TKS v De-ice boots v Heated leading edge
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One sheet I read about the C400 system is that the alternator was 50A at 80V (or IIRC 80A at 50V) which is 4kW, not the 40kW I posted earlier 
There were considerable problems with it, for a long time, which Lancair (and later Cessna) blamed on dealers installing it incorrectly (no idea if that's true).
Rubber boots remain popular, after all these years...
Known ice certification is not as clear as it might appear. Take the TB20: the G-reg version is certified but the N-reg one isn't - because the FAA requires a backup alternator and some other bits, which relate to systems redundancy but don't actually relate to ice protection.
By all accounts, TKS is incredibly effective even in the worst conditions in Europe. I know of pilots who fly in virtually all weather in the most northern bits of Europe and they say the ice just comes right off. Expensive though - 20 litres of TKS fluid is about £150 to £200 delivered and you can blow that away in an hour.
There were considerable problems with it, for a long time, which Lancair (and later Cessna) blamed on dealers installing it incorrectly (no idea if that's true).
Rubber boots remain popular, after all these years...
Known ice certification is not as clear as it might appear. Take the TB20: the G-reg version is certified but the N-reg one isn't - because the FAA requires a backup alternator and some other bits, which relate to systems redundancy but don't actually relate to ice protection.
By all accounts, TKS is incredibly effective even in the worst conditions in Europe. I know of pilots who fly in virtually all weather in the most northern bits of Europe and they say the ice just comes right off. Expensive though - 20 litres of TKS fluid is about £150 to £200 delivered and you can blow that away in an hour.
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The problem is that while an anti-ice system may be very effective, it can fail, and even if it doesn't fail, other things can.
Everybody who does instrument training or has an instrument rating has some modicum of exposure to partial panel work. In a controlled environment, it's not that big a deal. In solid IMC, bouncing around, dealing with ice and ATC, it's a very big deal. Flying light airplanes in IMC, especially airplanes equipped with dry vacuum pumps and single sources of instrument power, are begging for trouble.
Flying a single engine airplane IMC is a questionable act at best, given one engine. Flying a single engine airplane IMC with one generator and one vacuum or instrument source is more questionable. Flyin a single engine airplane in instrument conditions in ice with the deck already stacked against one, is playing roulette (russian, to be exact).
If one has flown airplanes with boots and hasn't had one side fail to inflate, or fail to shed ice, or bridge, then one hasn't flown much with boots.
If one has flown in ice but hasn't seen ice quickly build to overwhelm the capabilities of the ice protectiion in use, one hasn't flown much in ice.
The fact is that one can be in icing conditions in which the preceding aircraft and the following aircraft don't experience ice, but you do; severe ice. It happens.
I experienced an ice build-up in a piston Twin Commander years ago that caused us to go from a cruise speed to minimum controllable with a descent below MEA (in the mountains) in less than a minute. A 50 knot loss in less than a minute, and ice protection wouldn't slow it down. Ice shed from the propellers putting holes in both sides of the airplane, and causing a noise in flight that sounded like 12 gauge shotguns being fired continuously behind our heads. It developed unexpectedly, rapidly, and couldn't be controlled.
We were fortunate due to location and circumstances to be able to drift down to the surface where we stopped descending, and followed car taillights in cloud and snow to an airfield. Ice is very serious stuff.
Boots are popular, but they do fail, and boots do change the flight characteristics of the airplane during inflation, and during the case of assymetrical inflation. Also bear in mind that if one is using the same vacuum pump for instruments as for the boots, lose one, lose both.
Everybody who does instrument training or has an instrument rating has some modicum of exposure to partial panel work. In a controlled environment, it's not that big a deal. In solid IMC, bouncing around, dealing with ice and ATC, it's a very big deal. Flying light airplanes in IMC, especially airplanes equipped with dry vacuum pumps and single sources of instrument power, are begging for trouble.
Flying a single engine airplane IMC is a questionable act at best, given one engine. Flying a single engine airplane IMC with one generator and one vacuum or instrument source is more questionable. Flyin a single engine airplane in instrument conditions in ice with the deck already stacked against one, is playing roulette (russian, to be exact).
If one has flown airplanes with boots and hasn't had one side fail to inflate, or fail to shed ice, or bridge, then one hasn't flown much with boots.
If one has flown in ice but hasn't seen ice quickly build to overwhelm the capabilities of the ice protectiion in use, one hasn't flown much in ice.
The fact is that one can be in icing conditions in which the preceding aircraft and the following aircraft don't experience ice, but you do; severe ice. It happens.
