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Katana loosing engien power


fagraas

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Hi lads.

im experiensing some trouble when landing with the new katana.

when i slow down and want to, say go around or t&g. i cant get engien power. when i land, there is not enough power to taxi even. i have run the maintenance check and service check. no errors that need attention.

Im wondering if anyone have experienced the same problems. Im wondering if it could be weather related in the sim. but find that strange. but i have tried running carb heat on, fuel pump on. but nothing.

if someone wants to recreate. weather is: W347@04, V10m, ovc021, temp 59F/50F, alt 3007.

I was looking at the humidity. but would not the carb heat take care of this? prevent wather to form in the carb. or am i wrong.

hope someone have an idea.

Christer

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  • 2 weeks later...

What was the altitude of the airport? Can't remember if the Katana has a mixture lever or not, haven't flown her in days, and haven't had her long, but I'm pretty sure the high altitude/mixture is modelled. If it was above 4000ft, try leaning the mixture and see if the power comes back.

Might be totally wrong of course, but that's all I can think of without trying your flight :)

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Yes, this is totally wrong. The Katana adequately models the auto-mixture of the Rotax 912 so there is no mixture lever modelled. It WILL be carb icing.

Apply the beta patch, then learn how to apply carb heat to prevent carb icing. It's not intended as a de-icing solution, but as an icing prevention solution.

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Thank you Simon, it was just a guess as I hadn't flown the Katana in a while, and am not familiar with it yet.

You say it WILL be carb icing, so can I pick your brains a minute please? I understand what carb icing does, and how it occurs, but I'm totally lost as to how to recognise it may happen in FSX. What sort of clues would I be looking for to prevent the carb icing up? I know it's based on OAT and dewpoint etc. but where do I find this information in FSX while flying to a given destination? Obviously there would be indications in real life flying that a pilot would pick up on, but are there indications in the sim?

Thanks for any response.

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I know it's based on OAT and dewpoint etc. but where do I find this information in FSX while flying to a given destination? Obviously there would be indications in real life flying that a pilot would pick up on, but are there indications in the sim?

Hi,

either listen to ATIS or look on your OAT indicator in the cockpit to get the temperature. Carb Icing is likely to occur when the temperature is between -5°C to + 20°C. When flying in a zone within these temperatures, always apply carb heat when reducing a significant amount of power. And always apply it during the approach.

In case of a go around first apply full power and establish a positive climb. Finally remove the carb heat.

If the OAT is outside of the limits I described, there is no need to use carb heat.

Hope that helps a bit.

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I've experienced exactly the same issue and have found it very frustrating. What I don't understand is, even after landing for ten minutes I still have found it impossible to get the engine performing correctly. I know it is finger trouble, well I hope it is, but nevertheless would like to discover the correct procedures. I have understood it to be more a case of high humidity rather than temperature. Is this wrong?

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I have understood it to be more a case of high humidity rather than temperature. Is this wrong?

Hi,

this is indeed correct. But even in reality no one cares about it. Carb icing will normally only occur when the temperature is between -5°C to + 20°C. This is all you learn during flight training. Just use the carb heat accordingly. There's no much more you have to take into consideration.

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I've experienced exactly the same issue and have found it very frustrating. What I don't understand is, even after landing for ten minutes I still have found it impossible to get the engine performing correctly. I know it is finger trouble, well I hope it is, but nevertheless would like to discover the correct procedures. I have understood it to be more a case of high humidity rather than temperature. Is this wrong?

Please do use the search function. We have explained the criterion behind the concept of carb icing, and there are also graphs and charts that explain the circumstances that give rise to prevalence.

I have also explained, with pictures, why this `function` inherited from FSX is not necessarily correctly represented when considering the propensity for carb icing in the Rotax.- or rather lack of it. However, it DOES happen in combinations of temperature and humidity, but most specifically by the conditions in the venturi.

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Hi,

this is indeed correct. But even in reality no one cares about it. Carb icing will normally only occur when the temperature is between -5°C to + 20°C. This is all you learn during flight training. Just use the carb heat accordingly. There's no much more you have to take into consideration.

