Originally Posted by
skunker
You won't be able to find AA-codes on an itinerary that originates outside the US or doesn't travel to the US. That goes for all code-share partners.
I'm not sure that's true. LHR-CGK neither originates in nor travels to the US, but as a one-way flight search in aa.com I see this as the very first option:
AA 101 LHR-JFK
AA 6087 JFK-HKG Operated by Cathay Pacific
AA 6109 HKG-CGK Operated by Cathay Pacific