Part 91 vs. Part 135: How Private Jet Charter and Aircraft Management Work

Part 91 and Part 135 are Federal Aviation Administration (FAA) rules in Title 14 of the Code of Federal Regulations. The first, titled General Operating and Flight Rules, governs aircraft operation in the United States and is the main rulebook for private, non-commercial flying.¹

Part 135 governs commuter and on-demand operations by companies that hold, or must hold, an air carrier or operating certificate under Part 119.² The FAA calls these operations air charter and says they require a higher level of pilot training, maintenance procedures and safety rules than private flying.³

Compensation is the dividing line. Carrying passengers or property for compensation or hire generally requires a Part 119 certificate and operations specifications.⁴

In business aviation, the two can meet in one airplane: an aircraft management company can fly the owner’s trips under Part 91 and charter the jet under its own Part 135 certificate when the owner is not aboard.

This guide explains what each part covers, how they differ, how aircraft management and charter fit together, and what the distinction means for owners weighing charter income.

What Is Part 91?

Part 91 sets the baseline rules for operating aircraft in the United States, from right-of-way and fuel requirements to instrument flight and maintenance.¹ Charter operators follow it too, because Part 135 requires compliance with the other applicable FAA rules and then adds its own.²

An individual flying a personal aircraft, or a company flying its own employees, needs no operator certificate unless the airplane has a seating configuration of 20 or more passengers or a maximum payload capacity of 6,000 pounds or more; those airplanes fall under Part 125, which requires its own certificate and operations specifications.⁵ Part 91 also permits a few paid arrangements, such as time-sharing, that stop short of commercial operation.¹

What Is Part 135?

Part 135 covers the commuter and on-demand operations of Part 119 certificate holders and of anyone required to hold such a certificate.² In October 2026, the FAA’s Safe Air Charter page counted 1,837 Part 135 certificate holders and 11,582 authorized aircraft.³

Under 14 CFR 110.2, a commuter operation is scheduled service of at least five round trips a week on at least one route, using rotorcraft or non-turbojet airplanes with nine or fewer passenger seats. An on-demand operation includes compensated flights whose departure time and locations are negotiated with the customer, flown in common carriage with airplanes, including turbojets, of 30 or fewer passenger seats and a payload capacity of 7,500 pounds or less.⁶

Certificates and operations specifications

Part 119 issues an Air Carrier Certificate to a company authorized as a direct air carrier and an Operating Certificate to one authorized only as a U.S. commercial operator. A direct air carrier also needs economic authority from the Department of Transportation (DOT). Each certificate comes with operations specifications, or OpSpecs, which for on-demand operators set out the kind and area of operations authorized and the category and class of aircraft, and the holder may not operate in violation of them.⁴

Why compensation triggers certification

Part 119 applies to anyone operating, or intending to operate, civil aircraft as an air carrier or commercial operator, and 14 CFR 119.5(g) bars operating as a direct air carrier or commercial operator without an appropriate certificate and OpSpecs.⁴ A commercial operator carries persons or property by aircraft for compensation or hire. When compensation is doubtful, the FAA asks whether the carriage is merely incidental to the person’s other business or is itself a major enterprise for profit.⁷

FAA Advisory Circular 120-12A adds the common carriage test: a holding out of a willingness to transport persons or property from place to place for compensation. It urges anyone planning only private operations to look cautiously at proposals for revenue-generating flights.⁸

Part 91 vs. Part 135: Key Differences

The table compares a private Part 91 flight with an on-demand Part 135 flight in a business jet. Section numbers refer to Title 14, including Part 61 for pilots, Part 120 for drug and alcohol testing and Part 5 for safety management systems.^{9, 10, 11}