I experienced an ice build-up in a piston Twin Commander years ago that caused us to go from a cruise speed to minimum controllable with a descent below MEA (in the mountains) in less than a minute. A 50 knot loss in less than a minute, and ice protection wouldn't slow it down. Ice shed from the propellers putting holes in both sides of the airplane, and causing a noise in flight that sounded like 12 gauge shotguns being fired continuously behind our heads. It developed unexpectedly, rapidly, and couldn't be controlled.
We were fortunate due to location and circumstances to be able to drift down to the surface where we stopped descending, and followed car taillights in cloud and snow to an airfield. Ice is very serious stuff.
Boots are popular, but they do fail, and boots do change the flight characteristics of the airplane during inflation, and during the case of assymetrical inflation. Also bear in mind that if one is using the same vacuum pump for instruments as for the boots, lose one, lose both.
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We were fortunate due to location and circumstances to be able to drift down to the surface where we stopped descending, and followed car taillights in cloud and snow to an airfield.
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Flying a single engine airplane IMC is a questionable act at best, given one engine
I think I am going to give up.
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I believe I said it was a piston twin commander. It wasn't that slow, but following a line of cars taillights in the cloud on a mountain road doesn't require slow. Just enough cars to light the way. We knew where we were, and the cars were leaving a mill, headed for a small town. We landed at the airport at the small town.
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Ah yes, I see.
IMC in a SEP - well it is impossible to generalise and I am a little surprised you should take your view. No one wants to be bashing through hard IMC for any length of time; transitioning to VMC on top is what it is all about.
Of course IMC introduces new and different risks but when push absolutely comes to shove the difference between a SEP and a mulit is the expectation you might make an unscheduled landing. Save that, some SEPs are likely to be more reliable that some twins I know! Personally I have never been able to balance the risks against rewards of flying a SEP over terrain where I would be very uncomfortable to land or over an under cast that would give me little chance of landing. However to state the obvious the engine doesnt know it is in IMC. If it quits, the aircraft is just another glider and with a reasonable base it is probably not going to end a lot differently that if it quit on you in VMC. Just to distinguish in the simplest way between IMC and VMC seems illogical on the basis that you only have one engine; to distinguish because you only have one electrical power source or one vac pumps makes a great deal more sense.
Obviously whether it is SEP or multi dont go there if the aircraft cant cope with the forecast ice, turbulence or whatever hazards are associated with the IMC in question, but that is a factor of the aircraft not the number of engines it has.
IMC in a SEP - well it is impossible to generalise and I am a little surprised you should take your view. No one wants to be bashing through hard IMC for any length of time; transitioning to VMC on top is what it is all about.
Of course IMC introduces new and different risks but when push absolutely comes to shove the difference between a SEP and a mulit is the expectation you might make an unscheduled landing. Save that, some SEPs are likely to be more reliable that some twins I know! Personally I have never been able to balance the risks against rewards of flying a SEP over terrain where I would be very uncomfortable to land or over an under cast that would give me little chance of landing. However to state the obvious the engine doesnt know it is in IMC. If it quits, the aircraft is just another glider and with a reasonable base it is probably not going to end a lot differently that if it quit on you in VMC. Just to distinguish in the simplest way between IMC and VMC seems illogical on the basis that you only have one engine; to distinguish because you only have one electrical power source or one vac pumps makes a great deal more sense.
Obviously whether it is SEP or multi dont go there if the aircraft cant cope with the forecast ice, turbulence or whatever hazards are associated with the IMC in question, but that is a factor of the aircraft not the number of engines it has.
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Of course IMC introduces new and different risks but when push absolutely comes to shove the difference between a SEP and a mulit is the expectation you might make an unscheduled landing.
Loss of a vacuum pump in the single can be devastating; in the twin it can be a non-event. The same for loss of the alternator or generator, given one's higher expectations for electricity when flying under IFR.
However to state the obvious the engine doesnt know it is in IMC.
If it quits, the aircraft is just another glider and with a reasonable base it is probably not going to end a lot differently that if it quit on you in VMC.
well it is impossible to generalise and I am a little surprised you should take your view.
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When flying in precipitation and visible moisture, the engine faces a higher potential for induction ice.
Modern SE planes have backups and some have a total dual system. Look at the Cessna 400 as an example.
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Yes, I was also assuming the SEP in question was designed to operate in IMC and the pilot capable.
Of course dealing with an engine failure in IMC is challenging - dont go there if you think you cant.
Of course some twins have more redundancy of some systems that singles but the engine aside some singles are equally capable.
