Applicability

This regulation establishes the scope of Subpart E of Part 135, which covers flight crewmember requirements for commuter and on-demand operations. It tells you that the rules in this subpart apply to all Part 135 operations, with one important exception: the deviation authority found in § 135.3.

In practical terms, this means when you're operating under Part 135, you must follow the flight crewmember requirements laid out in Subpart E—things like pilot-in-command qualifications, second-in-command requirements, and crew pairing rules. However, if your operation has received specific authorization under § 135.3 (which allows deviations for certain operations), those approved deviations would take precedence.

This is essentially a "gateway" regulation that points you to where the crewmember rules apply and reminds you of the one exception that might modify them. It ensures pilots know which requirements govern their crew composition and qualifications.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*