Anti-ice

[ekisbey]

Originally posted by dust

who said smart level??

It's like a myth; it grows in the telling.

 

Are you implying there are builders NOT using a smart level?? What a horrific thought!

[Jim Sower]

John (this one gets long ...again ...),

<RE ... Hold up a minute here, Jim. Lets have some data, rather than wildly screaming "Oh sh.t, we're gonna die" ...>

I was clearly exagerating. I have been taking this whole thread as a pretty lighthearted exercise. I also did not state or imply that Rui had a death wish. I was and am playing around and having a little fun with the reappearance of some stuff that makes the rounds every couple of years.

 

Like, EZs and Cozys have been around for over 20 years. We're not plowing new ground here - not with pressurization, not with de-icing, somewhat with turbines. It's pretty much all been said. These ideas periodically just blossom and grow "outside the box" and generate a lot of enthusiasm (but a lot more heat than light) until someone sits down and does the math. The balloon pops and the principals go back to building, and making less dramatic excursions from the plans. It's a pattern, John, and I know you've seen it. But as long as we're here, how about a very quick, cursory look at the math.

 

I believe I mentioned on a recent post that 2 psi pressurization (which will lower the cabin altitude from about 22k all the way down to 18k) will subject the cabin structure to 288 lbs per sqft, or nearly TWO THOUSAND SIX HUNDRED pounds per square yard of surface area. Much of which is concentrated in latches, hinges and windows. Need we go any farther?

 

As to deicing, I would start with some principles of philosophy. I am a strong believer in the human trait that "... if you have it, you'll use it..." applies to de-ice equipment. It follows then, that such equipment would tend strongly to get you INTO one hell of a lot more trouble than it gets you OUT of. It's been my experience that virtually everyone I approach with this type of notion responds with "... but not ME ... I only want it as a backup ...". I regard such responses as sincere and well intended, and TOTAL BULLSHIT. Sort of like buying an SUV so you won't get stuck in the snow, and discovering that you get stuck more than ever, but in more remote, inaccessable paces:)

 

That said, let's move to engineering. Electric de-ice won't fly. For a plane the size of a Cozy, you're talking thousands of watts of heat. Like 5 or 6. That's upwards of 400 amps which production capacity you carry around ALL of the time just in case you need it. Which the fact that you have it kind of assures that you will, at least occasionally (see above). And, of course, moderate (much less serious) ice will defeat it. I'm not aware of ANY electrical de-ice systems that work, but there might be one.

 

As for hot water, one would have to examine carefully how much hot water would be required and determine if even a Mazde, with all its heat rejection problems could provide it. And then weigh all the valves and plumbing and valve actuators and what not. Then move on to structure. The Rutan derivatives use fiberglass foam sandwich construction. Piping hot water inside that sandwich would be a waste of time given the insulating attributes of the sandwich. Piping the water through a hollow D-section of the wing or canard opens up a LOT of engineering issues that nobody on this list - not Nat, not Jeff, not the Swings, not anyone this side of Burt are equipped to address. But suppose you did have the engineering capacity to address them (and weigh all the additional structural gee-gaws). It is my considered opinion that one of the first things you'd discover is that the whole idea has no discernable merit. The downside FAAAAR outweighs the upside. If you could de-ice the leading edges (at great cost, even if you don't count complete structural redesign of the flying surfaces) you would only be transferring the ice from the [heated] leading edge to the [unheated] top (further aft) surface(s) of the wing/canard. You would accomplish very little, if anything, useful.

 

I am reminded of the long and heated (pun intended) discussions a couple of years ago on the C-A list concerning pitot heat. Lots of guys had come up with ideas like automatic engagement of the heat (in case you didn't notice you were icing up), ceramic regions in the nose of their Cozy or Velocity plane that would structurally support a hot pitot probe without damaging the glass and foam, and Etc. etc. etc. It was pointed out in no uncertain terms that by the time your pitot system freezes, your flying surfaces have already iced up to the point that your super-slick fiberglass racing airplane has long since acquired the aerodynamic attributes of a flat river rock. I wondered to one of these "pioneers" why, if he was ballistic, in an unrecoverable dive, he would give a sh*t how fast he was going when he hit the ground. I got no response. I guess he was busy building his ceramic nose cone.

