Originally Posted by JDiver

Or use AA miles and money, it as has been mentioned already, only applicable to very expensive Premium Economy W fares and must meet certain conditions.

“Premium Economy with published World Traveller Plus fares booked in W (unrestricted fares only) on British Airways. Doesn’t apply to Excursion fares.

American Airlines, British Airways or Iberia flights or codeshare flights marketed and operated by American Airlines, British Airways or Iberia are eligible. Reservations booked through a source other than American Airlines must include at least one flight with an American Airlines flight number in order to be eligible (includes codeshare flights operated by British Airways or Iberia but booked as an American Airlines flight number.)“

See aa.com: Upgrade with miles on partner airlines