Embraer Performance Question

[FlyChicaga]

This question was posed to me today, and I'm curious what others think.

If you depart with the Anti-Ice in the ENG position, but do not expect to get ice on takeoff (strictly for contaminated runway), must you enter Anti-Ice ON on the takeoff data, and must you take the performance hit?

 

[flatspin7]

I would think that you would have to take the penalty for 2 reasons-


1) If you have the override switch in auto you will get an Ref Anti-Ice Disagree message

2) With the engine lip anti-ice on the bleed valve is open and you have the performance penalty- Even when taking off into ice you still only have the switch in ENG not ALL.

Thats just my $.02

 

[LJDRVR]

Hey M,

I'm just another dumb probationary FO like yourself, but I think that flatspin is correct. There's a distance penalty for both runway and climb. My take on that is the loss of performance is less bleed air equals longer takeoff run with decreased climb performance, regardless of whether or not icing conditions are encountered in the initial climb.

Just my .02, there are folks on here far more clever than I.

Cheers!

 

[FlyChicaga]

My take:

If you are going to have the Engine Anti-Ice on for takeoff, then you are going to need to a) take the performance penalty, b) enter it in the takeoff data, c) configure properly with engine bleeds on, packs off.

But I've been led to believe you can depart with the APU bleed open, engine bleeds closed, packs on, engine anti-ice on, no takeoff data for ice-on, and no performance hit. I just don't see how this is the case. So, hence me asking. Reason being that you won't encounter ice on the takeoff or climb, except for slush or lose snow remaining on the runway. But even for this, I'd say engine anti-ice should be used properly.

 

[flatspin7]

I'm not sure if the APU puts out enough bleed air for the anti-ice system, plus Its simply an improper configuration... No where in the book does it mention doing that.


Honestly 99% of the time I find that were landing structual limited and the anti-ice performance hit doesn't come close to factoring into anything, especially on any runway longer than 7500 feet.

 

[millhouse21]

If it's just a matter of engine anti-ice, then it shouldn't really be a problem to take off with the apu running the packs and the engine bleeds off. The reason is that the engine inlet anti-icing valve is upstream of the bleed shut-off valve. Thus, the engine anti-ice will still work with the engine bleeds closed.

Having said that, your SOP may say something different about the desired configuration. Also, you will want to have the engine bleeds on before entering actual icing conditions (obviously).

 

[Flechas]

I think that you would have to take the penalty for the weight because you are still taking bleed air (read thrust) from the engine, even if you have the engine bleeds closed. As far as the take off data, if it is only for contaminated runway, you could probably enter off, because you are not expecting to open the wing anti-ice valve. Also, since you are taking off with the engine bleeds closed, if you enter ON on the take off data, you will get an EICAS message related to wing anti-ice fail (APU bleed not enough for wing antii-ice).
So, taje the performance hit but do not enter Anti-Ice ON on the take off data.

Flechas

 

[TheRaven]

But I've been led to believe you can depart with the APU bleed open, engine bleeds closed, packs on, engine anti-ice on, no takeoff data for ice-on, and no performance hit. I just don't see how this is the case. So, hence me asking. Reason being that you won't encounter ice on the takeoff or climb, except for slush or lose snow remaining on the runway. But even for this, I'd say engine anti-ice should be used properly.

The wing/stab A/I system will come on with the selector in ENGINE at wheelspeeds above 25kts if the ice detectors sense ice, but you will instantly get the STAB and WING A/I FAIL, as they will not have adequate air supply from the APU.

So to preclude this from happening and getting a Caution message during climb it would be easier to just open the engine bleeds, select Ref A/I on, and close the apu bleed and packs for departure til you are in the air. Anyone who configures the system as you had asked about is over-riding the purpose of the Ice Detectors and needlessly inhibiting the wing and stab a/i system.

 

[rattler]

My take:

But I've been led to believe you can depart with the APU bleed open, engine bleeds closed, packs on, engine anti-ice on, no takeoff data for ice-on, and no performance hit. I just don't see how this is the case. So, hence me asking. Reason being that you won't encounter ice on the takeoff or climb, except for slush or lose snow remaining on the runway. But even for this, I'd say engine anti-ice should be used properly.

100% False, TheRaven is right.

 

[nimtz]

Ah Matt,

We have a training department for these questions. Why don't you just call or email them and ask somebody whose opinon OFFICIALLY matters. Trust me they want your questions and they want to help you learn the company way. Getting anon opinons on the internet does not promote standardization which our airline sorely needs.

 

[91100 100 set]

Do what your company SOP says. If you have to take a weight hit and leave revenue behind, it's not your problem. And don't let anybody tell you different.

 

[voteno]

What Performance?

 

[Flechas]

What Performance?

Your gear.

