DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2018-0794; Product Identifier 2017-NM-175-AD; Amendment
39-19625; AD 2019-08-04]
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
ACTION: Final rule.
SUMMARY: We are superseding Airworthiness Directive (AD) 2012-25-02,
which applied to certain Bombardier, Inc., Model CL-600-2B19 (Regional
Jet Series 100 & 440) airplanes. AD 2012-25-02 required revising the
airworthiness limitations section (AWL) of the instructions for
continued airworthiness (ICA) of the maintenance requirements manual
(MRM) by incorporating new procedures for repetitive inspections for
cracking of the rear pressure bulkhead (RPB). AD 2012-25-02 also
required revising the maintenance or inspection program to incorporate
a revised task. This AD also mandates modification of the RPB and adds
repetitive inspections for cracking of the RPB web, which terminates
certain actions in this AD. This AD was prompted by additional in-
service crack findings, which resulted in the development of a
structural modification to the RPB. We are issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective July 12, 2019.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of July 12,
The Director of the Federal Register approved the incorporation by
reference of a certain other publication listed in this AD as of
January 16, 2013 (77 FR 73902, December 12, 2012).
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
514-855-5000; fax 514-855-7401; email firstname.lastname@example.org;
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-2018-0794.
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-
0794; 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 (phone: 800-647-
5527) 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: Aziz Ahmed, Aerospace Engineer,
Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7329;
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to supersede AD 2012-25-02, Amendment 39-17283 (77 FR 73902,
December 12, 2012) (``AD 2012-25-02''). AD 2012-25-02 applied to
certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 &
440) airplanes. The NPRM published in the Federal Register on September
13, 2018 (83 FR 46428). The NPRM was prompted by additional in-service
crack findings, which resulted in the development of a structural
modification to the RPB. The NPRM proposed to continue to require
revising the AWL of the ICA of the MRM by incorporating new procedures
for repetitive inspections for cracking of the
RPB. The NPRM also proposed to mandate modification of the RPB and add
repetitive inspections for cracking of the RPB web, which would
terminate certain actions in this AD. We are issuing this AD to address
cracking in the RPB, which could result in reduced structural integrity
and rapid decompression of the airplane.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2011-30R2, dated June 12, 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-600-2B19
(Regional Jet Series 100 & 440) airplanes. The MCAI states:
Cracks on the forward face of the Rear Pressure Bulkhead (RPB)
web have been discovered on three CL-600-2B19 aeroplanes in-service.
A Temporary Revision has been made to Part 2 of the Maintenance
Requirements Manual (MRM) to revise the existing AWL task by
introducing an improved Non-Destructive Inspection (NDI) procedure
to ensure that fatigue cracking of the RPB is detected and
The original issue of this [TCCA] AD [which corresponds to FAA
AD 2012-25-02] mandated the incorporation of a new NDI procedure for
AWL task number 53-61-153.
Additional in-service findings have resulted in the issue of
revision 1 of this [TCCA] AD, which mandates a structural
modification to the rear pressure bulkhead with revised threshold
and repeat inspection intervals. This modification is intended to
preclude the onset of multiple site fatigue damage for the remaining
service life of the aeroplane. If not corrected, a failure of the
RPB could result in loss of structural integrity of the aeroplane.
Revision 2 of this [TCCA] AD requires an inspection to be
carried out prior to modification of the RPB. This revision also
requires an additional modification to be completed on the RPB prior
to terminating AWL task number 53-61-153. It also includes
provisions to account for certain repairs as well as [alternative
methods of compliance] AMOCs issued to earlier revisions of this
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-
We 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.
Support for the NPRM
Endeavor Air stated its support for the NPRM.
