Each holder of a certificate or permit issued by the Commission shall keep on file with the Commission an insurance policy, bond or certificate of insurance in lieu thereof, certifying that such policy or bond covers the liability of such air carrier in accordance with the provisions of this article, issued by an insurance company or association or other insurer authorized to transact business in this Commonwealth, and such insurance, bond or certificate of insurance filed with the Commission shall be kept in full force at all times. The policy, bond or certificate of insurance shall remain in the files of the Commission six months after the insurance or bond has expired or has been cancelled for any cause. If federal, state or municipal bonds are deposited with the State Treasurer in lieu thereof, such bonds shall remain so deposited until six months after the authority for use of equipment insured has expired or is cancelled for any cause, unless otherwise ordered by the Commission.