[4910-I3-PJ

DEPARTMENT OF TrNSPORTATION Federal Aviation Administration 14 CFR Part 39 

# Ol.f3G [Docket No. FAA-2010-*****; Directorate Identifier 2009-NM-230-AD] R1N 2120-AA64 Ainvorthiness Directives; Bombardier, Inc. Model CL-600-2B 19 (Regional Jet Series 100 & 440) Airplanes AGENCY: Federal Aviation Administration (FAA),

# DOl" ACTION: Notice ofproposed ruJemaking (NPRM). 

# il .. SUMMARY: We propose to adopt anew airworthiness iiirective (AD) for the product listed above. This proposed AD results from mandatory rOlltinUing airworthiness information (MCAl) 01iginated by an aviation authorilY

# ranother country to identify and correct an unsafe condition on an aviation product. The MeAl describes the unsafe condition as: 

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## ** There have recently been several in-service occurrences that have highlighted the1inability ofthe existing [wing ~ Ii-ice] system to detect a low-heat condition in the wing leading edge at aLltimes, with the potential consequence of unannunciated asymmetric ice bfuld-up on the wing. 

### * * * Such acondition, in combination with maneuverF close to stick shaker activatioll_,could possibly result inreduced cOllJllability oftbe aircraft.


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# ~I. * * The proposed AD would require actions that are intended to address the unsafe conditi described in the MeAl. DATES: We must receive comments on this propose'd by [INSERT DATE 45 DAYS AFTER DATJ OF PUBLICATION INTHE ~ DERAL REGISTER]. N~1JRR""C~S ROUTIN'HY"IIOL 

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mACTJON: Notice ofproposed rulcmaking (NPRM). Airw()f1hincs~ Dircdrves; Bombardier. Inc. Modd CL-600.:m 19 (Regional .let Seri('~

SVMMARY: We propose to adopt a new airv.'orthim.• ss irecli\'~ (AD) for the product!> 

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# ,~,,;. J::!.'---... IlEI'ARTMENT OF TRANSPORT ATlON

IDocket No. FAA-2010-'!<**ItI<; Directorate .Identifier 2009-NM-BO-A.l>1 rcdrral A\'iglion Admill~~tranOfl

IUN 2120-A1\64

liste-<.1 abovc. This prop()~cd AD results from mandatory c ntinuing ai"vorthiness 

# I information (MeAl) origimncd byan aviation authtlrily

# oranother country t() Identify and correct an unsafe C<lnl1ition on an aviation produl.:\. Tne MeAl describes the unsafe AGENCY: r~'deral Aviation Admit,istral'ion (FAA). DOT. 100 & 440) Airplanes 14CFR Port 39

conl1ilion as:

'" 1'.~ There h,l\'c recently been scve~1 iJl-Service 1CCUH~.l1Ce~ that,h;we highlighted the .inability Oflhc eXlsl'ing [wing anti-ice) system lOdl2ltCl~t.l low-IH:ntcondition in the wing le:"ding edge ata1l1imes. with lht' poterrlial consequence ofunannunciatcd asymmetric ice build-up 011 the \\'ing. *' '!< •• Such ••condition. in combination v.rithmaneuvers close Inst.ick shaker activatioll. could possibly resuh in reduced control ability or IJleaircraft . ..

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# • • • < Thc proposl'd AD would require aClions Ihat 'ire intcnded [0ad(lrl~:O;s tl1eunsal'e conc!irion '."fl·',·"" described in the MeAl. 

# J OATES; We.must receive commeTHs on this proposed A hy [lNSfRT DA n:. 45