 

Back to philosophy: I firmly believe (I was told by a guy who was talking like he knew) that there is NO system or safety device, no matter how complex or expensive or reliable that can overcome bad judgment and stupidity on the part of a pilot. That right there is, IMO, the crux of this whole matter. We are proposing that one of us is going to design and build just such a device. I think my money would be MUCH better spent on training and related efforts that would KEEP me out of trouble rather than investing it in some hideously expensive gee-gaw that might (or might not) GET me out of trouble that I had blundered into.

 

Just a theory .... Jim S.

[Joe Cygan]

You know Jim,I don't know you and you probably don't know me.Heck,I don't know most people on this list.You seem like a very intelligent guy with an outstanding awareness of aviation.So,when I give you my opinion please don't think that I'm trying to sh*t on you.In my opinion,you are correct about a lot of the stuff you mentioned in your last post.But,I have to tell you, that your type of put the stake in the new idea philosophy is probably why we still have magnetos on certified aircraft engines.I'm tired of the lets do it this way,because they did it that way yesterday attitude.You can develop anything no matter how ridiculous in nature or practical.I think we should give encouragement to people who want to step on grounds that never have been walked on before.I firmly believe that failure is one step closer to sucsess.

[Rui]

Jim,

 

Thanks for your reasoned and logical reply. I understand your statement about going beyond the limits thinking that some system will save your bacon (though the same thing can be said for airplanes in general; humans were never meant to fly, its just that this gee-gaw of ours lets us do it). In general I also agree that the extra complexity can cause more problems than it solves. I have rejected both pressurization and (nearly...) retracts for these types of reasons. I am still not convinced on rejecting the de-ice idea.

 

As you said, it looks like the electric idea is out. But I like John's idea of using coolant. I wasn't thinking of using a hollow D-channel as you suggest. I was thinking that I would embed rows of narrow aluminum tubes along the leading edges and glass over them. Kinda like what is done with the coaxial cable for antennas. Lots of testing would have to be done (ie. what spacing would be effective), to first see if this would actually work. Am I up to it? I'm not sure, I guess it depends on whether anybody can come up with a good technical reason why it can't work.

 

I did a search of the archives on Maddy's site last night and found a couple of references to unexpected ice.

They manouvered to avoid it, but it was still pretty scary. I am sketchy on the details (it was kinda late....) but I hope collect the relevant stories and put them on the web.

[Jim Sower]

Joe (long seems to be a major defect of mine ...),

I don't know you either. I know John Slade and maybe one other guy on the list (and have corresponded with a few more over the years). I know you are not trying to sh*t on me when you give an opinion. I would hope you do not think I am trying to sh*t on you when I give mine.

 

I have discovered over the years that new is not necessarily better. Some new ideas are good, some are not so good, some are plumb awful. The good ones bubble up into reality. The bad ones die quietly (or not so quietly as in the case of the dot bombs:)) If examining a new idea in the light of day and doing the math and a cost/benefit study of some sort is "putting a stake" in somebody's creation, then I am guilty as charged. When I come up with a new idea (which is quite often as a matter of fact), I have some choices to make. I can either examine it for flaws and prepare to defend it on its merits, or just pull it out of my ass, float it to the world and listen with such humility as I can muster while others do my light work (thinking it through) for me. In the latter case, I have several choices: I can agree the critics conclusions that my idea is/was flawed, or I can muster facts to rebut his argument, or I can whine about him dumping on my inspiration. I personally find the first two choices more useful than the last. I prefer to do some preliminary thinking-it-through on my own before floating it. This saves others needless and annoying effort doing my preliminary thinking for me, and spares me the embarrassment of public examination of my numerous brain farts.

 

<... your type of ... is probably why we still have magnetos on certified aircraft engines ...>

That is a bad rap. I have NEVER gone that route. I have been 86ed off the C-A forum for speaking out against complacency and bland acceptance of 1940s technology.

<... I'm tired of the lets do it this way,because they did it that way yesterday attitude ...>

As am I. And I have credentials around this. I would invite your attention to John Slade's web site. Read over his page on "Censorship on the C-A Forum. I am not reactionary. One of the few things that really piss me off are inferences that I am.

<... You can develop anything no matter how ridiculous in nature or practical ...>

I'm not sure what that means.

<... I think we should give encouragement to people who want to step on grounds that never have been walked on before ...>

As do I. You evidently missed the first paragraph of my post. NONE of the stuff we are discussing here is new. It might be new to you. I would invite your attention to the second paragraph of my post.