Request To Add Reference Terminating Action
Bombardier requested that we revise paragraph (g) of the proposed
AD to identify the terminating action provided in paragraph (o)(3) of
the proposed AD. Bombardier pointed out that, since paragraph (g) of
the proposed AD identifies terminating action in paragraph (m) of the
proposed AD, paragraph (g) of the proposed AD should also identify the
terminating action provided in paragraph (o)(3) of the proposed AD for
We do not agree to add reference to paragraph (o)(3) in the
introductory text of paragraph (g) of this AD. Instead, because
paragraph (o) of this AD already contains all of the terminating
actions for paragraph (g) of this AD, for simplicity and consistency we
have revised paragraph (g) of this AD to remove reference to
terminating actions that were identified in the proposed AD. This
change does not change the intent or requirements of paragraph (g) of
Request To Add Alternative Service Information for Repair
Bombardier requested that we revise paragraph (k) of the proposed
AD to reference Bombardier Repair Engineering Order (REO) 601R-53-61-
1285, Revision E, dated October 31, 2016; and Bombardier REO 601R-53-
61-1541, Revision F, dated November 12, 2014; as alternative service
information for the repair. Bombardier pointed out that this change
corresponds with the provisions of Part I, section C., of the MCAI.
We agree with the request. We have determined that the actions
specified in the alternative service information are acceptable for
compliance for the repair. Therefore, we have revised paragraph (k)(2)
of this AD to add the referenced REOs as alternative service
information for the repair.
Request To Add Credit for Previous Actions Using Previous Service
Bombardier requested that we revise paragraph (p) of the proposed
AD to provide credit for actions done before the effective date of the
AD using earlier revisions of the service information specified in part
III, section B., paragraphs (3), (5), (6), and (7) of the MCAI.
Bombardier did not provide a justification for this request.
We partially agree with the request to provide credit for
previously accomplished actions done using the earlier revisions of the
specified service information. We have determined that the service
information specified in part III, section B., paragraphs (3), (5),
(6), and (7) of the MCAI is acceptable for accomplishing the applicable
actions before the effective date of this AD, provided certain actions
are done using the required service information. Therefore, we have
added paragraph (p) to this AD to include the requested credit, and
have redesignated subsequent paragraphs accordingly.
Request To Allow Approved Alternative Actions and Intervals
Endeavor Air requested that we revise paragraph (n) of the proposed
AD, which would prohibit alternative actions and intervals once
revision of the maintenance or inspection program is accomplished,
except as approved in paragraph (p)(1) of the proposed AD (which
specified approval by the FAA only). The commenter asserted that
alternative actions and intervals should be allowed if approved by
specifying ``paragraph (p)(1) or (p)(2)'' (paragraph (p)(2) specified
approval by the FAA, TCCA, or the TCCA Design Approval Organization
(DAO)). The commenter stated that this change would reduce unnecessary
time and paperwork by eliminating the need for AMOC approval by the FAA
after the operator has already received a generic REO (GREO) or REO
that is TCCA DAO approved.
We do not agree to add reference to paragraph (q)(2) of this AD
(paragraph (p)(2) of the proposed AD) in paragraph (n) of this AD.
Since we do not currently have the authority to delegate AMOC approvals
to foreign civil aviation authorities, the FAA is responsible for these
approvals. We have not changed this AD in this regard.
Request To Allow Deviations to Certain Service Information
Air Wisconsin requested that necessary deviations from the
instructions in Bombardier REO 601R-53-61-1240, Revision D, dated
October 31, 2016, be acceptable along with this REO for compliance with
the requirements of paragraph (j)(2) of the proposed AD. Air Wisconsin
pointed out that paragraph (j)(2) of the proposed AD would require a
modification in accordance with Bombardier REO 601R-53-61-1240,
Revision D, dated October 31, 2016, and reported that it has
incorporated this REO on several of its airplanes. In some cases, Air
Wisconsin stated that it found it necessary to deviate from the
instructions of this REO (e.g., plugging holes with fasteners or
installation of next oversize fastener). Therefore, since there are no
approved deviations to the
inspection procedures in this REO, Air Wisconsin suggested that
necessary deviations to this REO be considered acceptable under the
The deviation is approved by signature by TCCA or
Bombardier, Inc.'s TCCA DAO; and
The damage-tolerance analysis was performed as shown by
the entry in block 6 (Additional Limitations) of the REO and the entry
was determined to be ``None.''
We do not agree with the commenter's request. We do not consider it
appropriate to include various provisions in an AD applicable only to
an operator's unique configuration of affected airplanes. However, if
an operator with an affected airplane cannot accomplish the required
actions specified in the service information, or prefers to use
different service information that is specific to their design, an AMOC
can be requested in accordance with the provisions specified in
paragraph (q) of this AD.
