Part 121: Operating Requirements: Domestic, Flag, and Supplemental Operations
Subpart A—General
- 121.1 - Applicability.
- 121.2 - Compliance schedule for operators that transition to Part 121; certain new entrant operators.
- 121.4 - Applicability of rules to unauthorized operators.
- 121.7 - Definitions.
- 121.9 - Fraud and falsification.
- 121.11 - Rules applicable to operations in a foreign country.
- 121.15 - Carriage of narcotic drugs, marihuana, and depressant or stimulant drugs or substances.
Subpart B—Certification Rules for Domestic and Flag Air Carriers [Reserved]
Subpart C—Certification Rules for Supplemental Air Carriers and Commercial Operators [Reserved]
Subpart D—Rules Governing All Certificate Holders Under This Part [Reserved]
Subpart E—Approval of Routes: Domestic and Flag Operations
- 121.91 - Applicability.
- 121.93 - Route requirements: General.
- 121.95 - Route width.
- 121.97 - Airports: Required data.
- 121.99 - Communications facilities—domestic and flag operations.
- 121.101 - Weather reporting facilities.
- 121.103 - En route navigation facilities.
- 121.105 - Servicing and maintenance facilities.
- 121.106 - ETOPS Alternate Airport: Rescue and fire fighting service.
- 121.107 - Dispatch centers.
Subpart F—Approval of Areas and Routes for Supplemental Operations
- 121.111 - Applicability.
- 121.113 - Area and route requirements: General.
- 121.115 - Route width.
- 121.117 - Airports: Required data.
- 121.119 - Weather reporting facilities.
- 121.121 - En route navigation facilities.
- 121.122 - Communications facilities—supplemental operations.
- 121.123 - Servicing maintenance facilities.
- 121.125 - Flight following system.
- 121.127 - Flight following system; requirements.
Subpart G—Manual Requirements
- 121.131 - Applicability.
- 121.133 - Preparation.
- 121.135 - Manual contents.
- 121.137 - Distribution and availability.
- 121.139 - Manual accessibility: Supplemental operations.
- 121.141 - Airplane flight manual.
Subpart H—Aircraft Requirements
- 121.151 - Applicability.
- 121.153 - Aircraft requirements: General.
- 121.155 - [Reserved]
- 121.157 - Aircraft certification and equipment requirements.
- 121.159 - Single-engine airplanes prohibited.
- 121.161 - Airplane limitations: Type of route.
- 121.162 - ETOPS Type Design Approval Basis.
- 121.163 - Aircraft proving tests.
Subpart I—Airplane Performance Operating Limitations
- 121.171 - Applicability.
- 121.173 - General.
- 121.175 - Airplanes: Reciprocating engine-powered: Weight limitations.
- 121.177 - Airplanes: Reciprocating engine-powered: Takeoff limitations.
- 121.179 - Airplanes: Reciprocating engine-powered: En route limitations: All engines operating.
- 121.181 - Airplanes: Reciprocating engine-powered: En route limitations: One engine inoperative.
- 121.183 - Part 25 airplanes with four or more engines: Reciprocating engine-powered: En route limitations: Two engines inoperative.
- 121.185 - Airplanes: Reciprocating engine-powered: Landing limitations: Destination airport.
- 121.187 - Airplanes: Reciprocating-engine-powered: Landing limitations: Alternate airport.
- 121.189 - Airplanes: Turbine engine-powered: Takeoff limitations.
- 121.191 - Airplanes: Turbine engine-powered: En route limitations: One engine inoperative.
- 121.193 - Airplanes: Turbine engine-powered: En route limitations: Two engines inoperative.
- 121.195 - Airplanes: Turbine engine-powered: Landing limitations: Destination airports.
- 121.197 - Airplanes: Turbine engine-powered: Landing limitations: Alternate airports.
- 121.198 - Cargo service airplanes: Increased zero fuel and landing weights.
- 121.199 - Nontransport category airplanes: Takeoff limitations.
