If you want to fly really low to the ground when the OAT is very low

[XarBat]

What would you use: Engine Anti-Ice or Dust Protector? I assume one of them does both since you cannot have both on at the same time.

[Speed]

What would you use: Engine Anti-Ice or Dust Protector? I assume one of them does both since you cannot have both on at the same time.

 

Dust protection, unless it's below freezing where you are flying. To be honest though, I'm not sure that the dust protection has any function in game right now- anyone know? Maybe if the real life function of dust protection is to extend the life of the engine, then dust protection will be very important once we get a resource management system :)

[BKLronin]

...dust protection has any function in game..

 

I can remember that my engine failed once when I hovered very low for a long amount of time. Since then I used dust protection when operating very low.

 

Not sure anyway :)

[Eddie]

To be honest though, I'm not sure that the dust protection has any function in game right now- anyone know?

 

It certainly does.

 

Providing you are moving, select anti-ice. Dust is only an issue if you are in the hover at very low level, whereas ice can be a very big problem regardless of speed or altitude. And FYI, it doesn't need to be below freezing for ice to be an issue.

[Bucic]

What would you use: Engine Anti-Ice or Dust Protector? I assume one of them does both since you cannot have both on at the same time.

Dust will only affect you in a hover. In forward flight at any not ridiculously low speed you have nothing to worry about i.e. you can freely use the anti-icing system.

 

Dust protection, unless it's below freezing where you are flying.

Icing conditions occur over 0 deg Celsius as well. It's not only temperature.

 

To be honest though, I'm not sure that the dust protection has any function in game right now- anyone know? Maybe if the real life function of dust protection is to extend the life of the engine, then dust protection will be very important once we get a resource management system :)

Dust influence on engines is well modelled in DCS. Not only damage after a certain time but also cumulative deterioration (confirmed by Yo-Yo, ED). So no, you can't ignore dust.

Edited December 2, 2011 by Bucic

[andysim]

FAA says anything under 10C with visible moisture (ie fog/sleet/cloud) for anti icing.

[bluepilot76]

I am not sure about this;

That chart and the below +10C thing is certainly the case for piston engines with a carbureta, because there is a massive reduction in temperature as the air speeds up and reduces in pressure in the carb.

 

As the air goes into a turbine the air pressure would decrease slightly at the inlet but all of the fans at the front are designed to increase the pressure so that a huge volume of combustion will occur in the chambor. Therefore I think that turbine pilots are concerned at temperatures closer to zero than piston pilots.

 

As for the dust protection, how long would you need to fly your shark in the dust before there was any effect? I can see wear being a great feature in a dynamic campaign but as it is we get a brand new shiny shark at the start of every mission dont we?

[Stretch]

Also, read the switch carefully. The dust protection position is actually ice AND dust protection. It's a two-fer.

[Bucic]

I am not sure about this;

That chart and the below +10C thing is certainly the case for piston engines with a carbureta, because there is a massive reduction in temperature as the air speeds up and reduces in pressure in the carb.

And you think air just hangs out like it usually does in case of turbine engines? :D The velocity differences are far greater for turbine engines, trust me. If you're still in doubt - Polish Mi-8 crash, 2003. After the investigation the helicopter technical documentation has been supplemented with a requirement to turn on (switch to manual mode) anti-icing system when temperature drops below +10 deg C.

 

As for the dust protection, how long would you need to fly your shark in the dust before there was any effect? I can see wear being a great feature in a dynamic campaign but as it is we get a brand new shiny shark at the start of every mission dont we?

Not too long, so you can test it yourself. As it is now wear is not carried over from mission to mission but even with the current implementation it's cumulative and it increases engine failure probability.

[AlphaOneSix]

The Russian standard is to have anti-ice on at temperatures of +5C and below if there is visible moisture. If there is no visible moisture, or the temperature is above +5C, you don't need to have any anti-ice on. The only difference in-game is that the moisture does not need to be visible. So in-game, always have your anti-ice on below +5C.

 

Furthermore, the anti-ice and dust protection systems use the same set of valves, so if you have anti-ice on for the engines, you also have the dust protectors on. So you end up with the following options:

 

Switch OFF: Anti-ice and dust protection OFF

Switch in ANTI-ICE: Anti-ice AND dust protection ON

Switch in DUST PROT: Anti-ice OFF and dust protection ON

 

Also, in carbureted engines, there is a very large pressure drop in the carburetor venturi. With the pressure drop comes a temperature drop, which accounts for icing above freezing temps outside. Turbine engines, on the other hand, compress the air coming into the engine, actually raising its temperature considerably. The problem with icing on turbine engines is not INSIDE the turbine, it's on the outside of the turbine, where if ice were to build up and then become dislodged, it could be ingested into the engine and cause damage. And since the outside of the inlet is just in normal air, it has to be below freezing to cause icing.

Edited December 2, 2011 by AlphaOneSix

[bluepilot76]

Hey, like I said Im not sure about it, but come on now, icing inside a turbine is surely not going to happen.. Icing of the intake WILL happen if anticing is not on in icing conditions.