 

[voteno]

Your gear.

Again, WHAT PERFORMANCE? or LACK OF!

The bicycle chain for "Your gear" has been stloen by those short people at Embraer to power the Whistling Sh!tcan of Death.

 

[Flechas]

Again, WHAT PERFORMANCE? or LACK OF!

The bicycle chain for "Your gear" has been stloen by those short people at Embraer to power the Whistling Sh!tcan of Death.

I know what you were refering to, I was just trying to make a joke here, but I guess you are too dense for that.

 

[wahoo250]

if im not mistaken with all three valves open the apu valve automatically closes...you cannot put three bleed sources into the system at one time.

 

[91100 100 set]

I'm pretty sure that is correct as well. Open the #1 Engine bleed (with the engine running of course) or the #2 with the crossbleed open, and the APU bleed closes. System logic.

 

[SkyBoy1981]

Yeah, engine bleeds have priority anytime they are turned on. I'm not sure that really has anything to do with what was being discussed here though. The question was, is it okay to takeoff with the engine bleeds closed, APU bleed open, packs on, FADEC Ref Anti-Ice ON, have the ice detection in ENG, and not apply a performance penalty. Yes, the lips will remain heated, but that heat is still coming from engine bleed that is taken out prior to the bleed valve. Whoever told you this probably thought the lip heat would come from APU bleed in this configuration, which isn't accurate. Anytime engine bleed is being used for anti-ice, the performance penalties should be applied. Also, if the FADEC Takeoff Data was selected for Anti Ice On, its going to calculate the reduce thrust setting during takeoff, obviously resulting in a longer takeoff roll and reduced climb performance. So the performance hit is a must regardless. Then, as someone else mentioned, if you enter icing conditions just after takeoff prior to getting the engine bleeds on you're setting yourself up for a master caution and some messages during a critical phase of flight. Finally, its just not the right way to do it. I agree with what someone else said though, Chicaga, talk to the training department about it. Thats what they are there for.

 

[wahoo250]

i misread a previous post...sorry

 

[CHQ Pilot]

Would you still apply a penalty if a ENG A/I valve was secured opened due to an MEL? I've seen several instances where one valve was secured open since there is no limitation to temperature on the lip (hence it fail safes open).

Also, when you set the A/I on the TO page, isn't that just preprogramming the FADEC to assure performance in the event of an engine failure? I may be wrong, but I thought it was to make sure before you left the ground that if you lost an engine and encountered icing conditions you would still have enough power available to meet the required climb gradient. If you didn't have enough reserve with the information entered on the TO page you would receive the ATTCS NO MARGIN warning. Like I said I may be wrong though.

 

[millhouse21]

Would you still apply a penalty if a ENG A/I valve was secured opened due to an MEL? I've seen several instances where one valve was secured open since there is no limitation to temperature on the lip (hence it fail safes open).

Eng A/I Valve secured open has its own penalty which can be found in the MEL. It only applies if it was otherwise an non-icing penalty. I.E. the other valve is closed. If both are open, the normal A/I penalty applies.

 

[Flechas]

All you guys are right about the engine bleed taking prioroty over APU bleed, and about the wing anti-ice valves opening if the override switch is in ENG past 25 KTS. However, the original question was regarding what to do if there is no icing in fligt, only contaminated runway. I belive he wants to know what to enter in the MFD and wheater or not to take the weight penalty.
I think the best would be to take the penalty and enter OFF in the MFD so you don't get an EICAS message, however, talk to the people inn training, or Greg Wooley, that way we all do the same for a change.
Let us know if you find out what they want.

 

[wahoo250]

i can tell you right now you need to take the penalty. its either considered on or its off. if any bleed source is being used you take the penalty...the engine is not producing the same amount of thrust. it really has nothing to do with whether your picking up ice or not. when they are open(the lips) and on auto you assume worse case scenerio, like everything else in aviation. im not the training dept but i can almost guarantee thats what they are going to say. but then again i may be wrong, i havnt looked at that stuff in a while so go easy on me.

 

[azdriver]

Hey guys,

please read the airplane manual:

you have to take penalty for anti ice on in the FADEC, you will need to swith the selector to eng before taxi unless you want the caution message and maybe pick up some ice on the engines inlets due to contamination of the taxiways/runways. After TO if no ice encounter you might want to swith the knob to auto, no rush needed. If you forget to do so, you will get a caution msg: NO ICE ANTI ICE ON. No big deal.

Anti ice on for FADEC = ice dect on eng, bleeds on and no reason wathsoever to turn the packs off. If there is any perf need to switch the (one or both) packs off the system logic will do so. That usually happen when temp is above certain values...

If you have bleeds off and enter ice condition you will get MASTER WARNING msg: Ice cond/wing and stab anti-ice INOP.


cheers