Key Takeaways

• The Federal Aviation Administration (FAA) has proposed to end its long-standing general prohibition on overland civil supersonic flight and to allow supersonic overland flights in the U.S. so long as operators can demonstrate, and the FAA finds, that sonic boom overpressure at the surface will not exceed 0.11 pounds per square foot (psf).
• The proposal would establish a novel performance-based framework in which the FAA sets the noise-based 0.11 psf standard but allows operators to propose methods to demonstrate compliance, subject to FAA’s approval.
• FAA acknowledges that this interim en route standard is a “first step of a multi-step regulatory process,” and anticipates announcing the future rulemakings required to fully enable commercial supersonic flights in the U.S., including a new landing and takeoff (LTO) standard.
• FAA would retain elements of its existing regulations that allow two types of supersonic operations that generate sonic booms and reach the surface:

1. offshore operations where the flight crew has information about flight limitations that will prevent sonic booms from reaching the U.S.; and
2. overland operations in the U.S., conducted in accordance with a Special Flight Authorization (SFA).

• Comments are due August 17, 2026. Environmental NGOs and noise advocates are already previewing opposition. Aviation stakeholders, including aircraft and aircraft engine manufacturers, airlines and general aviation operators, airports, and their trade associations, should consider submitting comments providing technical, policy, and legal input to help build an administrative record supportive of their positions.

Background

The FAA originally established the prohibition in 1973 to protect the public from exposure to sonic booms. On July 2, 2026, the FAA proposed to remove its ban on overland supersonic flight because it is “outdated,” “no longer appropriate,” and “unnecessary,” given technology advancements in flight techniques that prevent sonic booms from reaching the surface, and “increased interest in civil supersonic flight.” FAA’s action is in response to Executive Order (EO) 14304, Leading the World in Supersonic Flight.

Current FAA rules (14 C.F.R. §91.817) prohibit operation of civil aircraft at a speed greater than Mach 1 overland in the U.S. unless the operator holds an SFA (obtained pursuant to 14 C.F.R. §91.818). FAA proposes to amend §91.817 to remove this general ban and instead allow supersonic flights overland in the U.S. where the operator can demonstrate, and the Administrator finds, that sonic booms reaching the surface have an overpressure of less than or equal to 0.11 psf. The operator would also be required to comply with any conditions or limitations that the Administrator deems necessary to ensure compliance with the 0.11 psf standard. 

FAA also proposes to retain features of its existing regulations that would continue to allow supersonic flights, even where they create sonic booms, with overpressures that reach the surface and exceed the 0.11 psf standard. First, such flights would be allowed over land in the U.S., where the operators conduct them pursuant to an SFA issued by the Administrator, facilitating flights for research, development, testing, and other purposes in controlled areas. Second, the regulation would continue to allow supersonic flights that create sonic booms that reach the surface “offshore.” Such flights are allowed when flight crews have information about flight limitations that prevent a sonic boom from reaching the U.S., and those limitations are followed. 

The proposal would also add definitions of sonic boom, primary sonic boom, and secondary sonic boom to 14 C.F.R. § 1.1. Those definitions matter because FAA’s proposed 0.11 psf limit would apply to both primary sonic boom levels and to secondary direct and indirect sonic boom levels.

Analysis

The Proposal Would Effect Fundamental Changes in the FAA’s Approach to Regulating Overland Supersonic Flights

FAA proposes to remove the current speed-based prohibition (a categorical ban on overland flights exceeding Mach 1) and replace it with a noise-based operating certification standard (allowing such supersonic flights as long as they do not produce sonic booms at the surface exceeding 0.11 psf).

FAA’s approach is also novel in that, while the Agency would establish a noise-based limit, it does not require the operator to use a specified method to demonstrate compliance. Rather, an operator may propose a compliance method and, if FAA approves “measurement, modeling, or other methods,” and finds that the 0.11 psf standard will be met, the operator may conduct supersonic flights. FAA identifies factors it may consider in approving such industry-developed compliance methods and indicates that a Draft Advisory Circular will provide further guidance. 

This performance-based approach could enable industry to scale supersonic operations more easily than the current SFA-based system. Under FAA’s proposed approach, once the Administrator makes the required finding, the operator would not need approval for each individual flight or for specific operational areas, as long as the finding remains valid and the operator complies with applicable conditions and limitations.

Enabling Overland Supersonic Operations is Only a “First Step” – Future Regulations Will Be Required to Fully Enable Supersonic Operations

FAA recognizes that this proposal is only the first of several regulatory steps necessary to fully enable supersonic flights. While this proposal addresses en route noise, the FAA affirms it will undertake a future rulemaking to address landing and takeoff noise through an LTO standard, as well as technical standards for sonic boom abatement technology and “other operational requirements” for supersonics.

This has important implications. For example, FAA notes that issuing a certificate for a supersonic aircraft would require establishing an LTO standard of “particular applicability,” if it is generally applicable, and an LTO is not yet in place at the time a certificate application is received. 

FAA Intends to Continue Working through the International Civil Aviation Organization (ICAO) to Establish Supersonic Noise Regulations

Before proposing an aircraft noise standard for adoption into U.S. regulations, FAA typically works through ICAO’s Committee on Aviation Environmental Protection (CAEP) to ensure alignment with other countries. Here, although it continues to work on an en route low-boom noise standard for supersonics, ICAO/CAEP does not anticipate adopting the standard before 2031. However, FAA is now acting to adopt a U.S.-specific standard. 

Importantly, FAA states that this is an interim standard and indicates it will continue to work with ICAO/CAEP to develop an international en route standard for supersonics and, once ICAO adopts such a standard, consider adopting that standard into U.S. regulation through a future rulemaking. 

In contrast, ICAO is in the final stages of adopting a “globally harmonized” LTO standard for supersonics, which FAA plans to consider adopting through a future rulemaking.

The Regulation Could Have Implications for Sectors Beyond Aviation

The proposed rule applies to civil aircraft under 14 C.F.R. Part 91 and does not directly govern commercial space launch or reentry operations. Even so, the rulemaking could influence expectations for sonic boom analysis in launch licensing, reentry licensing, and National Environmental Policy Act (NEPA) reviews for spaceport or mission approvals. Commercial space companies may want to participate to preserve distinctions between aircraft and launch/reentry sonic boom impacts. A clear record of those differences could help avoid improper use of an aircraft-specific interim standard as a default benchmark for launch or reentry activities.

Next Steps

Comments on FAA’s Proposed En Route Standard Due August 17, 2026

The rule is likely to draw significant scrutiny under the Administrative Procedure Act if finalized. Early opposition is already identifying the kinds of issues that challengers may argue FAA failed to consider adequately, and aviation stakeholders may also consider the need to clarify practical aspects of the rule. 

Aviation stakeholders, including aircraft and aircraft engine original equipment manufacturers, aircraft operators (including commercial airlines and business jet operators), airports, and their trade associations, should consider preparing comments that respond to foreseeable objections by providing technical, policy, and legal input to help build an administrative record supportive of their positions. 

For more than 30 years, B&D’s Transportation practice has crafted effective regulatory, compliance, rulemaking, and litigation strategies for the aviation industry. We represent passenger and cargo air carriers, engine and equipment manufacturers, North America’s principal aviation trade association, and aerospace/defense sector leaders on matters involving the range of environmental and health and safety laws and regulations impacting their operations.