Flying in IMC

[WileEZ]

I just read in another thread that the canards are not suitable for flying in IMC.

 

I'm curious, if I was to somehow be able to heat the canards and main wings to some point above freezing, oh say to 60 degrees F (15.5 degrees c), would that be enough to let me fly in freezing IMC?

 

What would be the minimum temperature needed to prevent/get rid of ice buildup?

 

I have an idea on how to do this economically and safely, although it would have to be done during the build process. Well at least the mod is limited to the canards and main wings. And could possibly be retrofitted into the strakes in a completed canard. I need to explore/think this through a bit before I'm ready to share this idea with y'all.

 

But first, is heating the wings enough?

[TMann]

Just don't fly through visible moisture and it's not a problem.

 

If you're flying a GA aircraft in icing conditions, even with de-ice equipment, you can't continue into those conditions. It's designed to buy you enough time to FIX the problem ....... not ignore it.

[argoldman]

Just don't fly through visible moisture and it's not a problem.

 

If you're flying a GA aircraft in icing conditions, even with de-ice equipment, you can't continue into those conditions. It's designed to buy you enough time to FIX the problem ....... not ignore it.

What,------ Agreement from this corner,----- but agree I must.

 

If you were to deice your wings and canard, (suggest using TKS technology,) then you would have to deice your prop as it will become an ice laden club, and then deice your winglets. That might buy you enough time to get the hell out of where it is unhealthy as you gear legs and all other surfaces accumulate ice making you heavier and less airfoilable.

 

The heat of the exhaust may keep the prop inside diameter clear of ice, but the ice will shed from the unaffected parts and fly at your winglets. Singles shed it away from the plane and tailplane. Twins have ice plates to prevent damage to the fuselage from this effect.Many times they are installed later to cover up just this kind of damage

 

Become ice savvy or stay out of conditions where there have been no recent pireps when below freeing and in the clouds or snow.

 

By the way, it would seem that when flying through dry snow (no icing problem) there is the possible problem of the friction causing St. Elmo's fire, a very interesting but initially scary phenomenon. I experienced it many times in my Bellanca years ago.

 

 

Now back to the dead horse about not really flying IFR unless you do it all the time and are a "Professional."--- It would be interesting to do a study on frequency of accidents of actual IFR flights, that are flown by the "amateurs" who filed an IFR flight plan, compared with gen aviation accidents as a whole.

 

While you are at it, compare the results with accidents in the same arena flown by "professionals" in light planes, in general.

 

I for one, would be interested in the results.

 

Perhaps it would cause a modification in my thinking that is slowly succumbing to hardening of the attitude:irked:

[DemonFrog]

Also keep in mind that any ice that accumalated ahead of the prop will eventually fall off and directly into the prop. heating your canard may also cause ice to fly into the props. Also be aware that the canard designs we use are lifting body type craft, the fuse actually creates lift, and that makes it a critical surface. look up the clean aircraft concept if you are interested.

[WileEZ]

Okay, Point made and acknowledged!

 

Get out of IMC or better, don't fly into IMC or best, don't fly if you know there's unavoidable IMC on your route/leg.

 

BUT what if one got caught for whatever reasons, would heating the flying surfaces be enough to at least get the plane into a condition where you can at least have more options to extract your plane safely out of the IMC?

 

The way I'm looking at this is the "heating system" would be switched on if you know you cannot avoid the IMC at that moment and once safely out of icing conditions and a quick check to make sure there's no ice left, switch it off. Yes I know there's the problem of ice debris hitting various part of the airframe, but at least you would still have some lift and ability to fly out of IMC in a direction other than "straight down". Think of this as "cheap insurance" and I do mean "cheap".

 

I looked at the TKS technology and while I'm sure it's a good system, it add 80 to 100 pounds to the airframe, not to mention the $$$.

 

The idea I'm mulling over is a lot cheaper and very light. Maybe at most add 20 lbs. Still doing a bit of research on this, but so far seems sound. This is not really intended to let one fly into IMC with impunity, although it may help prevent ice from accumulating/building up in the first place. This can be extended to cover the winglets and/or fuse as well if desired. If I can prove this as a sound concept, I intend to release this idea as a "freebie". In other words, I have no intention of trying to set up a company and market this. Especially since all of the components can be obtained locally and cheaply by the builder for incorporation into the build. This concept can also be used on other composite airframes.

 

Drawbacks might be in the time required to heat up the flying surfaces (checking into this) and requiring somewhere between 5 to 10 HP while in operation.

