41 C.F.R. § 301-70.905

(a) Agencies must retain for two years copies of travel authorizations for senior Federal officials and non-Federal travelers who travel on the agency's Government aircraft.

(b) Agencies must also retain for two years the following information for each flight:

(1) The tail number of the Government aircraft used.

(2) The dates used for travel.

(3) The name(s) of pilot(s), other crewmembers, and qualified non-crewmembers.

(4) The purpose(s) of the flight.

(5) The route(s) flown.

(6) The names of all passengers.