - a hybrid between a traditional legacy airline and a low cost carrier.

But for the mercy of the legacy airlines, smaller cities would have no service.

You have the legacy airlines as well as other low-fare airlines copying what JetBlue has done.

Other airlines all over the world also report ancillary revenue from legacy airlines to low cost carriers.

Owing in large part to the foundation laid by Six, Continental became one of the largest and most profitable legacy airlines in the world.

Several large legacy airlines have filed for bankruptcy reorganization in an attempt to renegotiate terms of pension liabilities.

This is not to suggest that legacy airlines, or their hub-and-spoke airport systems, are doomed.

It developed out of Joseph Costigan's recognition that the Caribbean market was not sufficiently serviced by the legacy airlines.