Absolutely. One only applies carb heat to prevent carb icing. Applying it after it has started is pilot error.

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The way I've understood how carb icing works is that you can still get carb icing at cruise power if the conditions are right. I know what conditions may well cause carb icing, thanks to Simons graphic in another post elsewhere. I downloaded the picture for reference. What I don't understand is inside the sim, apart from ATIS, how do you find the dewpoint? OAT I'm okay with, I know where I can find that. I'm talking about flying along happily OAT say 9 deg, and all of a sudden you start losing power. By then it's too late for carb heat, but I haven't seen anything to indicate that carb icing may be problem. What I'm asking is what SIGNS are there in the simulator that carb heat is a risk? It's no good just saying between -5 and +20 deg use carb heat, because I'll be using it every single flight in the UK. Don't often see temps above +20 to be honest. So if I go by what has been written here, I'd take off and switch carb heat on, and then leave it on through the whole flight. That can't be right surely?

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Well yes, to a certain extent - and no, because the dewpoint is a variable, calculated from relative temperature,

The `yes` comes from the fact that carb icing is not a direct function of either temperature or humidity but rather the interaction of both in the `neck` of the intake system - accelerated air lowers in temperature, while humidity is a constant, so if accelerated air entering the carb is carrying a lot of moisture, then carb ice is a risk.

The `no`comes from the previously posted advice about the positioning of the carb intake of the Rotax in the Katana well away from the air intake, and close to the exhaust where there is some local heating, as well as reduction in humidity.

Having never really suffered from carb icing in the Katana in the UK, but knowing of a few that have, I can see that Marcel has trod a fine line between `realsim` and realism.

He has experienced carb icing in a Kat first hand, so it follows that he would include it as a `feature` of the 4X. However, most Rotax engines can easily be fitted with a carb heater, often using the heat from the exhaust, and the effect on power is minimal as it doesn't heat the air going into the carb venturi, it actually heats the carb body itself - ice still forms, but it doesn't stick, so it doesn't accumulate,

In simple terms, unless the engine is operating at persistent high power, carb heat should be applied as soon as power is reduced, whenever carb icing is suspected by latent weather conditions.

The problem seems to be that either is an extreme, not a minor inconvenience, as far as FSX is concerned..

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Ah, so if I'm understanding this correctly, it's like a switch as far as FSX is concerned? It either IS or ISN'T, and there's no in-between. Therefore there is no visual clues as such, and the only thing you really have to go on within the simulated environment is basically the OAT? Then the posts I've read so far make sense, but don't really solve my problem. Carb heat shouldn't really effect the engine, but I've noticed a significant increase in cylinder head temps once used. I've seen this mentioned elsewhere.

If one suffers from carb icing, and has to put down as soon as possible, what's the procedure after that? What actions would I need to take to restore the engine back to full power? Baring in mind that an inspection shows no faults, or maintenance required.

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You've hit the nail on the head. FSX has a far too simplistic notion on carb icing - even to the extent of applying it to fuel-injected aircraft! And in the sim the best clue is temperature, followed by the presence of cloud and/or precipitation. That gives the virtual pilot the clues that icing might be a potential threat. IRL, there can be other clues such as `fuzziness` and reduction in visibility, small droplets of moisture appearing in corners of the screen, even shininess of the roofs below when it's not raining. Like motorcycling, you develop a sixth sense for the likely onset, and apply carb heat early.

On the one hand the Rotax carb heat solution is doing more to the engine than it should in the Kat 4X, as it should just drop peak power by a few percent but otherwise be totally safe to use all the time, but if the carb icing was that severe as to cause that level of obstruction then it is likely that a significant increase in temps would result - although with a partly water-cooled engine I don't see how that might happen unless the ice was also forming and blocking the radiator - which does not feature accelerated air, so would simply be true icing conditions, in which you wouldn't fly an airplane like the Katana, anyway...

I'm sure Marcel has something planned for the full-release patch.

