FAR 47.403-1—Availability and unavailability of U.S.-flag air carrier service.
Plain-English Summary
FAR 47.403-1 explains when U.S.-flag air carrier service is considered available or unavailable for government-financed international air travel, and when foreign-flag service may be used instead. It covers the general rule requiring use of U.S.-flag carriers when available, the limited circumstances in which foreign-flag service may be deemed necessary, and the fact that lower cost, convenience, or payment in excess foreign currency do not by themselves make U.S.-flag service unavailable. The section also sets out scheduling principles for choosing routes and interchange points, including how to handle origin and destination points, missing U.S.-flag service at a point, and involuntary rerouting by a U.S.-flag carrier. In addition, it provides specific unavailability tests for travel between a U.S. gateway and a foreign gateway, for travel between two points outside the United States, and for short-distance travel where foreign-flag service is much faster. In practice, this section is important because it governs airfare selection for official travel, affects compliance with statutory and policy requirements favoring U.S.-flag carriers, and requires travelers and approving officials to compare travel time, routing, and connection impacts rather than simply choosing the cheapest or most convenient flight.
Key Rules
Use U.S.-flag service first
For U.S. Government-financed commercial foreign air travel, U.S.-flag air carrier service must be used if it is available, unless paragraph (a) allows foreign-flag service because U.S.-flag service cannot provide the needed transportation or would not accomplish the agency mission.
Foreign-flag service is limited
Foreign-flag air carrier service may be deemed necessary only when U.S.-flag service cannot meet the transportation need or would prevent the agency from accomplishing its mission. This is a narrow exception, not a general preference rule.
Cost and convenience do not control
U.S.-flag service is still considered available even if a foreign carrier is cheaper, more convenient, or preferred by the agency or traveler. Payment in excess foreign currency also does not make U.S.-flag service unavailable unless U.S.-flag carriers refuse that currency for the transportation at issue.
Follow routing principles
When U.S.-flag service is available, travelers should use it from the point of origin to the destination or, if no direct or through service exists, to the farthest interchange point on a usually traveled route. If the origin or interchange point is not served by a U.S.-flag carrier, foreign-flag service may be used only to the nearest interchange point that connects with U.S.-flag service.
Involuntary rerouting is allowed
If a U.S.-flag carrier involuntarily reroutes the traveler onto a foreign-flag carrier, the foreign-flag segment may be used even if other U.S.-flag service is available. This recognizes carrier-driven disruptions and operational changes.
Gateway travel time tests
For travel between a U.S. gateway airport and a foreign gateway airport, U.S.-flag service is not considered available if using it would add at least 24 hours of travel status time for origin/destination travel, or at least 6 hours of waiting or travel-status time for interchange-point travel, compared with foreign-flag service.
Foreign-to-foreign travel tests
For travel between two points outside the United States, the same general U.S.-flag preference applies, but U.S.-flag service is not reasonably available if foreign-flag service would eliminate two or more aircraft changes, or if U.S.-flag routing would add at least 6 hours of travel status time in the specified gateway and non-gateway situations.
Short-distance travel exception
For short-distance travel under the gateway or foreign-to-foreign rules, U.S.-flag service is not considered available when the foreign-flag scheduled flight time is 3 hours or less and the U.S.-flag itinerary would take twice as long.
Responsibilities
Contracting Officer
Ensure travel-related contract requirements and approvals align with the U.S.-flag carrier preference rules when government-financed foreign air travel is involved. Where travel costs or contract performance depend on air transportation choices, the contracting officer should verify that any foreign-flag use is supported by one of the regulatory exceptions.
Travel Approving Official
Determine whether U.S.-flag service is available under the rule, apply the routing and travel-time tests, and approve foreign-flag service only when the regulation permits it. The official should not approve foreign-flag travel solely because it is cheaper or more convenient.
Traveler / Government Employee
Select U.S.-flag air carrier service when available, use the prescribed routing principles, and document any facts showing that U.S.-flag service is unavailable or that an exception applies. The traveler must not substitute foreign-flag service based only on preference, convenience, or lower fare.
Agency
Establish travel controls and guidance that implement the U.S.-flag preference, including procedures for evaluating availability, documenting exceptions, and handling mission-based determinations. The agency must ensure compliance for government-financed commercial foreign air travel.
U.S.-flag Air Carrier
Provide service where available and, where relevant, accept excess or near-excess foreign currency for transportation payable only from such monies if it wishes to avoid the exception tied to currency acceptance. Carrier availability and routing options affect whether the government must use its service.
