How it Works: Mi-8 Ice Protection System

[AlphaOneSix]

Well, someone mentioned wanting to know about the ice protection system on the Mi-8, so here it is. As usual, there is a caveat.

 

The aircraft I work on are all newer, so none of our aircraft have the RIO-3 Ice Detector set anymore, which is what we have in DCS. The attached documentation only talks about the SO-121VM ice detection system. So I will expand here to fill in the gap.

 

The big difference is in how the two detectors work. The SO-121VM uses a vibrating head where the frequency of the vibration changes as ice builds up on the detector. When the frequency changes to a certain point, the detector sends the ICING signal. The older RIO-3 uses a radioactive source in the detector tip with a beta particle sensor in the base. As ice builds up on the detector tip, the beta rays are partially blocked, and when the beta ray sensor detects a sufficiently low number of beta ray emissions from the detector tip, it activates the ICING signal. In both cases, the amount of ice needed to set off an ICING signal is 0.3mm.

 

The difference on the anti-ice control panel that you should notice right away is that there is no ice detector test button and there is no ice detector heating switch. Both of these functions are built into the SO-121VM, so they were removed from the panel. But the ice detector heater works just like the right engine and windshield anti-ice, i.e. it's automatic unless you turn it on manually. The heating process for the RIO-3 is exactly the same as the SO-121VM that I discuss in the attached PDF. The test button just makes sure that the heating element in the ice detector is working.

Mi-8 Ice Protection System.pdf

[Corrigan]

Fantastic, thanks so much.

[zaelu]

Thanks! Don't stop! :thumbup:

[impact480]

Nice, Thank you!

[Fig]

This is gold!!! Thank you for this:)

[Rogue Trooper]

Lovely... musta missed this one!

[evilivan]

Many thanks for that - much appreciated.

 

Can you explain why the left engine de-icing is manual only? Am I missing something obvious?

[kuki767]

It is explained on the page 46 of the posted pdf:

 

"The left engine and DPD anti-ice will not activate automatically. It should be turned on manually approximately 1 minute after the right engine anti-ice activates, and only if the right engine continues to operate normally (i.e. has not lost power due to ice ingestion)."

[ebabil]

hi guys,

for the easiest way, what should we do when we hear icing warning?

is everything automatic and we should do nothing or turn on left engine a-i ?

should we turn it off after icing is over?

 

and, the round panel which shows main / rotor / blades etc. should we do something with this?

 

ps: i use auto start function

[Looney]

First, check if your circuit breakers for the de-icing system are actually engaged, otherwise, turn them on.

 

Next up,one post above yours;

 

The left engine and DPD anti-ice will not activate automatically. It should be turned on manually approximately 1 minute after the right engine anti-ice activates, and only if the right engine continues to operate normally (i.e. has not lost power due to ice ingestion)

[evilivan]

Thanks for the replies, gents (and hello Looney).

 

So for numpty here, to confirm my understanding of the logic:

 

- Ice starts to build

- Deice is activated

- There is a risk that the breakdown of any ice already formed could be in ingested by the engine and stop it

- Therefore the left engine is manual only to mitigate losing both engines

 

That it?

 

Thanks

[gospadin]

Thanks for the replies, gents (and hello Looney).

 

So for numpty here, to confirm my understanding of the logic:

 

- Ice starts to build

- Deice is activated

- There is a risk that the breakdown of any ice already formed could be in ingested by the engine and stop it

- Therefore the left engine is manual only to mitigate losing both engines

 

That it?

 

Thanks

 

Correct. If the automatic de-ice worked correctly and didn't lose too much power on the first engine, you engage the 2nd one manually.

[AlphaOneSix]

As mentioned before, the concern with the engine anti-ice is that if any ice has built up on the front of the engine, turning on the engine anti-ice could dislodge that ice and cause the engine to lose power. By waiting one minute after the right engine anti-ice has come on, you ensure that the right engine is still operating normally. Then you are safe to manually turn on the anti-ice for the left engine.

 

The aircraft is not meant to fly in purpose into icing conditions, nor is it meant to stay in icing conditions if you get into it. The idea is that you are supposed to exit the icing conditions as soon as possible.

 

Note that if you expect to enter icing conditions, you should turn on all the anti-icing equipment ahead of time, before icing occurs. You do this by turning the anti-icing switches from AUTO to MAN, and the left engine from OFF to ON. If the anti-ice did not come on automatically, and you know there is no icing at the moment, it is perfectly fine to turn on the left engine without waiting a minute after the right engine comes on.

 

The pilot's manual suggests turning on all anti-icing equipment any time you fly at +5C or below, just in case you get into icing inadvertently. But that's up to the pilot to figure out depending on moisture content, temperature, and the need to not lose engine power for the anti-icing system.

[evilivan]

Awesome detail; thanks very much :-)

[ebabil]

Bumping this good thread by asking a stupid question;

 

Yesterday, during a flight under stormy conditions (memory of a hero campaign 2nd mission)

After about an hour flight, my Vertical Velocity and Speed gauges froze. I had to hover or land on a ship but due to lack of VVI and speed indicator, vortex ring state caught me.

Is there a way to keep those gauges work or it is what it is?

[Quadg]

pitot tube heating.

 

switches amongst the ones with the external lights etc. on the right above co pilots head.

[ebabil]

pitot tube heating.

 

switches amongst the ones with the external lights etc. on the right above co pilots head.

 

Thanks it worked and i passed the mission

[grafspee]

i know that anti ice protection ilcuding heat pipes in leading edge of main rotor blades too

[DeMonteur]

Bumping this good thread by asking a stupid question;

 

Yesterday, during a flight under stormy conditions (memory of a hero campaign 2nd mission)

After about an hour flight, my Vertical Velocity and Speed gauges froze. I had to hover or land on a ship but due to lack of VVI and speed indicator, vortex ring state caught me.

Is there a way to keep those gauges work or it is what it is?

 

Did you turn on pitot tube heating?