Requirement	Part 91 (private flight)	Part 135 (on-demand charter)
Certificate	None for most private flights	Part 119 air carrier or operating certificate with OpSpecs (§§ 119.5, 119.49)
Pilot in command	Part 61 certificates and ratings, including a type rating for large or turbojet aircraft (§ 61.31)	Airline transport pilot certificate for passenger flights in turbojets or airplanes with 10 or more passenger seats; otherwise a commercial certificate with 500 hours (VFR) or 1,200 hours (IFR) (§ 135.243)
Flight time and rest	No limits for private flights	One- or two-pilot crews: 8 or 10 flight hours in 24 consecutive hours, at least 10 consecutive hours of rest, quarterly and annual caps (§ 135.267)
Maintenance	Annual inspection, or a selected program such as the manufacturer’s for large airplanes and multiengine jets and turboprops (§ 91.409)	Nine or fewer seats: Parts 91 and 43 plus manufacturer-recommended programs for engines, propellers, rotors and emergency equipment (§§ 135.411, 135.421); 10 or more seats: a continuous airworthiness maintenance program
IFR weather	Alternate required unless the destination forecast meets set ceiling and visibility levels (§ 91.169); Part 97 takeoff minimums do not apply (§ 91.175(f))	Destination forecast at or above landing minimums before an IFR takeoff (§ 135.219); no approach unless the latest report is at or above minimums (§ 135.225)
Runway	Airplane Flight Manual limits for transport category airplanes (§ 91.605)	Large turbine transport category airplanes must be able to stop within 60 percent of the effective runway length, or 80 percent for eligible on-demand operations, which need two pilots and an approved destination airport analysis (§§ 135.385, 135.4)
Drug and alcohol testing	Not required	Pre-employment, random, post-accident and reasonable-cause testing of safety-sensitive employees (Part 120)
Training and checking	Flight review every 24 calendar months; pilot-in-command proficiency check every 12 calendar months for turbojet or multi-pilot aircraft (§§ 61.56, 61.58)	Approved training program; knowledge test and competency check every 12 calendar months; for pilots in command, a line check every 12 calendar months and an instrument proficiency check every 6 calendar months under IFR (§§ 135.293 to 135.299, 135.341)
FAA oversight	No operator certificate, manual or management team	Inspections at any time or place, including en route; required management positions; FAA-acceptable manual (§§ 119.59, 119.69, 135.21, 135.73)
Safety management system	Not required	Required by May 28, 2027 for operators authorized before May 28, 2024 (§ 5.9)

Under Part 135, a crew may not depart under instrument flight rules unless the destination forecast is at or above landing minimums, and the runway rule can cap the weight a larger jet carries into a short runway.²

Crew rules add cost too: a three- or four-pilot crew may stay aloft up to 12 or 16 hours, but only with sleeping facilities on board for the relief pilot.²

Sharing Costs Under Part 91 Without a Part 135 Certificate

Part 91 lets owners of certain airplanes recover some costs without becoming a charter operator. These provisions sit in Subpart F, which covers large airplanes, multiengine turbojets and fractional program aircraft in operations not involving common carriage.¹ Because a large aircraft is one above 12,500 pounds maximum certificated takeoff weight, a turboprop or single-engine jet at or below that weight falls outside them unless it flies in a fractional program.⁷

Section 91.501(c) defines three cost-sharing arrangements:

• Time-sharing: the owner leases the airplane with flight crew to another person and may charge only the expenses listed in § 91.501(d), such as fuel, crew travel, landing fees, insurance for the specific flight and in-flight food, plus an additional charge equal to the cost of fuel, oil, lubricants and additives.
• Interchange: the owner leases the airplane in exchange for equal time on another person’s airplane, and any charge may not exceed the difference in the cost of owning, operating and maintaining the two airplanes.
• Joint ownership: one registered joint owner employs and furnishes the flight crew, and each registered joint owner pays a share of the charge specified in the agreement.¹

Crew salaries, home-base hangar rent and scheduled maintenance are absent from the time-sharing list, so those costs stay with the owner.