<... I firmly believe that failure is one step closer to sucsess ...>

As do I. I do not, however, believe we should rush pell-mell into developing every lame, half-assed idea that comes along just because it is NEW (again, I would invite your attention to the dot bombs). I prefer (and this is just my personal opinion) to first examine my new idea, try to determine if it has merit, and abandon it if it has none. I firmly believe that life is too short to spend mine pissing in the wind

 

Joe, I did not drive a stake in the pressurization idea. Mr. Newton did that. I only pointed out the TONS of load it would impart to the cabin structure. I then pointed that all that structural beefing up and redesign would give you the benefit of 18,000 ft cabin altitude at an actual altitude of 22,000 ft (as a matter of fact, 2 psi would give you a somewhat greater differential than 4000') and invited you to draw your own conclusions. Similarly, with the de-ice idea. All I examined it just a little. Nothing detailed, just off the top of my head notions of what would be required to make it happen. Having done that, I again took a look at the possible benefits and some of the possible pitfalls.

 

What we're talking about here is natural laws. I DID NOT INVENT THEM. THEY'RE NOT MY FAULT! Mr. Newton defined them. All I did was study Mr. Newton's scribblings and attempt to explain them to you. Any flaws or unfortunate consequences of YOUR "new" idea is NOT MY FAULT!!

 

At NO time did I make any sweeping unsupported generalities. I NEVER suggested that newness was automatically bad and that we should stick to "tried and true mags and carbs and ...".

 

If your idea has merit, you can surely defend it on its merits. If it has none, and you are lucky, some a**hole like me will save you a LOT of time and effort by pointing that out to you.

 

Best regards,

Jim S.

[Joe Cygan]

Jim,I read John Slade's "Canard Aviator's Mail list Censorship - is this what members want?"and I must say that the magneto analogy was not a good one to use in your case,sorry.You are my type of animal when it comes to engines.The only thing I can say about being censored is to walk away as fast as you can,you don't need that sh*t.(what a bunch of assholes)

Like I said,I do not know you and my response was based on what I was reading.My primary angle was to challenge you and to open some eye's.Obviously you have traveled down this path before and I respect that.I meant no malice towards you. Let's move on!

[John Slade]

>I don't know you and you probably don't know me

I know Jim Sower. Jim Sower is a friend of mine....

and I can vouch for his numerous brain farts. He's definately a reactionary, and he's argumentitive too. Let see you argue with that, Jim

 

>your type of put the stake in the new idea philosophy

In his defense, Jim wasn't putting the stake in a new idea. He was reiterating the physics which shows that an old idea still doesnt have much merit.

 

>probably why we still have magnetos on certified aircraft engines

No. That's because there's very little financial incentive to innovate in the certified world, and every incentive to keep producing the same old stuff. It's also because its kinda handy to have the engine keep running if you loose electrical power.

 

Yuknow... this discussion would be best held around a log fire over a couple of beers. I still don't think we'd invent a workable EZ de-ice system by morning.

[marbleturtle]

I have a little rubber tube on my car that sprays hot anti-freeze on my headlights. No wait, that's a coolant leak! Hmmm...

[Jim Sower]

Rui,

OK. Let's take another shot at your de-ice solution. Your idea of lots and lots of small tubes embedded in the leading edge has a lot more merit than my reaction of just a couple of larger tubes (actually, there HAS to be an even number if you are going to return the coolant, which is a really good idea ).

 

John slade has spent a lot of time reading everyone's heoric and often frustrating efforts to purge and keep the trapped air out of their Mazda cooling systems so that you're cooling with coolant and not air. He could probably speak to the matter of purging trapped air out of 400' of capilary tubes embedded in your wing much better than I could.

 

Let's suppose you're flying along in the klag and encounter mild ice. Let's further suppose that some ignorant dumb-ass duck is flying along in the same cloud, no clearance at all, and his poor eyes and ears are iced shut so he doesn't know you're coming. Whack!! Through absolutely no fault of your own, you've opened up your cooling system to the world. At whatever flow your pump can deliver, you're dumping coolant over the side. It's cold and cloudy outside and you're losing coolant like pouring piss out of a boot. What's your next move?? So you get it safely on the ground at East Bumblefuck county airport. Now what do you do? How do you fix this thing? How do you even locate it? If the tube ruptured inside the skin in the foam, and the skin didn't rupture, the coolant has been spreading (at 20 psi - ask John Slade how fluids run through foam) until it finds a place to leak through the skin. Maybe into the atmosphere near the site of the broken tube, maybe into the atmosphere somewhere else, maybe into the cabin, maybe (gawd forbid) into the fuel tank ...

