Ga. Code § 6-4-13
It is found, determined, and declared that the creation of the Georgia Airport Development Authority and the carrying out of its corporate purposes are in all respects for the benefit of the people of this state and constitute a public purpose and that the authority will be performing an essential governmental function in the exercise of the power conferred upon it by this chapter. The authority shall be required to pay no taxes or assessments upon any of the property acquired by it or under its jurisdiction, control, possession, or supervision or upon its activities in the operation or maintenance of the facilities erected, maintained, or acquired by it nor upon any fees, rentals, or other charges for the use of such facilities or other income received by the authority. The state covenants with the holders from time to time of the bonds, notes, and other obligations issued under this chapter that the authority shall not be required to pay any taxes or assessments imposed by the state or any of its counties, municipal corporations, political subdivisions, or taxing districts on any property acquired by the authority or under its jurisdiction, control, possession, or supervision or leased by it to others or upon its activities in the operation or maintenance of any such property or on any income derived by the authority in the form of fees, recording fees, rentals, charges, purchase price, installments, or otherwise, and that the bonds, notes, and other obligations of the authority, their transfer, and the income therefrom shall at all times be exempt from taxation within the state.
OCGA § 6-4-13