Employees may use Government aircraft—

1. (a) For official travel only when—

   1. (1) No scheduled commercial airline service is reasonably available (able to meet departure and/or arrival requirements within a 24-hour period, unless extraordinary circumstances require a shorter period) to fulfill the agency's travel requirement; or
   2. (2) The cost of using a Government aircraft is less than the cost of the City Pair coach fare or the lowest available full coach fare for scheduled commercial airline service, considering costs of non-productive or lost work time.
2. (b) For required-use travel when required for bona fide communications, security reasons, or exceptional scheduling requirements, including travel for official, personal, or political purposes.

3. (c) For space available travel when—

   1. (1) The aircraft is already scheduled for official purpose and additional use does not require a larger aircraft or result in more than minor additional cost;
   2. (2) The traveler is a Federal traveler or dependent stationed in a remote location not accessible to commercial airline service; or
   3. (3) The traveler is authorized to travel on a space available basis under 10 U.S.C. 2648 and in accordance with §§ 301-10.260 through 301-10.264.