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High-tech material could allow passenger planes to travel at speeds of over 4000 mph

By midian182 ยท 24 replies
Oct 19, 2017
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  1. The future of transport, it seems, is more speed. Prototype testing of Elon Musk’s Hyperloop One saw pods reach 192 mph, while Airbus has patents for an “ultra-rapid air vehicle” it says could travel over four and a half times faster than the speed of sound.

    The problem with aircraft is that when they reach incredibly high speeds, they generate a massive amount of heat. The material they’re constructed from needs to be able to withstand the high temperatures while also being both structurally stable and light. The answer to this conundrum may be boron nitride nanotubes (BNNTs).

    Researchers from NASA and Binghamton University found that the nanotubes, created through a combination of boron and nitrogen, could withstand temperatures up to 900 degrees Celsius (1652 Fahrenheit). The Carbon nanotubes used in today’s aircraft undergo structural degradation at 400 degrees Celsius (752 degrees Fahrenheit). BNNTs could allow aircraft to reach hypersonic speeds of Mach 5 (3806 mph) and above.

    As is often the case with advanced materials, BNNTs come with a restrictive price tag. Right now, it costs around about $1000 per gram, but costs are expected to fall over the next decade. The substance will likely start appearing in military aircraft first—Lockheed Martin could use it in the hypersonic SR-72—before making its way to commercial aircraft.

    While not able to hit hypersonic speeds, the British-French Concorde jet airliner, which had a mainly aluminum construction using a high-temperature alloy, could reach supersonic speeds of 1354 mph. It was retired in 2003 due to falling passenger numbers, likely the result of a crash in 2000 that killed 109 people and the 9/11 terrorist attacks.

    The highest speed ever recorded by a manned, powered aircraft was set in October 1967, when William J. Knight flew the experimental, rocket-powered North American X-15 at 4520 mph.

    Permalink to story.

  2. Uncle Al

    Uncle Al TS Evangelist Posts: 4,400   +2,860

    With the new SR-72 the target is Mach 5-6 or higher so it's certainly possible BUT they will have to solve the high maintenance costs and operating costs to make it reasonable. The SR-71 was build "loose" so it would be leaking fuel on take off to the point that before it could head off on it's mission it had to be refueled in the air. All tooling and molds were destroyed so they only way it could be maintained was by cannibalization of the other aircraft (reported to be up to 40). Also, it was difficult to fly, required specially fitted pressurized suits due to an altitude of 80,000+ feet and used stellar navigation. Despite this it was the single fastest plane ever built and operated and highly successful in it's mission and no anti-aircraft missile could ever catch it.

    Avoid all those issues and you'll have a truly amazing aircraft. Make it reasonable to the consumer for tickets and it will be a grand slam to the aircraft industry ....
    TempleOrion likes this.
  3. wiak

    wiak TS Enthusiast Posts: 51   +6

    The problem is that nobody wants to fly supersonic anymore, case in point concorde
  4. Uncle Al

    Uncle Al TS Evangelist Posts: 4,400   +2,860

    Actually there are a LOT of business people clamoring for another Concord but again, the operational & maintenance costs were so high they could not compete in the market place. As reported by the French press, the last accident was more of a convenient excuse to cancel the program. BUT, one point not to overlook was that when the Concord was in operation the internet was only a shadow of what it is today and so much business is handled over the web that the business fliers would be less, still enough to keep it full and in the air, especially if the price is right. During it's term the cost to fly the Concord was between 4,200 and 8,300 pounds for flights from England to the USA.
    TempleOrion likes this.
  5. ypsylon

    ypsylon TS Booster Posts: 137   +32

    So... then nuclear powered plane may return from the grave of Cold War failures?

    Possibly as the one major obstacle was lack of proper materials to build it. It was impossible to overcome in the '50s, '60s and '70s. Now...Who knows?
    TempleOrion likes this.
  6. Skidmarksdeluxe

    Skidmarksdeluxe TS Evangelist Posts: 8,647   +3,283

    The SR 71 was designed and built with 50's/60's technology and tech has come a long way since then. Although we are very unlikely to see hypersonic mass travel within the next decade, maybe even two, it will eventually come. Right now, the SR 72 program is probably far more advanced than the bureaucrats are letting on. To make hypersonic viable in the commercial market, the ability to carry cargo, and lots of it, is probably the most crucial thing. Hypersonic B52 test air frame?
    TempleOrion likes this.
  7. amstech

    amstech IT Overlord Posts: 1,989   +1,171

    If you watch the documentary on the SR-71, the main reason is was discontinued was not related to fuel issues or piloting setbacks.
    The plane was solely designed to spy and take pictures...the camera system is very old, as in ANCIENT...this massive camera takes several mile wide pictures and the roll of film is crazy long. It took large crews dozens of weeks to unroll the film and produce it, and that's if it stayed intact. This old school system was built into the plane and is a part of it.
    TempleOrion and JaredTheDragon like this.
  8. wiyosaya

    wiyosaya TS Evangelist Posts: 3,058   +1,536

    The technology behind this is called the SCRAMjet - https://en.wikipedia.org/wiki/Scramjet

