Allegiant Air flights
Allegiant Air is an American ultra low cost carrier that operates both scheduled and charter flights. In total the airline has close to 130 destinations that are all domestic. They have operating bases in cities like for example Austin, Las Vegas, Los Angeles and Pittsburgh.
An airline hub is an airport where the airline has a heavy presence and normally some kind of headquarters. On the other hand, a focus city is a destination where the airline operates limited point-to-point routes. In these cities, the airline doesn’t necessarily need to have an office (even though this sometimes is the case). Many low-cost airlines don't use the definition 'hub' but instead define their main airports of operations as an operating base.
CALLSIGN: ALLEGIANT
IATA Code: G4
ICAO Code: AAY