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2019-08-11 BOMBARDIER, INC.: Amendment 39-19632; Docket No. FAA-2018-0801; Product Identifier 2017-NM-147-AD.
(a) EFFECTIVE DATE

    This AD is effective July 11, 2019.

(b) AFFECTED ADS

    This  AD  replaces  AD  2008-24-14,  Amendment 39-15758  (73 FR 73785,
    December 4, 2008) ("AD 2008-24-14").

(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 and subsequent.

(d) SUBJECT

    Air Transport Association (ATA) of America Code 57, Wings.

(e) REASON

    This AD was  prompted by reports  of cracks on  the main landing  gear
    (MLG) trunnion fitting during fatigue testing; the introduction of new
    airworthiness  limitation   (AWL)  tasks   with  revised   inspection,
    modification, and safe-life requirements; and a determination that the
    trunnion fitting lower flange and both forward and aft bore holes  are
    also subject to  fatigue cracking. We  are issuing this  AD to address
    fatigue  cracking of  the  MLG  trunnion fitting.  Failure of  the MLG
    trunnion fitting could result in MLG collapse.

(f) COMPLIANCE

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

(g) RETAINED REVISION OF AIRWORTHINESS LIMITATION SECTION WITH NO CHANGES

    This  paragraph  restates  the  requirements of paragraph (f)(1) of AD
    2008-24-14,  with no changes.  Within 30 days  after December 19, 2008
    (the effective date of AD 2008-24-14),  revise the Airworthiness Limi-
    tations Section  (ALS) of the Instructions for Continued Airworthiness
    to incorporate AWL 57-21-161,  as  identified  in Bombardier Temporary
    Revision 2B-2136,  dated May 1, 2008,  to  the  Bombardier CL-600-2B19
    Maintenance Requirements Manual, Part 2, Appendix B-Airworthiness Lim-
    itations.  The initial compliance time  for the task starts  from  the
    applicable time specified in table 1 to paragraphs (g) and (j) of this
    AD or table 2 to paragraphs (g) and (j) of this AD, as applicable. Re-
    peat the inspection thereafter at the applicable interval specified in
    Bombardier Temporary Revision 2B-2136, dated May 1, 2008.

     TABLE 1 TO PARAGRAPHS (G) AND (J) - PRE-MODSUM TC601R15827 AIRPLANES 
    ______________________________________________________________________
    IF THE AIRPLANE HAS
    ACCUMULATED AS OF
    DECEMBER 19, 2008
    (THE EFFECTIVE DATE
    OF AD 2008-24-14)-             THEN PHASE IN THE INITIAL INSPECTIONó
    ______________________________________________________________________
    23,500 or fewer total          Prior to the accumulation of 25,000
    flight cycles                  total flight cycles.

    23,501 to 25,000 total         Prior to the accumulation of 26,000
    flight cycles                  total flight cycles, or within 1,500
                                   flight cycles after December 19, 2008
                                   (the effective date of AD 2008-24-14)
                                   whichever occurs first.

    25,001 to 26,000 total         Prior to the accumulation of 26,500
    flight cycles                  total flight cycles, or within 1,000
                                   flight cycles after December 19, 2008
                                   (the effective date of AD 2008-24-14)
                                   whichever occurs first.

    26,001 or more total           Within 500 flight cycles after December
    flight cycles                  19, 2008 (the effective date of AD
                                   2008-24-14).
    ______________________________________________________________________

    TABLE 2 TO PARAGRAPHS (G) AND (J) - POST-MODSUM TC601R15827 AIRPLANES 
    ______________________________________________________________________
    IF THE AIRPLANE HAS
    ACCUMULATED AS OF
    DECEMBER 19, 2008
    (THE EFFECTIVE DATE
    OF AD 2008-24-14)-             THEN PHASE IN THE INITIAL INSPECTIONó
    ______________________________________________________________________
    15,667 or fewer total          Prior to the accumulation of 16,667
    flight cycles                  total flight cycles.

