(1) An enforcement order comes into force:
(a) if a commencement time that is after the day on which the order is given to the aviation industry participant concerned is specified in the order--at that time; or
(b) otherwise--at the beginning of the seventh day after it is given to the aviation industry participant concerned.
(2) The order remains in force:
(a) for the period (if any) specified in the order; or
(b) until it is revoked by the Secretary.