As used in this part, unless the context otherwise requires:
(1) “Aeronaut” includes aviator, pilot, balloonist, and every other person having any part in the operation of aircraft while in flight;
(2) “Aircraft” includes balloon, airplane, hydroplane, and every other vehicle used for navigation through the air. A hydroplane, while at rest on water and while being operated on or immediately above water, shall be governed by the rules regarding water navigation; while being operated through the air otherwise than immediately above water, it shall be treated as an aircraft;
(3) “Commissioner” means the commissioner of transportation;
(4) “Department” means the department of transportation; and
(5) “Passenger” includes any person riding in an aircraft but having no part in its operation.