Cracking open the sound barrier

The Federal Register notice was published less than two weeks after FAA Acting Administrator Dan Elwell announced at the Paris Air Show that the agency was looking to overhaul decades-old rules against supersonic flights over land. Those rules were implemented during the 1970s, when the Concorde was being prepared to enter service, and the prohibition proved fatal to the Concorde’s profitability as an airliner.

The Concorde logged its first transatlantic supersonic flight in 1973 and entered service three years later, having won a competitive race to break the sound barrier with room on board for paying passengers. Boeing had emerged as the lone U.S. competitor, and the firm took orders for 122 supersonic transport (SST) airplanes in the 1960s. That Boeing offering had much in common with the Concorde (similar lines, if not as pretty), but the problem of the sonic boom, which can break windows, led to the realization that profitability would be a problem. The federal government pulled the funding in 1971 before the Boeing SST reached the prototype stage, leaving the Concorde the lone supersonic option, but only for overwater routes.

Boeing is back at it, announcing in February a partnership with aerospace startup Aerion to bring a new design, the AS2, to market. Lockheed Martin and NASA are meanwhile collaborating on the X–59 Quiet Supersonic Technology Aircraft with a prototype under construction. NASA has also tested public tolerance for mitigated sonic booms in Texas, part of an effort to propel aviation into a new, quieter, supersonic era.

“The U.S. Department of Transportation and the FAA are committed toward the safe and environmentally-sound research and development of supersonic aircraft,” Elwell said June 17 in Le Bourget, France. “We are confident in the next generation of aviation pioneers who want to open new opportunities for business, economic, and aviation growth.”

AOPA will study the proposed rules, which are crafted to create opportunities to test the AS2, X–59, and other prototypes like them, and submit comments before the Aug. 27 deadline. Additional rulemaking is expected to follow in 2020 that will establish new noise limits on supersonic operations.