https://www.aa.com/i18n/aadvantage-program/miles/redeem/award-travel/upgrade-with-miles.jsp
Upgrades are valid to the next cabin of service and are valid for a single one-way trip with a maximum of three segments. Upgrades are subject to capacity controls. Excluding award tickets and Basic Economy fare tickets, the following eligible fare types can be upgraded:
航空公司不是傻子。 腦子想想就知道 升艙不是一個容易的事。
- Discount Economy with published fares booked in H,K,M,L,V,G,Q,N,O,S and Military or Government fares booked in Y
- Full-Fare Economy with published fares booked in Y
- Discount Premium Economy with published fares booked in P
- Full-Fare Premium Economy with published fares booked in W
- Discount Business with published fares booked in I
- Full-Fare Business with published fares booked in J, D or R
