Originally posted by Ventures:
I just completed a ow RTW trip in First class and to my dismay the only airline that would not allow me to fly in First Class was AA. I flew LHR-HKG on BA in First and HKG-LAX on Cathay in First. Both experiences were wonderful. And then I had to deal with an aggressive AA agent in LAX who insisted that I am only allowed to fly in business class on my LAX-JFK flight. She explained that on a 3 class service flight my ticket "allows' me to fly only business. How strange, my BA and CX flights were 3 class, and the service and comfort of their first class far exceeds AA. So why is AA allowed to refuse me first class on a First Class oneworld RTW ticket? Can someone please explain.
If you have purchased a First Class (AONEW) Oneworld around the world ticket, you should be flying the highest class possible on a transcontinental 3-class flight.
All of this confusion comes from the ignorance of most major airlines in the US.
Look at the flight availability displays in the following cases

other fare codes have been omitted to save space)
1AA 180 P1 J5 Y7 LAXJFK 8 430P 1237A1 762
(three class transcontinental aircraft)
(on international flights such as LAX-LHR, the "P" is replaced with an "F")
1AA 152 F7 Y7 LAXEWR 9 1045P 654A1 757
(two class domestic US aircraft)
1AA 403 J5 Y7 DFWMEX 711P 953P 72S
(two class international flight from Dallas to Mexcio City, notice the use of "J" for the higher class of service instead of "F")
The only solution would be to stop calling the higher class of service on a two class aircraft within North America "First Class", and start calling it "Business Class" just like on two class service between Dallas and Mexico City.
Other airlines such as Cathay Pacific have called their higher class of service on two class aircraft (within Asia) "Business Class" (which has service a lot better than "first class" on a US two class aircraft) instead of "First Class".
Since you have originally boooked your flight from LAX-EWR in "A" class (two class flight), and then decided to rebooked in "A" class on a three class flight from LAX-JFK, the airline agent may have got confused.
Traditionally, if you buy a ticket with fare basis "F" from LAX-EWR and then decided to take a three class aircraft, you would be accomodated in Business Class. (only solution to avoid confusion would be for AA to use the "J" fare basis and market their higher class of service on two-class aircraft as "business class")