    15,668 to 16,667 total         Prior to the accumulation of 17,333
    flight cycles                  total flight cycles, or within 1,000
                                   flight cycles after December 19, 2008
                                   (the effective date of AD 2008-24-14)
                                   whichever occurs first.

    16,668 to 17,333 total         Prior to the accumulation of 17,666
    flight cycles                  total flight cycles, or within 666
                                   flight cycles after December 19, 2008
                                   (the effective date of AD 2008-24-14)
                                   whichever occurs first.

    17,334 or more total           Within 333 flight cycles after December
    flight cycles                  19, 2008 (the effective date of AD
                                   2008-24-14).
    ______________________________________________________________________

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

    This paragraph restates the requirements  of  paragraph (f)(2)  of  AD
    2008-24-14, with a new exception:  Except as required by paragraph (i)
    of this AD, after accomplishing the actions specified in paragraph (g)
    of this AD,  no alternative inspections or inspection intervals may be
    used unless the inspection  or  inspection interval is approved  as an
    alternative method of compliance (AMOC) in accordance  with the proce-
    dures specified in paragraph (p)(1) of this AD.

(i) NEW REQUIREMENT  OF  THIS  AD: REVISION OF EXISTING MAINTENANCE OR IN-
    SPECTION PROGRAM

(1) Within 60 days after the effective date of this AD:  Revise the exist-
    ing maintenance or inspection program, as applicable, by incorporating
    the AWL tasks specified  in figure 1 to  paragraphs (i)(1) and (o)  of
    this AD. Except as specified in paragraph (j) of this AD, the  initial
    compliance times for the tasks  are at the applicable times  specified
    in the temporary revisions (TRs) identified in figure 1 to  paragraphs
    (i)(1) and (o) of this AD, or within 60 days after the effective  date
    of this AD, whichever occurs later. When the information in AWL  tasks
    identified in the TRs specified  in figure 1 to paragraphs  (i)(1) and
    (o)  of  this  AD  has  been  included  in  the  general  revisions of
    Bombardier Maintenance Requirements Manual  (MRM), CSP A-053, Part  2,
    Appendix B, the general revisions may be inserted in the MRM, and  the
    TRs  may  be  removed. Accomplishing  the  revision  required by  this
    paragraph terminates the actions required by paragraph (g) of this AD.
    Where the  compliance times  for the  repetitive inspections  and life
    limits  specified in  the  TRs  identified in  figure 1  to paragraphs
    (i)(1) and (o) of this  AD specify "landings," those compliance  times
    are based on the landings of the affected part.

     FIGURE 1 TO PARAGRAPHS (I)(1) AND (O) - AWL TASKS TO BE INCORPORATED 
    ______________________________________________________________________
    SECTION WITHIN MRM,
    CSP A053, PART 2,
    APPENDIX B                AWL TASK     TR NUMBER     TR ISSUE DATE
    ______________________________________________________________________
    Structural AWLs           57-21-145    TR 2B-2237    June 19, 2014
                              57-21-161    TR 2B-2238    June 19, 2014
                              57-21-155    TR 2B-2239    June 19, 2014

    Structural Life Limits    57-21-162    TR 2B-2246    November 7, 2014
                              57-21-163    TR 2B-2246    November 7, 2014

    Structural Life Limits,   57-21-162    TR 2B-2241    June 19, 2014
    High Altitude Airfield    57-21-163    TR 2B-2241    June 19, 2014
    Operations (HAAO)
    ______________________________________________________________________

(2) Within 60 days after the effective date of this AD:  Revise the exist-
    ing maintenance or inspection program, as applicable,  by removing the
    AWL tasks specified in figure 2 to paragraph (i)(2) of this AD.

