It is unlawful for any municipality to require the payment of any license fee, tax or otherwise charge any sum of money for the use of any publicly owned public use airport for purpose of landing, taking off or any other purpose directly connected with that purpose for aircraft whose gross weight is twelve thousand five hundred pounds (12,500 lbs.) or less, except such planes used by regularly scheduled aeronautics; provided, that this section shall not be construed to make it unlawful to require payment for overnight storage of aircraft or to charge a fee or tax in conjunction with the purchase of aviation fuel; and provided further, that all airports operated by metropolitan airport authorities created pursuant to chapter 4 of this title are exempt from this section and that the department, for good cause shown, may exempt any publicly owned public use airport from all or any portion of this section.