DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-1008; Product Identifier 2018-NM-126-AD; Amendment
39-19666; AD 2019-12-11]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 &
440) airplanes. This AD was prompted by reports indicating there is a
possibility of excessive error in the signal generated by the angle of
attack (AOA) transducer. This AD requires replacing certain AOA
transducers. The FAA is issuing this AD to address the unsafe condition
on these products.

DATES: This AD is effective August 23, 2019.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 23,
2019.

ADDRESSES: For service information identified in this final rule,
contact Bombardier, Inc., 400 Cote-Vertu Road West, Dorval,
Quebec H4S 1Y9, Canada; Widebody Customer Response Center North
America toll-free telephone 1-866-538-1247 or direct-dial telephone 1-
514-855-2999; fax 514-855-7401; email ac.yul@aero.bombardier.com;
internet http://www.bombardier.com. You may view this service
information at the FAA, Transport Standards Branch, 2200 South 216th
St., Des Moines, WA. For information on the availability of this
material at the FAA, call 206-231-3195. It is also available on the
internet at http://www.regulations.gov by searching for and locating
Docket No. FAA-2018-1008.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-
1008; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this final rule, the regulatory evaluation, any comments received, and
other information. The address for Docket Operations is U.S. Department
of Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: John DeLuca, Aerospace Engineer,
Avionics and Electrical Systems Services Section, FAA, New York ACO
Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone
516-228-7369; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain Bombardier,
Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. The
NPRM published in the Federal Register on December 11, 2018 (83 FR
63594). The NPRM was prompted by reports indicating there is a
possibility of excessive error in the signal generated by the AOA
transducer. The NPRM proposed to require replacing certain AOA
transducers.
The FAA is issuing this AD to address this potential error, which,
if not detected by the stall protection computer, could lead to late
activation of the stall protection system and possible loss of control
of the airplane.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2018-17, dated June 29,
2018 (referred to after this as the Mandatory Continuing Airworthiness
Information, or ``the MCAI''), to correct an unsafe condition for
certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 &
440) airplanes. The MCAI states:

Bombardier has received reports from the manufacturer of its
Angle of Attack (AOA) transducers indicating that there is a
possibility of excessive error in the signal generated by the AOA
Transducer. It is possible that this error may not be detected by
the stall protection computer, which could lead to late stall
protection system activation and potentially result in the loss of
control of the aeroplane. The error could be a result of incorrect
assembly or/and internal wear in the AOA Transducer.
This [Canadian] AD mandates the modification or replacement of
the AOA transducers in order to prevent late activation of the stick
pusher in the stall protection system.

You may examine the MCAI in the AD docket on the internet at http://
www.regulations.gov by searching for and locating Docket No. FAA-2018-1008.

Comments

The FAA gave the public the opportunity to participate in
developing this final rule. The following presents the comments
received on the NPRM and the FAA's response to each comment.

Request To Reduce Proposed Applicability of This AD

Air Wisconsin Airlines (Air Wisconsin) recommended revising
paragraph (c) of the proposed AD to restrict the applicability to only
those airplanes equipped with the affected parts. Air Wisconsin
suggested adding the phrase ``having AOA transducers P/Ns [part
numbers] 45-150-340, C16258AA, or C16258AB'' to the end of the sentence
that specifies the airplane models and serial numbers. Air Wisconsin
pointed out that some airplanes might have unaffected part numbers
installed, either by having installed a supplemental type certificate
or prior accomplishment of the service information.
The FAA has not changed the AD as recommended by the commenter,
because the affected AOA transducers are rotable parts and might be
later installed on airplanes not initially delivered with the affected
AOA transducers, or that did not have an affected AOA installed on the
effective date of this AD. Paragraph (f) of this AD provides relief for
airplanes on which the AOA transducer has been replaced prior to the
effective date of this AD.

Request To Extend Proposed Compliance Time for Parts Installation
Prohibition

Air Wisconsin requested that the compliance time for the Parts
Installation Prohibition specified in paragraph (h) of the proposed AD
be revised to match the compliance time for the AOA replacement
required in paragraph (g) of this AD. Air Wisconsin suggested that,
based on the date of the service information and the amount of time
Bombardier recommends the service information be performed within, it
would appear as through there is not an imminent pending failure of the
parts.
The FAA disagrees with the request to extend the compliance time
for the parts installation prohibition specified in paragraph (h) of
this AD. In general, once the FAA has determined that an unsafe
condition exists, the FAA does not allow that condition to be
introduced into the fleet. In developing the technical information on
which every AD is based, the FAA considers the availability of
replacement parts that the AD will require to be installed. Replacement
parts are available to operators, and this AD prohibits installation of
the unsafe parts. The FAA's determination regarding compliance time is
consistent with TCCA's compliance time determination. The FAA has not
changed this AD in this regard.

Request To Clarify Airplanes Affected by Parts Installation Prohibition

Air Wisconsin requested a revision to paragraph (h) of the proposed
AD to clarify that ``any airplane'' means those airplanes identified in
paragraph (c) of the proposed AD.
The FAA finds that the requested change is unnecessary, because
paragraph (c) of this AD establishes the AD's applicability for the
airplanes in which the actions in paragraph (h) of this AD apply.

Request To Address Connection Between the Proposed AD and AD 2010-08-
03, Amendment 39-16258 (75 FR 19203, April 14, 2010) (``AD 2010-08-
03'')

Air Wisconsin requested that AD 2010-08-03 be addressed in this AD
because that AD applies to the same airplane model, serial numbers, and
AOA parts identified in the proposed AD.
The FAA disagrees with the request to reference AD 2010-08-03,
because that AD is not affected by this AD. Although, AD 2010-08-03 and
this AD both require actions on the AOA transducer, the two ADs address
different root causes or failure modes. The primary focus of AD 2010-
08-03 was heater element degradation and inaccurate calibration in AOA
transducers. The focus of this AD is possible excessive error in the
signal from the AOA transducer, which became known at a later time.
Therefore, since the required actions in this AD are not related to the
required actions in AD 2010-08-03, the FAA has not changed this AD in
this regard.

Conclusion

The FAA reviewed the relevant data, considered the comments
received, and determined that air safety and the public interest
require adopting this final rule as proposed, except for minor
editorial changes. The FAA has determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
The FAA also determined that these changes will not increase the
economic burden on any operator or increase the scope of this final
rule.

Related Service Information Under 1 CFR Part 51

Bombardier has issued Service Bulletin 601R-27-165, dated December
20, 2016. This service information describes procedures for replacing
certain AOA transducers with new or modified AOA transducers.
This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in the ADDRESSES section.

Costs of Compliance

The FAA estimates that this AD affects 525 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs

According to the manufacturer, some or all of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected individuals. The FAA does not control warranty coverage for
affected individuals. As a result, the FAA has included all known costs
in its cost estimate.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to transport category airplanes and
associated appliances to the Director of the System Oversight Division.

Regulatory Findings

This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect on the States,
on the relationship between the national government and the States, or
on the distribution of power and responsibilities among the various
levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Will not affect intrastate aviation in Alaska, and
(3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):