Tenn. Code Ann. § 49-7-130

No official, officer, or employee of a state university board, the board of regents, or the board of trustees of the University of Tennessee, or any institution under their control, shall be reimbursed for airplane travel in an amount in excess of standard coach fare for the applicable flight. Unless an emergency situation arises and the purchase or reimbursement for the purchase of tickets for travel by air in excess of the standard coach fare for the emergency situation is approved by the comptroller, no state appropriated or institution funds shall be otherwise used to purchase air travel at rates in excess of standard coach fare for the applicable flight.