What Is a Part 135 Operator? Certificates, Limits and Duties

A Part 135 operator is an organisation that holds an FAA air carrier or operating certificate authorising commercial on-demand and commuter flights under 14 CFR Part 135. The term describes the certificate holder, not the aircraft and not an individual flight. Two identical aircraft can fly the same route on the same day, one under Part 91 and one under Part 135, and the difference is entirely in who holds operational control and under what authority.

The certificate itself is issued under 14 CFR Part 119, which sets out who must be certificated and what each certificate permits. Part 135 then supplies the operating rules: crew qualification, maintenance, recordkeeping, and the rest. A Part 135 operator is therefore always working against two rule sets at once, which is the single most common source of confusion for operators coming from private flying.

Whether you need the certificate at all turns on compensation, common carriage and holding out rather than on aircraft size. That boundary is covered separately in Part 91 vs Part 135.

The FAA administers Part 135 certificates in four categories, which differ mainly in how many pilots and aircraft the operator may use. The precise limits for any given operator live in its operations specifications (OpSpecs), not in the regulation text, so two operators in the same category can hold materially different authorisations.

A single-pilot certificate authorises the certificate holder as the only pilot flying under it — the smallest form of the certificate and the least administratively demanding. A single pilot-in-command certificate names one PIC, though other pilots may serve in other crew positions, which suits an owner-operator growing beyond flying solo.

A basic certificate covers a small operation with limited numbers of pilots and aircraft, carrying most of the obligations of a standard certificate with a lighter administrative footprint. A standard certificate is the full authorisation, without those numerical limits, and is what most charter operators of any size will hold.

Moving between categories is not automatic. Adding pilots or aircraft beyond what your OpSpecs allow requires an amendment through your FSDO, and operators regularly discover this mid-growth rather than in advance.

Part 135 covers on-demand and commuter operations: charter flights sold to customers, air taxi work, and scheduled operations below the thresholds that would push an operator into Part 121. The specific routes, areas, aircraft and special authorisations are set out in the operator's OpSpecs rather than in the certificate itself.

It is worth being precise about what the certificate does not do. It does not authorise every commercial flight an operator might want to sell, it does not transfer with an aircraft, and it cannot be lent. An aircraft owner who places an aircraft on someone else's certificate has not become a Part 135 operator — the certificate holder retains operational control, and treating that arrangement casually is what turns into an illegal charter enforcement case.

The certificate is the beginning of the work rather than the end of it. A Part 135 operator carries continuing obligations that are audited on an ongoing basis:

A general operations manual and the other manuals required by 14 CFR 135.21, kept current and actually followed. Crew training, testing and currency under Subparts G and H, including recurrent cycles that do not pause when the operation is busy. An approved maintenance programme and airworthiness tracking, with the inspection programme requirements at 14 CFR 135.411 onward.

Recordkeeping under 14 CFR 135.63 and elsewhere, retrievable on request rather than merely stored. Drug and alcohol testing programmes, and security programmes where applicable. And a safety management system under 14 CFR Part 5: the FAA's 2024 final rule extends Part 5 to Part 135 operators, with a functioning documented SMS and a Declaration of Compliance required by May 28, 2027.

Each of these produces evidence somebody has to be able to produce during a surveillance visit. In practice the operators who struggle are rarely the ones who lack the programme; they are the ones who cannot find the record proving the programme ran.

Part 119 requires a certificate holder to have qualified people in specific management roles — in most Part 135 operations a Director of Operations, a Chief Pilot and a Director of Maintenance, with qualification requirements attached to each. Smaller operators may combine roles or seek a deviation, but the responsibilities do not disappear when the headcount is small.

These are accountable positions rather than titles. When an inspector asks who approved a manual revision or who authorised a flight with an open discrepancy, the answer needs a name attached to it and a record behind it.

Certification is a formal, gated process run with the local FSDO, and manual quality is the largest single driver of how long it takes. The full sequence, realistic timelines and cost drivers are covered in the Part 135 certification process guide.

The point worth making here is that the work does not change character after certification. The same manuals, records and programmes that earn the certificate are the ones surveilled for as long as it is held.

Navlyt maps an operator's own manuals against Part 135 requirements clause by clause, flags where a procedure is missing or has drifted from the regulation, and keeps the resulting corrective actions and evidence retrievable.

The recurring obligations above are the ones it is built around — see Navlyt for FAA Part 135 compliance, or work through the Part 135 audit checklist to see where your own gaps are. AI-assisted analysis is a starting point for your compliance officer, not a substitute for their judgement.