1. United States
2. N.C.
3. Letter

As your constituent, I am writing regarding S. 1759 and H.R. 3410, the Supersonic Aviation Modernization Act. I urge you to ensure that any bill emerging from committee includes critical amendments addressing sonic-boom noise and environmental protections before enabling routine overland civil supersonic operations. Interim Permission Without Complete Protections Both bills would allow the FAA to establish an interim sonic-boom noise standard permitting overland civil supersonic flights. However, this framework is fundamentally incomplete. The bills defer critical landing and takeoff (LTO) noise protections affecting airport-adjacent residents. Once operational, interim frameworks harden into permanent practice through regulatory momentum and industry investment. "Interim" standards historically become long-term, locking in inadequate safeguards before comprehensive protections are established. Unresolved Environmental Impacts These bills treat environmental concerns as secondary. Climate impacts include not only CO₂ but also non-CO₂ atmospheric chemistry effects from nitrogen oxides (NOx) at cruise altitude. Published peer-reviewed research shows NOx-driven changes to ozone and aerosols are material components of aviation's climate footprint—sometimes comparable to CO₂ effects. A credible framework must address both upfront, not defer them. Repeated Sonic Booms as Chronic Disturbance Even "lower" sonic-boom approaches involve repeated shock-wave events along flight corridors. This chronic disturbance differs fundamentally from isolated testing. Protective frameworks require enforceable operational limits—frequency controls, route constraints, predictability measures—that overpressure standards alone cannot capture. The Superior Path: International Harmonization The FAA's own rulemaking acknowledges a better alternative: working through the International Civil Aviation Organization (ICAO) to complete harmonized, globally aligned noise and environmental standards before enabling routine overland operations. Though the ICAO timeline extends to 2031, this approach is more defensible because it aligns U.S. protections with a mature international standard, reduces the risk that interim enablement becomes permanent, and ensures environmental impacts—including NOx effects—are core decision criteria rather than afterthoughts. Requested Action I respectfully urge you to ensure that any bill emerging from committee includes amendments requiring (1) complete environmental accounting including NOx-driven atmospheric effects before any interim standard takes effect, (2) comprehensive LTO noise protections, and (3) clear sunset provisions and reassessment triggers to prevent interim standards from becoming permanent. Alternatively, I urge you to oppose interim authorization in favor of completing international harmonization—a more durable, protective foundation. Thank you for your attention to these important matters.