Callsign SIA is Singapore Airlines
WHAT AIRLINE IS SIA?
SIA is the ICAO three-letter callsign prefix for Singapore Airlines. When a radio scanner, flight tracker or radar scope shows a flight like SIA123 or SIA45XY overhead, that's a Singapore Airlines aircraft talking to air traffic control.
Spot one yourself: open the live scope, enter your postcode, and tap any blip whose callsign starts with SIA for its type, registration, route and photo.