- 121.201 - Nontransport category airplanes: En route limitations: One engine inoperative.
- 121.203 - Nontransport category airplanes: Landing limitations: Destination airport.
- 121.205 - Nontransport category airplanes: Landing limitations: Alternate airport.
- 121.207 - Provisionally certificated airplanes: Operating limitations.
Subpart J—Special Airworthiness Requirements
- 121.211 - Applicability.
- 121.213 - [Reserved]
- 121.215 - Cabin interiors.
- 121.217 - Internal doors.
- 121.219 - Ventilation.
- 121.221 - Fire precautions.
- 121.223 - Proof of compliance with §121.221.
- 121.225 - Propeller deicing fluid.
- 121.227 - Pressure cross-feed arrangements.
- 121.229 - Location of fuel tanks.
- 121.231 - Fuel system lines and fittings.
- 121.233 - Fuel lines and fittings in designated fire zones.
- 121.235 - Fuel valves.
- 121.237 - Oil lines and fittings in designated fire zones.
- 121.239 - Oil valves.
- 121.241 - Oil system drains.
- 121.243 - Engine breather lines.
- 121.245 - Fire walls.
- 121.247 - Fire-wall construction.
- 121.249 - Cowling.
- 121.251 - Engine accessory section diaphragm.
- 121.253 - Powerplant fire protection.
- 121.255 - Flammable fluids.
- 121.257 - Shutoff means.
- 121.259 - Lines and fittings.
- 121.261 - Vent and drain lines.
- 121.263 - Fire-extinguishing systems.
- 121.265 - Fire-extinguishing agents.
- 121.267 - Extinguishing agent container pressure relief.
- 121.269 - Extinguishing agent container compartment temperature.
- 121.271 - Fire-extinguishing system materials.
- 121.273 - Fire-detector systems.
- 121.275 - Fire detectors.
- 121.277 - Protection of other airplane components against fire.
- 121.279 - Control of engine rotation.
- 121.281 - Fuel system independence.
- 121.283 - Induction system ice prevention.
- 121.285 - Carriage of cargo in passenger compartments.
- 121.287 - Carriage of cargo in cargo compartments.
- 121.289 - Landing gear: Aural warning device.
- 121.291 - Demonstration of emergency evacuation procedures.
- 121.293 - Special airworthiness requirements for nontransport category airplanes type certificated after December 31, 1964.
- 121.295 - Location for a suspect device.
Subpart K—Instrument and Equipment Requirements
- 121.301 - Applicability.
- 121.303 - Airplane instruments and equipment.
- 121.305 - Flight and navigational equipment.
- 121.306 - Portable electronic devices.
- 121.307 - Engine instruments.
- 121.308 - Lavatory fire protection.
- 121.309 - Emergency equipment.
- 121.310 - Additional emergency equipment.
- 121.311 - Seats, safety belts, and shoulder harnesses.
- 121.312 - Materials for compartment interiors.
- 121.313 - Miscellaneous equipment.
- 121.314 - Cargo and baggage compartments.
- 121.315 - Cockpit check procedure.
- 121.316 - Fuel tanks.
- 121.317 - Passenger information requirements, smoking prohibitions, and additional seat belt requirements.
- 121.318 - Public address system.
- 121.319 - Crewmember interphone system.
- 121.321 - Operations in icing.
- 121.323 - Instruments and equipment for operations at night.
- 121.325 - Instruments and equipment for operations under IFR or over-the-top.
- 121.327 - Supplemental oxygen: Reciprocating engine powered airplanes.
- 121.329 - Supplemental oxygen for sustenance: Turbine engine powered airplanes.
- 121.331 - Supplemental oxygen requirements for pressurized cabin airplanes: Reciprocating engine powered airplanes.
- 121.333 - Supplemental oxygen for emergency descent and for first aid; turbine engine powered airplanes with pressurized cabins.
- 121.335 - Equipment standards.
- 121.337 - Protective breathing equipment.
