04-25-2010, 09:18 AM
Wonderful discussion, been thinking about it for a few days. I'm thinking detection and avoidance with survivability for when you do hit too much...
First, how about a partical detector in a pitot tube to check a sample of the air the plane is flying through? There has to be some criteria for the bad dust vs. normal dust. Perhaps a laser beam passing through the airstream in the pitot tube with a detector that's programmed to pick up the charactoristics of the ash in question. That would be cool, especially if it could be reprogrammed for the current problem child ash cloud.
Second, the 747 incident said they were only able to see out the windscreen where the wipers had disrupted the airstream. Perhaps a bit of bypass air would act as a deflector to keep the ash from striking the glass and maybe even help for winter freezing issues?
Finally I think small weather balloons with the detector that could be launched where the clouds are suspect could be used the determine the height of the cloud and it's density at that time. With todays GPS technology a decent map could be plotted and the baloons recovered as well.
Granted if you chug enough ash the engines will fail, but avoid it and know your ingestion rate if you can't should give some insurance vs. not operating at all.
04-25-2010, 10:14 AM
One can partially diagnose blood by optic means without penetrating skin. Seems reasonable one should be able to detect, quantify and identify particles passing through a tube. Maybe a spectrophotometer, or a tiny fluorescent laser. Anyway, I'm in.
Originally Posted by Ranchero50
04-25-2010, 11:26 AM
the fact that the windscreens were protected by the air deflecting over the wipers gives you a clue - you would need some very large vortex particle separators to scrub the air going into the engines - or perhaps cyclones could be built into the intakes - like on the old Ford tractors.
The best cure is detection and avoidance - and no doubt, if volcanic activity increases over time, some method that combines several avoidance and scrubber technologies will be developed.
04-25-2010, 12:08 PM
Yes, one should, just as I speculated dozens of posts back; #133 actually.
Originally Posted by BadBeta
04-25-2010, 12:46 PM
The answer is simple.All one has to do is capture one of those skinny pumpkin headed big eyed cavetanned little bastards, and assuming the average one knows how the propulsion system functions and is manufactured for their saucers, make em fess up.If it won't talk show it an old 3 stooges episode and threaten it with the old peace sign in the eyes trick.If that's not enough pop in deliverance and imply you know how to give a real "earth style" anal probing. Sorry I couldn't come up with anything more viable or less taxing.
04-25-2010, 12:50 PM
Hdpg, this is a long thread, and there are many things that have been repeated several times. Either way, it wasn't my (re)suggestion so why quote me? I'm just jumping aboard whether it's your ship or someone elses.
04-25-2010, 01:00 PM
04-25-2010, 01:06 PM
Has there ever been an angrier thread on PM?
We're 14 pages and half a dozen or so fights into it, so surely it's to be welcomed if two people actually find themselves posting simillar ideas?
YZ, the local Leprachaun community would never forgive me if I waterboarded secrets out of a few of their members
04-25-2010, 01:10 PM
Yes. Absolutely. This one is quite civil I think?
Originally Posted by Alpacca Fortyfive
04-25-2010, 01:19 PM
Revenge my friend ,Revenge!
Originally Posted by BadBeta
04-25-2010, 02:41 PM
I took it that the wipers just prevented the airflow from actually impinging on that area (or drastically slowed the air), not that the vortexes had a protective effect.
Originally Posted by motion guru
I am not so sure that the particles can be effectively separated at several hundred cubic meters per second...... they are quite small and not THAT different from air in behavior.
But you are correct about large separators.... which isn't going to do the aerodynamics any good..... About like flying with the shuttle on top of the aircraft, possibly. Nor air induction efficiency either..... the engines will not work as well.
My very strong suspicion is that a protected aircraft could be made to fly, but the range, payload, and economic viability would take a big hit.
And for one week out of the last 25 years? It's a big price to pay for a week's capability in 25 years.
I suspect that if the airlines were not in such bad shape to begin with, they wouldn't be so hard hit by a week.
And there is the separate question of how necessary the week's grounding was...... Surely there were areas unaffected even within the blanket no-fly zone.... maybe not......
04-25-2010, 03:18 PM
There already exist rain doors that simply pop up at the lower edge of the windshield, (like a little spoiler) and by changing the airflow, work to drive the water up, and over the windshield, rather then impinging on it. Kinda like those things you bolt on the hood of your car, to keep bugs off? Do they work? for rain, yeah, sorta; Not 100%. For ash, your guess is as good as mine.
Something that (I dont think, correct me) hasn't been discussed, is P static, and it's effect on radios & navigation systems. You know all those lightning bolts in the (excellent) volcano pictures? Static build up. All transport aircraft carry devices that bleed off static accumulations, but at what ash level do they become ineffective?
04-25-2010, 05:16 PM
Just to put things into perspective to the la-la land dwellers. Thunderstorms are a major problem to air transport since the very early days of aviation. They have bought down hundreds of aircraft over the years, and still do. Lives lost? I have no idea, thousands? Cost? Billions of dollars. As I type I can absolutely guarantee there would be countless aircraft around the world being effected one way or another by thunderstorms, I would rarely do an international flight where I wouldn't take avoiding action around at least some. Members in the US are undoubtedly aware (though they may not know the cause) of the problems thunderstorms cause every summer as "the government" closes routes (read airspace, does that sound familiar to Irish BB members?) seemingly every day due to thunderstorm activity, causing major air traffic disruptions across the US. Incidentally a move that has foreign pilots like myself absolutely flabbergasted, but that's another story, and not one I'll pursue here.