    I highly doubt that any civilian transport will use nuclear technology. It is simply too dirty and too dangerous. Nuclear technology is even highly controversial for space transportation. Also for rocket engines, there is a viable concept called ion drive - https://en.wikipedia.org/wiki/Ion_thruster
    TempleOrion likes this.
  9. mbrowne5061

    mbrowne5061 TS Evangelist Posts: 1,029   +546

    The article incorrectly states that carbon nanotubes are used in aircraft today, I believe they meant carbon fiber. There are no carbon nanotubes used in any production product of any kind - we lack the techniques to mass produce them.

    On topic, I would imagine that it will be a similar problem with Boron Nitride nanotubes as it is with carbon nanotubes. We just can't make large batches - with useful properties - consistently. You're more likely to see CNNTs in any future aircraft before you see BNNTs.

    It is also not just about managing heat. The way an aircraft generates life drastically changes between subsonic, transonic, supersonic, and hypersonic flight profiles. A wing shape that is good for one is usually complete rubbish for any of the others, and the faster you go, the less lift you can generate at all. By the time you hit hypersonic, your flight has more in common with a ballistic trajectory than it does with a subsonic aircraft.
  10. senketsu

    senketsu TS Guru Posts: 812   +543

    as I recall the two problems with Concorde were the noise (sonic boom) and that the exhaust was thought to be ozone depleting (it did fly in the stratosphere).
    Everyone wants to get as fast as possible between where they are and their destination, it matters not how. It is a long way from where I live in North America to get anywhere else I would like to be, like 10+ hour flight alone, that is butt in the seat time much less airports, borders etc. Business, isn't it said time is money? Build it and they will come.
    TempleOrion likes this.
  11. VitalyT

    VitalyT Russ-Puss Posts: 4,115   +2,536

    It is as useful as a bycicle chain that can withstand 4000mph friction forces, downsizing the importance of everything else involved.
  12. Uncle Al

    Uncle Al TS Evangelist Posts: 4,400   +2,860

    The camera system you are referring to was ancient, but not it's primary system after the late 1960's. The last system is used involved digital imagery that was stored in the form of notches on a very thin wire which were later converted (1's and 0's in a different format). The recon photo's we got at the beginning of Desert Storm had sufficient detail for us to easily determine each outfit and in many cases the identity of individuals. I think you misunderstood what I said. The main issue for it's discontinuance was issues with O&M and operating costs; the example of fuel was just one of many, many examples. There were no pilot setbacks, it was a simple observation that because of the physical demands the SR-71 pilots were required to wear specialized, compressed flight suits. Something that would not go well in a commercial aircraft application. By the way, many of the things you are referenceing were not in the SR-71, they were in the earlier CIA version. The SR-71 was an USAF program and there were a number of improvements including critical element packages, ie: Camera systems, radar systems, navigation systems. This was evident by the aircraft that was donated to the USAF museum at Wright Patterson AFB.
    amstech likes this.
  13. hyperspaced

    hyperspaced TS Enthusiast Posts: 25   +8

    Supersonic = Low efficiency = High prices = No passengers.
  14. Capaill

    Capaill TS Evangelist Posts: 688   +343

    From what I remember of the SR-71, its fuel was in a semi-solid state on the ground. When in the air and travelling at high speed, the fuel would melt/liquify. I'm sure this was linked to the fact that the fuselage of the plane expanded and contracted at different speeds but it was still clever engineering. The SR-71 is one of my all-time favourite planes (along with the A10) - I'm delighted to hear its successor is on the way.
    TempleOrion likes this.
  15. Ultraman1966

    Ultraman1966 TS Booster Posts: 112   +23

    I thought the reason why we won't see supersonic flights any time soon again is due to the superboom issue from such a large aircraft (passenger)? I sincerely doubt that it is the material that is holding us back considering that the concorde is like 50 years old now and material science has made huge leaps and bounds since then.
    TempleOrion likes this.
  16. wiyosaya

    wiyosaya TS Evangelist Posts: 3,058   +1,536

    Your assessment of the effect of cost of the BNNTs is quite correct. A slightly different article I saw the other day goes into this - https://futurism.com/this-material-could-allow-nasa-planes-to-cross-the-country-in-under-an-hour/