- 121.339 - Emergency equipment for extended over-water operations.
- 121.340 - Emergency flotation means.
- 121.341 - Equipment for operations in icing conditions.
- 121.342 - Pitot heat indication systems.
- 121.343 - Flight data recorders.
- 121.344 - Digital flight data recorders for transport category airplanes.
- 121.344a - Digital flight data recorders for 10–19 seat airplanes.
- 121.345 - Radio equipment.
- 121.346 - Flight data recorders: Filtered data.
- 121.347 - Communication and navigation equipment for operations under VFR over routes navigated by pilotage.
- 121.349 - Communication and navigation equipment for operations under VFR over routes not navigated by pilotage or for operations under IFR or over the top.
- 121.351 - Communication and navigation equipment for extended overwater operations and for certain other operations.
- 121.353 - Emergency equipment for operations over uninhabited terrain areas: Flag, supplemental and certain domestic operations.
- 121.354 - Terrain awareness and warning system.
- 121.355 - Equipment for operations on which specialized means of navigation are used.
- 121.356 - Collision avoidance system.
- 121.357 - Airborne weather radar equipment requirements.
- 121.358 - Low-altitude windshear system equipment requirements.
- 121.359 - Cockpit voice recorders.
- 121.360 - [Reserved]
Subpart L—Maintenance, Preventive Maintenance, and Alterations
- 121.361 - Applicability.
- 121.363 - Responsibility for airworthiness.
- 121.365 - Maintenance, preventive maintenance, and alteration organization.
- 121.367 - Maintenance, preventive maintenance, and alterations programs.
- 121.368 - Contract maintenance.
- 121.369 - Manual requirements.
- 121.370–121.370a - [Reserved]
- 121.371 - Required inspection personnel.
- 121.373 - Continuing analysis and surveillance.
- 121.374 - Continuous airworthiness maintenance program (CAMP) for two-engine ETOPS.
- 121.375 - Maintenance and preventive maintenance training program.
- 121.377 - Maintenance and preventive maintenance personnel duty time limitations.
- 121.378 - Certificate requirements.
- 121.379 - Authority to perform and approve maintenance, preventive maintenance, and alterations.
- 121.380 - Maintenance recording requirements.
- 121.380a - Transfer of maintenance records.
Subpart M—Airman and Crewmember Requirements
- 121.381 - Applicability.
- 121.383 - Airman: Limitations on use of services.
- 121.385 - Composition of flight crew.
- 121.387 - Flight engineer.
- 121.389 - Flight navigator and specialized navigation equipment.
- 121.391 - Flight attendants.
- 121.392 - Personnel identified as flight attendants.
- 121.393 - Crewmember requirements at stops where passengers remain on board.
- 121.394 - Flight attendant requirements during passenger boarding and deplaning.
- 121.395 - Aircraft dispatcher: Domestic and flag operations.
- 121.397 - Emergency and emergency evacuation duties.
Subpart N—Training Program
- 121.400 - Applicability and terms used.
- 121.401 - Training program: General.
- 121.402 - Training program: Special rules.
- 121.403 - Training program: Curriculum.
- 121.404 - Crew and dispatcher resource management training.
- 121.405 - Training program and revision: Initial and final approval.
- 121.406 - Credit for previous CRM/DRM training.
- 121.407 - Training program: Approval of flight simulation training devices.
- 121.408 - Training equipment other than flight simulation training devices.
- 121.409 - Training courses using flight simulation training devices.
- 121.410 - Airline transport pilot certification training program.
- 121.411 - Qualifications: Check pilots and check flight engineers.
- 121.412 - Qualifications: Flight instructors.
- 121.413 - Initial, transition and recurrent training and checking requirements: Check pilots and check flight engineers.
- 121.414 - Initial, transition and recurrent training and checking requirements: Flight instructors.
- 121.415 - Crewmember and dispatcher training program requirements.
- 121.417 - Crewmember emergency training.
- 121.418 - Differences training and related aircraft differences training.
