Legal Interpretations
Siff 2007
Summary
The Question
Which part 121 flight, duty, and rest rules apply to all-cargo and charter passenger operations flown within the 48 contiguous states?
Background
A requester asked a question about part 121 flight, duty, and rest rules that the FAA found too unspecific for a definitive answer; the FAA offered general guidance instead.
The FAA’s Interpretation
Subpart S, not subpart Q, though the FAA gave no definitive answer. Part 121 all-cargo or charter passenger operations, even within the 48 contiguous states, are not domestic operations under subpart Q, which covers certain scheduled passenger operations. They are supplemental operations under 14 CFR 119.3, subject to 14 CFR 121.517 and the subpart S rules preceding 14 CFR 121.513.
- Requester
- Siff
- Issued
- December 14, 2007
- Subjects
- Air Carrier & Commercial Operations · Flight & Duty Time
Regulations Cited
Page 1
U,S.Department
of Transportation
Federal Aviation
Administration
DEC 1 4 2007
Martin L. Siff
314 Exeter Close
Easley, S.C.
29642-8804
Dear Mr. Siff:
Office of the Chief Counsel 800 Independence Ave .• S.W.
Washington. D.C. 20591
This is in response to your letter of December 6. Your question lacked the specificity necessary to give a definitive response. Nonetheless, we offer the following:
Ifthe carrier conducts operations under Part 121 and those operations are all-cargo or charter passenger-carrying operations, then Subpart S rules apply. Such all-cargo operations or charter passenger-carrying operations that are conducted within the 48 contiguous states are not "domestic operations" subject to Subpart Q. Such operations are "supplemental operations" (as defined in Section 119.3) and are still subject to Section 121.517 and those Subpart S rules that precede Section 121.513.
A "domestic operation" under the Federal Aviation Regulations, is, in relevant part, a scheduled passenger-carrying operation on certain airplanes. See Section 119.3 definitions of "domestic operation" and "scheduled operation". A "scheduled operation" under our rules relates only to passenger-carrying operations, not all-cargo operations. Thus, certain scheduled passenger carrying operations conducted under Part 121 are subject t9 Subpart Q. Supplemental operations (as defined in Section 119.3), including all-cargo and charter passenger-carrying operations in certain airplanes, are subject to the flight, duty and rest rules of Subpart S.
~ ~WL--RebeccaMac£,n
Assistant Chief Counsel
Regulations Division, AGC-200
Regulations Referenced
Snapshot retrieved August 6, 2026.