[4910-13-~1

llJT1N() SYMOOL

AGENCY: Federal Aviation Administration (FAA), Department of Transportation

above. This AD results from mandatory continuing airworthiness information (MeAl)

SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed

m

ACTION: Final rule; request for comments.

(DOT).

Federal Aviation Administration

RlN 2120-AA64

Ainvorthiness Directives; Bombardier. Inc. Model DHC-8-400 Series Airplanes

DEPARTMENT OF TRANSPORT AnON

0431

[Docket No. FAA-20l0-*****; Directorate Identifier 2010-N1\1-072-AD;

IIA2.71- -0':'-07

Amendment 39-"'1(,(***; AD 2010-**-**]

14 CFR Part 39

originated by an aviation authority of another country to identify and correct an unsafe ITIALSI,IG

condition on an aviation product. The MeAl describes the unsafe condition as:

* * * 1. A potential freezing of the AOA [angle of attack] Vane Resolver

** * may restrict the dynamic behavior (lag) of the vane and could lead to

a potential seize-up condition"at lower temperatures. This condition, ifnot

corrected, may provide inaccurate ADA data to the Stall Protection

System (SPS).

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'llTlNG H"'ElOL

2. As a result of ageing, the AOA vane heating element could degrade to a

point where there is insufficient heat to prevent ice build-up on the AOA

vanes. The ice build-up may lead to a change in the aerodynamic

properties of the AOA vane and, under certain conditions, send inaccurate

information to the SPS. This ageing condition cannot be detected by the

aircraft ADA vane heater current monitor.

'llTING SYMllOL

ITIA.lSl'1G
[4910-I3-P)

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

{lNCUlU'-o><C,;s

,~nSYMBOI.

ANE-172

[Docket No. FAA-201O-**~**j Directorate Identifier 201O-NM-072-AD;

Amendment 39-*****; AD 20**-**-**)

RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of Transportation

(DOT).

ACTION: Final rule; request for comments.

SUMMARY: We are adopting a new airworthiness directive (AD) for the products liste ANE~1570"()L

above. This AD results from mandatory continuing airworthiness information (MeAl)

originated by an aviation authority of another country to identify and correct an unsafe

condition on an aviation product. The MeAl describes the unsafe condition as:

* * *- 1. A potential freezing of the AOA [angle of attack] Vane Resolver,

which may restrict the dynamic behavior (lag) of the vane and could lead

to a potential seize-up condition at lower temperatures. This condition, if

nol corrected, may provide inaccurate ADA data to the Stall Protection

System (SPS). .

2. As a result of ageing, the ADA vane heating element could degrade to a

point where there is insufficient heat to prevent ice build-up on the ADA

vanes. The ice build-up may lead to a change in the aerodynamic

properties of the ADA vane and, under certain conditions, send inaccurate

information to the SPS. This ageing condition cannot be detected by the

aircraft ADA vane heater current monitor.

0\1"''''' SVMJlQL

J~TB
,

i

i

1491~13-PI

DEPARTMENT OF TRANSPORT AnON

Federal Aviation Administration

'IN<i'Y~""" SUMMAR Y: We are adopting a new airworthiness directive (AD) for the products liste ,\NE_17fI

14 CPR Part 39

IDocket No. FAA-2010-h***; Directorate Identifier 201O-NM-072-AD;

Amendment 39-*****; AD 2010~H_**1

RIN 2120~AA64

Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of Transportation

(DOT).

ACTION: final rule; request for comments.

above. This AD results from mandatory continuing airworthiness information (MeAl)

originated by all aviation authority of another country to identify and correct an unsafe

condirion on an aviation product. The MeAl describes the unsafe condition as·

* "' .• I. /\ pOLenlial freezingofLhe ADA langlcorauaekj Vane Resolver

'" .• '" lllay restrict the dynamic belHlvior (lag) of the vane and could lead to

a potential seize-up condition at lower temperatures. This condition, ifnol

corrected, may provide inaccurate AOA data to the Stall Protection

System (SPS).

2. As a result of ageing, the AOA vane heating element could degrade lO a

poinl when::tht::reis insufficient heat to prevent ice build-up on the AOA

vanes. TIle ice build-up may lead to a change in the aerodynamic

properties of the ADA vane and, under certain conditions, send inaccurate

information to the SPS. This ageing condition cannot be detected by the

aircraft AOA vane heater current monitor.

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AN~:'172

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