41 CFR § 301-70.905
What documentation must we retain for travel on our Government aircraft?
June 9, 2020
(a) You must retain for two years copies of travel authorizations for senior Federal officials and non-Federal travelers who travel on your Government aircraft.
(b) You 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 the 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.