All contracts for services or supplies required from time to time by the Authority in the acquisition, establishment, maintenance and operation of any Authority airport under this Act or all direct contracts for supplies to be used in the construction of any Authority airport or part thereof to be awarded under this Section, rather than as a part of a contract under Section 8, when the amount of any such supplies or services exceeds $5,000 shall be let to the lowest responsible bidder or bidders, on open, competitive bidding after public advertisement made at least 5 days prior to the opening of bids, in a newspaper of general circulation in a county in which an Authority airport is located, in such manner and on one or more occasions as may be prescribed by the Authority. Bidding is not required in any of the following cases:
(1) Where the goods or services to be procured are economically procurable from only one source, such as contracts for telephone service, electric energy and other public utility services, housekeeping services, books, pamphlets and periodicals and specially designed business equipment.(2) Where the services required are for professional, technical, planning or artistic skills.(3) Where the services required are for advertising, promotional or public relations services.(4) In emergencies, if an affidavit of the person or persons authorizing the expenditure is filed with the Authority within 10 days after such an authorization, setting forth the conditions and circumstances requiring the emergency purchase, the amount expended and the name of the vendor or contractor involved. If, however, only an estimate is available within the 10 days allowed for filing the affidavit, the actual cost shall be reported immediately after it is determined.(5) In case of expenditures for personal services.(6) Contracts for equipment and spare parts in support thereof for the maintenance and operation of any Authority airport, or any part thereof, whenever the Authority, by resolution, determines that a particular make and type of equipment is required for efficient maintenance and operation and proper servicing, for uniformity in and integration with the spare parts program and inventory control or for other reasons peculiar to the problems of the Authority airport or its previously acquired equipment. However, competition and competitive bids must be obtained by the Authority with respect to such specified equipment or spare parts, insofar as possible.(7) Contracts for insurance, fidelity and surety bonds.