Texas Tax Code - TAX § 21.055. Business Aircraft

(a) If an aircraft is used for a business purpose of the owner, is taxable by a taxing unit, and is used continually outside this state, whether regularly or irregularly, the appraisal office shall allocate to this state the portion of the fair market value of the aircraft that fairly reflects its use in this state.  The appraisal office shall not allocate to this state the portion of the total market value of the aircraft that fairly reflects its use beyond the boundaries of this state.

(b) The allocable portion of the total fair market value of an aircraft described by Subsection (a) is presumed to be the fair market value of the aircraft multiplied by a fraction, the numerator of which is the number of departures by the aircraft from a location in this state during the year preceding the tax year and the denominator of which is the total number of departures by the aircraft from all locations during the year preceding the tax year.

(c) This section does not apply to a commercial aircraft as defined by Section 21.05.