Last updated November 7, 2026 · By Seth Semilof

Part 91 and Part 135 are the two sets of FAA rules you will hear about most when you look at private jets. They decide who can legally fly you, how rested the pilots must be, which runways the jet can use and how it is maintained. This review compares the two side by side using the federal regulations themselves, explains fractional programs (Part 91 subpart K), and shows how to check that your charter is really flown under Part 135 before you pay.

Haute Jets is a private jet charter broker, not an operator. We arrange flights with Wyvern- and ARGUS-rated FAA Part 135 operators, with access to 3,500+ vetted aircraft. No jet cards, no membership fees. Most quotes arrive within 60 minutes.

Part 91 vs Part 135 at a glance

TopicPart 91Part 135
What it coversGeneral operating and flight rules for all civil aircraft, including private flightsCommuter and on-demand (charter) operations by an FAA certificate holder
Can passengers pay for the flight?Only in limited cases listed in 14 CFR 91.501(b), such as company flights charged at no more than costYes. This is the rule set for flying people for compensation or hire
FAA certificate neededNo air operator certificate for private flightsAir carrier or operating certificate under Part 119, with operations specifications listing each aircraft
Captain of a jetPilot certificate and ratings for the aircraftAirline transport pilot (ATP) certificate for a turbojet or any airplane with 10 or more passenger seats (14 CFR 135.243)
Second pilot under IFRRequired for airplanes certificated for more than one pilot and for large airplanes (14 CFR 91.531)Required when carrying passengers under IFR, unless an approved autopilot exception applies (135.101, 135.105)
Flight time and restNo comparable limits for private flights (fractional programs have their own under subpart K)Two-pilot crews limited to 10 hours of flight time in 24 consecutive hours, with at least 10 consecutive hours of rest (135.267)
Landing distanceFlight manual landing performance; no 60% margin for private flights (fractional programs have one, 91.1037)Large turbine transport category jets must be able to stop within 60% of the runway, with more margin on wet runways (135.385)
Weather at destinationGeneral Part 91 IFR rulesForecast at or above landing minimums before takeoff under IFR (135.219)
MaintenanceInspections under Parts 91 and 43 (for example, 91.409)Additional Part 135 maintenance rules; aircraft with 10 or more seats need a full maintenance program (135.411)
Drug and alcohol testingNot required for private flightsRequired for certificate holders and safety-sensitive staff (14 CFR Part 120)
FAA oversightGeneral oversight of pilots and aircraftFAA inspectors check charter pilots, crews and aircraft more often than private operations, per the FAA

Sources: 14 CFR Parts 91, 119, 120 and 135 (eCFR, current as of November 2026); FAA Safe Air Charter.

What is the difference between Part 91 and Part 135?

Part 91 is the baseline rulebook every civil aircraft in the United States follows. Part 135 sits on top of it for flights sold to the public. If you pay for a seat or for the whole aircraft on an on-demand trip, the operator generally needs a Part 135 certificate, and the extra rules in Part 135 apply on top of Part 91.

The FAA puts it plainly on its Safe Air Charter page: charter operations under Part 135 require a higher level of pilot training and certification, maintenance procedures and safety rules than pilots who may take family or friends for an airplane ride. The FAA also says its inspectors check Part 135 pilots, crewmembers and aircraft more often than private operations.

When can a Part 91 flight carry paying passengers?

Rarely, and only in specific cases. 14 CFR 91.501(b) lists operations that large and turbojet airplanes may conduct under Part 91 when common carriage is not involved. Examples include:

  • An owner flying for personal transportation, or carrying guests, with no charge, assessment or fee.
  • A company carrying its own officials, employees, guests and property when the trip is within the scope of its business, with no charge beyond the cost of owning, operating and maintaining the airplane.
  • Ferry, training and demonstration flights.

None of these is a charter you can buy. If someone offers you a seat or a whole aircraft for a fare and says the flight will be Part 91, treat it as a red flag and check it with the steps below.

Pilot requirements: who can fly a charter jet?

Under 14 CFR 135.243, the captain of a turbojet airplane, or of any airplane with 10 or more passenger seats, must hold an airline transport pilot certificate with the right category, class and type ratings. For other aircraft flown under instrument flight rules, the captain needs at least a commercial certificate with an instrument rating and 1,200 hours of flight time, including 500 hours cross-country, 100 hours at night and 75 hours of instrument time.

Part 135 also requires a second in command when passengers are carried under IFR (135.101), unless the operator holds a specific autopilot approval under 135.105. Every Haute Jets trip is flown by two FAA-certified ATP-rated pilots, with 24/7 flight monitoring.

Duty and rest limits

This is one of the clearest differences. For unscheduled one- and two-pilot crews, 14 CFR 135.267 says:

  • Flight time in any 24 consecutive hours may not exceed 8 hours for a single pilot or 10 hours for a two-pilot crew.
  • Each assignment must include at least 10 consecutive hours of rest in the 24 hours before it ends.
  • A duty period can run to 14 hours only if it is preceded and followed by at least 10 consecutive hours of rest.
  • Pilots must get at least 13 rest periods of 24 consecutive hours in each calendar quarter.

Private Part 91 flights have no equivalent limits. Fractional ownership programs, which fly under Part 91 subpart K, have their own flight, duty and rest rules in 91.1057 and the sections that follow it.

Runway and weather rules

Part 135 adds margins that matter when you pick an airport. Under 14 CFR 135.385, a turbine-powered large transport category airplane must be able to make a full-stop landing within 60% of the effective runway length at the destination. If the runway may be wet or slippery, it needs 115% of that distance, unless the flight manual allows otherwise or the operator holds an approved destination airport analysis program as an eligible on-demand operator.

