Texas constitution
Article 8: taxation and revenue
Section 1-j

(d) The governing body of a political subdivision, in the manner provided by law for official action, may extend the date by which aircraft parts exempted from ad valorem taxation under this section must be transported outside the State to a date not later than the 730th day after the date the person acquired or imported the aircraft parts in this State. An extension adopted by official action under this subsection applies only to the exemption from ad valorem taxation by the political subdivision adopting the extension. The legislature by general law may provide the manner by which the governing body may extend the period of time as authorized by this subsection.