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2019-08-04 BOMBARDIER, INC.: Amendment 39-19625; Docket No. FAA-2018-0794; Product Identifier 2017-NM-175-AD.
(a) EFFECTIVE DATE

    This AD is effective July 12, 2019.

(b) AFFECTED ADS

    This  AD  replaces AD  2012-25-02,  Amendment 39-17283  (77  FR 73902,
    December 12, 2012) ("AD 2012-25-02").

(c) APPLICABILITY

    This AD applies to  Bombardier, Inc., Model CL-600-2B19  (Regional Jet
    Series  100 &  440) airplanes,  certificated in  any category,  serial
    numbers 7002 through 8025 inclusive, 8030, and 8034.

(d) SUBJECT

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) REASON

    This AD was prompted by multiple reports of cracks on the forward face
    of the  rear pressure  bulkhead (RPB)  web, and  additional in-service
    crack  findings  that  resulted in  the  development  of a  structural
    modification to the RPB. We are issuing this AD to address cracking in
    the RPB, which could result in reduced structural integrity and  rapid
    decompression of the airplane.

(f) COMPLIANCE

    Comply  with this  AD within  the compliance  times specified,  unless
    already done.

(g) RETAINED REVISION OF THE MAINTENANCE PROGRAM WITH MINOR CHANGES

    This paragraph restates the requirements  of paragraph (i) of AD  2012
    -25-02,  with minor  changes. Except  for the  airplane having  serial
    number 7002, within 60 days after January 16, 2013 (the effective date
    of AD 2012-25-02): Revise the maintenance program by incorporating the
    revised inspection requirements specified in airworthiness  limitation
    section (AWL) 53-61-153 of Bombardier temporary revision (TR) 2B-2187,
    dated June 22, 2011, to Appendix B- Airworthiness Limitations, of Part
    2 of the Bombardier CL-600-2B19 Maintenance Requirements Manual (MRM).
    The initial compliance times for  the task are at the  applicable time
    specified in paragraph (g)(1) or (g)(2) of this AD.

(1) For  airplanes  on  which the special detailed inspection specified in
    AWL  53-61-153  of Bombardier  TR  2B-2187, dated  June  22, 2011;  or
    Canadair Regional Jet TR 2B-2109, dated October 13, 2005; has not been
    done as of January 16, 2013 (the effective date of AD 2012-25-02): The
    initial compliance time  for AWL 53-61-153  is at the  applicable time
    specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD.

(i) For airplanes that have accumulated 10,500 total flight cycles or less
    as of January 16, 2013: Before the accumulation of 12,000 total flight
    cycles.

(ii) For  airplanes  that  have  accumulated more than 10,500 total flight
     cycles  as  of  January 16, 2013:  Within  1,500 flight cycles  after
     January 16, 2013 (the effective date of AD 2012-25-02).

(2) For  airplanes  on  which the special detailed inspection specified in
    AWL  53-61-153  of Bombardier  TR  2B-2187, dated  June  22, 2011;  or
    Canadair Regional  Jet TR  2B-2109, dated  October 13,  2005; has been
    done as of January 16, 2013 (the effective date of AD 2012-25-02): The
    initial  compliance  time for  AWL  53-61-153 is  within  4,360 flight
    cycles   after  accomplishing   the  most   recent  special   detailed
    inspection, or within 1,500 flight cycles after accomplishing the most
    recent detailed inspection as  specified in AWL 53-61-153  of Canadair
    Regional  Jet TR  2B-2109, dated  October 13,  2005, whichever  occurs
    later.

(h) RETAINED NO ALTERNATIVE ACTIONS OR INTERVALS, WITH NEW EXCEPTION

    This paragraph restates the requirements of paragraph (j) of  AD 2012-
    25-02, with a new exception. Except as required by paragraphs  (j)(3),
    (l)(2), and (m) of this AD, after accomplishing the revisions required
    by  paragraph  (g)   of  this  AD,   no  alternative  actions   (e.g.,
    inspections) or intervals  may be used  other than those  specified in
    Bombardier  TR   2B-2187,  dated   June  22,   2011,  to   Appendix  B
    -Airworthiness Limitations,  of Part  2 of  the Bombardier CL-600-2B19
    MRM, unless the actions and  intervals are approved as an  alternative
    method  of  compliance  (AMOC)  in  accordance  with  the   procedures
    specified in paragraph (q)(1) of this AD.

