14 CFR § 135.261 - Applicability.
Sections 135.263 through 135.273 of this part prescribe flight time limitations, duty period limitations, and rest requirements for operations conducted under this part as follows:
(a) Section 135.263 applies to all operations under this subpart.
(b) Section 135.265 applies to:
(1) Scheduled passenger-carrying operations except those conducted solely within the state of Alaska. “Scheduled passenger-carrying operations” means passenger-carrying operations that are conducted in accordance with a published schedule which covers at least five round trips per week on at least one route between two or more points, includes dates or times (or both), and is openly advertised or otherwise made readily available to the general public, and
(2) Any other operation under this part, if the operator elects to comply with § 135.265 and obtains an appropriate operations specification amendment.
(c) Sections 135.267 and 135.269 apply to any operation that is not a scheduled passenger-carrying operation and to any operation conducted solely within the State of Alaska, unless the operator elects to comply with § 135.265 as authorized under paragraph (b)(2) of this section.
(d) Section 135.271 contains special daily flight time limits for operations conducted under the helicopter emergency medical evacuation service (HEMES).
(e) Section 135.273 prescribes duty period limitations and rest requirements for flight attendants in all operations conducted under this part.