DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0528; Product Identifier 2017-NM-028-AD;
Amendment 39-19091; AD 2017-22-11]
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: We are adopting a new airworthiness directive (AD) for certain
Bombardier, Inc., Model CL-600-2B16 (CL-604 Variant) airplanes. This AD
was prompted by reports of in-service incidents regarding the loss of
all air data system information provided to the flightcrew. This AD
requires revising the airplane flight manual (AFM) to provide
``Unreliable Airspeed'' procedures to the flightcrew to stabilize the
airplane's airspeed and attitude for continued safe flight and landing.
We are issuing this AD to address the unsafe condition on these
products.

DATES: This AD is effective December 20, 2017.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of December 20,
2017.

ADDRESSES: For service information identified in this final rule,
contact Bombardier, Inc., 400 Cote-Vertu Road West, Dorval,
Quebec H4S 1Y9, Canada; telephone: 514-855-5000; fax: 514-855-
7401; email: thd.crj@aero.bombardier.com; Internet: http://www.bombardier.
com. You may view this referenced service information at
the FAA, Transport Standards Branch, 1601 Lind Avenue SW., Renton, WA.
For information on the availability of this material at the FAA, call
425-227-1221. It is also available on the Internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2017-0528.

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-2017-
0528; or in person at the Docket Management Facility 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 Office (telephone
800-647-5527) is Docket Management Facility, 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: Assata Dessaline, Aerospace Engineer,
Avionics and Administrative Services Section, FAA, New York ACO Branch,
1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone: 516-228-
7301; fax: 516-794-5531.

SUPPLEMENTARY INFORMATION:

Discussion

We 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-600-2B16 (CL-604 Variant) airplanes. The NPRM published in the
Federal Register on June 5, 2017 (82 FR 25746) (``the NPRM''). The NPRM
was prompted by reports of in-service incidents regarding the loss of
all air data system information provided to the flightcrew. The NPRM
proposed to require revising the AFM to provide ``Unreliable Airspeed''
procedures to the flightcrew to stabilize the airplane's airspeed and
attitude for continued safe flight and landing. We are issuing this AD
to provide the flightcrew with procedures for ``Unreliable Airspeed''
that stabilize the airplane's airspeed and attitude for continued safe
flight and landing.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2017-01, dated January 6, 2017 (referred to after this as the Mandatory
Continuing Airworthiness Information, or ``the MCAI''), to correct an
unsafe condition for certain Bombardier, Inc., Model CL-600-2B16 (CL-
604 Variant) airplanes. The MCAI states:

A number of in-service incidents have been reported on CL-600-
2C10 aeroplanes regarding a loss of all air data information
provided to the crew. The air data information was recovered as the
aeroplane descended to lower altitudes. An investigation determined
that the root cause in both events was high altitude icing (ice
crystal contamination). If not recognized and addressed, this
condition may affect continued safe flight and landing.
Due to similarities in the air data systems, similar events
could happen on Bombardier Inc. CL-600-2B16 aeroplanes.
This [Canadian] AD mandates the incorporation of Aircraft Flight
Manual (AFM) procedures to guide the crew to stabilize the
aeroplanes airspeed and attitude for continued safe flight and
landing.

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-2017-
0528.

Comments

We gave the public the opportunity to participate in developing
this AD. We considered the comment received.

Request To Clarify Introduction of "Unreliable Airspeed" AFM
Procedures

The commenter, Marjolaine Bourget, stated that the ``unreliable
airspeed'' procedures, while provided in the AFM revisions identified
in the proposed requirements, were actually introduced in the previous
revision of the identified AFMs.
From this statement, we infer that the commenter was requesting
that we add a statement that the ``unreliable airspeed'' procedures
were introduced in the previous revision of the identified AFMs. The
commenter provided no justification for this request. We acknowledge
that the ``unreliable airspeed'' procedures were introduced in an
earlier revision of the identified AFMs. We have revised this AD by
adding new paragraph (h) to this AD that provides credit to operators
for previously completing the actions required by paragraph (g) of this
AD if they used the applicable previous AFM revision.

Conclusion

We reviewed the relevant data, considered the comment received, and
determined that air safety and the public interest require adopting
this AD as proposed, except for minor editorial changes. We have
determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

Bombardier, Inc., has issued Unreliable Airspeed, of Section 03-15,
Instruments System, of Chapter 3, Emergency Procedures, of the
following AFMs:

Bombardier Challenger 604 AFM, Publication No. CH 604 AFM,
Revision 103, dated November 28, 2016.
Bombardier Challenger 605 AFM, Publication No. CH 605 AFM,
Revision 41, dated November 28, 2016.
Bombardier Challenger 650 AFM, Publication No. CH 650 AFM,
Revision 6, dated November 28, 2016.
This service information provides revisions to the Emergency
Procedures section of the AFM to incorporate a procedure for
``Unreliable Airspeed.'' These documents are distinct since they apply
to different airplane configurations. 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

We estimate that this AD affects 128 airplanes of U.S. registry.
We also estimate that it takes about 1 work-hour per product to
comply with the basic requirements of this AD. The average labor rate
is $85 per work-hour. Based on these figures, we estimate the cost of
this AD on U.S. operators to be $10,880, or $85 per product.

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.
We are 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 to
the Director of the System Oversight Division.

Regulatory Findings

We 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;
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979);
3. Will not affect intrastate aviation in Alaska; and
4. 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):