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Part 91 vs Part 135: Differences and Which Rules Apply

FAA Part 91 vs Part 135 Regulations Compared

Federal Aviation Administration (FAA) Part 91 covers general operating and flight rules for non-commercial flights, while Part 135The FAA regulation governing on-demand commercial charter. Any operator selling you a seat or an aircraft must hold a Part 135 certificate. governs commercial commuter and on-demand operations for compensation or hire. If you pay a fare for a flight, that trip must operate under an air carrier’s Part 135 certificate unless it falls under specific Part 91 exceptions such as fractional ownershipBuying a share of a specific aircraft, typically 1/16 or larger, which entitles you to a set number of flight hours a year plus a monthly management fee. under subpart K. Federal regulations define which operating rules apply to private flights and commercial operations.

Commercial charter flights require specific pilot flight hours and mandatory rest periods under Part 135, while non-commercial flights operate under Part 91.

Part 91 vs Part 135 at a Glance

Federal regulations divide general aviation from commercial air transportation based on whether flights carry passengers or cargo for compensation or hire. The table below outlines the core differences established under Title 14 of the Code of Federal Regulations (14 CFR).

Which Rules Govern a Flight You Pay For

Under federal law, any flight where a passenger pays money for air transportation must operate under commercial operating regulations. Under 14 CFR 119.5(g), no person may operate as a direct air carrier or as a commercial operator without, or in violation of, an appropriate certificate and appropriate operations specifications. The primary framework for chartered private aircraft is Part 135, which regulates commuter and on-demand operations.

The definition of an on-demand operation appears in 14 CFR 110.2. It covers passenger-carrying operations conducted for compensation or hire where the departure time, departure location, and arrival location are negotiated directly with the customer. For turbojet airplanes or other airplanes with a passenger-seat configuration of 30 seats or fewer (excluding crewmember seats) and a payload capacity of 7,500 pounds or less, these flights represent common carriage governed by Part 135. The definition also includes noncommon carriage with fewer than 20 passenger seats and a payload capacity under 6,000 pounds.

Under 14 CFR 135.1(a), Part 135 applies directly to commuter or on-demand operations conducted by certificate holders under part 119. It also binds every person employed or used by those certificate holders, as well as each passenger on board an aircraft operated under the part. When you purchase a charter flight, including through an air charter broker, the flight must be operated by a certificate holder under Part 135 (119.5(g)); ask which operator will fly it.

To understand the full billing structure of commercial charter flights, review our guide to private jet charter cost.

What Money Changes Hands Under Part 91

Part 91 allows financial transfers only under narrow, explicitly defined regulatory exceptions. Operating under 14 CFR Part 91 subpart F governs large airplanes, turbojet multiengine airplanes, and fractional ownership program aircraft when they are not involved in common carriage. Under 14 CFR 91.501(a), subpart F does not apply whenever an aircraft is required to be operated under commercial rules such as Part 121, Part 125, Part 129, Part 135, or Part 137.

When subpart F does apply, 14 CFR 91.501(b) lists specific operations where an aircraft owner or operator may fly without obtaining a commercial air carrier certificate:

• Ferry or training flights.
• Aerial work operations, excluding firefighting.
• Demonstration flights conducted for prospective buyers.
• An operator’s personal transportation where no charge, assessment, or fee is collected.
• Carriage of a company’s own officials, employees, guests, and property on its own airplane within the scope of the company’s business, provided charges do not exceed ownership and operating costs.
• Operations conducted under time sharing, interchange, or joint ownership agreements.
• Fractional ownership program operations conducted under subpart K.

The federal definitions for private cost arrangements appear in 14 CFR 91.501(c). A time sharing agreement is an arrangement where a person leases an airplane with flight crew to another person, with no charge made other than the specific expenses authorized by paragraph (d). An interchange agreement involves leasing an airplane to another person in exchange for equal flight time on that other person’s airplane. A joint ownership agreement is an arrangement where one registered joint owner employs and furnishes the flight crew, and each joint owner pays a share of the agreed charges.

For time sharing agreements, 14 CFR 91.501(d) defines an exclusive list of eligible expenses. An operator leasing an aircraft under a time-sharing agreement may bill only:

• Fuel, oil, lubricants, and other additives.
• Travel expenses of the flight crew, including food, lodging, and ground transportation.
• Hangar and tie-down costs incurred away from the aircraft’s home base.
• Insurance obtained for the specific flight.
• Landing fees, airport taxes, and similar flight assessments.
• Customs fees, foreign permit fees, and related charges.
• In-flight food and beverages provided to passengers.
• Passenger ground transportation.
• Contract flight planning and weather reporting services.
• An additional charge equal to 100 percent of the actual fuel, oil, lubricants, and additives expense.

