CFR /  Title 14  /  Part 135  /  Sec. 135.109 Pilot in command or second in command: Designation required.

(a) Each certificate holder shall designate a--

(1) Pilot in command for each flight; and

(2) Second in command for each flight requiring two pilots.

(b) The pilot in command, as designated by the certificate holder, shall remain the pilot in command at all times during that flight.