Foreign-flag Air Carrier
May be used only when the regulation deems U.S.-flag service unavailable or when a valid exception applies. The carrier itself has no approval role, but its routing, timing, and connection structure may establish unavailability under the time and interchange tests.
Practical Implications
Travelers and approvers must compare more than price; they must evaluate routing, connection points, travel status time, and whether U.S.-flag service exists on the relevant leg of travel.
A common mistake is assuming a cheaper, faster, or more convenient foreign carrier can be chosen freely; under this section, those factors alone do not make U.S.-flag service unavailable.
Documentation matters. If foreign-flag service is used, the file should show which exception applied, such as mission necessity, lack of service at the origin/interchange point, excessive added travel time, or involuntary rerouting.
The gateway and short-distance rules create specific time thresholds that can override the general preference, so schedulers should calculate total travel status time carefully before booking.
For trips entirely outside the United States, the analysis still starts with the U.S.-flag preference, but the practical test often turns on whether foreign-flag routing avoids multiple aircraft changes or materially reduces total travel time.
Official Regulatory Text
(a) If a U.S.-flag air carrier cannot provide the international air transportation needed or if the use of U.S.-flag air carrier service would not accomplish an agency’s mission, foreign-flag air carrier service may be deemed necessary. (b) U.S.-flag air carrier service is considered available even though- (1) Comparable or a different kind of service can be provided at less cost by a foreign-flag air carrier; (2) Foreign-flag air carrier service is preferred by, or is more convenient for, the agency or traveler; or (3) Service by a foreign-flag air carrier can be paid for in excess foreign currency (unless U.S.-flag air carriers decline to accept excess or near excess foreign currencies for transportation payable only out of such monies). (c) Except as provided in paragraph 47.403-1 (a), U.S.-flag air carrier service shall be used for U.S. Government-financed commercial foreign air travel if service provided by U.S.-flag air carriers is available. In determining availability of a U.S.-flag air carrier, the following scheduling principles shall be followed unless their application would result in the last or first leg of travel to or from the United States being performed by a foreign-flag air carrier: (1) U.S.-flag air carrier service available at point of origin shall be used to destination or, in the absence of direct or through service, to the farthest interchange point on a usually traveled route. (2) When an origin or interchange point is not served by a U.S.-flag air carrier, foreign-flag air carrier service shall be used only to the nearest interchange point on a usually traveled route to connect with U.S.-flag air carrier service. (3) When a U.S.-flag air carrier involuntarily reroutes the traveler via a foreign-flag air carrier, the foreign-flag air carrier may be used notwithstanding the availability of alternative U.S.-flag air carrier service. (d) For travel between a gateway airport in the United States and a gateway airport abroad, passenger service by U.S.-flag air carrier shall not be considered available if- (1) The gateway airport abroad is the traveler’s origin or destination airport and the use of U.S.-flag air carrier service would extend the time in a travel status, including delay at origin and accelerated arrival at destination, by at least 24 hours more than travel by a foreign-flag air carrier; or (2) The gateway airport abroad is an interchange point and the use of U.S.-flag air carrier service would require the traveler to wait 6 hours or more to make connections at that point, or if delayed departure from, or accelerated arrival at, the gateway airport in the United States would extend time in a travel status by at least 6 hours more than travel by a foreign-flag air carrier. (e) For travel between two points outside the United States, the rules in paragraphs 47.403-1 (a), (b), and (c) shall be applicable, but passenger service by a U.S.-flag air carrier shall not be considered to be reasonably available if- (1) Travel by a foreign-flag air carrier would eliminate two or more aircraft changes en route; (2) One of the two points abroad is the gateway airport en route to or from the United States and the use of a U.S.-flag air carrier would extend the time in a travel status by at least 6 hours more than travel by a foreign-flag air carrier, including accelerated arrival at the over seas destination or delayed departure from the overseas origin, as well as delay at the gateway airport or other interchange point abroad; or (3) The travel is not part of the trip to or from the United States and the use of a U.S.-flag air carrier would extend the time in a travel status by at least 6 hours more than travel by a foreign-flag air carrier including delay at origin, delay en route, and accelerated arrival at destination. (f) For all short-distance travel under either paragraph (d) or paragraph (e) of 47.403-1 , U.S. air carrier service shall not be considered available when the elapsed travel time on a scheduled flight from origin to destination airport by foreign-flag air carrier is 3 hours or less and service by a U.S.-flag air carrier would involve twice such travel time.