Yes, your agency may authorize use of a non-contract fare when:
Note 1 to paragraph (c): This exception does not apply if the contract carrier offers the same or lower fare and has seats available at that fare, or if the fare offered by the non-contract carrier is restricted to Government and military travelers performing official business and may be purchased only with a contractor-issued charge card, centrally billed account (e.g., YDG, MDG, QDG, VDG, and similar fares) or GTR where the two previous options are not available.
Note 2 to § 301-10.111: A group of 10 or more passengers traveling together on the same day, on the same flight, for the same mission, requiring group integrity and identified as a group by the travel management service upon booking is not a mandatory user of the Government's contract City Pair Program fares. For group travel, agencies are expected to obtain air passenger transportation service that is practical and cost effective to the Government.
Note 3 to § 301-10.111: Contractors are not authorized to use contract City Pair Program fares to perform travel under their contracts.
Note 4 to § 301-10.111: Carrier preference is not a valid exception for using a non-contract City Pair Program fare.
41 C.F.R. §301-10.111