14 CFR §91.1059

1. (a)No program manager may assign any flight crewmember, and no flight crewmember may accept an assignment, for flight time as a member of a one- or two-pilot crew if that crewmember's total flight time in all commercial flying will exceed—
   1. (1)500 hours in any calendar quarter;
   2. (2)800 hours in any two consecutive calendar quarters;
   3. (3)1,400 hours in any calendar year.
2. (b)Except as provided in paragraph (c) of this section, during any 24 consecutive hours the total flight time of the assigned flight, when added to any commercial flying by that flight crewmember, may not exceed—
   1. (1)8 hours for a flight crew consisting of one pilot; or
   2. (2)10 hours for a flight crew consisting of two pilots qualified under this subpart for the operation being conducted.
3. (c)No program manager may assign any flight crewmember, and no flight crewmember may accept an assignment, if that crewmember's flight time or duty period will exceed, or rest time will be less than—