Originally Posted by
LondonElite
You can't upgrade flights using Amex/Chase miles on their own. You will generally need to transfer these into the FFP programme of the airline that you'll be flying (who issued your ticket) and then upgrade using your new airline miles. There are some pitfalls, however, including the need for upgrade space to be available, and being able to upgrade the particular economy fare you bought (not are upgradable). As mentioned above, you may be better off just redeeming for a business class ticket in the first place.
One additional point: You say 'first' but I think you mean business class. Domestic US first class is very different from international premium cabins, which generally offer economy/business/first, or a combined business-first concept.
Upgraded cabin either way. For example recently from Paris to Toronto, Air Canada's only upgrade was business, with a lay-flat seat. They had no "first" option.
I'd be happy with either upgrade. Even Air France's international "premium economy" is pretty good -- comparable to US Domestic first.
Thanks for the tips on the upgrade. I was planning to figure out what my best bet was, transfer my miles, and try to get the upgrade, but I hadn't figured in that it might not be available at all.
Any thoughts on what the best airline to approach this is for South America? American Airlines? Delta?