Two new discount airlines could soon hit the skies, offering cheap flights across the U.S.

The new carriers, Moxy and XTRA Airways, would join a crowded field that already includes big names such as Southwest, JetBlue, Spirit, Frontier and Allegiant, Travel and Leisure reports.

Both Moxy and XTRA aim to keep costs low by flying out of smaller, secondary airports rather than major hubs. Neither carrier has said which airports they would serve initially.

XTRA hopes to have five planes up and running by the end of 2019. By 2023, the goal is to have 45 planes.

“Doing the same thing as everyone else, but trying to do it better, hasn't worked, historically, very well in the airline industry,” XTRA CEO Andrew Levy said on NPR radio program "Here & Now." “So that's certainly not what we're trying to do, is out-Spirit Spirit or out-Allegiant Allegiant or anybody else like that. We aim to do something that's different.”

Moxy is being led by JetBlue founder David Neeleman. It is expected to get off the ground shortly after XTRA makes its debut.