- 121.419 - Pilots and flight engineers: Initial, transition, conversion and upgrade ground training.
- 121.420 - Pilots: Upgrade ground training.
- 121.421 - Flight attendants: Initial and transition ground training.
- 121.422 - Aircraft dispatchers: Initial and transition ground training.
- 121.423 - Pilots: Extended envelope training.
- 121.424 - Pilots: Initial, transition, conversion, and upgrade flight training.
- 121.425 - Flight engineers: Initial and transition flight training.
- 121.426 - Pilots: Upgrade flight training.
- 121.427 - Recurrent training.
- 121.429 - Pilots in command: Leadership and command and mentoring training.
Subpart O—Crewmember Qualifications
- 121.431 - Applicability.
- 121.432 - General.
- 121.433 - Training required.
- 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.
- 121.435 - Pilots: Operations Familiarization.
- 121.436 - Pilot qualification: Certificates and experience requirements.
- 121.438 - Pilot operating limitations and pairing requirements.
- 121.439 - Pilot qualification: Recent experience.
- 121.440 - Line checks.
- 121.441 - Proficiency checks.
- 121.443 - Pilot in command qualification: Route and airports.
- 121.445 - Pilot in command airport qualification: Special areas and airports.
- 121.447 - [Reserved]
- 121.453 - Flight engineer qualifications.
- 121.455–121.459 - [Reserved]
Subpart P—Aircraft Dispatcher Qualifications and Duty Time
- 121.461 - Applicability.
- 121.463 - Aircraft dispatcher qualifications.
- 121.465 - Aircraft dispatcher duty time limitations: Domestic and flag operations.
- 121.467 - Flight attendant duty period limitations and rest requirements: Domestic, flag, and supplemental operations.
Subpart Q—Flight Time Limitations and Rest Requirements: Domestic Operations
- 121.470 - Applicability.
- 121.471 - Flight time limitations and rest requirements: All flight crewmembers.
- 121.473 - Fatigue risk management system.
Subpart R—Flight Time Limitations: Flag Operations
- 121.480 - Applicability.
- 121.481 - Flight time limitations: One or two pilot crews.
- 121.483 - Flight time limitations: Two pilots and one additional flight crewmember.
- 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.
- 121.487 - Flight time limitations: Pilots not regularly assigned.
- 121.489 - Flight time limitations: Other commercial flying.
- 121.491 - Flight time limitations: Deadhead transportation.
- 121.493 - Flight time limitations: Flight engineers and flight navigators.
- 121.495 - Fatigue risk management system.
Subpart S—Flight Time Limitations: Supplemental Operations
- 121.500 - Applicability.
- 121.503 - Flight time limitations: Pilots: airplanes.
- 121.505 - Flight time limitations: Two pilot crews: airplanes.
- 121.507 - Flight time limitations: Three pilot crews: Airplanes.
- 121.509 - Flight time limitations: Four pilot crews: airplanes.
- 121.511 - Flight time limitations: Flight engineers: airplanes.
- 121.513 - Flight time limitations: Overseas and international operations: airplanes.
- 121.515 - Flight time limitations: All airmen: airplanes.
- 121.517 - Flight time limitations: Other commercial flying: airplanes.
- 121.519 - Flight time limitations: Deadhead transportation: Airplanes.
- 121.521 - Flight time limitations: Crew of two pilots and one additional airman as required.
- 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.
- 121.525 - Flight time limitations: Pilots serving in more than one kind of flight crew.
- 121.527 - Fatigue risk management system.
Subpart T—Flight Operations
- 121.531 - Applicability.
- 121.533 - Responsibility for operational control: Domestic operations.
- 121.535 - Responsibility for operational control: Flag operations.
- 121.537 - Responsibility for operational control: Supplemental operations.
- 121.538 - Aircraft security.
- 121.539 - Operations notices.
- 121.541 - Operations schedules: Domestic and flag operations.
- 121.542 - Flight crewmember duties.
