|New requirement for extra passenger data collection for passengers travelling to and from the USA|
Beginning 1st November 2010, all travelers To, From, Through and Overflying the USA will be required to submit additional information, at least 72 hours before flight departure. These details are:
This gives US authorities time to complete all necessary checks so that they can assess that the passenger is cleared or not cleared to make the trip. There are additional, secondary checks done when the passenger checks in which give a final clearance status.
For reservations made less than 72 hours before departure and go shows/standby:
In either case, the decision for accepting a passenger for travel to the USA is entirely that of the US Authorities.
(Copied from The Saudi airlines Official site )
Travellers to USA