---
kind: "unit"
title: "14"
title_heading: "Aeronautics and Space"
key: "chI/subchG/part121"
level: "part"
label: "Part 121"
heading: "Operating Requirements: Domestic, Flag, and Supplemental Operations"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/14/chI-subchG-part121"
sections_count: 391
---

# Part 121 — Operating Requirements: Domestic, Flag, and Supplemental Operations

Title 14 C.F.R. — Aeronautics and Space › Chapter I — Federal Aviation Administration, Department of Transportation › Subchapter G — Air Carriers and Operators for Compensation or Hire: Certification and Operations

## Sections

- [§121.1200-121.1399. Reserved](/cfr/14/121.1200-121.1399.md)
- [§121.1400-121.1499. Reserved](/cfr/14/121.1400-121.1499.md)

## Contents

- [Subpart A — General](/cfr/14/chI-subchG-part121-subpartA.md)
- [Subpart B — Certification Rules for Domestic and Flag Air Carriers [Reserved]](/cfr/14/chI-subchG-part121-subpartB.md)
- [Subpart C — Certification Rules for Supplemental Air Carriers and Commercial Operators [Reserved]](/cfr/14/chI-subchG-part121-subpartC.md)
- [Subpart D — Rules Governing All Certificate Holders Under This Part [Reserved]](/cfr/14/chI-subchG-part121-subpartD.md)
- [Subpart E — Approval of Routes: Domestic and Flag Operations](/cfr/14/chI-subchG-part121-subpartE.md)
- [Subpart F — Approval of Areas and Routes for Supplemental Operations](/cfr/14/chI-subchG-part121-subpartF.md)
- [Subpart G — Manual Requirements](/cfr/14/chI-subchG-part121-subpartG.md)
- [Subpart H — Aircraft Requirements](/cfr/14/chI-subchG-part121-subpartH.md)
- [Subpart I — Airplane Performance Operating Limitations](/cfr/14/chI-subchG-part121-subpartI.md)
- [Subpart J — Special Airworthiness Requirements](/cfr/14/chI-subchG-part121-subpartJ.md)
- [Subpart K — Instrument and Equipment Requirements](/cfr/14/chI-subchG-part121-subpartK.md)
- [Subpart L — Maintenance, Preventive Maintenance, and Alterations](/cfr/14/chI-subchG-part121-subpartL.md)
- [Subpart M — Airman and Crewmember Requirements](/cfr/14/chI-subchG-part121-subpartM.md)
- [Subpart N — Training Program](/cfr/14/chI-subchG-part121-subpartN.md)
- [Subpart O — Crewmember Qualifications](/cfr/14/chI-subchG-part121-subpartO.md)
- [Subpart P — Aircraft Dispatcher Qualifications and Duty Time](/cfr/14/chI-subchG-part121-subpartP.md)
- [Subpart Q — Flight Time Limitations and Rest Requirements: Domestic Operations](/cfr/14/chI-subchG-part121-subpartQ.md)
- [Subpart R — Flight Time Limitations: Flag Operations](/cfr/14/chI-subchG-part121-subpartR.md)
- [Subpart S — Flight Time Limitations: Supplemental Operations](/cfr/14/chI-subchG-part121-subpartS.md)
- [Subpart T — Flight Operations](/cfr/14/chI-subchG-part121-subpartT.md)
- [Subpart U — Dispatching and Flight Release Rules](/cfr/14/chI-subchG-part121-subpartU.md)
- [Subpart V — Records and Reports](/cfr/14/chI-subchG-part121-subpartV.md)
- [Subpart W — Crewmember Certificate: International](/cfr/14/chI-subchG-part121-subpartW.md)
- [Subpart X — Emergency Medical Equipment and Training](/cfr/14/chI-subchG-part121-subpartX.md)
- [Subpart Y — Advanced Qualification Program](/cfr/14/chI-subchG-part121-subpartY.md)
- [Subpart Z — Hazardous Materials Training Program](/cfr/14/chI-subchG-part121-subpartZ.md)
- [Subpart AA — Continued Airworthiness and Safety Improvements](/cfr/14/chI-subchG-part121-subpartAA.md)
- [Subpart BB — Subpart BB [Reserved]](/cfr/14/chI-subchG-part121-subpartBB.md)
- [Subpart CC — Subpart CC [Reserved]](/cfr/14/chI-subchG-part121-subpartCC.md)
- [Subpart DD — Special Federal Aviation Regulations](/cfr/14/chI-subchG-part121-subpartDD.md)