- 121.543 - Flight crewmembers at controls.
- 121.544 - Pilot monitoring.
- 121.545 - Manipulation of controls.
- 121.547 - Admission to flight deck.
- 121.548 - Aviation safety inspector’s credentials: Admission to pilot’s compartment.
- 121.548a - DOD Commercial Air Carrier Evaluator’s Credential.
- 121.549 - Flying equipment.
- 121.550 - Secret Service Agents: Admission to flight deck.
- 121.551 - Restriction or suspension of operation: Domestic and flag operations.
- 121.553 - Restriction or suspension of operation: Supplemental operations.
- 121.555 - Compliance with approved routes and limitations: Domestic and flag operations.
- 121.557 - Emergencies: Domestic and flag operations.
- 121.559 - Emergencies: Supplemental operations.
- 121.561 - Reporting potentially hazardous meteorological conditions and irregularities of ground facilities or navigation aids.
- 121.563 - Reporting mechanical irregularities.
- 121.565 - Engine inoperative: Landing; reporting.
- 121.567 - Instrument approach procedures and IFR landing minimums.
- 121.569 - Equipment interchange: Domestic and flag operations.
- 121.570 - Airplane evacuation capability.
- 121.571 - Briefing passengers before takeoff.
- 121.573 - Briefing passengers: Extended overwater operations.
- 121.574 - Oxygen and portable oxygen concentrators for medical use by passengers.
- 121.575 - Alcoholic beverages.
- 121.576 - Retention of items of mass in passenger and crew compartments.
- 121.577 - Stowage of food, beverage, and passenger service equipment during airplane movement on the surface, takeoff, and landing.
- 121.578 - Cabin ozone concentration.
- 121.579 - Minimum altitudes for use of autopilot.
- 121.580 - Prohibition on interference with crewmembers.
- 121.581 - Observer’s seat: En route inspections.
- 121.582 - Means to discreetly notify a flightcrew.
- 121.583 - Carriage of persons without compliance with the passenger-carrying requirements of this part.
- 121.584 - Requirement to view the area outside the flightdeck door.
- 121.585 - Exit seating.
- 121.586 - Authority to refuse transportation.
- 121.587 - Closing and locking of flightcrew compartment door.
- 121.589 - Carry-on baggage.
- 121.590 - Use of certificated land airports in the United States.
Subpart U—Dispatching and Flight Release Rules
- 121.591 - Applicability.
- 121.593 - Dispatching authority: Domestic operations.
- 121.595 - Dispatching authority: Flag operations.
- 121.597 - Flight release authority: Supplemental operations.
- 121.599 - Familiarity with weather conditions.
- 121.601 - Aircraft dispatcher information to pilot in command: Domestic and flag operations.
- 121.603 - Facilities and services: Supplemental operations.
- 121.605 - Airplane equipment.
- 121.607 - Communication and navigation facilities: Domestic and flag operations.
- 121.609 - Communication and navigation facilities: Supplemental operations.
- 121.611 - Dispatch or flight release under VFR.
- 121.613 - Dispatch or flight release under IFR or over the top.
- 121.615 - Dispatch or flight release over water: Flag and supplemental operations.
- 121.617 - Alternate airport for departure.
- 121.619 - Alternate airport for destination: IFR or over-the-top: Domestic operations.
- 121.621 - Alternate airport for destination: Flag operations.
- 121.623 - Alternate airport for destination; IFR or over-the-top: Supplemental operations.
- 121.624 - ETOPS Alternate Airports.
- 121.625 - Alternate airport weather minima.
- 121.627 - Continuing flight in unsafe conditions.
- 121.628 - Inoperable instruments and equipment.
- 121.629 - Operation in icing conditions.
- 121.631 - Original dispatch or flight release, redispatch or amendment of dispatch or flight release.
- 121.633 - Considering time-limited systems in planning ETOPS alternates.
- 121.635 - Dispatch to and from refueling or provisional airports: Domestic and flag operations.