            FIGURE 2 TO PARAGRAPH (I)(2) - AWL TASKS TO BE REMOVED        
    ______________________________________________________________________
    SECTION WITHIN MRM,
    CSP A053, PART 2,
    APPENDIX B                AWL TASK     TR NUMBER     TR ISSUE DATE
    ______________________________________________________________________
    Structural AWLs           57-21-164    TR 2B-2242    June 19, 2014
                              57-21-165    TR 2B-2242    June 19, 2014
                              57-21-166    TR 2B-2242    June 19, 2014
    ______________________________________________________________________

(j) NEW REQUIREMENT OF THIS AD: INITIAL COMPLIANCE TIMES FOR AWL TASKS

(1) For  AWL 57-21-161,  the compliance time for the initial inspection of
    AWL 57-21-161 is as specified  in table 1 to paragraphs (g) and (j) of
    this AD or table 2 to paragraphs (g) and (j) of this AD, as applicable
    or within 60 days  after  the  effective  date  of this AD,  whichever
    occurs later.

(2) For AWL 57-21-161,  the compliance time  for the limitation section is
    at the applicable time  specified  in  AWL 57-21-161  or  within 2,000
    flight cycles  after the effective date of this AD,  whichever  occurs
    later.

(3) For AWL 57-21-145 and AWL 57-21-155,  the  compliance  times  for  the
    initial inspections are  at the  applicable  times  specified  in  AWL
    57-21-145 and AWL 57-21-155  or  within 2,000 flight cycles  after the
    effective date of this AD,  whichever occurs later.  Where the compli-
    ance times for the initial inspections in the AWLs specify "landings,"
    those compliance times are based on the landings of the airplane.

(4) For AWL 57-21-145 and AWL 57-21-155, the compliance times for the lim-
    itation sections is at the applicable time specified  in AWL 57-21-145
    and  AWL 57-21-155  or  within 2,000 flight cycles after the effective
    date of this AD, whichever occurs later.

(k) NEW REQUIREMENT OF THIS AD: NO ALTERNATIVE ACTIONS OR INTERVALS

    After the maintenance  or  inspection program  has been revised as re-
    quired by  paragraph (i)  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.

(l) NEW REQUIREMENT OF THIS AD:  REWORK OF MLG TRUNNION TO MEET STRUCTURAL
    SAFE-LIFE LIMITS

(1) Except as specified in paragraph (m)(1)  of this AD:  At or before the
    accumulation of  34,900 total  flight cycles,  or within  2,000 flight
    cycles after the  effective date of  this AD, whichever  occurs later,
    rework the  MLG trunnion  (cold working  of fastener  holes in the MLG
    trunnion  fitting,  and  all  applicable  related  investigative   and
    corrective actions) in accordance with the Accomplishment Instructions
    of Bombardier Service Bulletin 601R-57-046, Revision C, dated December
    20,  2012.  Do  all applicable  related  investigative  and corrective
    actions before further flight.

(2) At or before the accumulation of 38,900 total flight cycles, or within
    2,000 flight  cycles after  the effective  date of  this AD, whichever
    occurs  later,  rework  the MLG  trunnion  (installation  of forcemate
    bushings in the MLG trunnion, and all applicable related investigative
    and  corrective  actions)   in  accordance  with   the  Accomplishment
    Instructions of Bombardier Service Bulletin 601R-57-047,  Revision  B,
    dated October  2, 2012.  Do all  applicable related  investigative and
    corrective actions before further flight.

(3) Except as specified in paragraph (m)(2)  of this AD:  At or before the
    accumulation of  34,900 total  flight cycles,  or within  2,000 flight
    cycles after the  effective date of  this AD, whichever  occurs later,
    rework the  MLG trunnion  (cold work  of holes  on the  web of the MLG
    trunnion,  and  all applicable  related  investigative and  corrective
    actions)  in  accordance  with  the  Accomplishment  Instructions   of
    Bombardier Service  Bulletin 601R-57-048,  Revision C,  dated  June 6,
    2013. Do all applicable  related investigative and corrective  actions
    before further flight.

