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Musical Wings Reduce Aircraft Stall Risk
notwrong writes "The Sydney Morning Herald is reporting that a Qantas engineer has found a way to help small aircraft avoid stalling at low speeds: pumping sound through the wings. He found that music also works, having tested Spiderbait and Radiohead (nice choices; Spiderbait apparently works better)."
I would think that playing the B-52's, U2, Eagles, Foo Fighters, a Flock of Seagulls, or Jefferson Airplane would be more appropriate, then again, who am I to say...
they don't play 'Crash and Burn' by Savage Garden.
http://www.livejournal.com/users/metricmusic
... you are the wind beneath my wings.
From now on, every small aircarft owner must pay royalties to the RIAA. Otherwise RIAAAF rules of engagement will not apply.
As a pilot, I think it's just fine. If you don't like it, don't use it. Oh by the way did you know that Boeing use a Linux supercomputer to help design their aircraft? And all the new in-flight entertainment systems are based around linux? And, oh, guess what, some new nav computers use.... you got it, Linux.
Suggest you quit your job and start living in a cave, to avoid linux. Oh, maybe you already do, troll.
filling wings with rock doesn't seem like such a good idea.
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Mr Salmon said that if they could make small aircraft perform better at low speed, it should be possible to build planes with smaller wings, which would be lighter, less thirsty, and thus cheaper to fly.
I can see the headlines already- "Airplane crashes due to smudged CD"
More seriously, have they done studies comparing the frequency of the sound vs air pressure/density? It's possible that other bands would perform better at altitude- maybe they could finally find an appropriate place to play Wings cd's...
I'll bring my air guitar.
Will the plane explode if you blast some Necrophagist, Psycroptic, or Nile?
If added noise makes the flight smoother, isn't this dither?
http://en.wikipedia.org/wiki/Dither
So what do you do if ya want complex and sofisticated system calls that the Integrity-178B doesn't provide? Well, use another real-time os on top of Integrity-178B or make it part of Integrity-178B but run it in user mode. So all the drivers are really in user mode in such a system. This all is needed so that no single program if corrupted can hang the system. (Trust me you don't want an airliner's computer to freeze with a BSoD or with a Oops!-Kernel Panic while in mid-air).
Another side note, FAA actually has a concrete limit on the failure due to software. So something like no more than once out of tens of millions of flight hours a plane full of people is allowed to completely crash and burn because of a software problem and have everyone on board die a horrible and painfull death and that would be perfectly "ok" with FAA. So the requirements to certify a system (OS) to fly a plane are very stringent. Linux doesn't even come close. It might be good enough to play music though...
I may be talking out of my ass here, but don't bird wings do the same thing when their feathers ruffle as air passes over them? Wouldn't this ruffling be the same as the vibration described in the article?
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This is a well known phenomenon. The question is how much energy is being used to get this reduction in drag?
Where does this energy come from? Either APUs, or more powerful main engines... which are heavier... which means bigger wings...
Probably a similar phenomenon to adding air blowers on wings. By blowing air out of the top of the wings and into air flowing over them you can have the flow stay attached on the wing much, much longer. This reduces the cross-sectional area of the turbulence and greatly reduces the induced drag.
I suspect that both methods work by adding kinetic energy to the flow, but IANAAE.
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My cousin had a similar idea 20 years ago. We attached bees to a plane's wings and the buzz really helps.
Besides, with enough bees we could even get VTOL.
The only problem is making all bees fly in one direction. We are trying to tame them and teach them to act like eskimo dogs, but it's been hard.
The flower-ahead-of-the-plane trick works for some time, but they get bored real fast. OTOH, when my cousin walks ahead of the plane, they fly it for hours trying to get to him.
Maybe it's like that duckling thing they made a film about. Oh, it's so cute!
We tried this years ago, but the plane would only stay up for 17 minutes and 2 seconds, wierd...
Imagine that you have a 3 line program that computes the absolute value of some input x say {if(x>=0) abs=x; else abs=-x; return abs;}. Ok do you think you'll be able to write another program that will verify that this program works correctly?
You would look at it and perhaps see that it has one branch. We give it inputs such that both paths in the branch are taken and then you look at the output and see if it is what you want it to be, and _also_ you look at all the rest of the memory and make sure that it didn't change. Maybe give it some extreme values, like the maximums and minimums and then also look at output and the _whole_ memory.
Then can you do the same for a 'for' loop that computes a dot product. You just give the program the known input then at every iteration look for some loop invariants and also check the rest of the memory that shouldn't be affected that it is indeed not affected and then check the output.
Also this means that the code itself has to be written in a certain way in order for its correctness to be checked easily. That means that a lot of nested 'if's are not a good idea, so they try to reduce the branching as much as possible and modularize the program. It is the burden of the software developers to submit their code for certification and pass before it is accepted by FAA or DoD.
This actually can be reduced to the SAT problem, which runs in exponential time (but there are ways to take shortcuts in some of the cases).
I would think that some actual application code that runs on it would define what the system does.
First though before you even let any application code run you have to make sure that no single appliation will ever take control of the memory and cpu for more than it's allowed share. That is what the separation kernel does. You run this small provem and scrutinized piece of code (note: you also need specialized hardware to make sure it will work) that makes absolutely sure (up to a margin of error) that no application will take more than its share of resourses. So if one application crashes it will not crash the system, instead the rest of the machine will continue to work. So that is why sometimes they will run two RTOSes on top of each other with the first being Integrity-178B that will make sure the other OSes on top are partitioned and separated and allocated only a given share of resourses.
A popular aftermarket wing mod is vortex generators... little pieces of metal or plastic carefully positioned at stretegic intervals along the top of the wing skin, usually just a little ways aft of the leading edge. This induces vortices in the airflow to help keep the boundary layer across the top of the wing from separating off from the surface, and thus lowers the stalling speed by some small amount.
...and yes one of the very first times I took off with music playing just had to be with Steppenwolf's Magic Carpet Ride, as I was haulin' ass down the runway thru rotation and climb-out (ST:First Contact reference).
I am a pilot who flies my own small plane and prefer to simply keep my airspeed up to avoid stalling the wings, and keep the music in my headsets. An iAudio X5 mp3 player fed thru a set of Lightspeed Thirty 3G ANR headsets while you're flying is a great experience.
This is very impractical (surprise!). What if you are in a region of flight where only the generated sound was keeping your plane in the air? Then you have an electrical failure. You fall like a brick. The ignition systems are already isolated from the main electrical system and fully end-to-end redundant specifically because of concern over electrical failures.
Also, it would pose engineering problems. Aircraft like the C172 I fly have wings that are specifically designed to stall in a very particular way. It's wings stall from the inside out, so that aileron control is maintained as long as possible. In fact, despite my repeated attempts, I've never been able to get into a stall deep enough for the ailerons to stop working. The point is that sound transducers would change all of this high precision engineering. What would happen if a single speaker went out? Would the plane go into an irrecoverable barrel roll?
Also, stalls really aren't that big a deal if you know your ass from a hole in the ground. The people who get into trouble with stalls are idiot doctors who bought their fancy Cirruses and flying lessons at the same time and never give flying the respect it truly deserves. But that is another story.