Supersonic aircraft will be free to use the airspace over the U.S. as long as they don’t make a big noise about it. The Administration said Tuesday it will abolish the current ban on supersonic operations over land that has been in place for more than 50 years in favor of sonic boom mitigation standards that will allow aircraft operators to figure out for themselves how not to bother the neighbors. “Manufacturers have demonstrated it is possible to fly supersonic aircraft without sonic booms reaching the surface by using sonic boom abatement techniques, making complete prohibition on civil supersonic flight outside of test areas no longer appropriate and an unnecessary restraint on the growth of the U.S. aviation sector,” the agency says in a Notice of Proposed Rulemaking (NPRM) released Tuesday. The full NPRM is copied at the bottom of this story.
The agency says that by creating the right flight profile for the atmospheric conditions, the ear-splitting boom can be mostly or even completely silenced for those on the ground. It says it will have to sign off on the methods used by manufacturers and operators meet the standards, but after that they’re free to fly fast as long as the noise standard is met. “FAA does not propose prescriptive means of compliance in this proposal, and operators may propose a means of compliance they deem appropriate for consideration,” the NPRM says. The threshold being proposed is 0.11 pounds per square foot of sonic boom overpressure at the surface. It has defined a sonic boom as “the acoustic event on the earth’s surface that is a manifestation of the shock wave system generated by an aircraft when it flies at a speed greater than the speed of sound.”
The NPRM cites the success of Boom Supersonic’s February 2025 test in which its scaled prototype of a future airliner called the Overture went supersonic without the noise reaching the ground. The company used a physics phenomenon known as “Mach cutoff” that causes the sound waves from an aircraft in the upper flight levels to bounce off the denser air closer to the ground and deflect upward without reaching the ground. The company hopes to build a small airliner that can cruise at Mach 1.7. NASA is also testing noise mitigation with its X-59 prototype, which recently went supersonic in testing.
So this NPRM essentially makes the massive expenditure to build one X-59 to see if sonic booms would peep off the groundlings in urban areas below it a total waste of money. The X-59 was NOT built to investigate some new method of mitigating the overpressure with its exaggerated shape … THAT is already known AND is dependent upon the specific airplane (shape, etc.) involved. Further, as noted above, it also involves use of localized atmospheric conditions to reduce the overpressure. No people moving supersonic airplane will ever look like the X-59. It’ll look like the Boom machine. There is no new “scientific” shape research being conducted by NASA with the X-59 … it’s all about seeing how much overpressure is acceptable to the masses and coming up with a specific number that is acceptable to make a recommendation to the FAA.
Where the 0.11 psf overpressure figure came from, I know not BUT … it had nothing whatever to do with the X-59. Sonic booms have been measured from the beginning and their effects are likewise known. There’s a whole area of houses specifically built at Edwards AFB in the 1950’s which were instrumented to measure sonic boom impact on structures, in fact. SO now someone in the DOT/FAA has decided that 0.11 psf overpressure is the ‘magic number’ and that’s that. X-59 no longer needed. The X-59 was built to see what that specific number was; now some bureaucrat has pulled that number out of … well … you know. Why couldn’t they — the people who are here to ‘help’ us — have done that long ago? They’d have saved nearly a billion bucks!
If you’re a taxpayer … you oughta be mad as hell over the NASA / X-59 waste of your tax dollars. I am! As a member of the team that built and tested the Shaped Sonic Boom Demonstrator (SSBD) airplane nearly 25 years ago, I’ve been harping on this fact over and over to no avail. Oh well … NASA Armstrong now has a new expensive unneeded ‘toy’ to play with at our expense. By doing absolutely nothing, the X-59 ‘forced’ the publishing of this NPRM … I guess in that respect, it served its purpose without doing a thing! One part of our government forced the ‘hand’ of another part of our government. Helluva way to run a ‘business.’
I am mad as hell about a lot of government waste. This one doesn’t even move the needle for me.
