FAR 52.247-63—Preference for U.S.-Flag Air Carriers.
Plain-English Summary
FAR 52.247-63 implements the Fly America Act requirement for international air travel paid for by the U.S. Government. This clause covers the definitions of international air transportation, the meaning of the United States for purposes of the rule, and what counts as a U.S.-flag air carrier. It explains that Federal agencies, contractors, and subcontractors must use U.S.-flag carriers for Government-financed international air transportation of personnel, personal effects, and property when such service is available. It also addresses what happens when a foreign-flag carrier is used, including the requirement to document the unavailability of a U.S.-flag carrier on vouchers, and it requires flowdown of the clause to subcontracts and purchase orders that may involve international air transportation. In practice, this clause is a compliance and cost-allowability rule: if a contractor ignores it, the Government may disallow the airfare expense unless the contractor can show that U.S.-flag service was unavailable or otherwise not required under the applicable exceptions and supporting regulations.
Key Rules
Fly America applies
Government-financed international air transportation must use U.S.-flag air carriers to the extent service is available. The rule applies to transportation of personnel, their personal effects, and property, and it is grounded in 49 U.S.C. 40118 and the implementing GSA regulations.
International travel definition
The clause defines international air transportation as travel between the United States and a foreign place, or between two foreign places. This matters because the preference applies only to international air transportation, not domestic-only travel.
U.S. and U.S.-flag definitions
For this clause, the United States includes the 50 States, the District of Columbia, and outlying areas. A U.S.-flag air carrier is an entity authorized under 49 U.S.C. 41102 to provide air transportation by certificate of public convenience and necessity.
Use U.S.-flag carriers when available
If a U.S.-flag carrier is available for the required international trip, the contractor must use it in performing the contract. Availability is the key trigger; if a U.S.-flag carrier can provide the service, the preference must be followed.
Document foreign-flag use
If the contractor uses a foreign-flag carrier, the voucher must include a statement explaining why a U.S.-flag carrier was unavailable or why foreign-flag service was necessary, with reasons tied to the FAR 47.403 framework. Without adequate support, the cost may be questioned or disallowed.
Flow down to subcontracts
The contractor must include the substance of the clause, including the subcontract flowdown requirement, in each subcontract or purchase that may involve international air transportation. This ensures lower-tier suppliers and subcontractors follow the same preference and documentation rules.
Responsibilities
Contracting Officer
Insert the clause when prescribed by FAR 47.405(a) and ensure the contract includes the required flowdown language when international air transportation may occur. The contracting officer also evaluates compliance issues and may rely on the clause and related regulations when determining whether airfare costs are allowable.
Contractor
Use U.S.-flag air carriers for Government-financed international air transportation whenever available, maintain support for any foreign-flag use, and place the required statement of unavailability on vouchers when applicable. The contractor must also flow the clause down to covered subcontracts and purchase orders.
Subcontractor or Lower-Tier Supplier
Follow the same U.S.-flag preference and documentation requirements when performing international air transportation under a flowed-down subcontract or purchase. The subcontractor must provide the information needed for voucher support and compliance.
Agency / Government
Apply the Fly America Act and related GSA regulations to Government-financed international travel and disallow foreign-flag airfare when satisfactory proof of necessity is not provided. The agency must also ensure its own travel and contractor travel practices align with the statutory preference.
Practical Implications
Contractors should check carrier availability before booking international travel, because the preference is based on availability, not convenience or price alone.
A common pitfall is assuming any foreign-flag ticket is acceptable if it is cheaper or easier to schedule; that is not enough unless a valid exception or unavailability can be documented.
Voucher support matters: if a foreign carrier is used, the contractor should keep contemporaneous records explaining why a U.S.-flag carrier could not be used.
The flowdown requirement is easy to miss in purchase orders and travel-related subcontracts, but failure to flow it down can create compliance gaps at lower tiers.
Because the clause ties directly to cost allowability, noncompliance can lead to questioned or disallowed travel expenses even when the travel itself was otherwise mission-related.
Official Regulatory Text
As prescribed in 47.405 (a) , insert the following clause: Preference for U.S.-Flag Air Carriers (Jan 2025) (a) Definitions . As used in this clause- "International air transportation" means transportation by air between a place in the United States and a place outside the United States or between two places both of which are outside the United States. United States means the 50 States, the District of Columbia, and outlying areas. U.S.-flag air carrier means an entity granted authority to provide air transportation in the form of a certificate of public convenience and necessity under 49 U.S.C. 41102 . (b) U.S. Government-financed international air transportation. 49 U.S.C. 40118 , Government-financed air transportation (commonly referred to as the Fly America Act), requires that all Federal agencies and Government contractors and subcontractors use U.S.-flag air carriers for U.S. Government-financed international air transportation of personnel (and their personal effects) or property, to the extent that service by those carriers is available. It requires the General Services Administration to issue regulations that, in the absence of satisfactory proof of the necessity for foreign-flag air transportation, disallow expenditures from funds, appropriated or otherwise established for the account of the United States, for international air transportation secured aboard a foreign-flag air carrier if a U.S.-flag air carrier is available to provide such services. (c) Use of U.S.-flag carriers for international air transportation. If available, the Contractor, in performing work under this contract, shall use U.S.-flag carriers for international air transportation of personnel (and their personal effects) or property. (d) Statement of unavailability of U.S.-flag air carriers. Use of U.S.-flag carriers for international air transportation. In the event that the Contractor selects a carrier other than a U.S.-flag air carrier for international air transportation, the Contractor shall include a statement on vouchers involving such transportation essentially as follows: Statement of Unavailability of U.S.-Flag Air Carriers International air transportation of persons (and their personal effects) or property by U.S.-flag air carrier was not available or it was necessary to use foreign-flag air carrier service for the following reasons (see section 47.403 of the Federal Acquisition Regulation): [ State reasons ]:__________________________________________________ (End of statement) (e) Subcontracts. The Contractor shall include the substance of this clause, including this paragraph (e), in each subcontract or purchase under this contract that may involve international air transportation. (End of clause)