Regulation Text
(a) No person may operate a civil aircraft in the United States at a true flight Mach number greater than 1 except in compliance with conditions and limitations in an authorization to exceed Mach 1 issued to the operator in accordance with § 91.818.
(b) In addition, no person may operate a civil aircraft for which the maximum operating limit speed MM0 exceeds a Mach number of 1, to or from an airport in the United States, unless—
(1) Information available to the flight crew includes flight limitations that ensure that flights entering or leaving the United States will not cause a sonic boom to reach the surface within the United States; and
(2) The operator complies with the flight limitations prescribed in paragraph (b)(1) of this section or complies with conditions and limitations in an authorization to exceed Mach 1 issued in accordance with § 91.818.
(Approved by the Office of Management and Budget under control number 2120-0005)[Docket 18334, 54 FR 34321, Aug. 18, 1989, as amended by Amdt. 91-362, 86 FR 3792, Jan. 15, 2021]
Research Notes
Section 91.817 — Civil aircraft sonic boom — prohibits civil aircraft sonic booms over U.S. land areas.
The prohibition: No person may operate a civil aircraft in supersonic flight in such a manner that the sonic boom reaches the U.S. land surface — with limited research exceptions.
Operational impact: This rule effectively prohibits supersonic commercial civilian flight over the U.S. mainland (the Concorde's transatlantic routes went supersonic only over the open ocean). The rule has been a key constraint on supersonic transport development for decades.
2020s supersonic developments: The FAA's 2024 noise certification rule for supersonic aircraft and ongoing research (NASA X-59, Boom Overture) may eventually relax the prohibition for low-boom supersonic aircraft. § 91.817 remains in effect pending those developments.
Reference: FAA Engineering Handbook; 14 CFR § 91.817; FAA Aviation Noise Office on supersonic certification standards.
Amendment History
Amendment History Coming Soon
Every time this regulation changes, we'll record it here — the date, what was amended, and a plain-English summary of what shifted.