Larry, I’m not going to “thumb down” your post because you made some relevant points. But you seem to think that scientific research should be conducted subject to a line-item-veto by the lay-public/taxpayers. That has never been so because, on the value of any given aspect of scientific research, they are often the least informed.
Museums are full of prototype aircraft that were not commercially successful, and I hope they continue to be. They document the often drunk-walk progress of aeronautical knowledge, and inform/inspire its growth. For every Bell X-1 hanging from the rafters, there are thousands of experimental articles sold for scrap. T’was always the case, and I hope t’will always be. In the words of a wise mechanical engineering professor I once had, “It’s not a failed experiment as long as you learned something from it.”
As opposed to your, “If we can’t monetize the results, it was a failure and a waste of money” attitude.
I’m not a “lay-public/taxpayer,” Aviatrexx. I spent 27 years at Edwards AFB and worked with NASA there many times, as well. I worked on a black program there after my USAF time, too. I KNOW what flight test is all about. But thanks for reminding me.
Read what I wrote AGAIN! The X-59 was built for one specific reason … to produce a sonic boom overpressure over various cities — Texas was first — and see what the public thought of the sound level and to determine a number so it could be codified. Now that the FAA has ‘decreed’ 0.11 psf as that number, the X-59 serves no purpose. NASA was/is producing a SCAM with this airplane. They’re making people think that they’re doing some sort of shaping research when — IN FACT — all they were doing is producing a ‘boom’ and seeing what people on the ground thought. And the FAA — had they acted in a more timely manner — would have made
I’m well aware of flight test failures and partial successes and the like. NASA (then) Dryden tested the SSBD airplane’s ability to mitigate the sonic boom overpressure 25 years ago. This research — by the very same NASA — was a success and cost so little that the actual number isn’t easily found. The X-59 will produce less of an overpressure but NO RESEARCH is being done for nearly a billion $$ by the time they’re done. We already know we can reduce the boom. Google, “Quieting the Boom.” My name is in that book. I didn’t fall off the turnip truck with an unfounded opinion … I know what I’m talking about here. The X-59 is nothing more than an expensive ‘make work’ project for NASA Armstrong. They’re famous for that. They’re also famous for many successes … the X-59 ain’t one of ’em.
SO … you tell me … what the heck is the X-59 doing that will serve us? Further, I invite a manager from NASA Armstrong to appear here and refute what I’m saying! Let’s hear from NASA Armstrong. Make me a liar.
As referenced above, Boom Aerospace has sufficiently proven to the FAA that an airplane traveling faster than M1.0 which produces no more than 0.11psf overpressure should be allowed over the US, the NPRM will allow public comment and that’ll be the end of it.
Do you yell at clouds too?
Larry, the hostess was calling for you…”Bitter, party of one?… Bitter, party of one?…”
Good to have primary source comments here. As a SETA for my second career, when a snarky NASA GS made a comment about overpaid contractors, I reminded him I could be fired for being incompetent.
That’s EXACTLY why I commented here, Rich. Thanks for seeing that. When I have first hand experience and something useful to add, I’ll comment. I don’t use opinions or BS to convolute a story or try to talk about apples while discussing oranges.
A billion here and a billion there … pretty soon it all adds up to some ‘serious’ money … OTHER people’s money! Further, I see no one from NASA Armstrong accepted my challenge to show up and refute what I’m saying here. They can’t because they know I’m right. I wish I could expose this program to a DOGE group.
The X-59 along with the X-57 “Maxwell” are two HORRIBLE programs that some manager at NASA Armstrong ought to hang for. At least with the X-59, we got a (useless) airplane. With the X-57, we didn’t even get that far. At an Airventure forum a couple or three years ago about that airplane, I ATE the project manager over the X-57 fiasco. You shoulda seen him stammering and stuttering trying to defend that program. At that point, realizing I had exposed them, the crowd turned on him too. Poor guy was a “Johnny Come Lately” who wasn’t responsible but — at that point — he was the tip of the spear and paid. Between the X-57 and the X-59, NASA Armstrong has flushed a billion of our bucks down the toilet.