 

Or let's suppose you just hit a crow on a perfectly nice day close to home. You're back at your own hangar/airplane factory safe and sound in maybe 10 or 15 minutes. This is better, but you're still looking at the same repair challenge as out in the boondocks. You have better tools and facilities, but still a rather formidable problem. I'll leave you with that.

 

On to examination of the problem itself.

It occurs to me that GA airplanes (virtually) NEVER have de-ice equipment. Not even the half $mil Lancair-IVs. Not even production planes like JFK Jr's that had everything for sale installed. Part 135 carriers (that operate in the troposphere) ALWAYS do. Why might that be? It occurs to me that air carriers HAVE to go. They've committed to their clients/passengers to depart point-A at a certain time and date and arrive at point-B some time after that. They have no choice. They go to great effort and expense to acquire and maintain compex de-ice equipment to that end. We GA folks OTOH have better choices. We don't have to go if we don't like the weather. Ask any grizzled old DC-6 or Convair or even more modern turboprop pilot if he would fly into ice if he had a choice. Keep in mind that these guys do that a LOT and are VERY GOOD at using their stuff to best advantage (BTW, you don't just turn that stuff on and continue the march) and have the best de-ice equipment available to work with.

 

I stand on my statement that if we have it, we'll use it. I seriously question the notion that you CAN de-ice a laminar flow wing to where it will fly. Maybe the leading edges, but what about the rest? And remember, the transports will carry a pretty good load of ice and still fly. Wind tunnel tests I have heard of indicate that enough ice to make a good Tom Collins or Margurita will seriously impair a laminar flow flying surface.

 

All of this leads me to the conclusion that: A) you most likely can't solve this problem in any satisfactory way, and B) if you could, you probably wouldn't want to, given the inadequacy/major shortcomings of even the best solutions in place today.

 

My own solution is to never go anywhere that I even have to maneuver to avoid ice. I don't worry about likelihood or probability of ice. I don't go even where there's a POSSIBILITY of ice. That pretty much thins out my flying opportunities here in the northern tier. That's one big reason we're moving to TN just a soon as we can.

 

Just a theory .... Jim S.

[marbleturtle]

> If you have the equipment, you will use it.

 

That's why I decided to rip the airbags out of my car!

[Jim Sower]

John,

I'll be brief (will wonders never cease:))

<... He's definately a reactionary ...>

Like the Royal Family and the C-A list? I think not, and I'll just have to see you outside if that's your inference :)

Like "... likely to react ... energetically ... and joyfully ...)

Yeah. That'd be me :)

 

<... best held around a log fire over a couple of beers ...>

Now why didn't I think of that??

[Rui]

Jim,

 

About dearating the coolant, I have never heard of this problem. Can you elaborate John (or just point to a web page that explains it).

 

About leaks. I have thought about this, the simple fix is to put a valve that shunts the coolant back to the engine, sort of like what the thermostat does to block off flow to the radiator when the coolant is cool, except that it would be manually controlled.

 

The thing that still worries me most is the delamination issue. I'm surprised nobody has mentioned it, is this a valid concern? I haven't had a chance yet to look up temps that you have to keep under, but I would assume that they are lower than typical coolant temps. This would make the risk of foam-glass delamination greater which worries me. I guess the only way to find out is to create a test piece of fibreglass with a network of tubes and run some hot water through it.... Maybe when I actually start building the plane.

 

One last point, the title of this forum is the Coffee House, a place for general chit-chat. Unfortunately I have no other venue to air my ideas (ie. I don't know anybody locally who has experience with fiberglass canards) so I post them on here hoping that others will see the errors of my ways and speak up. Fortunately this is exactly what is happening!!!

[John Slade]

>About dearating the coolant, I have never heard of this problem. Can you elaborate John

 

Not in any detail. I havent reached this stage yet. Suffice to say that air can and does get trapped in coolant systems, and a very small amount of air can raise coolant temps considerably. Effective purging and expansion bottles seem to solve the problem.

 

>put a valve that shunts the coolant back to the engine

That's exactly what I'm doing for my cabin heater.

 

>test piece of fibreglass with a network of tubes and run some hot water through it....

Yes. I WOULD worry about delamination and air pockets.

