Sec. 12.  AIRPORT AUTHORITIES.  (a) The Legislature may by law provide for the creation, establishment, maintenance and operation of Airport Authorities composed of one or more counties, with power to issue general obligation bonds, revenue bonds, either or both of them, for the purchase, acquisition by the exercise of the power of eminent domain or otherwise, construction, reconstruction, repair or renovation of any airport or airports, landing fields and runways, airport buildings, hangars, facilities, equipment, fixtures, and any and all property, real or personal, necessary to operate, equip and maintain an airport.
(b)  The Legislature shall provide for the option by the governing body of the city or cities whose airport facilities are served by certificated airlines and whose facility or some interest therein, is proposed to be or has been acquired by the Authority, to either appoint or elect a Board of Directors of said Authority.  If the Directors are appointed such appointment shall be made by the County Commissioners Court after consultation with and consent of the governing body or bodies of such city or cities.  If the Board of Directors is elected they shall be elected by the qualified voters of the county which chooses to elect the Directors to represent that county.  Directors shall serve without compensation for a term fixed by the Legislature not to exceed six (6) years, shall be selected on the basis of the proportionate population of each county based upon the last preceding Federal Census, and shall be residents of such county.  No county shall have less than one (1) member on the Board of Directors.
(c)  The Legislature shall provide for the holding of an election in each county proposing the creation of an Authority to be called by the Commissioners Court or Commissioners Courts, as the case may be, upon petition of five per cent (5%) of the qualified voters within the county or counties.  The elections must be held on the same day if more than one county is included.  No more than one (1) such election may be called in a county until after the expiration of one (1) year in the event such an election has failed, and thereafter only upon a petition of ten per cent (10%) of the qualified  voters being presented to the Commissioners Court or Commissioners Courts of the county or counties in which such an election has failed.  In the event that two or more counties vote on the proposition of the creation of an Authority therein, the proposition shall not be deemed to carry unless the majority of the qualified voters in each county voting thereon vote in favor thereof.  An Airport Authority may be created and be composed of the county or counties that vote in favor of its creation if separate propositions are submitted to the voters of each county so that they may vote for a two or more county Authority or a single county Authority.
(d)  The Legislature shall provide for the appointment by the Board of Directors of an Assessor and Collector of Taxes in the Authority, whether constituted of one or more counties, whose duty it shall be to assess all taxable property, both real and personal, and collect the taxes thereon, based upon the tax rolls approved by the Board of Directors, the tax to be levied not to exceed Seventy-Five Cents (75¢) per One Hundred Dollars ($100) assessed valuation of the property.  The property of state regulated common carriers required by law to pay a tax upon intangible assets shall not be subject to taxation by the Authority.  The taxable property shall be assessed on a valuation not to exceed the market value and shall be equal and uniform throughout the Authority as is otherwise provided by the Constitution.
(e)  The Legislature shall authorize the purchase or acquisition by the Authority of any existing airport facility publicly owned and financed and served by certificated airlines, in fee or of any interest therein, or to enter into any lease agreement therefor, upon such terms and conditions as may be mutually agreeable to the Authority and the owner of such facilities, or authorize the acquisition of same through the exercise of the power of eminent domain.  In the event of such acquisition, if there are any general obligation bonds that the owner of the publicly owned airport facility has outstanding, the same shall be fully assumed by the Authority and sufficient taxes levied by the Authority to discharge said outstanding indebtedness.  If any city or owner has outstanding revenue bonds where the revenues of the airport have been pledged or said bonds constitute a lien against the airport facilities, the Authority shall assume and discharge all the obligations of the city under the ordinances and bond indentures under which said revenue bonds have been issued and sold.
(f)  Any city which owns airport facilities not serving certificated airlines which are not purchased or acquired or taken over as herein provided by such Authority shall have the power to operate the same under the existing laws or as the same may hereafter be amended.
(g)  Any such Authority when created may be granted the power and authority to promulgate, adopt and enforce appropriate zoning regulations to protect the airport from hazards and obstructions which would interfere with the use of the airport and its facilities for landing and take-off.
(h)  An additional county or counties may be added to an existing Authority if a petition of five per cent (5%) of the qualified voters is filed with and an election is called by the Commissioners Court of the county or counties seeking admission to an Authority.  If the vote is favorable, then admission may be granted to such county or counties by the Board of Directors of the then existing Authority upon such terms and conditions as they may agree upon and evidenced by a resolution approved by two-thirds (2/3rds) of the then existing Board of Directors.  The county or counties that may be so added to the then existing Authority shall be given representation on the Board of Directors by adding additional directors in proportion to their population according to the last preceding Federal Census.  
(Added Nov. 8, 1966; amended Nov. 2, 1999.)  (TEMPORARY TRANSITION PROVISIONS for Sec. 12: See Appendix, Note 1.)