Overview
- The FAA published a Notice of Proposed Rulemaking on Tuesday, June 30 that would swap the decades‑old Mach‑limit for a noise‑based certification standard assessing shock‑wave pressure on the ground.
- The proposal outlines a developing ground‑impact threshold of roughly 0.11 pounds per square foot as the metric for allowing ‘boomless’ cruise and opens a public comment period before any final rule.
- Regulators say the change is grounded in recent advances such as NASA’s X‑59 quiet‑boom tests and operational techniques like ‘Mach cutoff’ that aim to bend or soften shock waves so they do not reach the ground.
- U.S. manufacturers and some airlines have expressed interest and placed tentative orders, but commercial service still depends on engine development, aircraft certification, airport and operational rules, and proof of viable economics.
- The FAA plans a second rule for takeoff and landing noise, expects to finalize both rules by mid‑2027, and faces public scrutiny, possible NEPA or legal challenges, and the need for international regulatory alignment to enable cross‑border flights.