How Iran's planes get around sanctions stopping them refueling
Economic sanction imposed by the US on Iran forbids companies and governments with economic ties with the US to trade with Iran.
This has affected travelling to foreign destinations on Iranian carriers as the airplanes cannot refuel in many European and some Asian airports.
Iranian carriers can land in London, but on their return journey they have to fly to the privately owned Manston airport in Kent, in south east England, to refuel.
Karen Zarindast reports.