No other charges may be billed under 91.501(d); confirm the consequence of a charge outside the list at the regulation.

The Fractional Ownership Exception Under Subpart K

Under 14 CFR 91.501(b)(10), fractional ownership program operations conducted under subpart K sit among the permitted non-common-carriage operations. Fractional ownership is defined under Part 91 subpart K with a minimum interest of one-sixteenth of a fixed-wing aircraft, as our fractional guide explains. For a flight sold outside that structure, ask which certificate covers it and verify at 14 CFR 91.501(b)(10).

You can learn more about how fractional contracts and share sizes work in our guide to fractional jet ownership. For flyers evaluating non-ownership private access, you can also review how programs compare across providers in our guide to compare jet cards.

Pilot Qualifications and Crew Rest Requirements

14 CFR 135.243 sets pilot-in-command experience thresholds for Part 135 operations.

For commuter operations using turbojet airplanes, airplanes with 10 or more passenger seats, or multiengine commuter airplanes, the pilot in command must hold an airline transport pilot (ATP) certificate with applicable category and class ratings, along with an aircraft type rating if required for the specific model.

For other on-demand operations under Part 135, the regulation sets minimum hours based on flight weather conditions:

• Visual Flight Rules (VFR) Pilot in Command: The pilot must hold at least a commercial pilot certificate. The pilot must have at least 500 hours of total pilot flight time, including at least 100 hours of cross-country flight time and at least 25 hours of night flight time. The pilot must also hold an instrument rating for an airplane or an ATP certificate.
• Instrument Flight Rules (IFR) Pilot in Command: The pilot must hold at least a commercial pilot certificate with appropriate category, class, and type ratings. The pilot must have logged at least 1,200 hours of total flight time, including at least 500 hours of cross-country flight time, 100 hours of night flight time, and 75 hours of actual or simulated instrument flight time (with at least 50 hours completed in actual flight). The pilot must also hold an instrument rating or an ATP certificate.

Under 14 CFR 135.267, unscheduled one- and two-pilot crews work within these limits:

• Daily flight time for a single-pilot crew is capped at 8 hours during any 24 consecutive hours.
• Daily flight time for a two-pilot crew is capped at 10 hours during any 24 consecutive hours.
• An extended-duty allowance permits a regularly assigned duty period of no more than 14 hours, provided the crew receives at least 10 consecutive hours of rest immediately before and after the duty period.
• Cumulative flight limits restrict flight crews to no more than 500 hours per calendar quarter, 800 hours across two consecutive calendar quarters, and 1,400 hours per calendar year.
• Certificate holders must provide each crewmember with at least 13 rest periods of at least 24 consecutive hours during each calendar quarter.

To explore training standards and hiring requirements in detail, review our reference on part 135 pilot requirements.

How to Verify Your Flight Certificate and Operational Control

When purchasing a charter flight, verifying operational control is worth doing before you pay. Operational control of a charter flight rests with the certificated Part 135 operator, not the broker.

Ask the broker which certificated operator will fly the trip.

Under 14 CFR 119.5(k), no person may advertise or otherwise offer to perform an operation subject to part 119 unless that person is authorized by the FAA to conduct that operation. When reviewing charter documentation, request the certificate name and certificate number of the operating entity. You can examine whether the charter company holds valid operations specifications issued by the FAA and confirm they cover the aircraft assigned, verifying with the FAA.

Read our detailed analysis on operational control for private jet charter to see what contract terms should appear in your charter agreement. You can also evaluate qualified broker services using our guide to the best private jet charter brokers.

Common Illegal Charter Traps to Watch For

An illegal charter occurs when an aircraft owner, management firm, or pilot conducts a flight for compensation without holding a valid commercial operating certificate under Part 119 and Part 135. Flights operating without required certificates violate commercial operating rules.

Our guide to operational control on a private jet charter explains how a dry-lease arrangement can make a charter illegal.

Another unlawful practice involves misusing the cost-sharing allowances of 14 CFR 91.501. Time sharing is a lease of an airplane with crew to another person (91.501(c)); seats offered to the public would be a different arrangement, so ask which certificate covers it.

Aircraft owners who wish to generate charter revenue legally can place their aircraft with a certificated management firm. A management company with an active Part 135 certificate adds the aircraft to its operations specifications and conducts flights for charter revenue. For an evaluation of how aircraft management contracts function, see our guide to private jet management companies.

