(a) In all counties of this state having a population of 550,000 or more according to the United States decennial census of 1950 or any future such census and in which there exists the office of tax commissioner, the tax commissioner shall be required to appoint from among the assistants or deputies in his office a chief deputy. Upon making the appointment, the tax commissioner shall notify the county governing authority, which shall record a copy of the appointment upon its minutes. The tax commissioner shall appoint the chief deputy at his will and pleasure, such appointment in no event to extend beyond the term of office of the person making the appointment.

(b) If the person appointed as chief deputy resigns, if the appointment is revoked, or if for any other reason the appointment is vacant, the tax commissioner shall appoint a new chief deputy and shall notify the county governing authority of the new appointment. The county governing authority shall record a copy of the new appointment upon its minutes.

(c) If a vacancy occurs in the office of tax commissioner in any county specified in subsection (a) of this Code section, the person appointed as chief deputy by the tax commissioner and certified to the county governing authority, upon qualifying for the office of tax commissioner in the manner provided by law, shall succeed to the office of tax commissioner and fill the unexpired term of the tax commissioner of the county.