DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0578; Product Identifier 2019-NM-111-AD; Amendment
39-19697; AD 2019-15-04]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was
prompted by a report of a mis-installed no-back pawl discovered on a
horizontal stabilizer trim actuator (HSTA). This AD requires an
inspection to verify the horizontal stabilizer trim electronic control
unit (HSTECU) part number, a software upgrade for certain HSTECUs, and
installation of HSTECUs with upgraded software. The FAA is issuing this
AD to address the unsafe condition on these products.

DATES: This AD becomes 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.
The FAA must receive comments on this AD by September 23, 2019.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
For service information identified in this final rule, contact
Bombardier, Inc., 200 Cote-Vertu Road West, Dorval, Quebec
H4S 2A3, Canada; North America toll-free telephone 1-866-538-1247 or
direct-dial telephone 1-514-855-2999; email ac.yul@aero.bombardier.com;
internet http://www.bombardier.com. You may view this referenced
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-2019-0578.

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-2019-0578;
or in person at the Docket Operations office between 9 a.m. and 5
p.m., Monday through Friday, except Federal holidays. The AD docket
contains this AD, the regulatory evaluation, any comments received, and
other information. The street address for the Docket Operations office
is listed above. Comments will be available in the AD docket shortly
after receipt.

FOR FURTHER INFORMATION CONTACT: Darren Gassetto, Aerospace Engineer,
Mechanical Systems and Administrative Services Section, FAA, New York
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
telephone 516-228-7323; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2019-23, dated June 18,
2019 (referred to after this as the Mandatory Continuing Airworthiness
Information, or ``the MCAI''), to correct an unsafe condition for
certain Bombardier, Inc., Model BD-100-1A10 airplanes. The MCAI states:

During an unscheduled inspection, a mis-installed no-back pawl
was discovered on a Horizontal Stabilizer Trim Actuator (HSTA). The
no-back mechanism is a primary means to prevent back driving of the
HSTA, and the Motor Brake Assemblies (MBA) are the secondary means.
If not corrected, unavailability of the no-back mechanism in
combination with loss of, or degraded HSTA MBA braking capability,
could lead to a loss of the aeroplane.
This [TCCA] AD mandates a software upgrade for the HSTECU to
verify the MBA for braking capability during the power up test.

You may examine the MCAI on the internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2019-0578.

Related Service Information Under 1 CFR Part 51

Bombardier has issued Service Bulletin 100-27-15, Revision 01,
dated June 11, 2019. This service information describes procedures for
an inspection to verify the HSTECU part number, a software upgrade for
certain HSTECUs, and installation of HSTECUs with upgraded software.
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.

FAA's Determination

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to the FAA's bilateral agreement with the State of Design Authority,
the agency has been notified of the unsafe condition described in the
MCAI and service information referenced above. The FAA is issuing this
AD because it has evaluated all pertinent information and determined
the unsafe condition exists and is likely to exist or develop on other
products of the same type design.

Requirements of This AD

This AD requires accomplishing the actions specified in the service
information described previously.

Justification for Immediate Adoption and Determination of the Effective
Date

Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5
U.S.C.) authorizes agencies to dispense with notice and comment
procedures for rules when the agency, for ``good cause,'' finds that
those procedures are ``impracticable, unnecessary, or contrary to the
public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without seeking comment prior to the
rulemaking. Similarly, Section 553(d) of the APA authorizes agencies to
make rules effective in less than thirty days, upon a finding of good
cause.
The FAA has received a report that a mis-installed no-back pawl was
discovered on a HSTA. The no-back pawl is a primary means to prevent
back driving of the HSTA, and the MBA are the secondary means. If not
corrected, unavailability of the no-back pawl, in combination with loss
of or degraded HSTA MBA braking capability, could lead to a loss of the
airplane.
The FAA therefore considers the prompt identification and
prevention of this unsafe condition to be an urgent safety issue.
Accordingly, notice and opportunity for prior public comment are
impracticable and contrary to the public interest pursuant to 5 U.S.C.
553(b)(3)(B). In addition, the FAA finds that good cause exists
pursuant to 5 U.S.C. 553(d) for making this amendment effective in less
than 30 days.

Regulatory Flexibility Act (RFA)

The requirements of the RFA do not apply when an agency finds good
cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and
comment. Because the FAA has determined that it has good cause to adopt
this rule without notice and comment, RFA analysis is not required.

Comments Invited

This AD is a final rule that involves requirements affecting flight
safety, and was not preceded by notice and opportunity for public
comment. The FAA invites you to send any written relevant data, views,
or arguments about this AD. Send your comments to an address listed
under the ADDRESSES section. Include ``Docket No. FAA-2019-0578;
Product Identifier 2019-NM-111-AD'' at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this AD. The agency will
consider all comments received by the closing date and may amend this
AD based on those comments.
The FAA will post all comments received, without change, to http://www.
regulations.gov, including any personal information you provide.
The agency will also post a report summarizing each substantive verbal
contact received about this AD.

Costs of Compliance

The FAA estimates that this AD affects 9 airplanes of U.S.
registry. The agency estimates the following costs to comply with this
AD:

Estimated Costs for Required Actions

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 agency 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

The FAA determined that 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, and
(2) Will not affect intrastate aviation in Alaska.

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):