The fact they could make that calculation tells you they knew a decent in depth technical amount about their endeavour.
Since we’re discussing interesting behaviour by scientists…
An interesting detail is that Banting and his assistant Best figured out how to isolate and use insulin 100 years ago. It worked like a miracle at the time… Obviously Nobel prize material. So when the time came to award the Nobel prize, it went to Banting and… McLeod. Why? McLeod was in charge of the lab Banting was working in, and McLeod said “undergraduates don’t get Nobel Prizes.” Banting was so annoyed he gave half his winnings to Best.
Tinkering is the first step to understanding, IMO. Taking things apart, playing with things, etc. Even da Vinci had to do a little grave robbing to figure out how people were put together…
There is still plenty of low-hanging fruit, IMO. Maybe not in theoretical physics, but almost everywhere else. And it won’t necessarily require learning everything from the past 200 years. In some cases, we might be better off forgetting some of that past knowledge. Supersonic passenger flight might make a comeback, for example… and if so, it won’t be because someone copied the Concorde.
Boom Aerospace, for one. Their testbed scale demonstrator has just done its first supersonic flight. Main accomplishment is significantly reducing sonic boom below the aircraft.
IIRC from his memoirs, Feynman got a reputation as “smart” when he figured out how to diagnose and fix a tube radio problem simply by listeningto it as it warmed up.
Just who I was thinking of. Founder was a high school dropout, as it happens. Did get a degree… in computer science, not aeronautics.
The laws around supersonic flight over land are dumb. That still has to change. They currently ban supersonic flight completely, rather than setting acceptable noise levels. It turns out that there are certain speed/altitude combinations where the boom doesn’t reach the ground at all (it curves away due to atmospheric refraction). And even in cases where the boom does reach the ground, there are things that can dramatically lower the intensity.
The Concorde had a number of design compromises, such as its folding nose. But that was only needed so the pilots could see over it on the ground! Today, we can do that with cameras. Or just landing on autopilot.
I vehemently disagree. I think the phrase “acceptable noise levels” is something of an oxymoron. Any major airport is a noise plague for hundreds of square miles around it. And that’s even with reduced noise from modern high-bypass jet engines. The Concorde, by contrast, was enormously loud, and any new SST likely would be, too, completely aside from the sonic boom. Just because we can build the damn things doesn’t mean we should.
Nonsense. All planes make noise, and there has been steady progress in reducing it through a variety of means. The law should just state what is acceptable and let manufacturers work out the rest. If that’s in effect a ban on supersonic planes, then so be it, but the law should not predetermine what is and isn’t possible. Technology isn’t static.
Part of the reason there hasn’t been a lot of progress on SSTs is exactly the near-airport noise problem @wolfpup cites. The “No Mach 1.0+ over land” law (not regulation, law) is huge, but complying with the near-airport noise regulations is another major obstacle.
But contrary to @wolfpup’s crotchety doomsterism, that’s a problem that Boom claims to have defeated. As in their products will be no louder near-airport than a current model subsonic airliner. And will comply with the ever-tightening regulations to come. Without any kind of special exemption.
The problem with a law against supersonic flight is that it eliminates a huge chunk of the potential market for such a plane, which means there is that much less motivation to solve the problem. Boom is betting they can get the law changed, but that’s a risky bet. We probably would have made more progress if the only obstacle was the noise.
Is there a ban in statutory law as well? AFAIK, this is the relevant regulation:
(a) No person may operate a civil aircraft in the United States at a true flight Mach number greater than 1 except in compliance with conditions and limitations in an authorization to exceed Mach 1 issued to the operator in accordance with § 91.818.
Either way, it’s dumb that it’s specified this way. Set a noise level and a maximum ground overpressure level instead. If you can exceed mach 1 without violating the constraints, great.
My recollection (which is getting increasingly untrustworthy 50 years on) is that Congress passed a law directing the FAA to promulgate that reg. So it is beyond FAA’s authority to change. Only an act of Congress can rescind the law that requires the regulation.
I’m insufficiently motivated to try to research this point.
Agree in general that regs, even FAA regs, should favor requiring a result, not mandating a process with the hoped-for outcome of getting that result. FAA is starting to lean in the direction of so-called “performance-based” or “outcome-based” regulation. But they have an installed base of gajillions of pages of regs and interpretations and … which are all based on the old mindset.
Entirely possible. I used a chatbot to find that regulation, and it didn’t know of any statutory law. That doesn’t mean one doesn’t exist.
Hence why we should be careful to regulate the things we care about, and not unrelated things. If we want to lower noise levels, regulate noise. If we want a level of safety, regulate that. But don’t force artificial restrictions on things that have no direct relevance, like the max speed a plane is allowed to fly at.
(IOW, what @LSLGuy just said. Though it applies to more than just the FAA.)
