Originally Posted by neildibiase
I was under the impression that I could not earn any AA miles on the TA segment, thus taking AA out of the running.
That's right; I blanked on the fact that you're originating in the US.
By any chance did you price out the flights using AA to LHR then the AA codeshare nos. on the BA flights to/from DAR/NBO? If you did that, you'd get 100% miles, you could sign up for the Plat challenge (all travelers) and most likely (assuming "L" fare bucket both ways, which is typical) make Plat status on the NBO-LHR leg, and Plat bonus (100% miles) on the whole return journey. Back of the envelope calc is around 23K usable miles from the trip (plus Plat status.) Check out the threads on the Platinum challenge on the AA board.