Proposed FAA rule would allow civil supersonic flight over the United States

The Federal Aviation Administration (FAA) has proposed to replace the United States’ longstanding ban on civil supersonic flight over US land with an interim rule that would permit supersonic flights with relatively quiet sonic booms. The proposal would allow civil supersonic air travel across the US, ending a 53-year ban on such flights.

Overview

In a notice of proposed rulemaking (NPRM) issued July 2, 2026,[1] the FAA proposed to repeal its existing prohibition on civil supersonic flight over US land, which is currently codified at 14 C.F.R. § 91.817. The FAA intends to replace the prohibition with an interim rule (Preliminary Rule) that would allow civil supersonic flight over the US if the aircraft operator obtains FAA approval, operates under any FAA-specified conditions, and limits supersonic boom overpressure – the increase in air pressure attributable to the sonic-boom shockwave – at surface level to 0.11 pounds per square foot (psf).

After issuing the Preliminary Rule, the FAA intends to issue a permanent rule (Part 36 Rule) setting noise-certification standards for civil supersonic aircraft under 14 C.F.R. part 36, which governs aircraft noise standards.

The NPRM seeks to implement Executive Order 14304, “Leading the World in Supersonic Flight,” which President Donald Trump signed on June 6, 2025.[2] The Executive Order directs the FAA to undertake both the Preliminary and Part 36 rules.

Background

The Preliminary Rule would replace the FAA’s restrictions on civil supersonic overland (CSO) flight with a pathway to regular CSO operations. In response to public opposition to sonic-boom-emitting test flights, the FAA in 1973 barred CSO flights without a Special Flight Authorization (SFA). Five years later, in response to Concorde flights, the FAA issued noise standards for supersonic aircraft, codified at 14 C.F.R. §§ 91.819 and 91.821.

In the decades since, Congress and the FAA have made efforts to limit these restrictions to permit some CSO operations, but shifting policy priorities, procedural challenges, and limited interest from aircraft manufacturers have impeded those efforts. Only four CSO SFAs have ever been granted.

The proposed rule

The Preliminary Rule would authorize an aircraft operator to conduct CSO flights, without needing to obtain an SFA for each flight, if the operator:

• Ensures no sonic-boom overpressure greater than 0.11 psf reaches the surface,
  
  
• Demonstrates such overpressure compliance to the FAA’s satisfaction, and
  
  
• Operates the aircraft in compliance with any other conditions and limitations set by the FAA.

The Preliminary Rule would require operators to demonstrate that their aircraft meet the 0.11 psf overpressure limit with respect to three types of sonic booms: “primary” sonic booms, which travel directly from the aircraft to the surface; “direct secondary” sonic booms, which refract off the atmosphere before reaching the surface; and “indirect secondary” sonic booms, in which a boom refracts off the surface, refracts off the atmosphere, and returns to the surface.

The Preliminary Rule would give operators several options for demonstrating compliance with the 0.11 psf limit, whether by “measurement, modeling, or other methods.” However, it would require each operator to obtain FAA approval of such method. The NPRM specifies several criteria the FAA expects to consider when evaluating operators’ proposed methods of compliance, such as the method’s verifiability and practicality.

Anticipated future rulemaking

The NPRM cautions that full commercial rollout of CSO flight will require the FAA to issue the Part 36 Rule, which would address landing and takeoff (LTO) noise standards for supersonic aircraft. The FAA already sets LTO noise standards for subsonic aircraft under 14 C.F.R. part 36. The NPRM also notes the FAA could, in the future, set technical standards for technology to abate sonic booms and establish other operational requirements for supersonic aircraft.

The FAA does not expect to receive type-certificate applications for supersonic aircraft until after the future LTO rulemaking. However, if it receives such an application, the FAA intends to issue an aircraft-specific LTO regulation.

Next steps

The NPRM’s July 2, 2026 publication in the Federal Register begins a 45-day public-comment period, ending August 17, 2026.[3] Aircraft manufacturers, environmental groups, and other stakeholders are likely to weigh in. It remains to be seen whether environmental groups will challenge the NPRM on environmental-procedure grounds.

The NPRM aligns in principle with legislation pending in Congress. In March 2026, the House passed H.R. 3410, the bipartisan Supersonic Aviation Modernization Act, which would require the FAA to permit CSO flights without an SFA so long as no sonic boom reaches the ground. The bill awaits action in the Senate.

DLA Piper’s Transport and Logistics practice is closely monitoring the FAA’s Preliminary and Part 36 rulemakings and is prepared to assist clients throughout the regulatory process. Our team can help develop and submit comments on the NPRM, advise on the process for obtaining FAA approval to pursue CSO operations, monitor rulemaking dockets and related congressional legislation, and provide diligence on transactions related to supersonic aircraft. For more information, please contact the authors.

 

^{[1] FAA, Notice of Proposed Rulemaking, “Enabling Supersonic Overland Flight,” 91 Fed. Reg. 40,470 (July 2, 2026), available at https://www.federalregister.gov/documents/2026/07/02/2026-13440/enabling-supersonic-overland-flight.
[2] Exec. Order 14304, “Leading the World in Supersonic Flight,” 90 Fed. Reg. 24,717 (June 11, 2025), available at https://www.federalregister.gov/d/2025-10800.
[3] Interested parties often petition the FAA to extend the comment period for a proposed regulation, so such a petition and extension are possible.}