Embraer 145 systems question

[johndt]

The issue:
In cruise flight the #2 bleed temp indicates in the middle of the green range on the ECS page of the MFD. The aircraft is not in icing conditions and the #1 bleed temp is at the bottom of the white range where it normally should be. In icing conditions the system operates normally. The #2 bleed temp indication modulates with power as you would expect: more power hotter bleed, less power cooler bleed. There are no EICAS messages associated with this condition, and the AOM is not clear on this. It only states that the green range indicates acceptable temperature for the anti-icing system.

The questions:
1) WTH?
2) Has anyone else seen this?
3) Is this a safety concern or an acceptable variance?

 

[Mike man]

states that the green range indicates acceptable temperature for the anti-icing system.

Sounds like you have got your answer. Or send an email to the EMB Program Manager (or whatever it is called at your airline).

 

[johndt]

Sounds like you have got your answer.

The problem I have with that AOM section is that when it speaks about "acceptable" it means the green range is hot enough to adequately de-ice the aircraft in icing conditions, not that this is an acceptable bleed temp for non-icing conditions. The elevated bleed temp and large split between what's normal on the #1 bleed and what's happening on #2 leads me to believe that there is a problem with the #2 bleed or associated systems.

 

[Mike man]

It is just one tail number you flew or the entire fleet?

 

[johndt]

It's just the one plane that behaves this way.

 

[CX880]

Fadec

 

[Whydoitry]

green good, red bad

 

[Mike man]

When I flew the 145 I had one plane one winter evening got some ice then got some type of anti-ice failure message, the circumstances seem to be the same if I am remembering correctly....anyway the MX guys replaced some type of valve/switch/thing-a-mabob which was under the cargo bin floor.

They said this was somewhat common and that this part fails when it gets gummed up with dust/debris in the bleed system.

It sounds to me like it will eventually fail and they will replace it, try talking to a line MX guy to see if he/she has ever heard of this.

Peace out

 

[johndt]

the MX guys replaced some type of valve/switch/thing-a-mabob which was under the cargo bin floor.

They said this was somewhat common and that this part fails when it gets gummed up with dust/debris in the bleed system.

It sounds to me like it will eventually fail and they will replace it, try talking to a line MX guy to see if he/she has ever heard of this.

Peace out

Thanks. They've tried replacing an anti-ice valve already; I know that. But that's apparently not the issue. I'm afraid that we are just waiting for a failure to figure out what's wrong with this plane.

 

[rjacobs]

The only thing you are worried about with the bleed temps is in icing. If they are both in the green in icing, you are good. If they are in the red, your gonna get a bleed overtemp. If they are in the white you will get a bleed low temp.

The rest of the time the temp does not matter. Its hot enough at the bottom of the white to run the packs as hot as they will go.

Do you have the pressure regulating shut off valves(engine bleed valves) installed or just the standard(open or closed)? If nobody knows(your mx should), when you go into icing, does the cross bleed open?

Something could be messed up with the engine bleed valve in the pylon or the valve in the 9th or 14th stage could not be opening fully on one side vs. the other.

To me though, as long as the temp is ok when I am in icing, I dont care about the rest of the time.

 

[OPECJet]

HP/LP or whatever the Brazilians call it valve stuck maybe? You didn't mention how the temps of fuel flow compared between the two engines.

I can't believe you guys can look at all that crap on the JungleJet. Same engines / avionics on the Cit. X and I never knew about any of that stuff. Cessna must have some slackers in the avionics ordering dept. Only way we know if the a/ice is working is by watching the temps rise, HP/LP valve operation under the right conditions, and CAS messages.

 

[35off]

cornholio

Fadec

You a ******************************. Stick with your CRJ700.

 

[rjacobs]

You didn't mention how the temps of fuel flow compared between the two engines.

I can't believe you guys can look at all that crap on the JungleJet. Same engines / avionics on the Cit. X and I never knew about any of that stuff. Cessna must have some slackers in the avionics ordering dept. Only way we know if the a/ice is working is by watching the temps rise, HP/LP valve operation under the right conditions, and CAS messages.

The -145 series can not read actual fuel temp at the engine, only tank temp in the left tank.

If you can see your HP/LP valve operation then you can see more than we can. The only thing for the bleeds we can see is temp. If we go into ice you get an EICAS message "Ice Condition" and you look up and see that the engine, wing and tail ice valves opened by looking at the buttons.

 

[CHQ Pilot]

It has been several years since I flew the 145, but I seem to recall the same situation and being told it is probably a faulty temp sensor. Someone probably knows how it works a lot better, but I also have a vague memory that the sensors could also be "adjusted" (kind of like adjusting an oven temp control that runs hot or cool from the set temp).

 

[OPECJet]

The -145 series can not read actual fuel temp at the engine, only tank temp in the left tank.

If you can see your HP/LP valve operation then you can see more than we can. The only thing for the bleeds we can see is temp. If we go into ice you get an EICAS message "Ice Condition" and you look up and see that the engine, wing and tail ice valves opened by looking at the buttons.

Meant temps (ITT) or fuel flow. Just to see if there is a big split between the two engines.

On the X we have a white CAS message that tells us when the HP bleeds are open. Not like you can't hear it or anything.... It's very obvious. We also have fuel temps for both tanks and at the engine. TMI in my opinion, but whatever...

Totally unrelated to the topic, but, I did have a typo in the last post which led down this road.

 

[johndt]

So the ITT and the fuel flow are slightly elevated in the affected engine but not drastically so. I don't think it's a faulty sensor b/c it modulates normally with thrust changes and if it was reading incorrectly I would think that it would show an overtemp during icing encounters which it doesn't.

A stuck 14th stage valve sounds likely. That would mean that the engine probably isn't achieving its rated thrust during landing and potential go-around, yes?

I was also thinking it could be either a pre-cooler problem which is no big deal until it fails and you're single bleed in icing conditions. Or it could be a small leak near the sensor?