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few more issues, please help.


Coban

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Hello gentlemen. I am enjoying Katana in every aspect, but lately I get high oil pressure. After take off, oil pressure sits on yellow arc, just about 90psi. I need some advice to drop it back to green. Second, sometimes I am not able to start engine, ignition will not fire easily, after a few attempts it will start. Third, and I find this so confusing, which is com/nav. I use it in Realistic mode, but what is the difference between Simple and Realistic mode for the radio ? If I enter a localizer, I see correct stuff on the gauge on main panel but I guess something wrong in radio display. It say LOC, but the line never centers, it stay on left always. I can upload a screenshot, if you did not understand what I mean. Cheers.

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As in real life high oil pressure means either the wrong oil, wrong oil level, a partial blockage, or the oil is cold. All of these things are properly simulated in the Katana X. So you need to be systematic:

1: check dipstick for correct oil level

2: Check oil type is correct for the prevailing weather conditions

3: Check maintenance isn't giving you red or yellow flag on the engine or oil

4: If you are flying in cold conditions, put the baffle in

5: Ensure you warm the engine properly before flying

The manual specifically states that oil pressure will advance in the yellow arc until the oil reaches normal operating temperature. ASSUMING THERE ARE NO FAULTS YOU ARE FLYING IT WRONG.

For engine start, follow the procedure.You are missing something in the checklist - fuel pump, choke (depending on hot or cold start) slight throttle open (again, depending on hot or cold start), forgetting to warm the engine properly, not using the baffle in cold weather, or using it in hot, etc. etc.

Or it could be the wrong fuel, or it might be related to the oil pressure and you have abused the engine by flying it at high power settings when cold - this will make it difficult to start. Again, check the maintenance module for areas of concern.

You MUST follow the checklist

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Okay Simon thanks a lot, I will check them on next fly. But there is two oil brand and two fuel brand, how to choose them ? One more thing, I am sure you have an idea about fuel flow of Katana. I just want to know how to calculate how much fuel I need. I drive car and I know how much litre it will burn roughly per mile, so is there an information related fuel burn rate for Katana 4x ? Please answer :) Cheers

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  • There are no two different "oil brands", however two oils with different viscosity. As described in the manual (and ideally standard knowledge for any rider of motorized vehicles!?!?) the W40 oil is rather for higher temperatures whereas the W20 oil is less "thick" and thus more adequate for lower temperatures You can find the exact recommended tempertures in the Katana manuals.
  • You will find the fuel burn table in the Performance manual. Fuel burn depends mainly on manifold pressure, propeller RPM and pressure altitude and is measured in Gallons/hour or Litres/hour. You won't get a mileage though with an airplane, as the range of an airplane depends much more on weather conditions than the range of a car.
    You may as well get a "mileage" of 12 or 25 miles per Gallon at exactly the same settings - depending on whether you have a strong headwind or tailwind.
    It is however very easy to estimate fuel burn and range once you completed your pre-flight preparations. Based on the performance charts you will know the fuel burn per hour as well as the calibrated air speed. Now you calculate the wind drift which will also give you the estimated ground speed. Divide the distance to your destination by the estimated ground speed to get the estimated flight time. Now multiply the fuel burn rate with the estimated flight time, add some litres for climb and reserves and you have the required amount of fuel for the trip.

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Wow thanks Bernd, you explained it very clearly. But could you put some examples for estimated ground speed, estimated flight time if you have time ? Regards

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Okay... - but I will keep it very easy.

i don't have the Katana manual at hands so my numbers will rather be estimates than real life figures:

You plan to fly to an airport 275 NM away. You plan to fly at 4500 ft altitude and you are lucky that QNH is exactly 1013 hPa today and you decide to fly at a fuel burn rate of 28 L/h. Your performance charts indicate that you will get this fuel burn rate at 125 kts CAS at 4500 ft with 2300 RPM and a manifold pressure of 24 (just a guess!).

When checking the weather report you notice that the wind blows at 15 kts directly at your nose - so the ground speed will be 125 kts CAS minus 15 kts headwind => 110 kts estimated ground speed.

Your destination is 275 NM away based on your flight plan, so 275 NM divided by 110 NM/h gives 2,5h. Flight time will be roughly 2,5 hours and multiplied by the fuel burn rate of 28L/h you will need about 70 litres for the trip. Add 5 litres for checking the engine and taxiing to the runway, 5 extra litres for the climb plus 30 mins reserves (14 litres) and you come up with 94 litres for this trip...

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Wow thanks Bernd, you explained it very clearly. But could you put some examples for estimated ground speed, estimated flight time if you have time ? Regards

Why would you need anyone to repeat this information? Manual 5 performance.pdf has exactly this info in readable, tabulated form INCLUDING allowances for pressure density and altitude. wind speed and relative direction, even maximum flight duration at given power settings...

At the risk of repeating ourselves, It's all IN THE MANUAL...