 

>Maybe when I actually start building the plane...

My recommendation would be to build the plane per plans while keeping these ideas in the back of you're mind. Once you've completed and flown the plane you'll be FAR better qualified to re-engineer / modify it, and you'll be able to recognise any differences in flying characteristics when you do. I took me 3 weeks to build my canard. Building a second one would take half the time, so experimenting after it's flown isnt such a big deal. After messing with my air conditioner system for a couple of weeks it's quite a relief to go do a job that the plans actually tell me how to do.

 

>so I post them on here hoping that others will see the errors of my ways and speak up.

One of the reasons I resigned from the CA list was that people were being slammed so much that they stopped asking. Also, ideas and comments which dont agree with the "moderator" are consistantly supressed. I believe that this is VERY dangerous because people will have a tendancy to implement bad ideas without throwing them open to discussion first.

 

Just one question remains, Jim. What does the Royal Family have to do with all this? Be careful. I used to work for the Queen.

[Jim Sower]

Rui,

<... dearating the coolant ...>

The Mazda community (or any other water cooled community) has their engine, radiator, all plumbing, reservoir, burp tank and everything else all under the cowl. It is relatively easy (certainly possible) to make it so an air bubble anywhere in the system can find its own way into the reservoir. They STILL have problems with air bubbles in the system. Not disolved air - trapped bubbles. I am at a complete loss how you would purge trapped air from a de-ice system with any hope of success, much less reliability. There has to be loops (inverted "U"s) everywhere. Air will accumulate in these loops and there's no practical way to purge it. You will ALWAYS have air in your system, and the more air, the more serious the consequences.

 

<... About leaks ... the simple fix is to put a valve ...>

That's after you've determined that there IS a leak. I ignored the shutoff valve part since it's so simple and easy (once you know that you need it). I believe that locating and repairing a leak would far and away the most difficult part. Reread my post about coolant seeping through the foam from here to yonder before it finds a path outside the sandwich where it is visible. You may eventually determine that you HAVE a leak, but you're clueless as to where it is, and have no good way to find out aside from destructive disassembly of your flying surfaces. Even then, how would you repair it?

 

<... worries me most is the delamination issue ...>

Delamination is a very serious issue. I've no idea how you might address it. Foam degradation is a related issue. My understanding (from discussions on post curing flying surfaces) is that blue styrofoam begins to melt somewhere between 150 F and 180F (depending on who you are talking to). That is at least 50F too low to support an anti ice system.

 

All of that having been said, is the problem worth solving? If you were able to address ALL of the above issues (I doubt you could solve ANY of them), what would you have? Not much I fear. If I'm not badly mistaken, the very best de-ice technology available is the boot type systems on the turboprop commuter airliners. It's very complex and expensive. It's difficult to use, and works only marginally on a GOOD day. You may have read the reports on the commuter that crashed last year SE of Chicago. Often, when ice is encountered, de-ice boots are inflated too soon or too late. One way creates a hollow chamber inside the ice layer that the boot cycles in and accomplishes nothing. The other (I'm not sure) may break up the ice on the leading edge but leave massive amounts still attached further aft. You need to study de-ice technology very VERY carefully before you decide that you can address this problem at all. The notion that all you have to do is dump some heat into the leading edge region of a flying surface is, I believe, totally bogus.

 

It's Sooooo much easier, safer and more effective to just not go where the problem is.

 

Study up. There's a LOT to learn about de-ice ... Jim S.

[Jim Sower]

John,

<... What does the Royal Family have to do with all this ...>

I needed an example of hidebound reactionary thought that everyone would understand. I also thought it would be amusing to yank your chain a bit :)

 

<... I used to work for the Queen ...>

Looking at the news here recently, I'm not at all sure I would have shared that

 

Night night .... Jim S.

[macleodm3]

Some of the early Mazda rotaries(but not my '80 RX-7) ) had an oil cooler that used the engine coolant to cool the engine oil... a liquid/liquid heat exchanger(my 87 VW had one too). One of these units could be used with either engine coolant used to heat wing anti freeze (H20 cooled engine)or the engine oil used to heat the wing anti freeze (air cooled engines). Come to think of it... you could use one of these heat exchangers to supply a warm (or even hot) liquid to the front of the fuselage to provide cabin heat/defog. If one of the long lines of plumbing to the front of the aircraft broke... you might get burned at worst, but the water or oil cooling system would remain completely intact at the rear of the plane. I know that it adds another system but at least its not an engine critical system. It could be created with a thermostat control to keep the HOT liquids out of the passenger area. The liquid could be circulated with one of the small electric water pumps that has recently been discussed. If I go modern water cooled route one of my concerns will be to keep hot antifreeze in the back, with the engine. The exchanger from the Mazda was small, slightly bigger than the oil filter. The VW unit is about 2 inches thick, 3 inches square. Both were coolant/oil heat exchange. On the negative side... the exchanger could always spring a leak and there goes your coolant or oil.

