10 U.S.C. § 9626: Aircraft supplies and services: foreign military or other state aircraft

The Secretary of the Air Force may, under such regulations as the Secretary may prescribe and when in the best interests of the United States, provide any of the supplies or services described in paragraph (2) to military and other state aircraft of a foreign country, on a reimbursable basis without an advance of funds, if similar supplies and services are furnished on a like basis to military aircraft and other state aircraft of the United States by the foreign country concerned. Routine airport services, including landing and takeoff assistance, servicing aircraft with fuel, use of runways, parking and servicing, and loading and unloading of baggage and cargo. Miscellaneous supplies, including Air Force-owned fuel, provisions, spare parts, and general stores, but not including ammunition. if such services are provided by Air Force personnel and equipment without direct cost to the Air Force; or if such services are provided under an agreement with the foreign country that provides for the reciprocal furnishing by the foreign country of routine airport services, as defined in that agreement, to military and other state aircraft of the United States without reimbursement. If routine airport services are provided under this section by a working-capital fund activity of the Air Force under section 2208 of this title and such activity is not reimbursed directly for the costs incurred by the activity in providing such services by reason of paragraph (1)(B), the working-capital fund activity shall be reimbursed for such costs out of funds currently available to the Air Force for operation and maintenance.