(i) RETAINED GENERAL REVISION OF THE MRM, WITH NO CHANGES

    This paragraph restates the requirements of paragraph (k) of  AD 2012-
    25-02, with no changes.  The maintenance program revision  required by
    paragraph (g) of this AD may be done by inserting a copy of Bombardier
    TR  2B-2187,  dated  June 22,  2011,  into  Appendix B-  Airworthiness
    Limitations, of Part 2 of the Bombardier CL-600-2B19 MRM. When this TR
    has  been  included  in  general revisions  of  the  MRM,  the general
    revisions  may  be  inserted   in  the  MRM,  provided   the  relevant
    information in the general revision is identical to that in this TR.

(j) NEW REQUIREMENTS OF THIS AD: INSPECTIONS, MODIFICATION AND MAINTENANCE
    OR INSPECTION PROGRAM REVISION

    Accomplish  the actions  required by  paragraphs (j)(1),  (j)(2),  and
    (j)(3)  of  this AD  at  the time  specified,  except as  provided  by
    paragraphs (l) and (m) of this AD.

(1) At the applicable time specified in figure 1 to paragraph (j)  of this
    AD: Do a nondestructive inspection for cracking of the forward face of
    the fuselage station  (FS) 621 pressure  bulkhead, in accordance  with
    AWL  53-61-153  of Bombardier  TR  2B-2187,  dated  June 22, 2011,  to
    Appendix B-Airworthiness Limitations, of  Part 2 of the  Bombardier CL
    -600-2B19 MRM.

(2) At the applicable time specified in figure 1 to paragraph (j)  of this
    AD: Modify the RPB and do a nondestructive inspection for cracking  of
    the FS 621 pressure bulkhead web, in accordance with Bombardier Repair
    Engineering Order (REO) 601R-53-61-1240, Revision D, dated October 31,
    2016.

(3) Before further flight after accomplishing the modification required by
    paragraph  (j)(2)  of  this AD:  Revise  the  existing maintenance  or
    inspection  program, as  applicable, by  incorporating the  inspection
    requirements  at  the   threshold  and  repetitive   inspection  times
    specified in the  in-service deviation inspection  requirements (SDIR)
    of Bombardier REO 601R-53-61-1240, Revision D, dated October 31, 2016.

      FIGURE 1 TO PARAGRAPH (J) OF THIS AD  MODIFICATION AND INSPECTION  
                                             PHASE-IN                     
    ______________________________________________________________________
    AIRPLANE FLIGHT CYCLES
    AS OF THE EFFECTIVE
    DATE OF THIS AD                           COMPLIANCE TIME
    ______________________________________________________________________
    For airplanes that have          Prior to the accumulation of 40,000
    accumulated 35,000               total flight cycles
    total flight cycles or
    less

    For airplanes that have          Within 5,000 flight cycles after
    accumulated more than            the effective date of this AD
    35,000 total flight cycles
    and less than 40,000 total
    flight cycles

    For airplanes that have          Prior to the accumulation of 45,000
    accumulated 40,000 total         total flight cycles
    flight cycles or more
    ______________________________________________________________________

(k) CORRECTIVE ACTION

(1) If any crack is found during any inspection required  by paragraph (j)
    (2), (l)(1), or (m) of this AD: Before further flight, repair using  a
    method approved by  the Manager, New  York ACO Branch,  FAA; Transport
    Canada  Civil  Aviation  (TCCA);  or  Bombardier,  Inc.'s  TCCA Design
    Approval Organization (DAO). If approved by the DAO, the approval must
    include the DAO-authorized signature.

(2) If any crack is found during any inspection required  by paragraph (j)
    (1) of this AD: Before  further flight, repair in accordance  with the
    applicable  service information  specified in  paragraph (k)(2)(i)  or
    (k)(2)(ii) of this AD, or using a method approved by the Manager,  New
    York  ACO  Branch,  FAA;  TCCA; or  Bombardier,  Inc.'s  TCCA  DAO. If
    approved  by the  DAO, the  approval must  include the  DAO-authorized
    signature.

(i) Bombardier REO 601R-53-61-1230, Revision F, dated October 31, 2011; or
    Bombardier REO 601R-53-61-1285, Revision E, dated October 31, 2016.