Originally Posted by thruthefence
Technologically the solution is far simpler, unlike the ash, there is no nasty abrasive particles to deal with. No "glass" destroying engines, damaging components, or impacting the air the passengers are breathing. Just a bunch of air that happens to be very rapidly moving in vastly different directions. Yet I can sit here and very confidently state that there is no commercial aircraft built that can reliable take-off, land, or even penetrate a major thunderstorm. Nor has there ever been. Nor is there likely to be for the foreseeable future. The solution is precisely the same as it is for the ash, you avoid it! Indeed the techniques for avoiding thunderstorms and windshear is progressing at an impressive rate.
So the message I'm trying to convey, seemingly unsuccessfully, is that if a solution to a "relatively simple" problem like operating in thunderstorms can't be found, then the chances of a solution to a very complex problem like operating in such a hostile environment as volcanic ash cloud in an economically viable aircraft (so forget your tractor air filters ) using currently available technology is pretty much zero. If that makes me a nah-sayer, that's fine by me, I'll be President of the club if that makes you feel better!
04-25-2010, 06:19 PM
I keep harping on the certification requirements for aircraft. It is an expensive process. The cost is borne by the aircraft manufacturer.
Over the years, restrictions to aircraft operations have existed, and been dealt with by incremental technological improvements in the equipment., and changes in the operating parameters of the aircraft itself.
eg blind, or instrument flight without a visual reference to the outside world.
flight into known icing allowing aircraft to fly where there is visible ice forming on the structure.
These two issues have been "solved" technically.
And yet, flight into IFR (instrument flight rules) and flight in icing conditions, continue to kill hundreds of people every year.
We have 'real time' weather in the aircraft GPS displays. We have sophisticated weather radar systems. We have stormscope/strikefinder technology, that displays lightning activity, an excellent indicator of severe, active weather systems. And still, we fly into thunderstorms. Air France flt 447 was a possible victim.
Last edited by thruthefence; 04-25-2010 at 06:21 PM.
Reason: cite an example
04-25-2010, 06:29 PM
just stumbled onto this NASA paper
give it a read, please.
written by much sharper folks then myself.
Last edited by thruthefence; 04-25-2010 at 06:31 PM.
04-25-2010, 07:05 PM
A link to that paper was posted by a member called cash days ago and you totally ignored it then; I would say you are stumbling about as good as bad beta.
Originally Posted by thruthefence
04-25-2010, 07:57 PM
As far as I am concerned, you are elected!
Originally Posted by Pete F
I am thinking we agree on the matter....... but there do seem to be some starry-eyed optimists with costless solutions........
Tractor air filter! LOL....... right-ho....... one that works at several hundred knots, hundreds of cubic meters of air per second, has better than 99% efficiency.... and presumably snaps in place on the front of any 767 or equivalent airbus without adding drag or messing up the CG......... not to mention the self-cleaning or non-clogging feature!
I still think that if you wanted to, one could build a *thing* that could take off and fly in ash clouds...... for a while..... but I seriously doubt if it could do much of anything else....... like carry passengers at a sensible speed over oceans.
04-26-2010, 12:10 AM
Personally I find it ironic that the naysaying pilots here have their daily work in a contraption which, at several stages of its evolotion, were deamed impossible or economically unviable by contemporary experts.
I guess the mindset of the engineers and designers were somewhat divergent from the end users on this board. That can be a good thing indeed - I'm not sure I would want to ride with a "it might work" optimist as a pilot.
What I don't get is the blanket negativism. Fair enough with feedback on specific suggestions, but going from there to a general can't be done is a big leap.
04-26-2010, 02:38 AM
We're possibly seeing the two ends of a spectrum clashing. I'll take it away from aircraft for a few lines.
Originally Posted by BadBeta
Comprehending Engineers-Take Seven
"Normal people ... believe that if it ain't broke, don't fix it. Engineers believe that if it ain't broke, it doesn't have enough features." ----- Scott Adams, The Dilbert Principle
Found allong with lots more humor at the expense of engineers at Varmint Al's Engineering Page - Finite Element Analysis of Structures Scroll up and down, there's lots of fun stuff there. Take 1 is particularly telling.
I'm not as extreme as the joke (even if I do have pretty good bicycle), but, I can see myself on that side of the spectrum, and there are jobs where you just wouldn't want the sort of person (like me) who's always wondering "What happens if I take this bit out and put that bit in instead? what if...?"
I think the all time worst example of such mal-recruitment was Chernobyl. They really had got the wrong personality types in the wrong jobs there.
But this isn't work, it's a fun thread
I've met three people who've been sucked into CBs. First two were in a sailplane, The lift was really good, then they were in cloud and couldn't see the wing tips (don't know if they even had a horizon fitted) and completely lost control, they didn't know which way up they were, there was hail hammering on the plane, and despite pulling on the brakes and letting go of the controls, they said there were some hideous creaks and groans coming from the structure. They thought they were going to die. It spat them out of the side, right way up, into bright sunshine, with a wall of cloud behind them.
The third is a hang glider pilot, who flies from a hill a few miles up the road. Apparently their vario sqeaks more rapidly as rate of climb increases. He'd been enjoying a good area of lift when it became ridiculous, and he wasn't able to get out of it before he went into the cloud. He doesn't know how long he was actually in it, but thought he was going to freeze to death. When he got out of the cloud (can't remember what altitude he said it was) he made the fastest descent he could. he said when he landed, the guy who owned the field came to see if he was ok and was astonished to find him covered in ice on a hot (for ireland) summer day.
All three were still flying last time I spoke to them, though I think they're a bit more careful of weather conditions these days, something about "old" and "Bold" being mutually exclusive
04-26-2010, 04:41 AM
Guilty as charged. Blew right by it, I guess.
My apologies to Cash; and to you (and anyone else who may have taken my oversight personally.)
A good piece of evidence, nonetheless.