(m) EXCEPTIONS TO REWORK SPECIFIED IN PARAGRAPH (L) OF THIS AD

(1) For  airplanes  on  which  Bombardier  Service  Bulletin  601R-57-046,
    Revision A, dated  December 21, 2009;  or Bombardier Service  Bulletin
    601R-57-046,  Initial Issue,  dated July  17, 2009;  was  accomplished
    prior to  the effective  date of  this AD:  Within 6  months after the
    effective  date  of  this  AD,   do  Part  G  of  the   Accomplishment
    Instructions of Bombardier  Service Bulletin 601R-57-046,  Revision C,
    dated December 20, 2012.

(2) For  airplanes  on  which  Bombardier  Service  Bulletin  601R-57-048,
    Revision A, dated  November 24, 2009;  or Bombardier Service  Bulletin
    601R-57-048,  Initial  Issue,  dated July  17, 2009;  was accomplished
    prior to  the effective  date of  this AD:  Within 6  months after the
    effective  date  of  this  AD,   do  Part  C  of  the   Accomplishment
    Instructions of Bombardier  Service Bulletin 601R-57-048,  Revision C,
    dated June 6, 2013.

(n) CREDIT FOR PREVIOUS ACTIONS

(1) This paragraph provides credit  for actions required  by paragraph (l)
    (1) of this AD, if  those actions were performed before  the effective
    date  of  this  AD,  using  Bombardier  Service  Bulletin 601R-57-046,
    Revision B, dated August 24, 2012.

(2) This paragraph provides credit  for actions required  by paragraph (l)
    (2) of this AD, if  those actions were performed before  the effective
    date of this AD, using the service information specified in  paragraph
    (n)(2)(i) or (n)(2)(ii) of this AD.

(i) Bombardier Service Bulletin 601R-57-047, Revision A, dated February 1,
    2012.

(ii) Bombardier Service Bulletin 601R-57-047,  Initial Issue,  dated  June
     29, 2011.

(3) This paragraph provides credit  for actions required  by paragraph (l)
    (3) of this AD,  if those actions were performed  before the effective
    date  of  this  AD,  using  Bombardier  Service Bulletin  601R-57-048,
    Revision B, dated August 24, 2012.

(4) This paragraph provides credit  for actions required  by paragraph (m)
    (1) of this AD,  if those actions were performed  before the effective
    date of this AD,  using  Part G  of the Accomplishment Instructions of
    Bombardier Service Bulletin 601R-57-046,  Revision B, dated August 24,
    2012.

(5) This paragraph provides credit  for actions required  by paragraph (m)
    (2) of this AD,  if those actions were performed  before the effective
    date of this AD,  using  Part C of the  Accomplishment Instructions of
    Bombardier Service Bulletin 601R-57-048,  Revision B, dated August 24,
    2012.

(o) REPAIRS AND ALTERNATIVE ACTIONS OR INTERVALS

(1) If any damage is found  during  an inspection  required  by  the  AWLs
    identified in figure 1 to paragraphs (i)(1) and (o) of this AD, repair
    before further flight using a method approved by the Manager, New York
    ACO  Branch,  FAA;  or  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.
    The approved repair instructions must specifically refer to this AD or
    Canadian AD CF-2017-27, dated August 2, 2017.

(2) Repairs  approved  by  Bombardier,  Inc.,  that deviate  from the AWLs
    identified in figure  1 to paragraphs  (i)(1) and (o)  of this AD  are
    acceptable methods of compliance if 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.
    The approved repair instructions must specifically refer to this AD or
    Canadian AD CF-2017-27, dated August 2, 2017.

(3) For repairs approved  before the effective date of this AD that affect
    the AWLs identified in figure 1  to paragraphs (i)(1) and (o) of  this
    AD and the approved repair  instructions do not specifically refer  to
    Canadian AD CF-2017-27,  dated August 2, 2017: Within 6 months  of the
    effective date of this AD,  contact the Manager, New York  ACO Branch,
    FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO Inc., for new or  revised
    limitations or inspection requirements  on the repair area  and comply
    with the revised  limitations or inspection  requirements. The new  or
    revised limitations or inspection requirements must specifically refer
    to this AD or Canadian AD CF-2017-27, dated August 2, 2017.

