The US doesn't trust Pakistan to security clear a jet before allowing it into it's airspace, for some reason the UK does. Hence they troop everyone off at MAN to rescreen to DfT standards which so meet the US minimum and fly on.....
This is of course, inconsistent to say the least. Like "Iraq Airways", who have to stop en route to the UK and be re-screened lest something unfortunate happen on the inbound flight.
Btw if AI do still have fifth freedom route licences on LHR-US, they have not been used in years, the only one who is still doing this is Kuwait Airways.
Last edited by Skipness One Echo; 28th Feb 2015 at 00:54.