    Interesting comments about lift. I have wondered why the pictures of NASA's prototype hypersonic craft were shaped differently than ordinary aircraft. Now I know. :)
    TempleOrion likes this.
  17. JaredTheDragon

    JaredTheDragon TS Guru Posts: 449   +295

    While close, it's not precise or technically true. Lateral speed is what generates lift, but the ratio of lift does fall off as you increase speed beyond a certain point. Diminishing returns. You're correct about approaching a ballistic trajectory as speed increases - this is known as the "gravity turn" when performing an entry into orbit. If you go faster laterally than you are falling due to gravity, you attain an orbital trajectory. While even these fast planes are far too slow for this, that's the physics.
    TempleOrion, mbrowne5061 and wiyosaya like this.
  18. Squid Surprise

    Squid Surprise TS Evangelist Posts: 2,099   +1,132

    As a couple of users have pointed out, the flaw with anything flying over the speed of sound is the sonic boom it creates... The Concorde was never allowed to go past the speed of sound until it was over the ocean.

    So while this would still be a tremendous thing for trans-Atlantic and trans-Pacific flights, you will NOT be going from New York to LA in one of these... at least, not past the speed of sound...
    TempleOrion likes this.
  19. p51d007

    p51d007 TS Evangelist Posts: 1,690   +980

    The MAIN problem with the Concorde, was the American aviation industry. Since they didn't have their own supersonic aircraft, they lobbied DC, to make it a law that "supersonic" flight was restricted over 99% of the United States, pretty much limiting that aircraft to land on the east coast. That, and the price of the tickets, pretty much doomed it from the U.S. market.
    TempleOrion and Vulcanproject like this.
  20. senketsu

    senketsu TS Guru Posts: 812   +543

    I read an article recently, it mentioned the Concorde set a New York to Seattle record, but that the flight was flown over Canada except at the start and finish because it was illegal to fly in US airspace supersonic.
    I also watched a show that said the big reason the SR-71 was retired was because it carried no weapons, it was a surveillance aircraft. Many military on the show said there is still a place for it. Show was old enough though that perhaps by now drones have filled the surveillance niche
    TempleOrion likes this.
  21. mbrowne5061

    mbrowne5061 TS Evangelist Posts: 1,029   +546

    Half true. They did lobby, but there were overland corridors established over the continental USA to allow for supersonic flight between coasts. They were established with the Air Force in mind, but I don't know if they are also limited to military use if Boeing was to release a commercially available supersonic aircraft.
    TempleOrion likes this.
  22. Vulcanproject

    Vulcanproject TS Evangelist Posts: 501   +611

    +++ this.

    Also, Concorde was expensive to fly and maintain largely because they only built 20. If they had built 500 then it would have been a different story. The interest was extremely high in Concorde until the USA aviation industry lobby killed it with unjustified legislation. There was a very high chance the order books would have been bulging without that.

    As it was the prices to fly on it with British Airways has a funny story. BA asked the rich and famous on the aircraft how much they thought their ticket cost in a customer survey on the day. Since none of them had booked it personally or knew the exact figure they all massively overestimated the cost. BA then simply made the actual price match expectations and hey presto, Concorde was plenty profitable for years....
    TempleOrion likes this.
  23. wiyosaya

    wiyosaya TS Evangelist Posts: 3,058   +1,536

    This wikipedia article tells a story that fits my memory of it - https://en.wikipedia.org/wiki/Boeing_2707 Boeing did have an SST design, but it was killed in 1971. It also sounds like the same forces worked against Concorde, too. Interestingly, the article states that a test of an SST generated some 9,500 complaints of building damage and some 4,600 formal damage claims. As I see it, that is a significant number of claims from just one test flight. Mitigating the booms is likely not a simple task, and covering the cost of formal damage claims seems like it would be an economic challenge.
  24. mbrowne5061

    mbrowne5061 TS Evangelist Posts: 1,029   +546

    Sounds like they didn't make any attempts at mitigating disturbances on the ground, and then decided it wasn't worth going all the way back to drawing board show they could show up to the market a decade late.
  25. wiyosaya

    wiyosaya TS Evangelist Posts: 3,058   +1,536

    Yes, market forces - like always. :( Perhaps, if this new craft gets off the ground, they will work on mitigating the damage from the sonic booms as part of the initial design.

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