(4) Canadian  AMOC  No.  AARDG-2018/A21,   dated  May 1, 2018,  which  was
    approved before the effective date of this AD by TCCA is an acceptable
    method of compliance to the corresponding requirements of this AD.

(p) 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, NY  11590;
    telephone 516-228-7300;  fax 516-794-5531.  Before using  any approved
    AMOC,  notify  your  appropriate  principal  inspector,  or  lacking a
    principal  inspector,  the  manager  of  the  local  flight  standards
    district office/certificate holding district office.

(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. The
    approved  corrective action  instructions must  specifically refer  to
    this AD or Canadian AD CF-2017-27, dated August 2, 2017.

(q) RELATED INFORMATION

(1) Refer   to   Mandatory  Continuing  Airworthiness  Information  (MCAI)
    Canadian AD CF-2017-27, dated August 2, 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-2018-0801

(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 (r)(5)
    and (r)(6) of this AD.

(r) 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 11,
    2019.

(i) Bombardier Maintenance Requirements Manual Temporary Revision 2B-2237,
    dated June 19, 2014.

(ii) Bombardier Maintenance Requirements Manual Temporary Revision 2B-2238
     dated June 19, 2014.

(iii) Bombardier  Maintenance Requirements  Manual  Temporary Revision 2B-
      2239, dated June 19, 2014.

(iv) Bombardier Maintenance Requirements Manual Temporary Revision 2B-2241
     dated June 19, 2014.

(v) Bombardier Maintenance Requirements Manual Temporary Revision 2B-2242,
    dated June 19, 2014.

(vi) Bombardier Maintenance Requirements Manual Temporary Revision 2B-2246
     dated November 7, 2014.

(vii) Bombardier Service Bulletin 601R-57-046,  Revision C, dated December
      20, 2012.

(viii) Bombardier Service Bulletin 601R-57-047,  Revision B, dated October
       2, 2012.

(ix) Bombardier Service Bulletin 601R-57-048,  Revision C,  dated  June 6,
     2013.

(4) The following service information was approved for IBR on December 19,
    2008 (73 FR 73785, December 4, 2008).

(i) Bombardier  Temporary  Revision  2B-2136,  dated May 1, 2008,  to  the
    Bombardier  CL-600-2B19  Maintenance  Requirements  Manual,   Part  2,
    Appendix B-Airworthiness Limitations.

(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 1-514-855-2999;  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 May 15, 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-2018-0801; Product Identifier 2017-NM-147-AD; Amendment
39-19632; AD 2019-08-11]
RIN 2120-AA640

Airworthiness Directives; Bombardier, Inc., Airplanes

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

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are superseding Airworthiness Directive (AD) 2008-24-14,
which applied to all Bombardier, Inc., Model CL-600-2B19 (Regional Jet
Series 100 & 440) airplanes. AD 2008-24-14 required revising the
instructions for continued airworthiness to incorporate certain
airworthiness limitations for the main landing gear (MLG) trunnion
fitting assembly. This AD requires revising the maintenance or
inspection program, as applicable, to incorporate certain airworthiness
limitations (AWLs). This AD also requires reworking the trunnion
fitting in order to meet new structural safe-life limits. This AD was
prompted by reports of cracks on the MLG trunnion fitting during
fatigue testing; the introduction of new AWL tasks with revised
inspection, modification, and safe-life requirements; and a
determination that the trunnion fitting lower flange and both forward
and aft bore holes are also subject to fatigue cracking. We are issuing
this AD to address the unsafe condition on these products.

DATES: This AD is effective July 11, 2019.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of July 11,
2019.
The Director of the Federal Register approved the incorporation by
reference of a certain other publication listed in this AD as of
December 19, 2008 (73 FR 73785, December 4, 2008).

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 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-2018-0801.