 

Deicing propellers is another whole issue, but one worth thinking about.

 

What I really need to know is what would be the minimum temperature(s) needed to prevent and/or get rid of the ice?

[Marc Zeitlin]

I just read in another thread that the canards are not suitable for flying in IMC.

Sigh. As I've written about a number of times, I did my Instrument Training in an accelerated week four years ago in my COZY MKIV. Never turned the AP on once the whole week. Flew about 10 hours of actual IMC during the training (in 40F rain on the good days), and got a bit of ice once - maybe 1/16" on the canard and wing leading edge.

 

The instructor never had to touch the stick once during that whole time, and I never lost control of the aircraft. I'm NOT god's gift to pilots, by any stretch of the imagination.

 

These are high performance planes - they are NOT stable in roll, and are sensitive in pitch. But that's not substantially different than many other high performance planes that are used for IFR flying all the time - Mooney's and Bonanza's come to mind.

 

All that said, I would NOT fly my COZY (or a LE) in IFR single pilot without an Auto-Pilot - the workload is just too high, and the opportunity to lose control while distracted by COMM or who knows what is just too high. But again, that's not substantially different than the recommendation I'd make for ANY single pilot IFR flight.

 

I'm curious, if I was to somehow be able to heat the canards and main wings to some point above freezing, oh say to 60 degrees F (15.5 degrees c), would that be enough to let me fly in freezing IMC?

Only if you're a fool. Assuming that it's technically possible to do so (which it isn't - there isn't enough heat generated on the airplane to heat that much surface area and melt that much ice), there are still the issues brought up by others of the winglets and prop, not to mention the canopy, pitot/static ports, etc.

 

What would be the minimum temperature needed to prevent/get rid of ice buildup?

Yes.

 

But first, is heating the wings enough?

No. Go review the phase change heat required to melt ice, look at the surface area of the aircraft, and realize that a flying surface can accrete an inch of ice/minute, if not more, in some icing conditions. Go figure out how much heat you'd need to melt even the surface of that ice. Then go review the latest in anti-ice equipment, including vibration, fluids, and boots.

[jppt2000]

Now back to the dead horse about not really flying IFR unless you do it all the time and are a "Professional."--- It would be interesting to do a study on frequency of accidents of actual IFR flights, that are flown by the "amateurs" who filed an IFR flight plan, compared with gen aviation accidents as a whole.

 

While you are at it, compare the results with accidents in the same arena flown by "professionals" in light planes, in general.

 

I for one, would be interested in the results.

Ummmmmm,

"Professional"? vs. "Amateur"? Where did that come from?

Staying current, and proficient before you go into the clouds with a very agile airplane is, I'm at a loss of words----------simply, life extending?

[TMann]

........that a flying surface can accrete an inch of ice/minute, if not more, in some icing conditions.

When I was going through my jumpmaster certification, that Sunday morning was fairly foggy. Someone took a C182 oaround the pattern ONCE and I think they had between 1.5 and 2 .0 inches of ice on every leading edge.

 

Talk about defrosting grandma's freezer!

[DemonFrog]

I am going to guess you are thinking about embedding something like the heat tape used to heat reptile cages? all the comments aside, heating the wings would in theory(?) at least slow the ice buildup, you would do well to have it on a seperate electircal system with a couple thermal probes, as ice and snow that stick will bring the temps of the surface lower. all i can say other than this is be extremely carefull and research this untill you can name the places your info is found from the top of your memory, read FAA occurences and nasa testing into the icing problem. good luck

 

P.S. aluminum heats faster and more evenly than composites, i believe that is why a lot of composite manufacturers are going with weeping wings.

mabye a thin aluminum strip outside the heating element (whatever you are going to use) but on the outside of the wing (so as not to create something like an air bubble structurally) to dissipate heat better.

[WileEZ]

Originally Posted by WileEZ

What would be the minimum temperature needed to prevent/get rid of ice buildup?

 

Yes.

 

No. Go review the phase change heat required to melt ice, look at the surface area of the aircraft, and realize that a flying surface can accrete an inch of ice/minute, if not more, in some icing conditions. Go figure out how much heat you'd need to melt even the surface of that ice. Then go review the latest in anti-ice equipment, including vibration, fluids, and boots.

Yes what?

 

I have been reviewing what was done in the past regarding deicing.

 

So far no answer to the question:

 

What is the minimum temperature needed to prevent/get rid of ice buildup?