(ii) Bombardier REO 601R-53-61-1240,  Revision D,  dated October 31, 2016;
     or  Bombardier REO 601R-53-61-1541,  Revision F,  dated  November 12,
     2014.

(l) ALTERNATIVE ACTIONS FOR CERTAIN AIRPLANES

    For airplanes on which the  actions required by paragraphs (j)(1)  and
    (j)(2) of this AD were performed before the effective date of this  AD
    using the REOs identified in figure 2 to paragraph (l) of this AD:  In
    lieu of accomplishing  the actions required  by paragraph (j)  of this
    AD, accomplish the actions required by paragraphs (l)(1) and (l)(2) of
    this AD within  6,000 flight cycles  after the effective  date of this
    AD.

(1) Perform a special detailed inspection  for  cracking  of Zone B of the
    RPB web,  in accordance with Part B of Bombardier REO 601R-53-61-1240,
    Revision D, dated October 31, 2016.

(2) Revise the existing maintenance or inspection program,  as applicable,
    by  incorporating  the  inspection requirements  at the  threshold and
    repetitive  inspection  times  specified  in Part  B  of  the  SDIR of
    Bombardier REO  601R-53-61-1240, Revision  D, dated  October 31, 2016.
    The inspection threshold is measured from the time of incorporation of
    the applicable REO specified in figure 2 to paragraph (l) of this AD.

                            ILLUSTRATION (Figure 2)

(m) ALTERNATIVE ACTIONS FOR AIRPLANE SERIAL NUMBER 7610

    For airplane serial number 7610:  In lieu of accomplishing the actions
    required by paragraph (j) of this AD; within 6,000 flight cycles after
    the effective date of this  AD, do a reinforcement of  K601R36010-A at
    left buttock line (LBL) 27.5 and perform a special detailed inspection
    for cracking  of the  FS 621  pressure bulkhead  web at  LBL 27.5,  in
    accordance  with  Bombardier REO  601R-53-61-5828,  Revision A,  dated
    March  16,  2017.  Before  further  flight  after  accomplishing   the
    reinforcement, or within 60 days after the effective date of this  AD,
    whichever occurs later: Revise the maintenance or inspection  program,
    as  applicable,  by  incorporating  the  inspection  requirements that
    include threshold and repetitive inspection times as specified in  the
    SDIR of Bombardier  REO 601R-53-61-5828,  Revision  A, dated March 16,
    2017.

(n) NO ALTERNATIVE ACTIONS OR INTERVALS

    After the maintenance  or  inspection program  has been revised as re-
    quired by paragraph (j)(3), (l)(2), or (m) of this AD, no  alternative
    actions  (e.g.,  inspections)  or intervals  may  be  used unless  the
    actions or intervals  are approved as  an AMOC in  accordance with the
    procedures specified in paragraph (p)(1) of this AD.

(o) TERMINATING ACTIONS FOR PARAGRAPH (G) OF THIS AD

(1) Accomplishment of the actions required by paragraph (j) or (l) of this
    AD terminates the requirements of paragraph (g)  of this AD,  for  the
    repaired area only.

(2) Accomplishment of the actions required  by  paragraph (m)  of  this AD
    terminates the requirements of paragraph (g) of this AD.

(3) For airplanes on which the actions required by paragraph (j) or (l) of
    this AD have  been done and  on which the  modification and inspection
    specified in REO 601R-53-61-1230, Revision F,  dated October 31, 2011,
    have been  done and  there were  no inspection  findings: The  actions
    required by paragraph (g) of this AD are terminated.

(p) CREDIT FOR PREVIOUS ACTIONS

(1) This paragraph provides credit for the actions required  by paragraphs
    (k)(1) and (k)(2) of  this AD, if those  repairs were done before  the
    effective date of this AD using a method approved by the Manager,  New
    York ACO  Branch, FAA;  TCCA; or  Bombardier, Inc.'s  TCCA DAO;  which
    references TCCA AD  CF-2011-30, dated August  24, 2011, or  AD CF-2011
    -30R1, dated November 1, 2016.

