FAR 91.821 — Supersonic Noise Limits
FAR 91.821 explains noise limits for civil supersonic airplanes operating in the U.S., including the Concorde exception and Stage 2 compliance under Part 36.
In Plain English
FAR 91.821 sets the noise rules for civil supersonic airplanes operating in the United States. In plain terms, if you want to fly a civil supersonic jet inside U.S. airspace, the aircraft must meet the Stage 2 noise limits of 14 CFR Part 36 as those limits stood on October 13, 1977, including any applicable trade-off provisions (which let manufacturers offset noise on one measurement point against margin on another).
There is one narrow exception:
- Concorde airplanes that already had flight time before January 1, 1980 are grandfathered and do not have to comply.
Why it matters operationally:
- It limits which supersonic designs can legally operate in U.S. airspace.
- It ties civil supersonic operations to a specific historical noise standard, which is why new supersonic designs must be engineered with these limits in mind.
- For today's pilots, it's mostly a regulatory awareness item — but expect a DPE to know it exists when discussing Subpart I (Operating Noise Limits).
Regulation Text
14 CFR § 91.821§ 91.821 Civil supersonic airplanes: Noise limits.
Except for Concorde airplanes having flight time before January 1, 1980, no person may operate in the United States, a civil supersonic airplane that does not comply with Stage 2 noise limits of part 36 in effect on October 13, 1977, using applicable trade-off provisions.
Oral Exam Questions a DPE Might Ask
Q1What noise standard must a civil supersonic airplane meet to operate in the United States?
Per FAR 91.821, a civil supersonic airplane must comply with the Stage 2 noise limits of Part 36 in effect on October 13, 1977, using applicable trade-off provisions.
Q2Is there any exception to the supersonic noise compliance rule in FAR 91.821?
Yes. FAR 91.821 exempts Concorde airplanes that had flight time before January 1, 1980, from the Stage 2 Part 36 noise compliance requirement.
Q3If a new civil supersonic jet wants to operate in U.S. airspace today, what regulation governs its noise compliance and what does it require?
FAR 91.821 governs it and requires the airplane to meet the Stage 2 noise limits of Part 36 as in effect on October 13, 1977, including the applicable trade-off provisions, since the Concorde exception would not apply.
Studying for a checkride?
Related Sections in Part 91