A O E A O T F L A T O A _
R R A C O A O M R Y Y E _
Fill in the missing two letters.
Please explain why, in the context you have discovered, these are the only two possible answers and there is no room for doubt.
The answer is
And the reason is ...
Each letter is the last letter of the NATO phonetic alphabet, in order. So we have alphA, bravO, charliE, deltA etc. The missing letters are for Mike and Zulu