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Thank you. I was thinking about it last night, and you have just described the exact clues for RL icing conditions that I thought of, the water droplets on the screen, 'fuzziness' (which I thought of as haze). At least I understood the theory then, that's helpful to know.

I would've thought summer time in the UK with real weather shouldn't be that much of a problem though, but obviously I was wrong. Think I'll go fly in Australia instead. Joking, I know it makes no difference, you can still get carb icing there too.

Thanks for the help much appreciated.

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Just some short information: The Katana does not use the FSX carb icing system. Ice in the 4X will accumulate faster or slower depending on the circumstances. It will cause power loss, rough engine running (may be hearable)... if there is already some ice causing power loss, it will be harder to melt it...

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Well that bit of information has just made it a whole lot harder :D So now, if the temps are between -5 and +20, it's cloudy, it's a Monday of Thursday, USE CARB HEAT? I guess it's pretty much a complete guess then :P Well just so you know, the weather here right now is pretty ###############, and I can't get enough power to climb with a brand new plane. I'm lucky to get 100 AGL and 60 knots. Tried everything. I'm restricted to flying in simple mode at the moment. I've completely reset the data aswell, and that didn't work. That could be why I don't see any of these planes locally, too damn damp and cold here :hahaha_s:

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Well that bit of information has just made it a whole lot harder :D So now, if the temps are between -5 and +20, it's cloudy, it's a Monday of Thursday, USE CARB HEAT?

Use carb heat only when reducing a significant amount of power. Remove it when throttling up.

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Hmmmm, I still have issues with carb heat. I literally had my engine running for 6 min today while taxiing out for departure at Santa Barbara, CA. Temp 17 dewpoint 14.

Got one pattern in then engine lost power - landed successfully on a road. Seems to be a common practice for me!

I've basically stopped flying this plane because almost everytime I fly I get serious carb icing.

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I personally would like to see in a forthcoming patch either losing this feature, which is probably unthinkable to some, or better to have the ability to somehow monitor it or switch it off by choice.

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I agree. Its prevalence in the sim is not representative of the real world, and its function is causing damage which does not apply in the real aircraft engine. There is plenty of other mishandling that can cause breakage and dilapidation, so losing this one wouldn't hurt.

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Use carb heat only when reducing a significant amount of power. Remove it when throttling up.

After reading other posts on the behaviour of carb icing, it appears that this statement isn't actually accurate. Carb icing can be suffered even at cruise power if conditions are right. From what I understand so far, if dew point is close to OAT then carb icing can be problem, no matter what power settings. If dew point is much much lower than OAT, and OAT is above 20, then it isn't so much a problem. So I'll go fly in the desert, where it's hot and not damp :)

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After reading other posts on the behaviour of carb icing, it appears that this statement isn't actually accurate. Carb icing can be suffered even at cruise power if conditions are right. From what I understand so far, if dew point is close to OAT then carb icing can be problem, no matter what power settings. If dew point is much much lower than OAT, and OAT is above 20, then it isn't so much a problem. So I'll go fly in the desert, where it's hot and not damp :)

Hi, indeed it is. But always you have to follow the instructions stated in the POH of your airplane ;) . Procedures are different for nearly every aircraft type. Only what the POH states, is correct.

I have to admit I have no flight hours on Diamond aircraft at all. But I have a lot of experience on PA-28 aircraft and very few hours on Cessna 152/172.

What I tell is from experience and what I learned at my flight academy. As already said in the forum, there are many reasons that affect the occurence of carb icing. We pilots don't care much about it, just follow the learned procedures. And these include switching on carb heat when reducing significant amount of power. As I mainly fly PA-28 aircraft I can almost only tell you from this particular type, and Piper even stats in the POH that carb heat is NOT A MUST to be applied when known that you are not icing conditions. Anyway we always use it as a precaution.

Of course the Rotax engine might be different, but I think more or less the procedures are the same.

And also note this is "just" a simulator, although it is realistic there are dozens of factors that cannot be replicated in a simulator.

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