While comments on the FAA’s proposal to establish noise standards for supersonic aircraft are not due until July 13, the notice of proposed rulemaking is already drawing opposition from environmentalists. The agency announced the notice of proposed rulemaking (NPRM) in late March and officially published it in the Federal Register on April 13, saying that given the interest in development of supersonic aircraft the proposed standards “would facilitate the continued development of airplanes by specifying the noise limits for the designs.”

The proposal was welcomed by aviation entities seeking to pursue development while balancing environmental impacts. Noting NBAA’s participation on the International Civil Aviation Organization’s Committee on Aviation Environmental Protection, Stewart D’Leon, NBAA’s director of technical operations, said, “Supersonic noise has been a dominant topic because all of the parties involved want to come to a global agreement that leads to environmentally acceptable and economically viable supersonic airplanes.”

NBAA described the proposal as the “next step in the development of innovative airframe and powerplant technology that will benefit the aviation industry.”

The Center for Biological Diversity, however, reiterated its belief that enabling civil supersonic aircraft to fly would be disastrous for the climate. “The pollution from existing planes is already a major threat to public health that the FAA is ignoring,” said Clare Lakewood, climate legal director at the Center for Biological Diversity. “The current reduction in air traffic, and the cleaner air we now breathe, should be reasons for the Trump administration to adopt measures to protect people and the climate from conventional aircraft, not excuses to pave the way for super-polluting supersonics.”

The center cited concerns that supersonic aircraft would burn five to seven times more fuel per passenger than standard aircraft and pointed to a study by the International Council on Clean Transportation, which concluded that a new fleet of supersonic airplanes would emit 96 million metric tons of carbon pollution every year. Further, the center contended, such aircraft could exceed subsonic limits for nitrogen oxides by 40 percent, adding that nitrogen oxides are linked to respiratory disease, heart attacks, and strokes. “We shouldn’t have to choke on dirty air just so a few people can shave an hour off a cross-country flight,” Lakewood said.