Delta is part of the US Civil Reserve Air Fleet which consists of 1163 aircraft both freight and passenger that can be called at anytime and the airline's income can be subsidised up to 40% of the airlines revenue by the US Government. 70% of the US military airlift capacity is carried out by civil airliners. Australia use Portugese aircraft flown by aircrew from wherever to fly our diggers around the planet. US troops are flown by US citizens on US registered aircraft.