- 121.637 - Takeoffs from unlisted and alternate airports: Domestic and flag operations.
- 121.639 - Fuel supply: All domestic operations.
- 121.641 - Fuel supply: nonturbine and turbo-propeller-powered airplanes: Flag operations.
- 121.643 - Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Supplemental operations.
- 121.645 - Fuel supply: Turbine-engine powered airplanes, other than turbo-propeller: Flag and supplemental operations.
- 121.646 - En-route fuel supply: Flag and supplemental operations.
- 121.647 - Factors for computing fuel required.
- 121.649 - Takeoff and landing weather minimums: VFR: Domestic operations.
- 121.651 - Takeoff and landing weather minimums: IFR: All certificate holders.
- 121.652 - Landing weather minimums: IFR: All certificate holders.
- 121.653 - [Reserved]
- 121.655 - Applicability of reported weather minimums.
- 121.657 - Flight altitude rules.
- 121.659 - Initial approach altitude: Domestic and supplemental operations.
- 121.661 - Initial approach altitude: Flag operations.
- 121.663 - Responsibility for dispatch release: Domestic and flag operations.
- 121.665 - Load manifest.
- 121.667 - Flight plan: VFR and IFR: Supplemental operations.
Subpart V—Records and Reports
- 121.681 - Applicability.
- 121.683 - Crewmember and dispatcher record.
- 121.685 - Aircraft record: Domestic and flag operations.
- 121.687 - Dispatch release: Flag and domestic operations.
- 121.689 - Flight release form: Supplemental operations.
- 121.691 - [Reserved]
- 121.693 - Load manifest: All certificate holders.
- 121.695 - Disposition of load manifest, dispatch release, and flight plans: Domestic and flag operations.
- 121.697 - Disposition of load manifest, flight release, and flight plans: Supplemental operations.
- 121.698–121.699 - [Reserved]
- 121.701 - Maintenance log: Aircraft.
- 121.703 - Service difficulty reports.
- 121.705 - Mechanical interruption summary report.
- 121.707 - Alteration and repair reports.
- 121.709 - Airworthiness release or aircraft log entry.
- 121.711 - Communication records: Domestic and flag operations.
- 121.713 - Retention of contracts and amendments: Commercial operators who conduct intrastate operations for compensation or hire.
Subpart W—Crewmember Certificate: International
Subpart X—Emergency Medical Equipment and Training
- 121.801 - Applicability.
- 121.803 - Emergency medical equipment.
- 121.805 - Crewmember training for in-flight medical events.
Subpart Y—Advanced Qualification Program
- 121.901 - Purpose and eligibility.
- 121.903 - General requirements for Advanced Qualification Programs.
- 121.905 - Confidential commercial information.
- 121.907 - Definitions.
- 121.909 - Approval of Advanced Qualification Program.
- 121.911 - Indoctrination curriculum.
- 121.913 - Qualification curriculum.
- 121.915 - Continuing qualification curriculum.
- 121.917 - Other requirements.
- 121.919 - Certification.
- 121.921 - Training devices and simulators.
- 121.923 - Approval of training, qualification, or evaluation by a person who provides training by arrangement.
- 121.925 - Recordkeeping requirements.
Subpart Z—Hazardous Materials Training Program
- 121.1001 - Applicability and definitions.
- 121.1003 - Hazardous materials training: General.
- 121.1005 - Hazardous materials training required.
- 121.1007 - Hazardous materials training records.
Subpart AA—Continued Airworthiness and Safety Improvements
- 121.1101 - Purpose and definition.
- 121.1103 - [Reserved]
- 121.1105 - Aging airplane inspections and records reviews.
- 121.1107 - Repairs assessment for pressurized fuselages.
- 121.1109 - Supplemental inspections.
- 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.
- 121.1113 - Fuel tank system maintenance program.
- 121.1115 - Limit of validity.
- 121.1117 - Flammability reduction means.
- 121.1119 - Fuel tank vent explosion protection.