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More On Silent Supersonic Planes

Posted by timothy on from the more-of-a-phhhhffftt dept.

Reverberant writes "Popular Science describes the latest attempt at developing a supersonic plane designed to minimize sonic booms. The article describes some of the history behind the research, and recent attempts at validating the theory. Also note that researcher Ken Plotkin is a frequent contributer to alt.sci.physics.acoustics."

23 of 297 comments (clear)

  1. windows by dollargonzo · · Score: 5, Interesting

    is it just me being paranoid, or is not having any windows and having cameras send external images to the cockpit a "bad thing." obviously, without computer systems, the planes are almost useless, but if anything happens to the camera, the pilot can't even *see* outside the plane.

    --
    BSD is for people who love UNIX. Linux is for those who hate Microsoft.
    1. Re:windows by pjt33 · · Score: 3, Interesting

      I beg to differ. Instruments can fail, sometimes for unexpected reasons.

    2. Re:windows by the+pickle · · Score: 4, Interesting

      Assuming all hydraulic systems are fully operative, a 777 or 747 can actually do the last 50 feet, too.

      We pilots are there in case something goes wrong, and because ATC doesn't issue the exact same route every single time. Someone has to input the proper arrival procedure for the destination, since weather changes a LOT. ;)

      p

      --
      In Korea, long hair is for old people!
  2. It's about time! by stroustrup · · Score: 2, Interesting

    As I grew up I watched so many programs like "Beyond 2000" on discovery channel and felt excited about being in the years beyond 2000. This is 2004 and none of the promises came true. We are at about the same level as we were in 1999 technologically. Or even worse as concorde is gone. Somebody, move us into the future!

    --


    If you lost your job today, don't despair. You may die tomorrow anyway.
  3. Re:Towards A Silent Sonic Booms by Anonymous Coward · · Score: 1, Interesting

    Slightly OT, but did you notice that when you actually click the link to visit this article (The Slashdot article, not the linked-to article), the name changes to "More On Silent Supersonic Planes"?

  4. Re:A picture of the modified plane... by Jeff+DeMaagd · · Score: 2, Interesting

    Interesting. The article you quote was dated July 29, 2003.

    Slashdot: Year-old News for Nerds

  5. really a problem? by prockcore · · Score: 2, Interesting

    I've never heard a sonic boom... so I'm not really sure how loud they are, but a co-worker described it as "pretty much sounds like thunder".

    Is that really a big problem? It seems kind of dumb to me to ban supersonic flight over cities.

    1. Re:really a problem? by slashname3 · · Score: 2, Interesting

      Just hearing one once in awhile may not be bad. But if you had one for every flight that passed over head you would get tired of it pretty quickly.

      When the shuttle was flying and they landed at Cape Canaveral I would hear the sonic booms as they would pass over Orlando. Was woken up a few time in the early morning hours as they went over at 30000 or 40000 feet and it was enough to make the windows rattle. In that case it was a double sonic boom, like two claps of thunder. BOOM BOOM!

      Multiply that by a few hundred times and it would become unbearable as all those commercial flights passed over head. So that is the reason they limit super sonic flight over land.

  6. Let's rather make subsonic planes silent by Anonymous Coward · · Score: 5, Interesting

    That's very interesting, but would not it make more sense to make the normal, subsonic planes more silent? They are much more in use, and the noise causes a lot of grief near airports, especially at night. Here in Brussels, this problem is already for years on the political agenda, being a very difficult problem to solve (economics vs. health...), so silent planes are really a must!

  7. EVERYONE has heard a sonic boom by GuyMannDude · · Score: 5, Interesting

    I've never heard a sonic boom... so I'm not really sure how loud they are, but a co-worker described it as "pretty much sounds like thunder".

    EVERYONE has heard a sonic boom at one point: the crack of a whip. That sound you hear is not the tip of the whip hitting anything. It's the sound of the tip accelerating beyond the speed of sound and creating a mini-sonic boom. That little flick at the end causes the tip to snap out at incredible speed.

    Now as far as a big sonic boom, I haven't heard one either. I'm sure there are some pretty strict regulations about not creating sonic booms in civilian areas.

    GMD

    --
    watch this
    1. Re:EVERYONE has heard a sonic boom by Dragoon412 · · Score: 2, Interesting

      In Michigan, we usually have the Blue Angels or the Thunderbirds fly over Traverse City during the 4th of July. I can't say they do it every year, but I know that last year, the Thunderbirds broke the sound barrier right out over Lake Michigan near shore (you could actually see the shockwave); you could feel it in your stomach. It wasn't exactly shattering windows and setting off car alarms, but it was far from subtle.

      Think of standing in front of a *really* powerful subwoofer, but without any crappy booty music coming out of it. ;)

    2. Re:EVERYONE has heard a sonic boom by CvD · · Score: 3, Interesting

      Here in the Netherlands about two months ago a bunch of cities were subjected to sonic booms of 2 F16's scrambling to intercept a commercial airliner that wouldn't respond to any sort of radio contact. It was some sort of charter from Scandinavia to Spain if I remember right (I can't find any news article about it any more). Later turned out to be a huge misunderstanding, but I guess they didn't take any chances and had the jets intercept.