That is why I was surprised by SNS3's comments - I'd taken these as read amoung the more experienced pilots including a realisation that the way the engine performs in IMC will be different but icing and heavy rain aside there is no more or less reason for an injected engine to fail in IMC than in VMC.
Added to clarrify: dealing with failures in IMC is always going to be more challenging than in VMC, I am not suggesting other wise. However all the failures that can happen on a mulit can equally as well happen on a single so my assumption is that the pilot is capable of delaing with the systems failure. As we have said the chances of that failure may be more, less or the same depending on the aircraft type and unrelated to the number of engines.
Of course dealing with an engine failure in IMC is challenging - dont go there if you think you cant.
Of course some twins have more redundancy of some systems that singles but the engine aside some singles are equally capable.
That is why I was surprised by SNS3's comments - I'd taken these as read amoung the more experienced pilots including a realisation that the way the engine performs in IMC will be different but icing and heavy rain aside there is no more or less reason for an injected engine to fail in IMC than in VMC.
Added to clarrify: dealing with failures in IMC is always going to be more challenging than in VMC, I am not suggesting other wise. However all the failures that can happen on a mulit can equally as well happen on a single so my assumption is that the pilot is capable of delaing with the systems failure. As we have said the chances of that failure may be more, less or the same depending on the aircraft type and unrelated to the number of engines.
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Few here or elsewhere will be flying the Cessna 400.
While the twin "breathes" the same air, the twin also "knows" it's in IMC. I flew the Piaggio Avanti for a thousand hours or so. It was so sensitive to visible moisture that upon entering a cloud, even a little puffy fair weather cumulus cloud, the airplane lost lift and wanted to pitch forward. On autopilot, it was practically unnoticable, but when hand flying one had to move the control yoke up to two inches aft. Point is, the airplane "knows" when it's IMC, and yes, the powerplants do have an increased potential for difficulty.
Modern single engine airplanes do lack that one formality that separates them from the multi's, of course; a second engine.
While the twin "breathes" the same air, the twin also "knows" it's in IMC. I flew the Piaggio Avanti for a thousand hours or so. It was so sensitive to visible moisture that upon entering a cloud, even a little puffy fair weather cumulus cloud, the airplane lost lift and wanted to pitch forward. On autopilot, it was practically unnoticable, but when hand flying one had to move the control yoke up to two inches aft. Point is, the airplane "knows" when it's IMC, and yes, the powerplants do have an increased potential for difficulty.
Modern SE planes have backups and some have a total dual system.
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While the twin "breathes" the same air, the twin also "knows" it's in IMC.
Of course there will be some performance changes but when I fly my SR22 into IMC that is the extent of it; I am no more expecting the engine to quit because I am in cloud than not.
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Come on be serious - I meant in the context that the engine doesnt say to itself oow I am in IMC, I had better quit.
Of course there will be some performance changes but when I fly my SR22 into IMC that is the extent of it; I am no more expecting the engine to quit because I am in cloud than not.
Ever notice how every little tick and pop and rattle becomes more evident in IMC or at night, and how each tiny nuance of the engine and propeller and airplane become manifest by an order of magnitude in feel and sound? The airplane knows that you experience this phenomenon. Just like a horse can feel it through the reins, the airplane can feel it through your butt, and it knows. IO540 is right to give up, because there's no getting around it. You can fool mother nature, but you can't fool the airplane. It knows.
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I would also vote for TKS being a better solution than boots. Negative points are indeed that usable time is limited, fluid costs money, you have to apply them before you enter the clouds and it's such a mess in the hangar afterwards :-)
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I used to work for a company that sprayed heating mats onto surfaces for deicing use. It was mainly used on the inlet for turbo props and the leading edge of rotor blades for helicoptors.
I don't know why it wasn't used on leading edges of wings. I guess that the area on the inlet was small and on the helos you had lots of power to spare. (i'm not going to explain that comment
) Also I would guess it could re-freeze as it ran back over the wing.
But I don't know why it wasn't used on aircraft as I didn't work on heating mats, I was working on the Eurofighter and the Tornado (& gippen & a320 & F100 & F16) As an aside is that the first time someone has admitted NOT knowing something on here?
I don't know why it wasn't used on leading edges of wings. I guess that the area on the inlet was small and on the helos you had lots of power to spare. (i'm not going to explain that comment
) Also I would guess it could re-freeze as it ran back over the wing. But I don't know why it wasn't used on aircraft as I didn't work on heating mats, I was working on the Eurofighter and the Tornado (& gippen & a320 & F100 & F16) As an aside is that the first time someone has admitted NOT knowing something on here?