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-2018-0801;
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 2008-24-14, Amendment 39-15758 (73 FR 73785,
December 4, 2008) (``AD 2008-24-14''). AD 2008-24-14 applied to all
Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440)
airplanes. The NPRM published in the Federal Register on October 1,
2018 (83 FR 49317). The NPRM was prompted by reports of cracks on the
MLG trunnion fitting during fatigue testing; the introduction of new
AWL tasks with revised inspection, modification, and safe-life
requirements; and a determination that the trunnion fitting lower
flange and both forward and aft bore holes are also subject to fatigue
cracking. The NPRM proposed to require revising the maintenance or
inspection program, as applicable, to incorporate certain AWLs. The
NPRM also proposed to require reworking the trunnion fitting in order
to meet new structural safe-life limits. We are issuing this AD to
address fatigue cracking of the MLG trunnion fitting. Failure of the
MLG trunnion fitting could result in MLG collapse.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2017-27, dated August
2, 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 main landing gear (MLG) trunnion fitting web
discovered during fatigue testing led to the issuance of [Canadian]
AD CF-2008-21 [which corresponds to FAA AD 2008-24-14], which
mandated new inspection requirements to ensure that fatigue cracking
of the trunnion web would be detected and corrected.
Additional fatigue test article findings and in-service findings
have shown that the trunnion fitting lower flange and both forward
and aft bore holes are also subject to fatigue cracking. Failure of
the main landing gear trunnion fitting could result in the collapse
of the main landing gear. Bombardier Inc. has decided to implement a
series of design changes to improve the fatigue life of the trunnion
fitting that is now a safe-life assembly.
New and revised Airworthiness Limitation (AWL) tasks for the MLG
trunnion fitting assembly have been introduced in order to require new inspection,
modification, and safe-life requirements. This [Canadian] AD
mandates the incorporation of these new and revised AWL tasks, and
removal of the AWL tasks they replace, to ensure that fatigue
cracking of the MLG trunnion fitting is detected and corrected. This
[Canadian] AD also requires rework of the trunnion fitting in order
to meet new structural safe-life limits.

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-
0801.

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

Air Line Pilots Association, International stated its support for
the NPRM.

Request To Clarify Compliance Times in Paragraph (l) of the Proposed AD

Air Wisconsin Airlines requested that we clarify the compliance
times for the rework specified in paragraph (l) of the proposed AD. Air
Wisconsin Airlines stated that the AWLs do not include requirements to
incorporate the service information identified in paragraph (l)(1),
(l)(2), and (l)(3) of this AD. Air Wisconsin Airlines added that
Bombardier Service Bulletin 601R-57-046, Revision C, dated December 20,
2012, would be required only if Bombardier Service Bulletin 601R-57-
048, Revision C, dated June 6, 2013, is done and therefore there is no
requirement to do Bombardier Service Bulletin 601R-57-046, Revision C,
dated December 20, 2012.
We agree to clarify the compliance times for the rework required by
paragraph (l) of this AD. We acknowledge that the compliance times for
incorporating the rework are not clear. We note that Bombardier Service
Bulletin 601R-57-046, Revision C, dated December 20, 2012, is not
contingent on whether Bombardier Service Bulletin 601R-57-048, Revision
C, dated June 6, 2013, is done. As specified in certain AWLs, ``SB
601R-57-046 shall be incorporated at or before 34,900 flight cycles.''
However, we acknowledge that the AWLs do not specify requirements
to incorporate Bombardier Service Bulletin 601R-57-047, Revision B,
dated October 2, 2012; and Bombardier Service Bulletin 601R-57-048,
Revision C, dated June 6, 2013. Since the AWLs do not specify
compliance times for incorporating that service information, operators
would need to accomplish the actions specified in that service
information within 2,000 flight cycles after the effective date of this
AD.
However, we have determined that the actions specified in
Bombardier Service Bulletin 601R-57-046, Revision C, dated December 20,
2012; Bombardier Service Bulletin 601R-57-047, Revision B, dated
October 2, 2012; and Bombardier Service Bulletin 601R-57-048, Revision
C, dated June 6, 2013; must be done within the initial compliance times
specified in the service information, or within 2,000 flight cycles
after the effective date of this AD, whichever occurs later. We have
coordinated with TCCA to clarify the compliance times for incorporating
the service information. We have added compliance times to paragraphs
(l)(1) through (l)(3) of this AD accordingly.