[marbleturtle]

How about little spray jets that squirt hot anti-freeze onto the wing... like headlight/windsheild sprayers on a car? Obviously not a long term solution, just a quickie fix to help get out of a jam.

[unick3]

Icing on your bird is a bad thing. I have had clear ice, rime ice and snow build up on my canard and main wings. What really freaked me out is when I had icing on my prop.... when half of it breaks off it really give you a shaking up!!

 

Take it from me, the best thing to do is to stay out of icing conditions.

 

The only system I thought would even be possible is a liquid deice system. You pump deicing liquid from the front of the leading edges and use a flinger ring on the prop. The cirrus is using a titanium LE with laser cut holes (800/sq in) to weep the liquid onto the wing surfaces.

[dust]

i'm still weeping

[Richard Riley]

At least to answer the very first post - the amount of electricity it would take to de-ice wings is prohibitive. Thousands of amps. The problem is the supply of cold wind whipping away the heat is effectively infinite. Your wings are going to be the temprature of the air, whatever that is.

 

I looked into doing a weep system on Berkut with molded wings. It is possible, but it's expensive. Don't forget the LE's of the winglets, the canard *and* the s-channel/elevator LE. Probably have to put some spray heads in the s-channel to get the elevator. And you have to do an area of the canopy so you can see.

[dust]

I live in michigan, we have 73 sun days a year, in the winter it is below freezing and cloudy. in the future, after we are flying, if i can install a weeping system on the leading edges and prop or a heated prop to help when accidental ice is encounterred, it will go in, end of story.

I'm not counting on it being feasible, but I won't pass it up if i can put it in, ice is scarry, my buddy came back from boston and came through the clouds to land and picked up 3/4 inch in no time flat.

 

mike

 

BTW, I love the weather and would never dream of moving.

[marbleturtle]

I weep for you...

[ekisbey]

Building upon the engine-heated cooolant concept...

 

I'm not comfortable with the idea of a system of tubes or ducts running under the skin. In order to be effective, you'd need a very large number of fairly closely spaced "capillaries." It takes a certain amount of pressure to force liquid through a tube. The longer the tube, the more pressure required. Smaller tubes take even more pressure. Each bend or joint or valve adds even MORE pressure. Add to that the altitude and we're talking a lot of PSI. A leak in a system like this isn't going to be a minor event; the pressure required might reach explosive decompression level. The thought of scalding coolant blasting through easily melted foam at high pressure inside a confined space seems to qualify in my mind as a Very Bad Thing. This isn't to say the idea doesn't have merit, but all those tubes are not only complex and open the possibility of leaks, they're also going to be heavy. Don't forget to add the weight of the coolant as well.

 

Since the materials we're working with here aren't exactly heat tolerant, you'd also need a method of monitoring the heat being dissapated and where it's being dissapted from. All that heat has to go through the foam before it can get to the air outside.

 

I just thought of this: how about using a web of thin copper tape to distribute the heat from a larger central pipe(s) deeper in wing? A larger pipe would allow a higher volume of coolant at a lower pressure and could be better protected by the surrounding material. Copper tape doesn't leak. It's also somewhat less invasive to the structure of the wing than ducts or tubes would be, and can run closer to the surface.

[John Slade]

Another issue to worry about - lightning strikes are known to seek out any embedded metal. If there's nowhere for all the volts to go, they tend to dissipate explosively, so I've heard.

[ekisbey]

I'm laughing here... First we're talking about flying in icing condidtions and now it's icing with lightning. The weather just keeps getting worse and worse!

 

Okay, where were we? A twin tubine powered, retractible gear, air conditioned, pressurized, de-icing, lightning proof composite aircraft equipped with a ballistic chute and a blind goose deflector and can be built in a 12x20 space with a pocket knife and a smart level (or a dousing rod, if you're not into the whole smart level thing).