US ultra-low-cost carrier based in United States.
| IATA Code | G4 |
|---|---|
| ICAO Code | AAY |
| Callsign | ALLEGIANT |
| Operating Status | Active (per OpenFlights airline registry) |
| Country | United States |
| Category | US ultra-low-cost carrier |
When you see a segment line like this in a PNR, the airline code identifies Allegiant Air:
2 G4 587 Y 15JUL 2*JFKLHR HK1 800A 2000P
The two-letter code G4 at the start of the segment line is Allegiant Air's IATA code — every flight segment operated by Allegiant Air in a GDS PNR (Amadeus, Sabre, Galileo, or Worldspan) begins with this code, followed by the flight number.
Allegiant Air is a us ultra-low-cost carrier, based in United States. Its ICAO code, AAY, is used for air traffic control and flight planning, while its radio callsign is “ALLEGIANT”.
Once a G4 segment is sold, the fare quote and ticketing entry differ by system. The starting point in each is:
Amadeus: FXP Sabre: WPNCB Galileo: FXP
Each of these prices the itinerary using the lowest applicable fare for the G4 segment(s) in the PNR — the exact fare basis and rules still need to be checked against Allegiant Air's current fare filing, since GDS pricing reflects what's filed, not a fixed rate.
Like most airlines, Allegiant Air's fare classes follow the standard GDS booking-class letter system. See our complete booking class guide for what each letter (F, J, Y, and so on) typically means.
Allegiant Air's IATA code is G4. This two-letter code appears at the start of every flight segment operated by Allegiant Air in a GDS PNR.
Allegiant Air's ICAO code is AAY. The ICAO code is a separate, usually three-letter identifier used mainly in air traffic control and flight planning, distinct from the IATA code travel agents see in a PNR.
Paste the raw PNR text into PNRGenius and it will automatically detect Allegiant Air's segments (marked with the G4 code) and build a clean, client-ready itinerary in seconds.
Paste any PNR with a G4 segment and get a client-ready itinerary in seconds — free, no signup.
Try the Free Converter →