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Anti ice usage and N1%

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Has it been reported that the N1% is over exagurated when using anti ice? Before i submit a ticket...

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Has it been reported that the N1% is over exagurated when using anti ice? Before i submit a ticket...

 

Exaggerated in what way, compared to what real world data source...?

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Two NG pilots one with 15 years

 

Going to need more concrete proof than that. We have an entire technical team of operators (pilots, maintenance people, and so on), along with Boeing data.

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My goodness, if you know they are right then one cannot argue with that....LOL

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I know my sources are right

 

...again...based on what real world data source...? What verifiable proof do you have other than your word, of what someone else's word is?

 

We cannot simply go changing things based on something some random person claims some other random person said on an internet forum. That's not how we work. Our Tech Team is comprised of people who we have verified to have experience with the aircraft as pilots, maintenance personnel, or other useful sources. I'm sorry, but allusions to "some pilot said" don't hold much weight against that.

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I don't even understanding using anti ice at all in the sim, other then procedural - but that's like flipping a switch for the sake of flipping a switch.. a dummy switch. Kinda like flipping the seat belt sign at cruise, its not like anyone is sitting in the back waiting to take a pee. But even if you forgot to run any sort of anti ice... would anything happen? Is ice even modeled?

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Its not about that Nick its about Exagurated N1 which is too high compared to real life so on approach and final, you will technically have a high rate of descend.

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I don't even understanding using anti ice at all in the sim, other then procedural - but that's like flipping a switch for the sake of flipping a switch.. a dummy switch. Kinda like flipping the seat belt sign at cruise, its not like anyone is sitting in the back waiting to take a pee. But even if you forgot to run any sort of anti ice... would anything happen? Is ice even modeled?

 

Hi,

 

I know it is off topic but I cannot help answer that. It is not a question whether it is usefull or has any effect, but rather how realistically you want to fly the aircraft. You could also do without the beacon lights or strobes. There is no real ground crew risking their life and no one to file a case against you for not complying with regulations and procedures?

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...again...based on what real world data source...? What verifiable proof do you have other than your word, of what someone else's word is?

 

We cannot simply go changing things based on something some random person claims some other random person said on an internet forum. That's not how we work. Our Tech Team is comprised of people who we have verified to have experience with the aircraft as pilots, maintenance personnel, or other useful sources. I'm sorry, but allusions to "some pilot said" don't hold much weight against that.

 

My source does use the NGX and flys the real NG and says The N1 increase from using Anti-Ice is negligible and has no noticeable impact on your descent rate.

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My source does use the NGX and flys the real NG and says The N1 increase from using Anti-Ice is negligible and has no noticeable impact on your descent rate.

 

Again. I keep asking for real, verifiable data and keep getting assertions. That's not how this works.

 

The sky is actually green, and clouds are purple. Believe me. I know a scientist and he said so.

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Real verifiable data is the pilots i speak to. I'm sure to take there word for it over desktop PC sim addon.

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Vernon,

 

If you have actual data that proves your "theory",  please feel free to submit it to our support portal. Continuing to tell us your friend says it's so doesn't give you any more credibility that you are correct in your assertions.  As Kyle previously outlined,  we have a team of real world pilots that we use to confirm performance and behavior of our products during the builds and while I don't doubt you have a friend who flies the 737, please tell me would make him more qualified than the pilots we currently use for testing the products we produce?  I am more than willing to look at something that you can prove with actual data but telling me it's so isn't sufficient i'm afraid.  We need actual data from a verified source.

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My source does use the NGX and flys the real NG and says The N1 increase from using Anti-Ice is negligible and has no noticeable impact on your descent rate.

That's... ridiculous, Vernon. Your source may need to reevaluate. Engine anti-ice has a very noticeable impact on descent rate. Why do you think there's an entry on the Descent Forecasts page to tell the box when you plan to use it? So the box can take that into account when calculating descent.

 

I haven't quite been flying 73s for 15 years (but certainly long enough to be familiar with A/I in descents) but I've been flying jets for longer than that. This is pretty standard stuff.

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My source does use the NGX and flys the real NG and says The N1 increase from using Anti-Ice is negligible and has no noticeable impact on your descent rate.

Hi Vernon,

 

In response to your PM you asked if using anti-ice during final approach would increase your ROD with which I replied "The N1 increase from using Anti-Ice is negligible and has no noticeable impact on your descent rate"

 

Back to basics.... When you select the engine anti-ice on bleed air is taken from the engine to heat the engine cowling, the EEC selects "Approach Idle" which is what gives a slight increase in N1/N2 etc.

 

Now without firing the sim I don't know how accurately this is simulated. I’ve been flying the -800 for 4 years and I still couldn’t tell you how much N1 increases in real life, I just know it does for above said reason! In response to your post I think it’s a little unwise to claim the N1% is over exaggerated, I’m flying tomorrow and I’ll tell you exactly how much it increases by so you can compare it yourself!

 

That's... ridiculous, Vernon. Your source may need to reevaluate. Engine anti-ice has a very noticeable impact on descent rate. Why do you think there's an entry on the Descent Forecasts page to tell the box when you plan to use it? So the box can take that into account when calculating descent

 

To be fair I've never used or have ever flown with a Captain who has used TAI FCST due to the unpredictably of turning it on and off during a typical descent in Europe through all the gnarly weather and I've never considered how this will affect my descent profile. It does make a small difference to your descent of course but as you know from your experience, it makes very little difference to your planned profile compared to say a speed change from ATC or a massive shortcut!!

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Agreed in the sense that I rarely plug it in the box unless it seems likely to be on all the way down, which definitely happens some of the places we fly in the winter. But in my experience, using TAI for more than a few minutes = speed brake or increase in descent speed to stay on path. I don't know what the actual N1 increase is, I've never really paid attention to that, I don't guess it's more than a percent or two, and I also don't know what the ngx sim does... but in terms of descent rate, it's definitely enough to have a notable impact. Every jet I've flown has behaved that way.

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I love when someone that has most likely never flown a plane in real life starts telling professional pilots how it should be...  :fool:

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Probably the case on other jets! The problem is there are too many other variables thrown in which have a far bigger impact to your descent rate then the use of TAI. I can certainly remember using TAI recently pretty much from TOD all the way to approach, we didn't pre-populate the DES page with TAI information and all the way down VNAV did a sterling job keeping the aircraft on it's descent profile and speed.

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The Embraer family was definitely impacted worse, with the 145 being the very worst, particularly with the restrictions on flap usage in icing conditions that that particular airline imposed for the first few years I was there... but I've never seen a jet not be affected like this.

 

I have a feeling we're agreeing, just using different interpretations of what's significant. Sure other factors like a speed assignment, shortcut or wind change can have a bigger effect, and we all know what a stellar job the 73 box does with VNAV planning anyway ;-). But watch next time you turn it on in smooth air... bet you'll see a couple hundred fpm descent rate change.

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Speaking of Anti Ice, if you need to climb through the 20's using engine and wing anti ice, how much would this bog down your climb rate ?

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Speaking of Anti Ice, if you need to climb through the 20's using engine and wing anti ice, how much would this bog down your climb rate ?

It would be measurable but definitely not as bad as "bogging" you down.  Keep in mind that the only reason for the increase N1 during descent is to keep the bleed manifold pressurized; during climb power, this is never going to be a problem.  It's not a matter of flow and much as it is pressure, although the two are related engineers are usually looking at only one or the other as a constraint.

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