Not sure if or why it's referred to as a C-17A in RAF service. Boeing and the USAF just use C-17 and the proposed B version remained just that.
Edit: I've just seen reference to C-17A in American transcripts, perhaps the Americans dropped the 'A' when production ceased with just the one variant produced.
RAF designations have caused confusion in the past. I remember speaking to a somewhat perplexed defence attaché when trying to get last minute dip clearances for a Nimrod R1, Sentinel R1, and Shadow R1; he wondered why the same aircraft had three different names!
Last edited by Willard Whyte; 20th Jul 2020 at 13:59.