FAR 91.819 — Supersonic Noise Limits
FAR 91.819 restricts civil supersonic airplanes not meeting Part 36 Stage 2 noise limits, including a 10 p.m.–7 a.m. curfew and acoustical change rules.
In Plain English
FAR 91.819 governs civil supersonic airplanes that have not been shown to meet the Stage 2 noise limits of Part 36 (as in effect on October 13, 1977) when operating in the U.S. after July 31, 1978.
If you operate one of these airplanes to or from a U.S. airport, two key restrictions apply (except in an emergency):
- Acoustical changes: If the airplane's type design is changed after July 31, 1978 in a way that qualifies as an "acoustical change" under § 21.93, you cannot land or take off unless the acoustical change requirements of Part 36 are met. This applies whether or not a type design change approval is sought under Part 21.
- Nighttime curfew: No flight may be scheduled or otherwise planned for takeoff or landing between 10 p.m. and 7 a.m. local time.
Why it matters: supersonic airplanes are inherently loud, so the FAA limits when and how noncompliant aircraft can operate near U.S. communities to control noise exposure.
Regulation Text
14 CFR § 91.819§ 91.819 Civil supersonic airplanes that do not comply with part 36.
(a)This section applies to civil supersonic airplanes that have not been shown to comply with the Stage 2 noise limits of part 36 in effect on October 13, 1977, using applicable trade-off provisions, and that are operated in the United States, after July 31, 1978.
(b)Except in an emergency, the following apply to each person who operates a civil supersonic airplane to or from an airport in the United States:
(1) Regardless of whether a type design change approval is applied for under part 21 of this chapter, no person may land or take off an airplane covered by this section for which the type design is changed, after July 31, 1978, in a manner constituting an “acoustical change” under § 21.93 unless the acoustical change requirements of part 36 are complied with.
(2) No flight may be scheduled, or otherwise planned, for takeoff or landing after 10 p.m. and before 7 a.m. local time.
Oral Exam Questions a DPE Might Ask
Q1Which civil supersonic airplanes does FAR 91.819 apply to?
Per FAR 91.819, it applies to civil supersonic airplanes that have not been shown to comply with the Stage 2 noise limits of Part 36 (in effect October 13, 1977) and that are operated in the United States after July 31, 1978.
Q2What time-of-day restriction does FAR 91.819 place on these airplanes?
Under FAR 91.819(b)(2), no flight may be scheduled or otherwise planned for takeoff or landing after 10 p.m. and before 7 a.m. local time, except in an emergency.
Q3If the type design of a covered supersonic airplane is changed after July 31, 1978, what must the operator ensure before takeoff or landing?
Per FAR 91.819(b)(1), if the change constitutes an "acoustical change" under § 21.93, the airplane must comply with the acoustical change requirements of Part 36 — regardless of whether a type design change approval is applied for under Part 21.
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Related Sections in Part 91