Under 135.219, a Part 135 flight may not take off under IFR unless the forecast at the destination is at or above landing minimums for the time of arrival. Under 135.225, a pilot generally may not begin an instrument approach unless the airport has an approved weather reporting source showing conditions at or above minimums. These rules are why an operator may suggest a longer runway or a nearby airport than the one you had in mind.

Maintenance and testing

14 CFR 135.411 splits Part 135 aircraft by seat count. Aircraft type certificated for nine or fewer passenger seats are maintained under Parts 91 and 43 plus additional Part 135 rules. Aircraft with 10 or more passenger seats need a full maintenance program under 135.415, 135.417 and 135.423 through 135.443.

Part 135 certificate holders must also run FAA drug and alcohol testing for safety-sensitive staff under 14 CFR Part 120. The FAA lists FAA-approved drug and alcohol testing among the protections that illegal charter operators avoid.

What is Part 91K?

Part 91 subpart K (14 CFR 91.1001 onward) covers fractional ownership programs, where owners buy a share of an aircraft and a program manager runs the fleet. It is a Part 91 rule set with added requirements for the program manager, including crew flight, duty and rest rules. It is not on-demand charter. When you charter a jet through Haute Jets, the flight is operated by a Part 135 certificate holder.

Part 91 vs Part 121 vs Part 135

Rule setUsed forExample
Part 91General operating rules; private and corporate flights not sold to the publicAn owner flying family on their own jet
Part 135Commuter and on-demand operations by a certificate holderA private jet charter you book for your group
Part 121Domestic, flag and supplemental operations by air carriersScheduled airline flights

Source: 14 CFR 91.1, 121.1 and 135.1.

How do I confirm my charter is a Part 135 flight?

Ask for the operator, then check it. The FAA recommends these steps:

  1. Get the operator’s name and the aircraft’s tail number. A broker should tell you who the direct air carrier is. Under DOT rules for air charter brokers (14 CFR 295.23), a broker’s advertising must say it is a broker, not the operator.
  2. Ask for the certificate and operations specification D085. FAA inspectors say a copy of the operator’s certificate plus its D085, which lists authorized aircraft, shows the aircraft you are offered is authorized.
  3. Check the FAA lists. The FAA publishes a Part 135 Operators and Aircraft list, searchable by operator name or N-number and updated weekly, plus the AVInfo Air Operator Search. If an operator or aircraft is not listed, the FAA says to contact the local Flight Standards District Office.
  4. Watch for red flags. The FAA warns about companies that supply the aircraft and crew but try to transfer operational control to you in a document, quotes with no federal excise tax, no safety briefing, evasive answers, and pilots who coach passengers on what to tell an FAA inspector.

The FAA’s Safe Air Charter page lists 1,837 Part 135 certificate holders and 11,582 Part 135 authorized aircraft. Haute Jets arranges flights only with Wyvern- and ARGUS-rated operators. Request a quote.

Get a quote

Tell us your route, dates, passengers and bags, and we will send options from Wyvern- and ARGUS-rated Part 135 operators. Most quotes arrive within 60 minutes. Request a quote or call (800) 257-5661. For more on vetting, read our guides to vetting a charter broker, FAA Part 135 and Wyvern and ARGUS ratings.

FAQs

What is the main difference between Part 91 and Part 135?

Part 91 is the general rulebook for all civil flying, including private flights. Part 135 adds stricter rules for charter flights sold to the public, covering pilot certificates, duty and rest, runway margins, maintenance, drug testing and FAA oversight. The operator must hold an FAA certificate to fly under Part 135.

Is Part 135 safer than Part 91?

Part 135 sets higher minimum standards. The FAA says charter operations require a higher level of pilot training and certification, maintenance procedures and safety rules, and that its inspectors check Part 135 operators more often than private ones. Safety on any flight also depends on the operator, crew and aircraft.

Can I pay for a private jet flight under Part 91?

Generally no. 14 CFR 91.501(b) allows a few cost-limited cases, such as a company carrying its own staff at no more than cost, but a charter sold to you for a fare must be flown by a Part 135 certificate holder. A Part 91 offer for a fare is a red flag.

Do Part 135 charters need two pilots?

Under 14 CFR 135.101, a second in command is required when carrying passengers under IFR, unless the operator has an approved autopilot exception under 135.105. Captains of turbojets need an ATP certificate under 135.243. Every Haute Jets trip is flown by two FAA-certified ATP-rated pilots.

What are the Part 135 pilot rest rules?

For unscheduled two-pilot crews, 14 CFR 135.267 limits flight time to 10 hours in any 24 consecutive hours, eight for a single pilot, and requires at least 10 consecutive hours of rest before the assignment ends, plus 13 rest periods of 24 hours each quarter.

What is Part 91K?

Part 91 subpart K (14 CFR 91.1001 onward) governs fractional ownership programs, where owners hold a share of an aircraft and a program manager runs it. It adds rules for the program manager, including crew duty and rest, but it is not on-demand charter.

How can I check if a charter operator is legal?

Ask for the operator’s name, FAA certificate and operations specification D085 listing the tail number. Then check the FAA’s Part 135 Operators and Aircraft list or the AVInfo Air Operator Search. If the operator or aircraft is missing, contact the local FAA Flight Standards District Office.

How do I get a quote for a Part 135 charter?

Request a quote at https://www.hautejets.com/request-a-quote or call (800) 257-5661. Most quotes arrive within 60 minutes. No jet cards, no membership fees.

Sources