For steps to follow when booking an on-demand flight, review our resource on how to charter a private jet.

Who Should Choose Which Operating Structure

Choosing between operating under Part 91 or Part 135 depends on aircraft ownership status, personal flight goals, and whether you intend to collect revenue from passengers:

• Choose a pure Part 91 flight operation if you own or lease an aircraft solely for personal travel, family flights, or company corporate transport where no passengers pay for transportation.
• Choose a Part 135 charter or jet cardA prepaid block of flight hours on a set aircraft category, bought at a fixed or capped hourly rate. No aircraft ownership is involved. if you do not own an aircraft and want to pay directly for private flights. A Part 135 flight carries the pilot qualification and duty limits in 135.243 and 135.267, and operational control rests with the certificated operator.

Who This Is Not For

This guide does not cover airline operations under Part 121, which 14 CFR 91.501(a) lists among the parts that take an aircraft outside subpart F. Training flights and aerial work appear here only as 91.501(b) exceptions.

What Would Change Our Answer

Our assessment of Part 91 vs Part 135 operations rests on the published text of the Code of Federal Regulations. The following conditions would alter the operating rules and requirements governing a specific flight:

• Elimination of compensation: If an operator flies friends, colleagues, or business partners without any charge, payment, or expense reimbursement, the flight can fall within a 91.501(b) exception, such as personal transport with no charge; verify at the regulation.
• Aircraft size: The on-demand definition in 14 CFR 110.2 turns on seat configuration and payload capacity, so check the aircraft against those limits.
• Fractional program membership: A flight under subpart K is listed at 91.501(b)(10); for a seat sold outside the program, verify the certificate.

Takeaway for Charter Clients and Aircraft Owners

The division between Part 91 and Part 135 establishes the legal line between private aircraft operation and commercial air travel. Part 91 covers operations where an owner flies without charging passengers, while Part 135 establishes pilot qualifications and duty limits whenever flights are sold for compensation or hire.

Our findings are based on our reading of published federal aviation regulations in the electronic Code of Federal Regulations, including 14 CFR 110.2, 14 CFR 119.5, 14 CFR 135.1, 14 CFR 135.243, 14 CFR 135.267, and 14 CFR 91.501. Jet & Beyond ran no internal flight tests or operational audits. The answer depends on aircraft size and seat count, whether compensation is charged, whether the flight is under a subpart K fractional program, and whether the arrangement is a wet or dry lease.

When you pay for a private charter flight, confirm that the company operating your flight holds an active commercial operating certificate and approved operations specifications. To verify the operating certificate and safety standards of your next charter trip, consult our complete guide on how to charter a private jet.

Frequently Asked Questions

Is Part 135 safer than Part 91?

The regulations set different requirements for Part 91 and Part 135, including pilot flight time minimums and crew duty limits under Part 135. No accident-rate figure is quoted here; check FAA and NTSB data for accident records.

Can a Part 91 aircraft be chartered?

An owner who wants charter revenue places the aircraft on a certificated carrier's Part 135 operations specifications; a pure Part 91 flight department cannot carry passengers for compensation, per our management guide.

Is fractional ownership Part 91 or Part 135?

Fractional ownership flights conducted for program share owners fly under 14 CFR Part 91 subpart K, which applies to programs where owners hold at least a one-sixteenth interest in a fixed-wing aircraft. For a seat sold outside the program, ask which certificate covers it.

Can I pay for a flight on a Part 91 aircraft?

Passenger fares are not allowed outside the 91.501(b) exceptions. Financial transfers are limited by 14 CFR 91.501 to non-commercial corporate cost sharing, approved joint ownership, equal-time interchange agreements, or time sharing agreements that bill only specific listed operational expenses.

What pilot requirements does Part 135 add?

Under 14 CFR 135.243, a pilot in command flying on-demand under instrument flight rules must hold at least a commercial pilot certificate with an instrument rating or airline transport pilot certificate, along with at least 1,200 hours of total flight time, 500 hours of cross-country time, 100 hours of night time, and 75 hours of instrument flight time. Commuter flights in turbojet aircraft require an airline transport pilot certificate.

How do I check an operator's Part 135 certificate?

Ask the air carrier or charter broker to supply the legal name and certificate number of the certificated Part 135 operator holding operational control of the flight, along with a copy of its operations specifications, and confirm with the FAA.

We update this guide as aircraft, program, and route pricing changes. Spotted something out of date? Tell us and we'll check it.