Mad Dog elevator position after deicing

[Sparviero70]

Hello everybody!
It's my first post, so let me introduce myself: I am a (fresh made) de/antiicing instructor in one of the European airlines, and I have a little question to the more knowleable of You:
After the whole treatment of MD80 is finished, PIC must be informed (at least at my airline) if both elevators stay trailing edge down. Apparently it indicates some kind of malfunction (or possibility of one). If elevators are deflected "up" or asymetrically it's OK.
So far I couldn't find the satisfactory answer, what EXACTLY is the reason for such procedure... :ugh:
I will be really greateful if any of Mad Dog Wizards will enlighten me in this matter!
Thanks in advance! :)

[Tree]

Speculation only: It may indicate that de-icing fluid is trapped internally.

[Sparviero70]

Thanks a million IGh!
If I understood the problem correctly, in MD pilot actually controls the trim tab of the elevator that moves freely (no direct mechanical connection between the stick and the elevator - only between the stick and the tab; right?). The design of the elevator allows accumulation of deicing fluid residue INSIDE, so if both elevators are hanging down, it indicates, that we have serious problem with fluid leftovers, which may lead to unexpected change in plane's response to control inputs. Is this an issue, or am I getting it completely wrong? :rolleyes:
Sparviero

[safetypee]

I suspect that the issue relates to the EASA
Safety Information Notice 2008-29 Anti-Icing. (www.easa.eu.int/ws_prod/c/doc/Safety_Info_Reports/SIN%202008-29%20De-Anti-Icing.pdf)

The BAe146 / Avro RJ have similar servo-tab control systems to those in the MD. These aircraft use (used) a specific control check to aid de-icing fluid drainage, the tabs and control surfaces have an assortment of drain holes to minimize fluid buildup.

Fokker issued a service letter 50/60 Revision 2, Feb 28/07 on similar issues.

Anti-Icing Fluid Residues. (www.sae.org/events/icing/presentations/2007s2dyer.pdf)
Flight Control Restrictions Due to Deicing/Anti-icing Fluid Residues. (www.sae.org/events/icing/presentations/2007s2hille.pdf)
Ongoing work "Deicing/antiicing fluids" (www.easa.eu.int/ws_prod/r/doc/CRD%202007-11.pdf)
Deicing/antiicing fluids. (www.boeing.com/commercial/aeromagazine/aero_08/deice_story.html)
Deicing/antiicing fluid residues. (www.boeing.com/commercial/aeromagazine/articles/qtr_1_07/article_03_1.html)