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On 6/6/2021 at 3:18 AM, Jan Gonzales said:

Is this normal for the N1 to reduce this much when wing and cowl anti ice is on? Tried throttle on Max, toga and climb detent.

Cowl anti ice alone should have no effect on N1, but wing anti ice uses a massive amount of bleed air from the engine. Whenever a large amount of bleed air is being extracted from the engine, N1 is reduced to prevent ITT (exhaust gas temperature) from exceeding upper limits. The N1 reduction in the sim may be somewhat excessive - I do not have access to documentation from the real aircraft that gives the actual percentage. It will vary depending on altitude. At higher altitudes, the performance loss due to the use of wing anti ice will be more pronounced.

 

Standard practice with most operators is to use cowl anti-ice any time TAT is between +10 and -20C,  and visible moisture is present. Wing anti-ice would be used in response to actual detected icing (which would display an amber “ICE” message on the CAS). That message will turn green if both cowl and wing anti ice is turned on.

 

If the aircraft is clear of clouds or precipitation, icing should not occur no matter what the air temperature might be.

 

In MSFS the icing effect has long been overdone. Supposedly that was improved in SU4. In a real aircraft, icing does not typically form if the TAT temperature is -20C or colder. At that temperature, all moisture in clouds will be in the form of ice crystals, and ice crystals will not “stick” to the airframe and accumulate. Usually, once an aircraft is at or above approx FL250, icing is not a concern, and neither cowl nor wing anti ice is needed. At least prior to SU4, I have seen the ICE warning at air temperatures where icing should not be occurring.

 

In the sim CRJ, I do not use wing anti ice unless there is an actual ice warning, and I turn it off once the warning clears.

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33 minutes ago, JRBarrett said:

Standard practice with most operators is to use cowl anti-ice any time TAT is between +10 and -20C,  and visible moisture is present. Wing anti-ice would be used in response to actual detected icing (which would display an amber “ICE” message on the CAS). That message will turn green if both cowl and wing anti ice is turned on.

 

In flight >

- Cowl anti-ice must be switched on when the temperature is between +10°C of TAT  and -39°C of SAT with visible moisture (clouds, rain, snow, sleet or ice crystals).

When the temp is -40°C of SAT, or below there is no need for cowl-anti unless you get an icing caution CAS message.

 

- Wing anti-ice must be switched on when the temperature is between +10°C of TAT  and -39°C of SAT with visible moisture (clouds, rain, snow, sleet or ice crystals) and your speed is less than 230 KIAS, or whenever you get the icing CAS caution message. (Do not hold in icing conditions with slats/flaps extended)

 

On ground >

 

- Cowl anti-ice must be switched on when OAT is 10°C or below when visible moisture in any form is present (such as fog with visibility of 1500 meters [one mile] or less, rain, snow, sleet and ice crystals)

The cowl anti-ice system must also be ON when the OAT is 10°C (50°F) or below when operating on runways, ramps, or taxiways where surface snow, ice, standing water, or slush is present.

 

- Wing anti-ice system must be ON for take-off when the OAT is 5°C (41°F) or below and visible moisture in any form is present (such as fog with visibility of 1500 metres [one mile] or less, rain, snow, sleet and ice crystals).

Wing anti-ice system must also be ON for take-off when the OAT is 5°C (41°F) or below and the runway is contaminated with surface snow, slush or standing water.

As @JRBarrett said, wing anti-ice eats up a lot of power from the engines. Special attention must be taken when calculating takeoff performance with wing anti-ice.
Also remember to keep within the N2 green range when you have wing anti-ice switched on. Descending through icing conditions might force you to descend with some amount of thrust with the spoilers extended in order to stay within that required N2 range without accelerating.

 

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Our three company aircraft (CRJ-200) have an STC for low temperature wing anti ice on the ground. Basically it uses bleed air at reduced temperature and pressure to heat the leading edges continuously during taxi without danger of overheating them. Not sure if this is something unique to the CRJ-200, or is also available on the 700/900. The 200, since it has no slats, is much more sensitive to leading edge contamination causing an impact on takeoff performance.

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13 minutes ago, JRBarrett said:

Our three company aircraft (CRJ-200) have an STC for low temperature wing anti ice on the ground. Basically it uses bleed air at reduced temperature and pressure to heat the leading edges continuously during taxi without danger of overheating them. Not sure if this is something unique to the CRJ-200, or is also available on the 700/900. The 200, since it has no slats, is much more sensitive to leading edge contamination causing an impact on takeoff performance.

 

To be honest I haven't seen this in our manuals, but the FCOM for the CRJ 1000 states that wing anti-ice must be switched on right before takeoff power is applied if the aircraft was de-iced, so that the fluid applied to the wings doesn't get fried. 

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32 minutes ago, Nicco54 said:

 

To be honest I haven't seen this in our manuals, but the FCOM for the CRJ 1000 states that wing anti-ice must be switched on right before takeoff power is applied if the aircraft was de-iced, so that the fluid applied to the wings doesn't get fried. 

 

The 200 has the same restriction. 

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4 hours ago, Chaxterium said:

 

The 200 has the same restriction. 

The low temp ground wing anti-ice optional system won’t “cook” Type 4 fluid, and is certified for unlimited use during taxi. Not a substitute for for wing A/I on takeoff, (if conditions require it), but it will help keep the leading edges clear after de-icing and before takeoff.

 

Our 200s (actually Challenger 850s), have some “bells & whistles” not often found on airline CRJ-200s, including the WAAS/LPV approach STC, and SafeFlite autothrottles.

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3 minutes ago, JRBarrett said:

The low temp ground wing anti-ice optional system won’t “cook” Type 4 fluid, and is certified for unlimited use during taxi. Not a substitute for for wing A/I on takeoff, (if conditions require it), but it will help keep the leading edges clear after de-icing and before takeoff.

 

Our 200s (actually Challenger 850s), have some “bells & whistles” not often found on airline CRJ-200s, including the WAAS/LPV approach STC, and SafeFlite autothrottles.

 

I was referring to aircraft without the supplemental ground wing anti-ice system. 

 

I loved the 200 but flying an 850 with all of those bells and whistles would have been cool!

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Thanks for this information.  But from what is happening in sim at least is that Wing does not eat that much alone when turned on and also cowl alone.  It eats up a lot when BOTH are switched on together. I don't know if this is correct or not in real life.  Thanks.

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10 hours ago, Jan Gonzales said:

Thanks for this information.  But from what is happening in sim at least is that Wing does not eat that much alone when turned on and also cowl alone.  It eats up a lot when BOTH are switched on together. I don't know if this is correct or not in real life.  Thanks.

The cowl AI uses a relatively small amount of bleed air in the real airplane compared to the wings. I will ask the developers to look at how it is coded.

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On 6/9/2021 at 8:01 AM, JRBarrett said:

The cowl AI uses a relatively small amount of bleed air in the real airplane compared to the wings. I will ask the developers to look at how it is coded.

Should be added on the real jet you will see a noticeable reduction in climb performance when the cowl anti ice is on. At heavier weights we could realistically see our vertical speed decrease to 1000-500 fpm as low as the high 20’s. And that will become quite a sever decrease in climb performance if the wings are on as well.

 

Infact I wouldn’t be at all surprised if the plane stopped climbing in the low to mid 30’s with just the cowls on. Luckily we are almost always colder then -40C before we get to that point so we can turn off the cowls to regain some climb performance.

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