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yea, I saw those graphics and they explain everything perfectly. Thanks. In meantime, today I was flying, and manifold pressure just gone. It was so realistic, I would lie if I say I didn't get scared when I heard that scary sound coming from plane. The sound was like wuhzzzz, and of course I just crashed onto mountains. I will check manual for that. (in case If I can't find anything) do you guys have an idea what might cause that ? Cheers.

Update.

Guys I couldn't find anything in manual related to this. I had this crash, while climbing to 5000 feet. OAT was 4 Celsius. Propeller RPM around 2200. Throttle at full.

Before take off, I done all necessary maintenance, and all gauges were on green all the way till crash. What exactly happened is manifold pressure went to 0, and of course no thrust, started losing speed and crashed onto mountains. Though engine was still running.

Edit : I found something in manual, it says ;

Max. T/O Power (5min) 2385RPM

Max. Continuous Power 2260 RPM

But in checklist, it says, for cruise throttle as required. So I already reduce propeller RPM to 2200, should I also reduce throttle ? Because all the way, from take off to crash, I had full throttle, only reducing propeller RPM to 2200 after safe altitude, which was 500feet.

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Seriously no joy. All day I could not land even once. Simply engine losing RPM then it dies. CHT gauges shows maximum degree. Whatever I do, I can not reduce it nor increase manifold RPM. Tried carburoter heat, it makes worst. It will kill engine in no time. If CHT at max, is icing still possible ? If the problem icing, why carburoter heat can not solve the problem ? This happens when I climb to 4500 feet or more, below that there is no problem at all. Anyone has an idea ?

Regards

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Read the topics on carb icing and carb heat - it will be most informative... carb heat is NOT a pancea nor is it an instant cure.

And note that the aircraft is NOT approved for flight into icing. What you got was a warning you didn't heed, and it killed you, virtually speaking.

Another lesson learned from this masterful simulation!

And no, you cannot run at full power continuously, you need to draw back on the Manifold Pressure as well as the RPM. But do note that full POWER is NOT the same as full throttle - as a non-turbocharged aircraft you may need to increase the throttle as you climb to maintain the POWER setting in the charts. That's why the charts refer only to the MP and not the throttle position.

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Oh Snave... - in a way you are right of course but though your answer is correct and funny for those who enjoyed a good training, it may as well just confuse those who still lack the required knowledge and understanding...

Coban, the power of an engine depends on a healthy air-fuel-mixture and the higher the altitude is the lower the air-density becomes. In most other GA SEP aircraft you have to adjust the mixture accordingly to balance the air-fuel-mix but your Katana's Rotax engine is a bit more advanced and controls the mixture internally.

Still the result of less air - and thus less fuel - is less POWER! The higher you fly the less power will be generated by the engine. What Snave correctly mentioned is that even at full throttle above certain altitudes the generated POWER is way lower than the critical thresholds. Therefore the charts show MP (manifold pressure) and not a throttle setting.

Regarding your engine problems I have to side Snave, too. It all sounds like a typical carburator icing. The cold air and the moisture together with the Venturi effect (I would google that if I were you) reduce the temperature in the carburator by up to 20°C - which leads to ice building in the cold carburator (which is far away from the warm cylinder heads). This is normally a process which takes several minutes and in the beginning it is only noticable by a decreasing manifold pressure, next indication is a decreasing indicated air speed. That is the last safe point to engage carburator heating. This will in the beginning reduce the engine power further (due to the warmer air it leads into the carburator) but it will melt the ice also and after some minutes your carburator will be ice-free again and your engine will produce max power again.

The advice to any pilot is always... - if in doubt, pull the carburetor heat! In high humidity even at temperatures of 15°C (sometimes at even higher temperatures!), when it rains, in a descent and at temperatures around 0°C always pull the carb heat! In temperatures between -10°C and 10°C keep an eye on the manifold pressure (check it at least once per minute) and if MP decreases pull the carb heat immediately.

In case of a full carburetor icing or even engine loss, use your altitude to find an emergency landing field asap (to avoid a crash). If you are high enough engage carb heat nonetheless and glide as slow as weight of the aircraft and pressure altitude permit. The slower you fly and the lower you get the warmer the carburetor will get and with a lot of luck you may even be able to restart the engine in flight...

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Thanks a lot Bernd, and Simon. I read other carb heat, icing related topics as well.

So what I got is, Katana X is not meant to fly in icing conditions.

Second, if there is a low risk of icing, you can use carb heat, however carb heat is there for Anti-Ice, not De-Icing.

What I didn't understand is, why don't we just use carb heat during the all flight ? What is the negative affect of carb heat in non icing situations ?