(2) This paragraph provides credit  for  the actions required by paragraph
    (k)(2)  of  this  AD,  if  those  actions  were  performed  before the
    effective date of this AD  using the service information specified  in
    paragraph (p)(2)(i),  (p)(2)(ii), (p)(2)(iii),  (p)(2)(iv), (p)(2)(v),
    or (p)(2)(vi) of this AD, provided that the maintenance or  inspection
    program is revised by incorporating the inspection requirements at the
    threshold and  repetitive inspection  times specified  in the  SDIR of
    Bombardier REO 601R-53-61-1230, Revision F, dated November 7, 2011.

(i) Bombardier REO 601R-53-61-1230, dated February 10, 2005.

(ii) Bombardier REO 601R-53-61-1230, Revision A, dated November 6, 2009.

(iii) Bombardier REO 601R-53-61-1230, Revision B, dated October 5, 2005.

(iv) Bombardier REO 601R-53-61-1230, Revision C, dated November 10, 2005.

(v) Bombardier REO 601R-53-61-1230, Revision D, dated July 19, 2006.

(vi) Bombardier REO 601R-53-61-1230, Revision E, dated August 18, 2011.

(3) This paragraph provides credit  for the actions required  by paragraph
    (k)(2)  of  this  AD,  if  those  actions  were  performed  before the
    effective date of this AD  using the service information specified  in
    paragraph (p)(3)(i), (p)(3)(ii), (p)(3)(iii), (p)(3)(iv), or (p)(3)(v)
    of this  AD, provided  that the  maintenance or  inspection program is
    revised by incorporating the inspection requirements at the  threshold
    and repetitive inspection  times specified in  the SDIR of  Bombardier
    REO 601R-53-61-1285, Revision E, date October 31, 2016.

(i) Bombardier REO 601R-53-61-1285, dated March 24, 2005.

(ii) Bombardier REO 601R-53-61-1285, Revision A, dated November 6, 2009.

(iii) Bombardier REO 601R-53-61-1285, Revision B, dated April 14, 2010.

(iv) Bombardier REO 601R-53-61-1285, Revision C, dated August 19, 2011.

(v) Bombardier REO 601R-53-61-1285, Revision D, dated October 31, 2011.

(4) This paragraph provides credit  for the actions required  by paragraph
    (k)(2) of this AD if those actions were performed before the effective
    date of this AD using  the service information specified in  paragraph
    (p)(4)(i),   (p)(4)(ii),   (p)(4)(iii),   (p)(4)(iv),   (p)(4)(v),  or
    (p)(4)(vi) of  this AD,  provided that  the maintenance  or inspection
    program is revised by incorporating the inspection requirements at the
    threshold and  repetitive inspection  times specified  in the  SDIR of
    Bombardier REO 601R-53-61-1541, Revision F, dated November 12, 2014.

(i) Bombardier REO 601R-53-61-1541, dated November 27, 2005.

(ii) Bombardier REO 601R-53-61-1541, Revision A, dated February 8, 2008.

(iii) Bombardier REO 601R-53-61-1541, Revision B, dated March 16, 2009.

(iv) Bombardier REO 601R-53-61-1541, Revision C, dated August 19, 2011.

(v) Bombardier REO 601R-53-61-1541, Revision D, dated October 31, 2011.

(vi) Bombardier REO 601R-53-61-1541, Revision E, dated November 5, 2013.

(5) This paragraph provides credit  for the actions required  by paragraph
    (m) of this AD, if  those actions were performed before  the effective
    date of this AD  using Bombardier REO 601R-53-61-5828,  dated November
    1,  2016,  provided  that the  maintenance  or  inspection program  is
    revised by incorporating the inspection requirements at the  threshold
    and repetitive inspection  times specified in  the SDIR of  Bombardier
    REO 601R-53-61-5828, Revision A, dated March 16, 2017.

(q) OTHER FAA AD PROVISIONS

(1) Alternative Methods of Compliance (AMOCs):  The Manager,  New York ACO
    Branch,  FAA, has  the authority  to  approve  AMOCs for  this AD,  if
    requested using the  procedures found in  14 CFR 39.19.  In accordance
    with 14 CFR  39.19, send your  request to your  principal inspector or
    local Flight  Standards District  Office, as  appropriate. If  sending
    information directly to the manager of the certification office,  send
    it to ATTN: Program  Manager, Continuing Operational Safety,  FAA, New
    York ACO Branch,  1600 Stewart Avenue,  Suite 410, Westbury,  New York
    11590; telephone: 516-228-7300; fax: 516-794-5531.