 

I'm aware of the surface area issue. I just need to know the minimum temperature required. I know it's somewhere above the freezing point and I'll rather not have to figure this out the hard, long, expensive way if someone have that answer or can point me to the appropriate resources that's relating to the temperature and not just deicing in general. But if I need to, I will. It'll just take far longer.

 

Once I know what minimum temperature I need to be at, I can calculate the rest. At this point, it's an intellectual exercise. And yes, I know it's more than just getting to the proper temperature, I also need to calculate the heat transfer rate and so on. If this turns out to be unworkable for whatever reasons, I'll post and say so.

 

I just need the minimum temperatures and not some arbitrary numbers so I can move on with the rest of the calculations. Obviously, the lower the required temperature that will do the job, the less power required.

 

Humor me if you will, if you know the answer or can point me to the right places, please give. If not, well...

[TMann]

Yes what?

 

Ha ha haaaaaaaaaa! I love it.

What is the minimum temperature needed to prevent/get rid of ice buildup?

 

Why do you think that heat is the only way?

The Aztec uses inflatable boots. They cycle between a slight inflation back to normal which causes the ice to fracture and get blown away ........ to where though?

The prop is still behind you.

[DemonFrog]

I believe the yes means something like you need different temps for different forms of ice? other than that i have no idea

 

thinking back to my classes, ice buildup can be affected by droplet size, wing shape, and speed. i believe the only way to find a temp applicable to a certain aircraft is testing. not what anyone wants to hear, but an unfortunate fact. luckily, a small section of wing can be built with your proposed system and possibly tested by nasa. (not sure how much that would cost though)

[Marc Zeitlin]

Yes what?

Sorry, I should have said "Mu". That's what I meant.

 

See:

 

http://en.wikipedia.org/wiki/Mu_(negative)

 

for an explanation, especially with respect to the Buddha nature of dogs and the definition in "Zen and the Art of Motorcycle Maintenance".

 

Unask the question.

[DemonFrog]

that was actually a rather interesting read, thank you

 

i got nothing as far as temps through a google search.

[WileEZ]

I am going to guess you are thinking about embedding something like the heat tape used to heat reptile cages? all the comments aside, heating the wings would in theory(?) at least slow the ice buildup, you would do well to have it on a seperate electircal system with a couple thermal probes, as ice and snow that stick will bring the temps of the surface lower. all i can say other than this is be extremely carefull and research this untill you can name the places your info is found from the top of your memory, read FAA occurences and nasa testing into the icing problem. good luck

 

P.S. aluminum heats faster and more evenly than composites, i believe that is why a lot of composite manufacturers are going with weeping wings.

mabye a thin aluminum strip outside the heating element (whatever you are going to use) but on the outside of the wing (so as not to create something like an air bubble structurally) to dissipate heat better.

No not heat tapes, not enough heat transfer. Beside, this apparently has been done and was proven unsuitable (using heat tapes). Yes separate electrical system, dedicated just to the deice system, alternator coupled to the engine via an electric clutch and a very small 12 volts battery. Aluminum strips apparently is not such a great idea, yes heats up faster and and more evenly, but it also cools off faster in free air, thus requiring quite a bit more power.

 

Yes this idea is along the same lines as the heat tape idea, but a bit different. Need to research, build and test. NASA reports, while useful and informative, still did not give the critical temperature point(s) needed to prevent/melt ice while in flight. I may have missed a report or two as there's a lot of research that NASA has done on this subject and I haven't read them all yet. I'm still reading and searching for more reports (not only NASA, but whatever I can find via web search.) I've already accounted for composite integrity and part of the planned testing will be for just this issue.

 

I'm still mulling this over and thinking this through. Just need to find the minimum temperature point and move on from there. This whole thing may prove to be unworkable, then again, it may not. I'm willing to build some test panels/foils and test and document the concept if the paper design and calculations works out. I do plan to share the information whether it works or not. Even if this doesn't pan out, the information gathered hopefully would be useful enough that an entirely different, cheap and safe deice system could be worked out.

 

I know that many airframe manufacturers have done this same thing, but they, for some reasons, are reluctance to share with "outsiders".

 

Thank you for your useful and relevant post.

[WileEZ]

Why do you think that heat is the only way?

The Aztec uses inflatable boots. They cycle between a slight inflation back to normal which causes the ice to fracture and get blown away ........ to where though?

The prop is still behind you.

Heat's not the only way, it's just where this one particular train of thought is taking me.

 

As to inflatable boots, you probably can do the same thing on the cheap by using bicycle or motorcycle inner tubes and cut until you end up with a long flat piece. Glue or fasten appropriately and use a 12 volts inflator type compressor to inflate to however many pounds needed to break the ice and deflate. Those inner tubes hold up well to freezing conditions, although UV damage will be an issue to address.

