41 CFR 301-70.801 – When may we authorize travel on Government aircraft?
You may authorize travel on Government aircraft only as follows:
(a) For official travel when—
(1) No scheduled commercial airline service is reasonably available to fulfill your agency’s travel requirement (i.e., able to meet the traveler’s departure and/or arrival requirements within a 24-hour period, unless you demonstrate that extraordinary circumstances require a shorter period); or
(2) The cost of using a Government aircraft is not more than the cost of the city-pair fare for scheduled commercial airline service or the cost of the lowest available full coach fare if a city-pair fare is not available to the traveler.
(b) For required-use travel, i.e., when the traveler is authorized to use Government aircraft because of bona fide communications needs (e.g., 24-hour secure communications are required) or security reasons (e.g., highly unusual circumstances that present a clear and present danger to the traveler) or exceptional scheduling requirements (e.g., a national emergency or other compelling operational considerations). Required-use travel may include travel for official, personal, or political purposes, but must be approved in accordance with §§ 301-10.262(a) and 301-70.803(a).
(c) For space available travel when—
(1) The aircraft is already scheduled for use for an official purpose and carrying an official traveler(s) on the aircraft does not cause the need for a larger aircraft or result in more than minor additional cost to the Government; or
(2) The Federal traveler or the dependent of a Federal traveler is stationed by the Government in a remote location not accessible to commercial airline service; or
(3) The traveler is authorized to travel space available under 10 U.S.C. § 2648 and regulations implementing that statute.