Fractional ownership under Subpart K

Part 91 Subpart K governs fractional programs, which require elements such as a single program manager, two or more airworthy aircraft, multi-year agreements and a dry-lease exchange among owners. The minimum interest is one-sixteenth of a subsonic fixed-wing aircraft, and the manager works under FAA management specifications and added crew, duty time and training rules. An owner has operational control of a program flight carrying its designated passengers or property, but not of a flight operated under Part 135.¹

How Aircraft Management and Part 135 Charter Work

What an aircraft management company does

An aircraft management company runs a business aircraft on its owner’s behalf. Federal tax law defines aircraft management services to include scheduling, flight planning and weather forecasting; obtaining insurance; maintenance, storage and fueling; hiring, training and providing pilots and crew; and establishing and complying with safety standards. Amounts an owner pays for those services on its own aircraft are exempt from the federal excise tax on air transportation, which applies to what charter customers pay.¹²

The owner pays for the service and the operating costs. Management agreements typically charge the owner a management fee and pass through the aircraft’s operating expenses, such as maintenance, fuel, landing fees and parking, either at cost or with a set margin.¹³

Charter on the operator’s certificate

When the owner is not flying, a management company with a Part 135 certificate can charter the aircraft if the aircraft is authorized for charter under that certificate. The FAA’s public list shows which aircraft are authorized.¹⁴ Part 135’s aircraft requirements do not prohibit a certificate holder from using or authorizing the aircraft for operations outside Part 135, so one jet can fly both the owner’s Part 91 trips and charter customers.²

The owner is paid for charter use, which offsets part of the cost of ownership. Owners are typically paid either a share of the charter revenue or a fixed rate for each hour the aircraft flies charter.¹³ The management agreement sets the method, the amounts and which charter costs are charged back.

Operational control

Operational control is the exercise of authority over initiating, conducting or terminating a flight.⁷ On charter flights, the certificate holder is responsible for it and must name in its manual each person authorized to exercise it.²

No certificate holder carries that responsibility on the owner’s Part 91 trips, so the management agreement should state who does. Ownership through a separate company, or a lease to an affiliate or the operator, raises further operational control questions that deserve their own legal review.

Charter Brokers vs. Part 135 Operators

The DOT’s broker rules call the company that provides the flight and controls its operational functions the direct air carrier; in jet charter, that is the Part 135 operator. An air charter broker holds out, sells or arranges single entity charter flown by a direct air carrier, acting as an indirect air carrier or as a bona fide agent.¹⁵

DOT regulates brokers under 14 CFR Part 295, which was published in September 2018. Brokers may arrange flights only with carriers that hold DOT economic authority and FAA safety authority, and their advertising must state clearly that they are air charter brokers without operational control of aircraft and that a properly licensed direct air carrier will provide the flight.¹⁵

Before contracting, a broker must disclose the corporate name of the direct air carrier in operational control, the capacity in which the broker is acting, and whether it holds liability insurance covering the charterer and passengers, with its limits. On request, it must also disclose the total cost, third-party fees the charterer pays directly and, when acting as the charterer’s agent, business ties that may affect its choice of carrier. If required information is not provided within a reasonable time, the charterer may cancel for a full refund.¹⁵

Part 295 also treats misrepresenting pilot qualifications, safety records or insurance as unfair or deceptive, along with selling a flight the carrier cannot legally perform.¹⁵ The carrier name in the disclosure is the starting point for checking whether a flight is legal.

Illegal Charter and How to Verify an Operator

Illegal charter is compensated flying without the required certificate and authority. Part 119 bars both operating and advertising such flights without FAA authorization, and Part 135’s rules apply to unauthorized operators as well.^{2, 4}

Owners can create the problem too. Under FAA definitions, anyone who uses, causes the use of or authorizes the use of an aircraft operates it, so an owner who lets someone sell trips outside a certificate holder’s authority risks being treated as an illegal operator.^{4, 7}

The FAA calls illegal air charter a serious safety hazard, and in October 2026 its Safe Air Charter page reported more than $18 million levied against rogue operators.³ Its consumer guidance lists these red flags.¹⁶

• The company supplies the aircraft and at least one crewmember but tries to shift operational control to the customer through a document.
• No federal excise tax is charged, though legitimate operators have to charge it.
• There is no safety briefing or passenger briefing card.
• Questions get evasive answers.
• Someone coaches passengers on what to say if an FAA inspector meets the aircraft.

