§ 125.331
Carriage of persons without compliance with the passenger-carrying provisions of this part.
The following persons may be carried aboard an airplane without complying with the passenger-carrying requirements of this part:
(a)  A crewmember.
(b)  A person necessary for the safe handling of animals on the airplane.
(c)  A person necessary for the safe handling of hazardous materials (as defined in subchapter C of title 49 CFR).
(d)  A person performing duty as a security or honor guard accompanying a shipment made by or under the authority of the U.S. Government.
(e)  A military courier or a military route supervisor carried by a military cargo contract operator if that carriage is specifically authorized by the appropriate military service.
(f)  An authorized representative of the Administrator conducting an en route inspection.
(g)  A person authorized by the Administrator.