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In most situations carb heat supplies wamer air to the carb venturi. But not in the Rotax, which uses a heated venturi to prevent ice build up. The real Rotax uses, as you will have seen from the images and references I posted, a certain amount of exhaust heat to pre-warm the air - which helps take some of the moisture out of it, as well as a heated `throat` to the venturii itself. Both these measures mean that power is reduced so carb heat is not used when peak power is needed or likely - take-off, high-power settings and go-around are the obvious times.

So you wouldn't want carb heat in those circumstances, nor when the ambient weather conditions don't propagate carb icing anyway - the auto mixture of the Rotax is really rather crude, so fuel consumption also suffers when carb heat is introduced unnecessarily. Carb heat is also less prevalent at very low power settings - when the fuelling demand is low enough that the air entering the venturii is not being accelerated particularly much, nor is the fuel flow demand likely to be affected by a partial blockage.

Sadly, FSX is not that sophisticated! Again if you look at the carb ice topics you will find a chart which shows the really rather narrow parts of the flight/weather envelope when carb icing is prevalent in the Katana. Although we did argue about its prevalence in the real bird FSX does use a very much narrower `qualifying measure` to introduce icing (there is no relative humidity involved in the sim, as best anyone can tell) so it's rather more `on` or `off` in the sim - which makes its use and the degree of icing rather more obvious than it usually is in proper flying, but it still punished you for forgetting it!

So carb heat is off for take-off and climb; on for cruise and descent or before any downward power adjustment; then off again for landing when go-around power might be needed.

And yes, you've understood the difference between de-ice and anti-ice perfectly!

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Hi Snave,

I never flew a Katana (or a Rotax engine) in real life... - I'm more focused on slightly larger birds... B)

Is it true that you cruise with carb heat applied as a standard or is that only true in Englands climate? I never fly the Continental or Lycoming engines with carb heat engaged unless weather (rain, high humidity, temperatures between -5°C and +5° at ground level) really requires this. Please don't take the temperatures above too seriously, each aircraft behaves differently and while our clubs C172N is very robust concerning carburetor icing, a C182 I've flown got carb icing as soon as there was a cloud visible in the distance, even at 20°C!)

However even with mixture lever on board carb heat has the big disadvantage that engine power and/or fuel consumption suffer from it. You mentioned yourself that the automatic mixture control of the Rotax engine is rather "crude", so why do you recommend to cruise with carb heat on?

I rather fly with an eye on prop RPM, carburetor temperature indicator (we have such a nice device in our C172M), manifold pressure (if available) and EGT... - which for me is a great indicator of carb icing in our PA28. As soon as ice builds in the carburetor the mixture gets fatter and thus EGT goes down slightly but perfectly visible. The EGT display indicates a beginning icing 3-5 minutes before RPM decreases in our PA28.

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As I mentioned to Marcel when the icing prevalence was first discussed, I have never experienced carb icing in any serious fashion in a Rotax-engined Katana, as the positioning of the carb inlet above the exhausts and toward the rear of the cowling means the air is significantly warmed and dried before being ingested.

That is not to say it doesn't happen, but the only time I use carb heat is on first power reduction prior to descent. However, others who fly longer flight profiles than I with the Rotax have mentioned that during the course of a flight, passing through different weather patterns and ambient conditions you can detect the onset of carb icing at lower power settings when the `soak` is such that ice does start to form then the issue is that not all Katanas are equipped with the heated venturii, but if you've got it it's better to use it to prevent carb ice. Because it's a twin-carb engine the Rotax often gives little incipient warning of carb ice until it really has happened and then carb heat is a poor fixative measure when it is simply good pilotage to use it if you have it and icing is likely. Personally, I don't fly the `economy` flight profile so maintain power and heat that keeps the carbs out of the icing zone - the Rotax is so frugal anyway compared to the behemoth iron blocks.

The effect of carb heat on power and consumption is significantly less in the Rotax than Lyco's and Conti's, even though it is there.

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2012-2-18_14-29-30-65.jpg

2012-2-19_17-6-39-150.jpg

First picture, there is a massive smoke comes out from the wheels while taxing in rainy weather, on wet ground. Isn't that a bit too much ?

Second one, there is a blue, weird shaped thing, just under the attitude gyro, does not look like anything that would make sense..Any idea what is that ?

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that weird blue thing is the diamond aircraft corporation logo.. Google is your friend. enter diamond aircraft logo.. see images.. it is sometimes white and sometimes blue. Mostly blue..

now that is some detail hey..!!

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...and the "white smoke" is just water spray and whether it's too much or not depends on the amount of water on the runway, speed, runway material, etc. - but in any case it does not depend Marcel's Katana model but rather on the FSX display engine.

It might sometimes look a bit "too much" but please keep in mind that the Katana is a pretty small plane in comparison and the FSX doesn't seem make a big difference between a moskito and a A380...

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Thanks guys..Now I know, it is just how it is, nothing wrong with my installation..

By the way, the real Diamond Aircraft logo looks so good, but the one in sim, looks plain rubbish..sorry :D

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