Further, as we explained in the ``Differences Between this Proposed
AD and the Service Information'' section in the NPRM, the MCAI includes
the following statement: ``If it is not possible to complete all of the
instructions in Part II of this [Canadian] AD due to the configuration
of the aeroplane . . . contact Bombardier Inc. . . . for approved
instructions.'' This issue is addressed in 14 CFR 39.17, which states
that ``If a change in a product affects your ability to accomplish the
actions required by the AD in any way, you must request FAA approval of
an AMOC . . . .'' Since we do not currently have the authority to
delegate AMOC approvals to foreign civil aviation authorities, the FAA
is responsible for these approvals.
We have not changed this AD regarding this issue.
Request To Extend Compliance Time
SkyWest Airlines (SkyWest) requested that we extend the phase-in
compliance times required by paragraph (j) of the proposed AD, which
would require a modification according to a schedule based on
accumulated flight cycles. SkyWest reported that, due to its fleet
utilization and the phase-in intervals, the work might need to be done
outside of a scheduled heavy maintenance visit. SkyWest proposed an
alternative phase-in schedule to allow a cushion of time in order for
them to reach the next heavy maintenance visit.
We do not agree with the commenter's request to extend the phase-in
compliance times specified in figure 1 to paragraph (j) of this AD. We
have determined that the compliance times, as proposed, represent the
maximum interval of time allowable for the affected airplanes to
continue to safely operate before the modification is done. Since
maintenance schedules vary among operators, there would be no assurance
that the airplane would be modified during that maximum interval.
Further, this commenter did not provide data verifying the safety of
the proposed intervals. Although we have not changed the AD regarding
this issue, under the provisions of paragraph (q)(1) of this AD, we
will consider requests for approval of an alternative compliance time,
if data are submitted to substantiate that such an adjustment would
provide an acceptable level of safety. We have not changed this AD in
Request To Clarify Credit for Prior Accomplishment
Air Wisconsin requested that we revise paragraph (j) of the
proposed AD to specify that the actions are required ``unless already
accomplished.'' Air Wisconsin stated that several of its airplanes have
been modified using the applicable service information.
We do not agree to revise paragraph (j) of this AD. Paragraph (f)
of this AD requires compliance with all AD requirements ``unless
already done.'' Therefore, the commenter's proposed wording is
unnecessary. We have not changed this AD regarding this issue.
Request for Clarification of Locations for Nondestructive Inspection
Air Wisconsin requested that we clarify whether the NDI specified
in paragraph (j)(1) of the proposed AD is for areas that have not been
modified using various REOs or Supplemental Type Certificate (STC)
ST02308NY that would remain in place. The commenter added that the NDI
may not be possible for those areas modified using Bombardier REO 601R-
53-61-1541; or Bombardier REO 601R-53-61-1285, Revision D, dated
October 31, 2011, or Revision E, dated October 31, 2016; which were
approved by certain AMOCs; because the NDI has not yet been developed
for those areas.
We agree that clarification is necessary. Unless this AD provides
specific credit for an existing modification or repair NDI, an
evaluation needs to be accomplished to determine whether the inspection
associated with the existing modification or repair meets an acceptable
level of safety. An AMOC is required for an alternative action based on
the existing modification or repair. We have not changed this AD
regarding this issue.
Request for Clarification of Affected Serial Number
Air Wisconsin noted that paragraph (m) of the proposed AD applies
to ``any airplane having serial number 7610,'' and asked whether more
than one Model CL-600-2B19 airplane had that serial number.
We agree that clarification is necessary. There is only one
airplane with serial number 7610. We have revised paragraph (m) of this
AD to specify ``For airplane serial number 7610.''
Request To Clarify Terminating Requirements
Air Wisconsin requested that we clarify paragraph (o)(1) of the
proposed AD by explaining how compliance with paragraph (j) or (l) of
the proposed AD would not entirely terminate the requirements of
paragraph (g) of the proposed AD.