I used to live near an air base where aircraft would occasionally go supersonic. I remember being at school and just hearing and feeling the noise blast through you, rattling the walls. It was pretty awful, and it was still a rare event.
The speed restriction is an operational one, and is as far as I know precisely to avoid having literally everyone under such a flight path experience that boom as the plane overflies, especially if the operator wants to do so several times a day. No fucking thank you. Municipal/airport regulations are demanding even quieter planes, though presumably these planes won’t be supersonic on takeoff and landing.
Note that 14 CFR 91.818 has a built-in way to actually operate supersonic; with permission from the FAA.
Here is a link to the Special Flight Authozation granted to Boom Supersonic for the purpose of overland tests in the Mojave desert. Those flight tests are, presumably, designed in part to demonstrate that in certain operating conditions (altitude, temperature, whatever) the boom is negligible, doesn’t hit the ground, etc. With that data, Boom can petition the government for expanded Special Flight Authozations and gradually build up to a complete certification envelope that the regulator (FAA) deems acceptable (likely with public consultation, but most rulemaking is subject to public consultation, that’s how the FAA works).
You can’t just say “it’s theoretically possible, let us fly our demos over suburbia all day until we get it right”. You just have to do the work, piece by piece.
As for cameras in lieu of windscreens; that would not be directly compliant to airworthiness standards (different than operating standards), namely 14 CFR 25.773 “Pilot Compartment View”. Fortunately, there’s other processes that can be followed to obtain a deviation from needing to comply with the rule as written, likely Equivalent Safety Findings and/or Special Conditions.
Then restrict the magnitude of the boom. It’s just baffling that people can’t tell the difference between these two things:
Supersonic flight is banned
Sonic booms over a certain magnitude are banned
#2 is the kind of law that you want. But #1 is the law that we have. There should be an avenue for innovation in this space, but there isn’t.
To be more concrete, there is a speed and altitude range where sonic booms are completely suppressed on the ground due to atmospheric refraction. Here’s how Boom illustrates the concept:
The Concorde was actually incapable of performing in this regime, since the engines didn’t have enough thrust at altitude to get through the transonic regime. It had to go supersonic at a low enough altitude that the booms were not suppressed. This is one of the areas in which Boom is claiming to innovate.
Yes, for testing purposes. No one is getting special authorizations for regular passenger flights. The law can still provide for exemptions while the planes are being tested and where they haven’t yet solved the problem.
The more fundamental question that’s not being addressed here is why we need the stupid thing in the first place. All it does is cut a few hours off a long trip at a huge cost, which is still spent in a cramped aluminum tube. I’d rather spend much less and be far more comfortable in business class or first class. Are we really all in such an all-fired hurry that we really need this thing? The Concorde, which was more a national vanity project than ever a good idea, was finally retired. Let it stay retired
There’s no certified aircraft that could get flight authorization for supersonic flights with regular paying customers.
Such a plane does not currently exist. Boom’s plane hasn’t been certified for all the other stuff required to allow operation “while being tested” until the problem is solved. They could bother to do that, and have operating limitations that simply don’t go into flight regimes that are supersonic, but that’s a waste of money.
If someone were to revive the Concorde, it’ll have the same operational restrictions and if they want to change those restrictions they can apply for an SFA, do the work to show the changes are appropriate and get them approved. Exactly like Boom is doing now. The avenue for innovation absolutely exists; Boom or Concorde Revived or whoever would demonstrate that sonic booms of a particular magnitude in different flight conditions can be acceptable, and approval will be granted. It’s a negotiation, not a blanket ban for everyone under all circumstances forever and ever.
You can’t just take a nice set of theoretical graphics, hammer together something vaguely plane shaped, and be allowed to fly it over cities and people without controls in the interest of “innovation”. That approach gets people killed.
Then supersonic flight will remain de facto banned until such time that they can produce sound levels below a certain magnitude.
There is a certain type of person that think “X causes Y. I don’t like Y. Therefore, we should ban X.” These people should not be allowed to write laws.
No, it is currently illegal for civil craft to operate supersonically overland outside of testing purposes. End of story. The law has to change for Boom to operate supersonic overland passenger flights no matter what else they do.
This is true. They have a highly optimistic take on their ability (read as “their very well-heeled customers’ ability”) to prevail upon Congress (?) & the FAA to change the law(?)/reg. If their tech solution to boom reduction / elimination works.
I personally have little doubt the boom reduction process will work to reduce. Whether it will reduce enough to make enough people happy with putting up with the rest to persuade Congress (?) and/or FAA to take the leap of faith to approve certification and repeal(?) / recision of the Mach 1.0+ ban is a different question.
Like everything else in the USA, on top of all the technological and routine political / bureaucratic issues it’s now got a huge yuge orange senile question mark hovering over it.
We shall see. I admire their 'nads even as I think they will see them chopped off.
I am as guilty as anyone here, but I now wonder what all this has to do with the invention of telephones.