      It was pretty cool... a very low boom as if someone had set off explosives somewhere a distance away. The windows rattled in their frames. I didn't know it was a sonic boom at the time, but it was mentioned on the news later.

      --
      The Official Steve Ballmer Webpage
  8. There will still be protests by SteakandcheeseUm · · Score: 3, Interesting

    I am almost certain that people wont want it flying over their neighborhoods. I can remember watching a show about all of the hubub people made about the Concord landing at their local airport. You would have thought the world was going to end!

    Then, once they heard the landing (which wasn't any louder than a regular plane landing), they went back to their caves and silently watched the news for another issue to get their panties in a bunch about. *sigh*

  9. Just more of the same? by Anonymous Coward · · Score: 2, Interesting

    It seems that they are doing this using the traditional method of changing the shape of the aircraft. What about more novel methods such as striation, the same way tha dolphins achieve much higher efficiency than their shape would suggest. I'm surprised I never hear about this being applied to aircraft because it seems like such a simple thing to do.

    Or an interesting method I heard about involving many tiny flaps on the surface which can dynamically shape the airflow to minimize turbulence?

  10. Re:We already have surprise by Wyatt+Earp · · Score: 2, Interesting

    Yep because no technology has ever come from military research or wars.

    Plastic surgery, radar, GPS, lightwieght turbine engines, helicopter advances, LORAN, jet engines, no nothing good came from defense R&D.

  11. Dissapointing... by iawix · · Score: 3, Interesting

    The research airplane in this experiment failed to reduce the sound of the sonic boom as much as hoped.

    In fact, this research is primarily intended for the next generation business jets , not the military. The future of such planes is up in the air in the moment, because not only do they have to reduce the wake of sonic booms (they shatter windows and suprise people), the regulations have to change. I for one know that the FAA is slow at that.

    Regarding the need for windows in airliners: A Boeing 777 pilot today needs to be able to see a few hundred feet ahead of him on takeoff, but after rotating off the runway, he doesn't need to see anything at all. Modern airliners can land and auto-flare... that is, land themselves in ZERO visibility conditions. The pilots undergo extra training for this, of course.

    --
    FAA Certified Flight Instructor
    1. Re:Dissapointing... by slashname3 · · Score: 1, Interesting

      "The pilots undergo extra training for this, of course."

      Yeah, it is hard to teach a pilot to sit on his hands during the landing. For some reason they want to be in control of the plane for such critical operations. :)

    2. Re:Dissapointing... by calidoscope · · Score: 2, Interesting
      but after rotating off the runway, he doesn't need to see anything at all.

      I beg to differ. Unless the plane is in controlled airspace, there will be aneed to look out for other traffic (actually not a bad idea even in controlled airspace). The 1978 crash in San Diego took place between two aircraft that were both in contact with air traffic control.

      --
      A Shadeless room is a brighter room.
  12. Re:The whole point of this project... by grozzie2 · · Score: 2, Interesting
    The B2 and the F117A "Stealth Fighter" proved how well they work the first time we went to war with Iraq.

    Sending 'stealth' planes into airspace that has no defending air force is not exactly a 'proof of the concept'. Coulda flown into iraq using a concorde, complete with it's huge sonic trail, would not have made any difference, there was no air force to defend anyways.

    Stealth planes are not undetectable, they are just more difficult to detect than traditional aircraft. Countries with the will, and the technology, have long since built better detection systems, so flying into thier airspace with a 'stealth' machine will be no different than flying in with a traditional airplane. they are gonna see it coming well in advance, and the only surprise will be to the american taxpayer, those billion dollar airplanes are not nearly as sneaky as the military would have you believe.

  13. Professor Paul R. Garabedian by Phragmen-Lindelof · · Score: 2, Interesting

    I may be incorrect about this, but I seem to recall that the mathematician Paul Garabedian independently developed the mathematical theory for shockless supersonic flight at the same time that people in AE developed a theory. The Popular Science article does not mention Garabedian.

    1. Re:Professor Paul R. Garabedian by Anonymous Coward · · Score: 1, Interesting

      The paper you cite looks like shockless flow at transonic speeds. That is important, but isn't relevant for low boom supersonic design. FWIW, the theory tested with the modified F-5 was published in 1969. The author of the Popular Science article was told that.

      Another incorrect detail in the PS article is that it was never a "little jig": it was always a Dance of Joy.

      A really good source for the history of how this theory evolved is the paper by Seebass and George in the Journal of the Acoustical Society of America Vol 51, Number 3, Part 2, pp686-694, 1972.

      KJP

  14. Re:Typical filler in the article by WormholeFiend · · Score: 2, Interesting

    I'll never understand why science writers always clutter up their articles with crap like that turtle in the story.

    that's because the magazine is Popular Science, and not Hardcore, Adless, Emotionless & Subject-Verb-Object-Only-Sentences Science. ;)

  15. IFR by mnemonic_ · · Score: 2, Interesting

    A lot of rookies think they're better at IFR (Instrument Flight Rules) than they really are. They fixate too much on a single dial or meter, and end up augering in (with perhaps perfect speed) in a sim. Skilled IFR is mostly actually flying by the seat of one's pants; looking at all those instruments eventually gives a pilot an almost intuitive knowledge of how the aircraft behaves. He need only glance down a few times per several seconds to have a fair idea of what the plane's doing, using his experience to connect the pieces of data.