We agree that clarification may be necessary. Paragraph (o)(1) of
this AD specifies that accomplishing the requirements of paragraph (j)
or (l) terminates the requirements of paragraph (g) of this AD ``for
the repaired area only.'' The inspections required by paragraph (g) of
this AD must be repeated for non-repaired areas. This requirement
corresponds with the MCAI. We have not changed this AD regarding this
Request for Credit for Previous Repairs
Bombardier requested that we revise paragraphs (k)(1) and (k)(2) of
the proposed AD to give credit for repairs done before the effective
date of the AD, if those repairs were approved by the FAA, TCCA, or
Bombardier's TCCA DAO and referred to the MCAI. Bombardier noted that
this credit is provided in part I, section C., of the MCAI.
We partially agree. We agree to provide credit for repairs
specified in paragraphs (k)(1) and (k)(2) of this AD, if those repairs
were done before the effective date of this AD, and were done in
accordance with a method approved by the Manager, New York ACO Branch,
FAA; TCCA; or Bombardier's TCCA DAO; and the approval references TCCA
AD CF-2011-30, dated August 24, 2011, or AD CF-2011-30R1, dated
November 1, 2016. However, we do not agree to include that credit in
paragraphs (k)(1) and (k)(2) of this AD. Instead, we have added
paragraph (p)(1) to this AD to provide the requested credit. (As
explained previously, we have redesignated paragraphs (p)(1) and
(p)(2) of the proposed AD as paragraphs (q)(1) and (q)(2) of this AD.)
Request To Correct Paragraph References
Bombardier noted a typographical error in paragraph (p)(1)(ii) of
the proposed AD, which specified that previously approved AMOCs are
acceptable for ``paragraphs (g), (k), and (l)'' of the proposed AD.
Bombardier asserted that the correct paragraph references are (g), (h),
We agree that paragraph (p)(1)(ii) of the proposed AD included a
typographical error in the paragraph references. We have revised
paragraph (q)(1)(ii) of this AD (paragraph (p)(1)(ii) of the proposed
AD) to reference the correct paragraphs.
We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
this final rule with the changes described previously and minor
editorial changes. We have 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.
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of this final
Related Service Information Under 1 CFR Part 51
Bombardier, Inc., has issued the following service information.
Bombardier REO 601R-53-61-1230, Revision F, dated October
31, 2011. This service information describes procedures for a repair to
the pressure bulkhead web frame station (FS) 621.00, lintel
Bombardier REO 601R-53-61-1240, Revision D, dated October
31, 2016. This service information describes procedures for a repair
and modification to FS 621.00 pressure bulkhead web.
Bombardier REO 601R-53-61-5828, Revision A, dated March
16, 2017. This service information describes procedures for a repair to
FS 621.00 pressure bulkhead web at left buttock line (LBL) 27.5.
This AD also requires Bombardier Temporary Revision 2B-2187, dated
June 22, 2011, to Appendix B-Airworthiness Limitations, of Part 2 of
the Bombardier CL-600-2B19 MRM, which the Director of the Federal
Register approved for incorporation by reference as of January 16, 2013
(77 FR 73902, December 12, 2012).
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 457 airplanes of U.S. registry. We
estimate the following costs to comply with this AD:
Estimated Costs for Required Actions
||Cost per product
||Cost on U.S. operators
|Up to 917 work-hours x $85 per
hour = $77,945
||Up to $6,000
||Up to $83,945
||Up to $38,362,865
We have determined that revising
the maintenance or inspection
program takes an average of 90 work-hours per operator, although we
recognize that this number may vary from operator to operator. In the
past, we have estimated that this action takes 1 work-hour per
airplane. Since operators incorporate maintenance or inspection program
changes for their affected fleet(s), we have determined that a per-
operator estimate is more accurate than a per-airplane estimate.
Therefore, we estimate the total cost per operator to be $7,650 (90
work-hours x $85 per work-hour).
We have received no definitive data that would enable us to provide
cost estimates for the on-condition actions specified in this AD.
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
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.
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
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
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 removing Airworthiness Directive (AD)
2012-25-02, Amendment 39-17283 (77 FR 73902, December 12, 2012), and
adding the following new AD: