In US: It is possible to do it online once your school gives you the approval or in any police station. But it is necessary to provide them your US address. Most of the time the flight school brings you to a local police station and you do it online, there is no cards and no mailing. It is important to mention that the fingerprints for VISAS and IMMIGRATION are different departments. https:// secure.natacs.aero/ afsp/ find_location.asp From Dubai: Is also possible to do it. You need to make sure you get the details of the course from the school. IR and Multi takes a week to get approved. PPL just a few days.