No certificate holder may use any person nor may any person serve as pilot in command of an airplane unless, within the preceding 12 calendar months, that person has passed a line check in which he satisfactorily performs the duties and responsibilities of a pilot in command in one of the types of airplanes he is to fly.
A pilot in command line check for domestic and flag operations must—
Be given by a pilot check airman who is currently qualified on both the route and the airplane; and
Consist of at least one flight over a typical part of the certificate holder's route, or over a foreign or Federal airway, or over a direct route.
A pilot in command line check for supplemental operations must—
Be given by a pilot check airman who is currently qualified on the airplane; and
Consist of at least one flight over a part of a Federal airway, foreign airway, or advisory route over which the pilot may be assigned.