Last week when the FAA released its proposed guidance on the certification and flight-testing of commercial supersonic aircraft, the big news was that the FAA did that at all, reversing a nearly 50-year-old ban on overland flight of supersonics. The United States wasn’t alone in its continental Mach One speed limit, and the most noteworthy of the supersonic transports, Concorde, was limited to ripping up the North Atlantic crossing at Mach 2 but was required to slow down as it neared shore.
It’s hard to say how much of a difference more liberal rules would have made to the success of the aircraft, which was a technological wonder and a commercial failure. The major operators, British Airways and Air France couldn’t sell tickets for as much as they needed to charge for them in order to make a profit, so the remarkable experiment that was Concorde was relegated to little more than a branding effort.
Even before Concorde flew, aerodynamicists were fiddling with ways to tame sonic booms, and those efforts have continued unabated, as have, unfortunately, the booms. There are several angles boom minimization have taken, but most center around some combination of changing the shape of the nose by extending it forward while using a short-span delta wing and long, tapered fuselage with a dramatic area- rule design. So you get long, thin airplanes with pointy noses, which is precisely the route Concorde’s designers took.
While multi-mode turbofan engines have emerged that are far more powerful by weight and far more fuel efficient, there’s no getting around the fact that flying supersonic will be loud, even when subsonic, and inefficient, especially when supersonic.
So the FAA’s proposed rules, which were immediately challenged by environmental groups saying we don’t need less efficient commercial jets, isn’t based on designers being able to eliminate sonic booms or make supersonic aircraft competitive with existing commercial airliners or bizjets, but rather, their ability to make them slightly less boomy and slightly more efficient than they could do before.
As someone who grew up in an area irregularly hit by sonic booms courtesy of secret NASA planes heading out from Edwards Air Force Base and those from conventional fighters, F-4s and F-105s, I learned how to swap out panes of window glass at an early age. The booms of next-gen supersonic aircraft are said to be much quieter, more on the order of a car door slamming.
Maybe that would have played in a pre-pandemic world, but one effect of the coronavirus shutdown of much travel has been a growing awareness of how much of an impact transportation plays on the environment. We’re talking an L.A Basin free of smog, downtown areas that are suddenly pedestrian friendly, intersections in New York City that used be honk-fests from early to late now quiet. For better or for worse, it’s changed the way people see the world and how we get around in it. Not to mention that supersonic bizjets are like super yachts on steroids.
The very rich are the only potential customers, and we’re talking aircraft that could be double the price of a Gulfstream G700, which goes for around $70 million. In an era where we’re concerned about getting 25 million unemployed Americans food for the table, the idea of multi-billionaires booming overhead in their quarter billion dollar jets will not be an easy sell to environmentalists or to the public below those fight paths.
The FAA’s proposed guidance on mapping out a supersonic future was certainly ill-timed. It could also be DOA, as it will be a hot button that few politicians will want to get behind. An NPRM on the certification and testing of electric aircraft would have been timely. This one is tone-deaf, no matter how tame the boom gets.