To verify an operator, use the FAA’s spreadsheet of Part 135 operators and the aircraft authorized for charter, which is searchable by operator name or N-number and updated weekly. If an operator or aircraft is missing, the FAA advises contacting the local Flight Standards District Office.¹⁴ The FAA also suggests asking to see the operator’s certificate before paying.¹⁶

What the Distinction Means for Owners and Investors

Earning charter income means placing a private aircraft inside a regulated commercial operation. The arrangement resembles other managed real assets, such as the properties held in private real estate funds: one party owns the asset, a manager runs operations, and written agreements decide how revenue and costs flow.

Compliance costs

A certificate holder carries costs a private flight department may not, including management personnel, an FAA-acceptable manual, an approved training program with recurring checks, and drug and alcohol testing.^{2, 4, 10} Existing Part 135 operators must also implement a safety management system and declare compliance to the FAA by May 28, 2027.¹¹

Maintenance requirements grow too. For aircraft with nine or fewer passenger seats, § 135.421 requires the manufacturer’s recommended maintenance programs, or an FAA-approved program, for each engine, propeller, rotor and item of emergency equipment.² FAA Advisory Circular 135-7B notes that such programs may include overhaul, inspection or replacement of parts at specific time intervals.¹⁷

Legal operators, the FAA says, incur relatively high overhead costs to maintain aircraft, train and test crews and stay compliant.¹⁶ How much of that reaches the owner depends on the management agreement.

Utilization

Charter hours run on the same maintenance clock as owner hours, because inspection programs schedule work by time in service, calendar time, number of system operations or a combination of these.^{1, 2}

Illustrative arithmetic: an owner flies 150 hours a year and a major inspection falls due every 300 flight hours, so it arrives every two years. If charter adds 150 hours a year, the inspection arrives every year, so the owner should budget for that cost and its downtime twice as often.

Charter bookings also compete with owner trips, so the agreement should set priority and notice rules for owner use.

Operational control and liability

On charter flights, the certificate holder holds operational control and the responsibility that comes with it.² For arrangements outside a certificate, the FAA advises anyone entering an aircraft lease to make sure they understand, and are willing to accept, their responsibilities for compliance with air safety regulations.¹⁶

Insurance and other terms to settle in writing

• Which policy covers charter flights, and who are the named insureds?
• Does hull coverage stay in force when the aircraft flies commercially?
• When a broker sells the trip, what liability insurance has it disclosed under Part 295?¹⁵
• Which flights operate under Part 91 and which under Part 135, and who holds operational control on each?

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Frequently Asked Questions About Part 91 vs. Part 135

First Step: Find the Aircraft on the FAA List

The FAA’s Part 135 spreadsheet answers the first question an owner or investor should ask: is this aircraft authorized for charter with this operator? Search it by N-number, confirm that the certificate holder shown is the company named in the management agreement, and call the local Flight Standards District Office if either is missing.¹⁴

Until the aircraft appears under that certificate, treat any charter revenue projection for it as unproven.

