14 CFR § 135.267 - Flight time limitations and rest requirements: Unscheduled one- and two-pilot crews.
(a) No certificate holder 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) 500 hours in any calendar quarter.
(2) 800 hours in any two consecutive calendar quarters.
(3) 1,400 hours in any calendar year.
(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 other commercial flying by that flight crewmember may not exceed -
(1) 8 hours for a flight crew consisting of one pilot; or
(2) 10 hours for a flight crew consisting of two pilots qualified under this part for the operation being conducted.
(c) A flight crewmember's flight time may exceed the flight time limits of paragraph (b) of this section if the assigned flight time occurs during a regularly assigned duty period of no more than 14 hours and -
(i) 8 hours for a flight crew consisting of one pilot; or
(ii) 10 hours for a flight crew consisting of two pilots; and
(3) If the combined duty and rest periods equal 24 hours.
(d) Each assignment under paragraph (b) of this section must provide for at least 10 consecutive hours of rest during the 24-hour period that precedes the planned completion time of the assignment.
(e) When a flight crewmember has exceeded the daily flight time limitations in this section, because of circumstances beyond the control of the certificate holder or flight crewmember (such as adverse weather conditions), that flight crewmember must have a rest period before being assigned or accepting an assignment for flight time of at least -
(1) 11 consecutive hours of rest if the flight time limitation is exceeded by not more than 30 minutes;
(2) 12 consecutive hours of rest if the flight time limitation is exceeded by more than 30 minutes, but not more than 60 minutes; and
(3) 16 consecutive hours of rest if the flight time limitation is exceeded by more than 60 minutes.
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