Embraer 145 tech help
 

Hi - I work for a UK operator flying the Embraer 145.

When I test the ice protection system on the ground with the engines off, you normally get a few EICAS messages that signify that the system is working - "Ice Det 1(2) Fail", "Bleed 1(2) Lo Temp" and "Ice Condition".

However, quite often you get additional messages that shouldn't pop up - i.e. "Wing A/Ice Fail" and "Stab A/Ice Fail". To me this indicates that the test has failed but I am a bit confused about this - i.e. why do these additional messages sometimes appear and do they mean that the equipment isn't working? Even if they do appear, the engineers say that it is OK and the system always works as it should in the air!

We also test the system sometimes at the holding point with all engines running and occasionally you'll get the same messages appearing. Several times people have returned aeroplanes and cancelled flights as a result of these messages but the thing always seems to work when it actually detects ice in the air.

Can anybody shed any light on this and offer some thoughs on why these messages appear and if it is a problem??

Ta
xx

caveat: I don't know the ERJ-145 architecture, so this is more guesswork than knowledge:

Could the fail messages you occassional get be due to a combination of low engine settings and external conditions.

If you have a bleed air anti-ice system and you run a system test at idle conditions, there may not be much energy in the bleed flow. That might mean - especially if it's cold, or precipitating - that there's not enough bleed energy to raise the wing temperature sensor(s) to the operating range, which means the system thinks the WAI isn't actually working and posts the Wing A/I Fail message?

Whereas I'd expect you usually have somewhat higher engine power in flight, and don't get that problem?

Why do you say that?

Cheesypeas, If you look in your manual vol 1 1-02-79 pg 13 (mine is rev 26) it says you'll get these messages if you have EICAS version 16.5 or earlier. This is due to low bleed temp as the APU bleed is not designed to operate as deicing. Get your operator to upgrade to latest EICAS (think it's 20.1?) this will cover your "Wing A/Ice Fail" and "Stab A/Ice Fail", "WG A/ICE ASYMMETRY" messages.
BIGBAD, have you ever flown an ERJ? I got airbourn this passed week, at max gross and climbed to service ceiling (FL370) from FAJS (5500'). ISA was +20,dropped to +10 all the way up to cruise, and was at M.775 within 24min. No need to cook my engines either. Don't remember ITT goining above 815C.

snotneus

I do fly the emb 145 and did fly the CRJ 200 & 700 - the embraer is very much a poor man's CRJ - it is a pile of junk compared to the CRJ.

I would regularly climb at MTOW to FL410 and cruise at M0.8 (red line M0.85) in the CRJ - the jungle jet can't come close - max cruise FL370 at M0.78 red line :yuk: :yuk: :yuk:

gimme a CRJ anyday

Hi there - we do have late EICAS - 20.5 it is but I think it is just the valves being slow to open.

The Embraer is a great aeroplane - it serves us well and gets us all to our destinations relaibly and efficiently - just as it should. OK there are faster/more powerful/ larger aircraft out there but it does the job.

Bit late in replying, but we have been getting the same wing/stab a-ice fail messages when checking the anti-ice system first flight of the day. Monitoring them over time, a pattern developed and they seem to appear on those days when the apu has been running a pack beforehand, usually if the engineers got out to the aircraft before us. The check requires you to ensure APU bleed closed, but the messages appear as if there is still some residual air in the system. If the first flight anti-ice check is done before any APU bleed air has been used, the fail messages dont seem to be dispalyed.

100 above is correct. If you do the test before engine start the APU must be off....you are testing everything apart from the valves (which need to be tested after engine start).
The valves are electrically operated and pnumatically actuated so they need enough pressure to open them and keep them open as well as the eletrical signal commanding them open.
1. The APU bleed air cannot supply this mass airflow
2. If you try to make it you run the risk of an overtemp.