14 CFR §121.507
- (a)No certificate holder conducting supplemental operations may schedule a pilot—
- (1)For flight deck duty in an airplane that has a crew of three pilots for more than eight hours in any 24 consecutive hours; or
- (2)To be aloft in an airplane that has a crew of three pilot for more than 12 hours in any 24 consecutive hours.
- (b)No pilot of an airplane that has a crew of three pilots may be on duty for more than 18 hours in any 24 consecutive hours.