(i) Before using any approved AMOC,  notify your appropriate principal in-
    spector, or lacking  a principal inspector,  the manager of  the local
    flight standards district office/certificate holding district office.

(ii) AMOCs approved previously for AD 2012-25-02 are approved as AMOCs for
     the corresponding provisions in paragraphs (g), (h),  and (i) of this
     AD.

(2) Contacting the Manufacturer:  For any requirement in this AD to obtain
    corrective  actions   from  a   manufacturer,  the   action  must   be
    accomplished using  a method  approved by  the Manager,  New York  ACO
    Branch, FAA; or  TCCA; or Bombardier  Inc.'s TCCA DAO.  If approved by
    the DAO, the approval must include the DAO-authorized signature.

(r) RELATED INFORMATION

(1) Refer   to   Mandatory  Continuing  Airworthiness  Information  (MCAI)
    Canadian Airworthiness  Directive CF-2011-30R2,  dated June  12, 2017,
    for related information. This  MCAI may be found  in the AD docket  on
    the  internet  at  http://www.regulations.gov  by  searching  for  and
    locating Docket No. FAA-2018-0794.

(2) For  more  information  about this AD,  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; fax 516-794-5531.

(3) Service information  identified in this AD that is not incorporated by
    reference is available at the addresses specified in paragraphs (s)(5)
    and (s)(6) of this AD.

(s) MATERIAL INCORPORATED BY REFERENCE

(1) The Director of the Federal Register  approved  the  incorporation  by
    reference (IBR) of  the service information  listed in this  paragraph
    under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use  this service information as applicable to do the actions
    required by this AD, unless this AD specifies otherwise.

(3) The following service information  was  approved  for  IBR on July 12,
    2019.

(i) Bombardier Repair Engineering Order 601R-53-61-1230, Revision F, dated
    October 31, 2011.

(ii) Bombardier Repair Engineering Order 601R-53-61-1240 Revision D, dated
     October 31, 2016.

(iii) Bombardier Repair Engineering Order 601R-53-61-1285 Revision E dated
      October 31, 2016.

(iv) Bombardier Repair Engineering Order 601R-53-61-1541 Revision F, dated
     November 12, 2014.

(v) Bombardier Repair Engineering Order 601R-53-61-5828, Revision A, dated
    March 16, 2017.

(4) The following service information was approved  for IBR on January 16,
    2013 (77 FR 73902, December 12, 2012).

(i) Bombardier Temporary Revision 2B-2187 dated June 22, 2011, to Appendix
    B-Airworthiness Limitations,  of  Part 2 of the Bombardier CL-600-2B19
    Maintenance Requirements Manual.

(ii) [Reserved]

(5) For service information identified in this AD, 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 ac
    .yul@aero.bombardier.com; internet http://www.bombardier.com.

(6) 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.

(7) You  may  view  this  service  information  that  is  incorporated  by
    reference at the National Archives and Records Administration  (NARA).
    For information on the availability of this material at NARA, call 202
    -741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-
    locations.html.

Issued in  Des Moines,  Washington, on  April 19, 2019,  Michael Kaszycki,
Acting  Director,  System   Oversight  Division,  Aircraft   Certification
Service.

FOR FURTHER INFORMATION CONTACT: Aziz Ahmed, Aerospace Engineer,  Airframe
and Mechanical Systems Section, FAA, New York ACO Branch, 1600 Stewart Ave
Suite 410, Westbury, NY 11590; telephone 516-228-7329; fax 516-794-5531.
PREAMBLE 

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]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

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

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,
2019.
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 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-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;
fax 516-794-5531.

SUPPLEMENTARY INFORMATION:

Discussion

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
corrected.
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
[TCCA] AD.

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-
0794.

Comments

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
consistency.
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
this AD.

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
Information


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
following conditions:
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
this regard.

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
(NDI)


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
issue.

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),
and (i).
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.

Conclusion

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
rule.

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
installation.
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

Labor cost Parts cost 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
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

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 removing Airworthiness Directive (AD)
2012-25-02, Amendment 39-17283 (77 FR 73902, December 12, 2012), and
adding the following new AD: