A sponsor who is required to include in a construction contract the labor provisions required by §151.49 shall require the contractor to comply with those provisions and shall cooperate with the FAA in effecting that compliance. For this purpose the sponsor shall --

(a) Keep, and preserve, for a three-year period beginning on the date the contract is completed, each affidavit and payroll copy furnished by the contractor, and make those affidavits and copies available to the FAA, upon request, during that period;

(b) Have each of those affidavits and payrolls examined by its resident engineer (or any other of its employees or agents who are qualified to make the necessary determinations), as soon as possible after receiving it, to the extent necessary to determine whether the contractor is complying with the labor provisions required by §151.49 and particularly with respect to whether the contractor's employees are correctly classified;

(c) Have investigations made during the performance of work under the contract, to the extent necessary to determine whether the contractor is complying with those labor provisions, particularly with respect to whether the contractor's employees are correctly classified, including in the investigations, interviews with employees and examinations of payroll information at the work site by the sponsor's resident engineer (or any other of its employees or agents who are qualified to make the necessary determinations); and

(d) Keep the Area Manager fully advised of all examinations and investigations made under this section, all determinations made on the basis of those examinations and investigations, and all efforts made to obtain compliance with the labor provisions of the contract.