 

The reason I brought it up is that those icing graphs with the clouds and +10C etc etc are all over the piston engine PPL manuals, I recognise them very clearly. They relate to carburettor icing which is the most common cause of engine failure in light aircraft and is very easy to occur is you are not aware of the dangers. therefore they are drummed into you all the time in PPL training. Dont recall them so often through CPL or MCC training but maybe I am just getting rusty.

 

I suppose the reduction in pressure as the air goes over the aircraft structure will cause the icing point to occur in warmer than 0C, but not 10C warmer.

 

Other thing to look out for is supercooled water droplets falling from cold air above in warm air below, then definatley you will have problems.

 

Anyway having said all that I better go and read up on that nasty crash.

[bluepilot76]

And you think air just hangs out like it usually does in case of turbine engines? :D The velocity differences are far greater for turbine engines, trust me. If you're still in doubt - Polish Mi-8 crash, 2003. After the investigation the helicopter technical documentation has been supplemented with a requirement to turn on (switch to manual mode) anti-icing system when temperature drops below +10 deg C..

 

Bucic, afraid a quick search on google only revealed a wikipedia article, mentioning an inversion and dodgy thermometer, can you provide the technical details so I can understand why the engines iced up?

 

I see that Mi8 has very long inlet (intake) which would have some serious icing potential in it.

[AlphaOneSix]

Mi-8/17 flight manual says to turn on ice protection at +5C.

[Bucic]

The problem with icing on turbine engines is not INSIDE the turbine, it's on the outside of the turbine, where if ice were to build up and then become dislodged, it could be ingested into the engine and cause damage.

It's worth mentioning that apart from inlets another group of icing prone elements in front of the compressor are compressor support stators. Not dislodged ice on inlets and stators cause unstable airflow/choking which, AFAIK, can lead to engine flameout as well.

 

And since the outside of the inlet is just in normal air, it has to be below freezing to cause icing.

This is a common misconception. Wherever there is an open curved surface there is also pressure and temperature drop, generally speaking. In case of Russian-style engine inlets it's locally rather dramatic. This picture may give you a hint on pressure/temperature drop distribution ;)

[AlphaOneSix]

Fair enough, as long as you consider +5C to be "dramatic", at least for the Mil and Kamov helicopters.

[Bucic]

Hey, like I said Im not sure about it, but come on now, icing inside a turbine is surely not going to happen.. Icing of the intake WILL happen if anticing is not on in icing conditions.

Would you drop that turbine already?! :D Nobody said icing normally occurs inside the turbine (the engine section) except you :)

 

I suppose the reduction in pressure as the air goes over the aircraft structure will cause the icing point to occur in warmer than 0C, but not 10C warmer.

The regulations are there for a reason... Let's settle for the +5, as cited by A16.

 

Bucic, afraid a quick search on google only revealed a wikipedia article, mentioning an inversion and dodgy thermometer, can you provide the technical details so I can understand why the engines iced up?

 

I see that Mi8 has very long inlet (intake) which would have some serious icing potential in it.

Unf. I can't find the tech report. I don't see what it could possibly change apart from being an interesting read though.

 

_______

A real treat for you:

The author refers to the article of Col. pil. Ryszard Michałowski „Cing still dangero-

us” published in AADF Review No. 4/2004, dealing with the failure of Mi-8 helicopter

from 36th Special Transport Air Regiment that took place on December 4, 2003. The

article discusses research and assessments commissioned by the MoD Flight Acci-

dents Examination Board in order to explain that failure.

The paper covers even thermo/aerodynamic calculations of temperature drop and black boxes data graphs.

 

Document for download, pdf, Polish http://www.eskadra.net/biblioteka/twsilnik.pdf

Edited December 3, 2011 by Bucic

[bluepilot76]

I agree, lets settle on +5C. That seems reasoneable. Now Im off to fly the A10 through some clouds. If I dont get any airframe icing Im coming to see you about it! haha.

[Bucic]

I agree, lets settle on +5C. That seems reasoneable.

It was not up for voting, dude :P A16 just has his solid source and I didn't. I've only read somewhere about the limit supposedly being changed for Mi-8s in one of Mil service bulletins. That's why +5 it is.

Edited December 3, 2011 by Bucic

[bluepilot76]

Would you drop that turbine already?! :D Nobody said icing normally occurs inside the turbine (the engine section) except you :)

 

Oh ok,,,I guess I was confused when you put the piston engine icing chart up. It seemed to indicate you might not know what you were talking about.

 

Thanks for giving me the permission to use a sensible value like 5C again...

[XarBat]

Also, read the switch carefully. The dust protection position is actually ice AND dust protection. It's a two-fer.

 

That is what I was asking; anybody confirm that anti-ice does both?

[AlphaOneSix]

Furthermore, the anti-ice and dust protection systems use the same set of valves, so if you have anti-ice on for the engines, you also have the dust protectors on. So you end up with the following options:

 

Switch OFF: Anti-ice and dust protection OFF

Switch in ANTI-ICE: Anti-ice AND dust protection ON

Switch in DUST PROT: Anti-ice OFF and dust protection ON

 

I already did.