I was measured at RAF Cranwell at 1.98m which is dead on 6ft 5ins - hence why the RAF said no even though I passed everything else. Just a touch annoying!! I rang BA but they wouldn't have any of it. It's an internal BA thing that no other airline has - believe me, i've rung them all and the schools and the CAA to check and they all said it's not a problem. Like I said it's just BA.
Give it a shot but it sounds like you'll have to be looking elsewhere for sponsorship.
Good luck!