EMB 145 stiffed elevator

[azdriver]

Good afternoon,

Recently my airline experience various elevator loss of control during flight apparently due to residual anti ice fluid that in some particular condition expanded and block totally the elevator movement.

Embraer in September 2001 issued a recommendation about the inspection of flight surface due to worries of excessive residual anti ice powder that could cause flight control related problems. It seems like this recomm. never follow thru the maintenance program of my airline; now, after the pilot union reps met with the fleet manager, flight safety manager and maintenance manager the only thing they could say to justify this was that this occurrence happen with many 145 operator in Europe. Now, after we specifically requested the names of those operators they were very reluctant to provide the names.

My question for 145 pilots is: did this happen in your airline? If yes what are the details?

Thanks in advance

azdriver

[Volmet South]

I'm not a 145 driver however I have read several tech logs describing this very incident. This appears to me to be a design flaw whereby de-ice fluid can form pools which then freeze and lock the elevator. The descent to warmer air must have been interesting to say the least.

Any European / North American 145 operator stands a good chance of having an incident. In my humble view, this is a generic problem.

[Wild Colonial Boy]

We operate a large number of 145/140/135s and we have never been told of or experianced any such deice related problems,I am not famililar with "powder" de-icing we use Type I,II and IV fluids and the only trouble I had with that is when someone thought it would be a good idea to fill the APU compartment to the brim with said fluid.
As far as flight controls are concerned we have had pitch trim runaways and uncommanded swerving occur in our aircraft and EMB was quick to put procedures in place.

Not wishing to hijack your original post I would like to know if anybody has experianced an oscillation that gets steadily worse until the A/P finally kicks off.I have experianced it on three different occasions twice in the descent and once in cruise.It is apparent the A/P is over compensating towards the end and on the last two occasions simply kicking off the A/P has stopped it immediately.

I have spoken to other pilots who have experianced the same thing and wonder at what point EMB be made aware.
These oscilations cannot be good for the frame over an extended period.

I have over 3000hr in type and not prone to hysterics.

[azdriver]

The so call powder it is the residual anti/de ice fluid that dries up and then becomes powder or in other cases somehow very dense material more known as GEL.

In all 3 cases the desent, approach and landing were rather interesting. Even circling at lower altitudes didn't help. All the crews involved landed only with trim input, and 2 out of 3 the trim was partial....


The post flights inspections of the elevator found the elevetor control block by the upmentioned material that somehow expanded and frozen up.


It is not uncommon for other aircraft but I'm specifically looking for E-145 cases
cheers

[TDK mk2]

I don't fly the Embraer but we are warned about the hazards of this residual powder that can remain after type 2 and presumably type 4 fluid has dried up.

Could it be an application issue? Our deicing operators are (hopefully) well trained on where to not aim their fluid at.

As for A/P oscillations I've often noticed a slight roll oscillation in the cruise when flying as a passenger in the Embraer. Is that like what you're talking about WC Boy?

[208]

after prolonged rain the dried type/ii or iv fluid rehydrates, the aircraft then takes off and the gel freezes causing the control restrictions mentioned. The airline I work for had a number of problems at the end of the winter with virtually all of our 146/rj aircraft each aircraft took around 12 hours of constant flushing to remove all the remaining deice fluid residue from the aerodynamically dead areas, but touch wood we did not have this problem with the emb 145

[B1/B2]

Hi,

Intersting, "azdriver" - the incident you refer too, did it occur in VIE on easter sunday (also your location of the boot makes me think it did). Only the Austrian authorities made such a deal out of the event they were even concidering trying to ground all 145s to sort the problem ??? Just wondering as we've suffered severly with the problem on our AVROs (around 85% of A/C AOG at one point - Elevators and ailerons too) and its still causing problems occasionally now. There were instances where upon inspection we've found the Type IV fluid gel in the elevator system on our 145's too but it has not effected the aircraft control in flight.

It takes approximatly 10 hours of cleaning to get each elevator clean then just when it looks good, 10 minutes later its full of the stuff again and all the drain holes are clogged. And the next problem, it seems to have caused damage/corrosion to some of the control surface bearings so they had to be replaced.

I've spoken to alot of our crews about this problem and it seems once in warmer conditions the control gradually comes back but at higher altitudes, ALT capture and hold is very uncomfortable and upto (on one occasion) 1500 ft +- deviation during capture of a high FL.

Problem seems to be over now as the weather gets better but we'll certainly have to get prepared for next year, as it can't be brushed under the carpet.

As far as 145 roll occilations I think its fairly generic to the 135/145 family but if it gets quite bad its (normally) cured with a good rigging and check of the aileron cable tensions.

[Wild Colonial Boy]

The oscilations I am refering to start off as a very gentle nose to tail then rapidly intensivefy.They are not very subtle.

[no sig]

Boeing have a similar issue on some 737,s and require the evelvator to be in a specific position during deicing operations to assist drainage and prevent the build up of residue.

[Piltdown Man]

Exactly the same problem last week on a FK70 landing in AMS. This time the "gel" caused 100% loss of ailerons - only a minor amount of control being regained before landing.

[9gmax]

same problem seems to be happening on ATR 42 and ATR 72 fleet. Special training and adapted procedures have been introduced in ATR fleet to overcome (partly) the problems encountered.
Information on this subject can be downloaded for free from the official ATR website

http://www.atraircraft.com/download.htm

[axv]

As for A/P oscillations I've often noticed a slight roll oscillation in the cruise when flying as a passenger in the Embraer. Is that like what you're talking about WC Boy?
Just a very tiny input on the ruddertrim will solve this problem in most of the cases. Don't forget, it's still a pocket rocket. ;)

[azdriver]

Sorry i did not come back to all of you sooner, I'm on a trip with very loong days. So a quick respond to B1/B2: one of the event was in VIE on easter sunday....

The final investigation from our flight safety department just came out. Give me some time to translate it and it will be posted.

Ciao