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References

1. Electronic Code of Federal Regulations — “14 CFR Part 91, General Operating and Flight Rules.” Federal rules for operating aircraft in the United States, including inspection programs (§ 91.409), time-sharing, interchange and joint ownership agreements (§ 91.501) and fractional ownership programs (Subpart K).
2. Electronic Code of Federal Regulations — “14 CFR Part 135, Operating Requirements: Commuter and on Demand Operations and Rules Governing Persons on Board Such Aircraft.” Operating rules for commuter and on-demand certificate holders, covering pilot qualifications, flight time and rest, weather and runway limits, operational control, training and maintenance.
3. Federal Aviation Administration — “Safe Air Charter.” The FAA’s air charter safety page, describing the higher standards that apply to charter, the hazard posed by illegal operators and counts of Part 135 certificate holders, authorized aircraft and penalties levied.
4. Electronic Code of Federal Regulations — “14 CFR Part 119, Certification: Air Carriers and Commercial Operators.” Rules on who must hold an air carrier or operating certificate, the contents of operations specifications, required management personnel and FAA inspections.
5. Electronic Code of Federal Regulations — “14 CFR Part 125, Certification and Operations: Aircraft Having a Seating Capacity of 20 or More Passengers or a Maximum Payload Capacity of 6,000 Pounds or More; and Rules Governing Persons on Board Such Aircraft.” Rules for operating larger aircraft when common carriage is not involved, including the applicability threshold in § 125.1 and the certificate and operations specifications required by § 125.5.
6. Electronic Code of Federal Regulations — “14 CFR Part 110, General Requirements.” Definitions used in Parts 119 through 135, including commuter operation and on-demand operation.
7. Electronic Code of Federal Regulations — “14 CFR 1.1, General Definitions.” FAA definitions of terms including commercial operator, large aircraft, operate and operational control.
8. Federal Aviation Administration — “Advisory Circular 120-12A, Private Carriage Versus Common Carriage of Persons or Property.” FAA guidance, issued April 24, 1986, on the elements of common carriage and the concept of holding out.
9. Electronic Code of Federal Regulations — “14 CFR Part 61, Certification: Pilots, Flight Instructors, and Ground Instructors.” Pilot certification rules, including type ratings (§ 61.31), flight reviews (§ 61.56) and pilot-in-command proficiency checks (§ 61.58).
10. Electronic Code of Federal Regulations — “14 CFR Part 120, Drug and Alcohol Testing Program.” FAA drug and alcohol testing requirements for Part 119 certificate holders operating under Parts 121 and 135 and for employees who perform safety-sensitive functions.
11. Electronic Code of Federal Regulations — “14 CFR Part 5, Safety Management Systems.” The FAA’s safety management system rule, including the May 28, 2027 compliance date for existing Part 135 operators in § 5.9.
12. Legal Information Institute, Cornell Law School — “26 U.S. Code § 4261: Imposition of Tax.” The federal excise tax on air transportation of persons, including the subsection (e)(5) exemption for amounts aircraft owners pay for aircraft management services.
13. U.S. Securities and Exchange Commission — “Wheels Up Experience Inc., Form 10-K for the Fiscal Year Ended December 31, 2022.” Annual report filed March 31, 2023, describing the company’s aircraft management revenue and how owners of managed aircraft were paid when their aircraft flew member trips.
14. Federal Aviation Administration — “FAA-certificated Aircraft Operators (Legal Part 135 holders).” The FAA’s weekly-updated spreadsheet of Part 135 certificate holders and the aircraft authorized for charter, searchable by operator name or N-number.
15. Electronic Code of Federal Regulations — “14 CFR Part 295, Air Charter Brokers.” DOT rules, published September 17, 2018, defining air charter brokers and setting their advertising, disclosure, refund and fair-practice requirements.
16. Federal Aviation Administration — “Thinking of Chartering an Aircraft?” FAA consumer guidance on verifying a charter operator and on red flags that indicate a company may not be a legitimate operator.
17. Federal Aviation Administration — “Advisory Circular 135-7B, Part 135: Additional Maintenance Requirements for Aircraft Type Certificated for Nine or Less Passenger Seats.” FAA guidance, issued August 11, 2016, on complying with the § 135.421 maintenance requirements.

This article is for educational purposes only. Novacrest offerings are available to verified accredited investors through official offering documents. Nothing in this article constitutes investment, legal, tax, or financial advice. Private real estate investments involve risk, including possible loss of principal. Prospective investors should review all offering documents and consult their own attorney, accountant, and financial adviser before investing.