14 CFR § 121.509 - Flight time limitations: Four pilot crews: airplanes.
---identifier: "/us/cfr/t14/s121.509"source: "ecfr"legal_status: "authoritative_unofficial"title: "14 CFR § 121.509 - Flight time limitations: Four pilot crews: airplanes."title_number: 14title_name: "Aeronautics and Space"section_number: "121.509"section_name: "Flight time limitations: Four pilot crews: airplanes."chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"subchapter_number: "G"subchapter_name: "AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS"part_number: "121"part_name: "OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS"positive_law: falsecurrency: "2026-04-05"last_updated: "2026-04-05"format_version: "1.1.0"generator: "[email protected]"authority: "49 U.S.C. 106(f), 40103, 40113, 40119, 41706, 42301 preceding note added by Pub. L. 112-95, sec. 412, 126 Stat. 89, 44101, 44701-44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44729, 44732; 46105; Pub. L. 111-216, 124 Stat. 2348 (49 U.S.C. 44701 note); Pub. L. 112-95, 126 Stat. 62 (49 U.S.C. 44732 note); Pub. L. 115-254, 132 Stat. 3186 (49 U.S.C. 44701 note)."cfr_part: "121"---
Identifier
/us/cfr/t14/s121.509
Currency
2026-04-05
Positive Law
No
Updated
2026-04-05
Chapter
Federal Aviation Administration, Department of Transportation
Authority
49 U.S.C. 106(f), 40103, 40113, 40119, 41706, 42301 preceding note added by Pub. L. 112-95, sec. 412, 126 Stat. 89, 44101, 44701-44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44729, 44732; 461... 49 U.S.C. 106(f), 40103, 40113, 40119, 41706, 42301 preceding note added by Pub. L. 112-95, sec. 412, 126 Stat. 89, 44101, 44701-44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44729, 44732; 46105; Pub. L. 111-216, 124 Stat. 2348 (49 U.S.C. 44701 note); Pub. L. 112-95, 126 Stat. 62 (49 U.S.C. 44732 note); Pub. L. 115-254, 132 Stat. 3186 (49 U.S.C. 44701 note).
# 121.509 Flight time limitations: Four pilot crews: airplanes.(a) No certificate holder conducting supplemental operations may schedule a pilot—(1) For flight deck duty in an airplane that has a crew of four pilots for more than eight hours in any 24 consecutive hours; or(2) To be aloft in an airplane that has a crew of four pilots for more than 16 hours in any 24 consecutive hours.(b) No pilot of an airplane that has a crew of four pilots may be on duty for more than 20 hours in any 24 consecutive hours.[Docket 6258, 29 FR 19218, Dec. 31, 1964; 30 FR 3639, Mar. 19, 1965, as amended by Amdt. 121-253, 61 FR 2613, Jan. 26, 1996]