SecWar has now issued an order to all Government and contractor agencies to get their poopus maximus together and start producing in a more timely manner and on budget. In fact, they’ve now issued orders to Government agencies to provide priority use of their facilities to smaller companies who are more lithe and able to move faster and who need test ranges to prove their products. Good idea! A friend’s Son works for such a company who is going to build cruise missiles for a fraction of the cost of the big boys. NOW they’re ‘cookin’ with gas!’
Besides any other issues, X-57 had me wondering what happens in icing to all those small propellers/shrouds. No direct experience with boundary layer designs, but recall being told that field upkeep was going to be a killer with all the complex ducting/ports to keep clear/viable.
Called it a day as the doors were starting to open up, worn out by the bureaucracies and a good time for new blood. Whenever someone demanded “outside the box” solutions I suggested they first look in their trashcan.
Let’s try this again Larry. Money on the X-59 was better spent than money and non-monetary costs incurred on the newly acquired presidential glamour jet. The non-monetary costs will be difficult to measure but do and will included foreign access to influence in high places of the administration. Adding it all up, the X-59 project is a bargain compared to the glamour jet.
This article is about the X-59 and NOT an interim USAF 1 747 !!! I’ll debate you on the X-59 but will not when you start talking about something else. But …
“Boeing Co. reduced some of the technical challenges dogging its delayed delivery of two jets that will serve as Air Force One, according to congressional auditors.
The defense contractor is likely to deliver the first of the modified pair by 2028 and has made progress on “completing the engineering design for the environmental control system, resolving cabin decompression issues, and hiring and retaining more qualified mechanics,” the Government Accountability Office said Thursday in its annual assessment of US weapons programs.
Boeing remains almost three years behind its original schedule to deliver the jets, GAO said, with each estimated to cost $3.3 billion, or about 7% more than last year’s projection. President Donald Trump on Wednesday took the inaugural flight on a 747 plane donated by Qatar that is intended to serve as a “bridge” until Boeing’s first jet is delivered.
The Air Force One jets are a high-profile target of the Pentagon’s campaign to upend defense industry practices, with Defense Secretary Pete Hegseth and the department’s weapons buyer, Michael Duffey, looking to accelerate the production and delivery of munitions, drones and major systems to replenish wartime stockpiles.”
As someone who flew in an acft blamed for every burned out lightbulb within a 400nm radius and avoided a fur farm to keep Uncle Sam from stressing and paying for dead fur donors, I can imagine that any ADS-B track exceeding 0.999M will be closely followed by lawyers for clients with an extensive number of broken windows and priceless ceramic tchotchkes.
Deep pockets and a difficult to prove negative…I can already see the late night commercials…
As an ATC type in the early ’70s at LA Center in Palmdale, Palmdale had already put up a big sign on Sierra Hwy proclaiming that Palmdale’s AF Plant 42’s big airport would be the supersonic capital of the World. Fifty years later, the SST has come and gone and Plant 42 is still waiting. This is old stuff.
You mean the LAX replacement to the east of Plant 42 that LA County spent untold millions to buy land for that never materialized? 🫤 THAT, too. Well … maybe the X-59 can land somewhere around Lake LA.
Ha. ha. I remember there was talk of tunneling through the mountains to provide trans up to the high desert with the Plant 42 proposal. They even had one of our ZLA controllers design a terminal idea to provide gates and such. He was an outstanding controller, but not much of an imaginative terminal designer. When asked about how the passengers were suppose to get into the terminal from the SSTs, his response was “F##K the passengers”! He later died of a brain tumor. But he could flat move some aircraft!
Why do I get this feeling we are about to enter a FAFO cycle?
… or FAF0.