 

Likewise, liquid deicing, take copper or aluminum tubes to a laser place. Have them "drill" a series of really small holes. Embed at or just above leading edges. Pump warmed glycol solution... Keeping them holes clean and clear is gonna be a bugger though.

 

Yes I know the prop is still behind me, one thing at a time...

[WileEZ]

Sorry, I should have said "Mu". That's what I meant

Sorry, but when I'm in a technical frame of mind, I tend to take things literally. Buddhism at those times tend to be the furthest thing from my mind.

 

Instead of thinking in Buddhism terms, I'm thinking that's a pretty useless and pointless answer. I asked a technical question, and expect a technical answer.

 

I'm not asking a "Buddha question", although it can be said I'm looking for enlightenment, I prefer it in the form of a direct and useful answer.

 

If someone ask me "what is the sound of one hand clapping", I'll reply "clap" "clap" "clap". That's the sound of my hand clapping against my leg. Else it's just a hand waving in the air and doesn't meet the definition of clapping. That's how my mind work when I'm in a technical frame.

 

BTW, thanks for the link, it's an interesting article.

[DemonFrog]

there are aircraft that use heated leading edges (bigguns) mabye if you could get a hold of a technical manual for one it could give you some data to work with?

[steve]

Also keep in mind that any ice that accumalated ahead of the prop will eventually fall off and directly into the prop. heating your canard may also cause ice to fly into the props. Also be aware that the canard designs we use are lifting body type craft, the fuse actually creates lift, and that makes it a critical surface. look up the clean aircraft concept if you are interested.

is that true? i think i saw nat say that it was not a lifting body, more over not the straks (bad air off the canard)

lots of stuff about flat plate lift but no lifting force.

or i got into neverquits beer and made it all up !

[DemonFrog]

i just remember reading some posts and about the velo that the fuse creates lift, mabye you are right about it being plate lift

[WileEZ]

there are aircraft that use heated leading edges (bigguns) mabye if you could get a hold of a technical manual for one it could give you some data to work with?

Actually, I did! Most of them apparently use the exhaust or bleed-off from the engine/turbine to provide the heat.

 

Unfortunately, nothing about the freezing points, only about the working temperatures.

 

One interesting system used the coolant from a liquid cooled engine to heat the leading edges, it's actually part of the "radiator" setup. (IICR, I read this in one of the innumerable NASA reports.) I don't know if this was ever used outside of test planes.

 

I haven't found any that used electric heat so far. Technical information other than NASA is kinda hard to find. Still looking.

 

NASA is full of interesting and useful reports! It's real easy to get sidetracked!

[DemonFrog]

i came across one that said lancair was working with a heated one, considering that speeds from their craft are semi close to EZs it might be worth giving them a call.

[Kent Ashton]

As to inflatable boots, you probably can do the same thing on the cheap by using bicycle or motorcycle inner tubes and cut until you end up with a long flat piece

Fun to dream but let's be realistic. there's no way you can fit a bike inner tube to our wing and have anything remotely close to the near-laminar airfoil we have now. It calls for a custom molded boot and a sophisticated inflator system. It would demand an entirely new wing designed for the deice system: expensive, complex, heavy, draggy.

 

Don't waste your time. Build to plans and go flying. Light IMC is possible. When there is ice, stay home or buy an airline ticket.

-Kent

[Marc Zeitlin]

i just remember reading some posts and about the velo that the fuse creates lift,...

The fuselage does create lift, albeit extremely non-linearly (which is why predicting deep stall behavior at high AOA's is so difficult). The lift curve slope is very shallow, however - it's not an efficient lifting surface.

 

mabye you are right about it being plate lift

What, exactly, is "plate lift", that's different from any other form of lift?

[Marc Zeitlin]

Actually, I did! Most of them apparently use the exhaust or bleed-off from the engine/turbine to provide the heat.

Correct. And this is an extremely large amount of energy - bleed air is VERY hot, and there can be a LOT of it.

 

I haven't found any that used electric heat so far. Technical information other than NASA is kinda hard to find. Still looking.

See below.

 

i came across one that said lancair was working with a heated one, considering that speeds from their craft are semi close to EZs it might be worth giving them a call.

You're thinking of:

 

http://www.airplanedeice.com/thermaWing/airFoilProtection/

 

Note that this is a 150A alternator at 80V, for a total of 12KW, or 16 HP, and it weighs 36 lb.