Originally Posted by
cornishsimon
To the best of my knowledge there are no BA metal flights from the USA to Asia and south America that don't route you through London.
The voucher is where you are coming unstuck as this requires you to be on a BA aircraft
+1
If you have a BA companion cert (as in BA Chase), it can only be on BA metal.
That means you have to fly to/thru London, coming and going.