---
kind: "section"
citation: "14 C.F.R. § 121.509"
title: "14"
number: "121.509"
heading: "Flight time limitations: Four pilot crews: airplanes."
url: "https://uscodex.org/cfr/14/121.509"
---

# §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.

## Notes

### Amendments

[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]

### Source

Source: Docket 6258, 29 FR 19218, Dec. 31, 1964; 30 FR 3639, Mar. 19, 1965, unless otherwise noted.

### Authority

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).

### Amendments

[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]