A Government aircraft is one that is operated for the exclusive use of an executive agency and is a—
(a)
Federal aircraft, which an executive agency owns, bails, loans, or borrows; or
(b)
Commercial aircraft hired as commercial aviation services (CAS), which an executive agency—
(1)
Leases or lease-purchases with the intent to take title;
(2)
Charters or rents; or
(3)
Hires as part of a full service contract or an inter-service support agreement (ISSA).