(a) Except as provided in paragraph (b) of this section, no person may
operate a civil aircraft within the United States with knowledge that
narcotic drugs, marihuana, and depressant or stimulant drugs or substances
as defined in Federal or State statutes are carried in the aircraft.
(b) Paragraph (a) of this section does not apply to any carriage of
narcotic drugs, marihuana, and depressant or stimulant drugs or substances
authorized by or under any Federal or State statute or by any Federal or
State agency.