When it comes to which air forces have the largest transport fleets, the United States Air Force dominates. The country’s fleet of C-5M and C-17 may look in a similar league to Russia, but on closer examination, the gap widens massively. All US tanker aircraft (KC-46As, KC-135s, KC-130s) have a secondary transport role, as do the tankers in service with European and other Allied air forces. Meanwhile, Russia has very few tanker aircraft, and the number of transport aircraft (Il-76s, An-124, Antonov turboprop series) in operational service is lower than nominal inventory numbers suggest.