All funds accumulated from any special sales tax, excise tax or use tax, now or which may hereafter be imposed under the laws of this Commonwealth on aviation motor fuel purchased or used in this Commonwealth in the propulsion of aircraft, and all funds heretofore or hereafter accumulated from any fees for licensing or registering of airmen, aircraft and airports, now or hereafter imposed under the laws of this Commonwealth, and all funds heretofore, and which may hereafter be, appropriated to the Department for the purpose of the promotion and development of aviation and airports, including the expense of the administration by the Department of the laws pertaining to aviation, as now or as may be hereafter enacted, and the jurisdiction for the administration thereof conferred on the Department, are hereby constituted a special fund within the Commonwealth Transportation Fund for the administration of the aviation laws, heretofore or hereafter enacted, insofar as the administration has been, or shall be, imposed upon the Department, for the construction, maintenance and improvement of airports and landing fields and for the promotion of aviation in the interest of operators and in the interest of the public. However, of the moneys expended for the construction, maintenance and improvement of airports at least thirty-five percent thereof computed over a period of three years shall be expended on carrier and reliever airports. Beginning July 1, 1998, any balances remaining in this fund at the end of the year shall be available for use in subsequent years for the purposes set forth in this chapter, and any interest income on such fund shall accrue to the fund. In considering or evaluating the application for or award of any grant of moneys under this section, the Board shall take into account the capacities of all airports within the affected geographic region.