Tex. Transp. Code § 24.004
A person holding an airman certificate shall keep the certificate in the person's possession when the person is operating an aircraft within this state or serving in connection with an aircraft flown or operated in this state. The person shall present the certificate for inspection on the demand of:
Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.