Liftbrief / Direct questions
12. What is the difference between Part 91, Part 135 and Part 91 Subpart K?
They describe different operating frameworks, not interchangeable quality labels. For procurement, establish which framework applies to the flight you are purchasing and why. The FAA distinguishes Part 135 charter requirements from private operations and identifies fractional ownership programmes separately under Part 91 Subpart K. (faa.gov)
| Framework | Buyer interpretation |
|---|---|
| Ordinary Part 91 private operations | Do not treat private owner-operation arrangements as general authority to sell charter transportation |
| Part 135 | The common framework relevant to US on-demand business-aircraft charter |
| Part 91 Subpart K | Specific rules for qualifying fractional ownership programmes |
Be particularly careful if a seller provides an aircraft and crew but asks you to sign paperwork accepting operational control. The FAA identifies this combination as a warning sign requiring scrutiny. (faa.gov)
A genuine aircraft lease or fractional arrangement deserves specialist review; the correct response is not to assume every lease is improper.
Ask:
- Who has operational control on each flight?
- What responsibilities would the buyer accept?
- Which agreements create those responsibilities?
- Does a replacement flight use a different carrier or operating framework?
This hub focuses on business-aircraft procurement. Larger airline-style charters and public-charter products require their own regulatory analysis.