50 USC 404k - Travel on any common carrier for certain intelligence collection personnel

(a) In general 
Notwithstanding any other provision of law, the Director of National Intelligence may authorize travel on any common carrier when such travel, in the discretion of the Director
(1) is consistent with intelligence community mission requirements, or
(2) is required for cover purposes, operational needs, or other exceptional circumstances necessary for the successful performance of an intelligence community mission.
(b) Authorized delegation of duty 
The Director of National Intelligence may only delegate the authority granted by this section to the Principal Deputy Director of National Intelligence, or with respect to employees of the Central Intelligence Agency, to the Director of the Central Intelligence Agency.