"Relief is coming for the Boston commuter," promised American Airlines' full-page ads. American, hoping for some relief itself, was touting its fancy new Boston-New York Jet Express service, which begins this week. Once king of the route, the airline is challenging the upstart that has virtually swept the rich Northeast Corridor since 1961: Eastern Air Lines' pinchpenny but popular Air-Shuttle.
Eastern drew chuckles from other airlines six years ago when it put 28 aging, piston-engine Constellations in shuttle service between Boston, New York and Washington. When passengers found they could drop in and...