The 'A-' rating on Philadelphia Parking Authority, Pa. 's series 1978 airport parking revenue bonds reflects: * Strong demand for parking at the airport, highlighted by the authority's exclusive contract to provide airport parking facilities through maturity of the bonds; * Good growth in operating revenues and net operating income, and strong 2.46 times (x) coverage of maximum annual service during fiscal 1994; * A relatively weak additional bonds test, which permits the issuance of parity debt if projected revenues during five subsequent years provide at least 1.5x coverage of future maximum annual debt service; * The ability to substitute certain pledged airport parking revenues with city revenues which may be of lesser credit quality; and * An open flow