“XYZ 001” is often a flagship flight for an airline. AA 1 was several flavors if transcon, iirc. Pan Am PA 001 when I took it flew a 707 around the world - one I recall iirc was SFO-HNL-HND, and from there it went on. PA 2 traveled the reverse, eastward. See PA 2 in 1966, a year I flew both, below.

PA was the first with round the world service, using a Lockheed L-749 Constellation, 17 June 1947. As PA didn’t hold domestic rights, PA 1 westbound originated in LAX or SFO and terminated at LGA (later, JFK). The final PA RTW was 1982. �� (My last Connie flights were on L-749 N121 operated by the then Federal Aviation Agency. ❤️)

AA only flew overseas briefly iirc using its subsidiary, American Overseas Ailrines, which it acquired in 1945 and sold to Pan Am in 1950 to become its Atlantic Division.

Link PA RTW routes