As used in this chapter and sections
1346
(b) and
2401
(b) of this title, the term “Federal agency” includes the executive departments, the judicial and legislative branches, the military departments, independent establishments of the United States, and corporations primarily acting as instrumentalities or agencies of the United States, but does not include any contractor with the United States.
“Acting within the scope of his office or employment”, in the case of a member of the military or naval forces of the United States or a member of the National Guard as defined in section
101
(3) of title
32, means acting in line of duty.