14 CFR Part 135 — On-Demand Air Carrier and Air Taxi Rules
14 CFR Part 135 governs on-demand and commuter air carrier operations conducted for compensation or hire in the United States. This includes charter flights, air taxi operations, medevac transports, and scheduled services using small aircraft. Part 135 occupies the regulatory space between private flying (Part 91) and scheduled airline operations (Part 121), and it imposes significantly higher standards on pilots, aircraft, maintenance, and recordkeeping than Part 91 alone.
What Operations Require Part 135 Certification
Per 14 CFR §119.3 and §135.1, Part 135 applies to operations conducted for compensation or hire involving:
- On-demand operations using aircraft with 1 to 30 passenger seats (or payload capacity up to 7,500 lbs)
- Commuter operations — scheduled passenger operations with aircraft of 9 or fewer passenger seats
- Air taxi operations — for-hire air transportation on an unscheduled basis
- Air ambulance / medevac operations when conducted for compensation
Operations that do NOT require Part 135 certification include: private flights conducted entirely under Part 91 (even in a charter aircraft if the owner is operating their own plane), fractional ownership programs meeting specific criteria under Part 91 Subpart K, and operations specifically exempted under §119.1(e) such as agricultural operations, banner towing, and non-stop sightseeing within 25 NM.
Part 135 Pilot Requirements
Part 135 imposes specific pilot qualification requirements beyond the basic certificate requirements of Part 61. These requirements apply to both PIC and SIC positions.
PIC Requirements (§135.243)
| Operation Type | Certificate Required | Additional Requirements |
|---|---|---|
| Turbojet aircraft | ATP with appropriate category/class rating | Type rating required for aircraft over 12,500 lbs |
| IFR operations (non-turbojet) | Commercial + instrument (or ATP) | 1,200 hr total; 500 hr XC; 100 hr night; 75 hr IMC |
| VFR operations only | Commercial with appropriate category/class | 500 hr total; 100 hr XC; 25 hr night |
| Helicopters (IFR) | Commercial + instrument helicopter | 1,200 hr total per §135.243(b) |
SIC Requirements (§135.245)
A second-in-command under Part 135 must hold at least a commercial pilot certificate with instrument rating and the appropriate category and class rating. For operations requiring an SIC, there is no minimum experience requirement beyond the certificate itself, though operators typically impose additional minimums through their Operations Specifications and training programs.
IFR PIC Experience Requirements (§135.243(b))
For non-turbojet IFR operations, a PIC must have accumulated at least:
- 1,200 hours total flight time as a pilot
- 500 hours cross-country flight time
- 100 hours night flight time
- 75 hours actual instrument or simulated instrument flight time
Part 135 Rest and Duty Limitations
Part 135 flight and duty time limitations are found in §§135.265–135.273. The rules differ depending on whether the operation is scheduled (commuter) or unscheduled (on-demand), and whether the flight is conducted in one or two pilot crew. Key provisions:
- Maximum flight time: 8 hours in any 24-consecutive-hour period for on-demand operations with one pilot; 10 hours with two pilots
- Maximum duty time: 10 hours for on-demand operations (§135.267); 14 hours for scheduled/commuter operations under certain circumstances (§135.265)
- Required rest before duty: 10 consecutive hours of rest must precede a duty period; rest period must equal at least the duty period for duty periods exceeding 14 hours
- Weekly rest: Crewmembers must receive at least 24 consecutive hours of rest in every 7 consecutive calendar days
- Annual limit: No crewmember may be scheduled for more than 1,400 hours of flight time in any calendar year (§135.265)
Part 135 Equipment Requirements
§135.149 — Equipment Requirements: General
All Part 135 aircraft must meet minimum equipment requirements appropriate to the operation. Required equipment includes functioning instruments per §91.205, emergency equipment (first aid kits, flotation equipment for overwater operations, survival equipment for remote areas), and the instruments and equipment listed in the applicable aircraft flight manual and type certificate data sheet.
§135.159 — Equipment Requirements for IFR Operations
IFR operations under Part 135 require all instruments required by §91.205(d) plus: at least one additional attitude indicator and directional gyro (or equivalent) to allow continued IFR flight if any one instrument fails, an alternate static pressure system, a heated pitot tube, an approved ground proximity warning system (GPWS/TAWS) for turbine aircraft, and a Traffic Collision Avoidance System (TCAS) for turbine aircraft with more than 10 passenger seats.
Part 135 vs Part 91 vs Part 121
| Feature | Part 91 | Part 135 | Part 121 |
|---|---|---|---|
| Operation type | Private/General Aviation | On-demand charter / air taxi | Scheduled airline |
| Compensation allowed | No (with narrow exceptions) | Yes | Yes |
| Air Carrier Certificate required | No | Yes (via Part 119) | Yes (via Part 119) |
| Pilot minimums (PIC IFR) | Commercial + instrument | 1,200 hr total + specific XC/night/IMC | ATP (1,500 hr or reduced) |
| Rest rules | None for GA | §135.265–§135.273 | §117 (stricter) |
| 100-hour inspection | Yes (if for hire) | Yes + additional checks | Continuous airworthiness |
| Passenger briefings | Not required | Required (§135.117) | Required |
| Aircraft size | Any | 1–30 pax seats (on-demand) | 30+ pax or 7,500+ lbs payload |
Common Part 135 Questions Pilots Ask
Q: What training and checking is required under Part 135?
Part 135 operators must conduct initial training, transition training, recurrent training (every 12 months for most crewmembers), and proficiency checks. §135.293 requires proficiency checks every 12 calendar months for PICs, and §135.297 requires instrument proficiency checks every 6 months for IFR-qualified crewmembers. All training must be conducted in accordance with the operator's FAA-approved training program.
Q: What are the minimum weather requirements for Part 135 IFR departures?
Under §135.219 and §135.221, no pilot may take off under IFR when weather is below takeoff minimums for the departure airport. Part 135 also imposes destination and alternate weather requirements: the alternate must meet §135.221 alternate minimums (generally 600-2 for precision approaches, 800-2 for non-precision). Operators may have more restrictive alternate requirements in their OpSpecs.
Frequently Asked Questions
What operations require a Part 135 certificate?
Part 135 applies to for-hire operations using aircraft with 1–30 passenger seats, including on-demand charter, air taxi, and commuter scheduled operations with 9 or fewer passenger seats. Operations with 10+ seats on a scheduled basis fall under Part 121.
What are the PIC requirements under Part 135?
Under §135.243, IFR PIC must hold commercial + instrument (or ATP) and have at least 1,200 hours total, 500 hours XC, 100 hours night, and 75 hours IMC. Turbojet PICs must hold an ATP with appropriate category/class rating.
What are the Part 135 rest requirements?
Under §135.267, maximum flight time is 8 hours per 24-hour period for single-pilot on-demand ops. A 10-hour rest period must precede each duty period. After 14 consecutive duty hours, 10 consecutive hours of rest are required.
What is the difference between Part 135 and Part 91?
Part 91 governs private, non-commercial flying. Part 135 governs for-hire air carrier operations and requires an Air Carrier Certificate, stricter pilot minimums, rest rules, passenger briefings, and maintenance standards not required under Part 91.
Can a single-pilot operation be conducted under Part 135?
Yes. Many Part 135 operators conduct single-pilot IFR operations with proper FAA authorization in their Operations Specifications. The aircraft must be type-certified for single-pilot IFR operations, and the pilot must meet Part 135 PIC requirements.