Originally Posted by
Peabody17
I don’t believe the Federal Aviation Regulations ever refer to “airline”.
14 CFR 61.51 Subpart G: Airline Transport Pilot
https://www.ecfr.gov/cgi-bin/text-id....61.g&rgn=div6
14 CFR 1.1 (definitions) lists air carrier, but not airline:
https://www.ecfr.gov/cgi-bin/text-id....1_11&rgn=div8
Part 119 covers certification for air carriers or commercial operators, or both. It does not cover "airlines," because airlines hold an air carrier certificate.