Glossary
Part 91
Why it matters
Why part 91 matters
Legitimate on-demand charter for paying passengers operates under Part 135, not Part 91. Confusing the two is how buyers accept illegal charter or gray-market flights that lack commercial oversight, insurance, and operational control standards.
Cost
How it affects cost
Part 91 flights may appear cheaper because they avoid commercial charter compliance costs. That discount is not a bargain if the trip is actually commercial transportation sold without a Part 135 certificate.
Example
A quick example
Related terms
Other terms to know
Common questions
What is the difference between Part 91 and Part 135?
Part 91 covers private, non-commercial flying. Part 135 covers on-demand charter and commuter operations with stricter crew, maintenance, and operational control rules for commercial passenger flights.
Can I legally charter a flight under Part 91?
Paying for on-demand transportation for yourself or guests generally requires a Part 135 operator. Part 91 is not a substitute for commercial charter when you are buying a flight as a service.
How do I spot Part 91 misuse on a quote?
Red flags include refusal to name a Part 135 certificate holder, lease-only contract language, prices far below market, and pressure to wire before operator identity is verified.
Is flying on a friend's Part 91 aircraft the same as charter?
No. True guest travel on an owner's aircraft under Part 91 is a different regulatory situation from hiring a commercial charter. If money changes hands as transportation for hire, Part 135 rules apply.
Guides that explain this
- Part 135 Charter Explained for BuyersWhat Part 135 means for charter buyers, how it differs from Part 91, and how to verify the operator before deposit.
- Charter Quote Red Flags: Read a Proposal Like an OperatorOperator and broker literacy for $15k–$80k trips: Part 135, ARGUS and Wyvern, FET, segment fees, repositioning, minimum hours, duty time, de-icing, airport pairs, category mistakes, and quote red flags.
- Wet Lease vs Dry Lease: What Charter Passengers Should KnowHow wet and dry lease structures differ from Part 135 charter, why lease language on a quote is a red flag, and what to verify before deposit.
- Broker vs Operator: Who Are You Actually Hiring?Charter broker vs Part 135 operator: who holds the certificate, who you pay, wire safety, substitution clauses, and what to verify before deposit.
- Private Jet Safety BasicsHow private charter safety works, including operator certification, third party audits like ARGUS and Wyvern, crew standards, and questions to ask.
Calculators that use this
Last reviewed May 2026. Estimates use planning assumptions that we revisit periodically.