Request To Reword Requirement Paragraph

Air Wisconsin Airlines requested that paragraph (g) of the proposed
AD be reworded to indicate that paragraph (f)(1) of AD 2008-24-14
required incorporation of Bombardier Maintenance Requirements Manual
(MRM), CSP A-253, Part 2, Appendix B task AWL 57-21-161, because
Temporary Revision (TR) 2B-2136 (Global alternative method of
compliance (AMOC) with log #14-83) was superseded by TR 2B-2153 and
later incorporated into a general revision of Bombardier Maintenance
Requirements Manual (MRM), CSP A-253, Part 2, Appendix B.
We disagree, because the requirements specified in paragraph (g) of
this AD are a restatement of the actions required by paragraph (f)(1)
of AD 2008-24-14 and are still applicable until the new actions
required by paragraph (i) of this AD are done. The FAA cannot impose
the latest requirements for a paragraph that has the initial compliance
date of AD 2008-24-14 since the latest documents were not available at
the time that AD 2008-24-14 became effective. Additionally, paragraph
(i) of this AD addresses the commenter's concerns regarding the latest
documents. For clarity, we have added a statement to paragraph (i) of
this AD to specify that accomplishing the revision required by
paragraph (i) of this AD terminates the revision required by paragraph
(g) of this AD.

Request To Clarify Compliance Table Reference

Air Wisconsin Airlines observed that the reference to ``table 1 or
table 2 to paragraphs (g) and (j) of this AD, as applicable'' in
paragraph (g) was not in AD 2008-24-14 and therefore is a change to
that paragraph, because paragraph (j) is a new requirement of the
proposed AD. We infer that the commenter would like us to clarify the
inclusion of a reference to ``paragraph (j)'' within paragraph (g) of
the proposed AD.
We agree to clarify the paragraph in question. The inclusion of
``paragraph (j)'' within paragraph (g) of this AD is merely as part of
the designation of one of the tables referenced and has no bearing upon
the requirements of paragraph (g) of this AD. 1 CFR parts 8 and 21
require orderly codification of regulations. This means that all
elements of an AD, including tables and figures, must be properly
designated. A table's designation includes the sequential number of the
table, the paragraphs to which it applies, and the location of the
table within the AD. The Office of the Federal Register (OFR) requires
a complete designation when a table is cross-referenced. Both of the
tables in question are referenced in paragraphs (g) and (j) of this AD,
therefore, the correct reference is to ``table 1 to paragraphs (g) and
(j)'' and ``table 2 to paragraphs (g) and (j),'' as stated in
paragraphs (g) and (j) of this AD. We have not changed this AD with
regard to table designations.

Request To Reword Compliance Time

Air Wisconsin Airlines requested that we reword the compliance time
statement in paragraph (j)(2) of the proposed AD to specify the
compliance time instead of referring to the AWL. The commenter stated
that rewording would simplify the paragraph.
We acknowledge the commenter's request. However, the information is
contained in the AWL and we matched the language in the MCAI by
referring to the AWL. Unless the language in the MCAI is not
enforceable, we generally do not deviate from the MCAI. We have not
changed this AD in this regard.

Request To Address Missing Compliance Time

Bombardier requested that we add paragraph (j)(4) to the proposed
AD in order to align with the instructions in paragraph B.3. of the
MCAI. Bombardier stated that paragraph (j)(3) of the proposed AD
mentions the compliance time for the initial inspection but not for the
limitation for AWL 57-21-145 and AWL 57-21-155. Additionally, Air
Wisconsin Airlines asked whether our intent in paragraph (j)(3) of the
proposed AD was to ``speak only to the initial inspections in AWL 57-
21-145 and AWL 57-21-155.'' We infer Air Wisconsin Airlines is also requesting
that we address the missing compliance time statement for the limitation
sections of AWL 57-21-145 and AWL 57-21-155.
We agree with the request to include the information in paragraph
B.3. of the MCAI in this AD. The compliance time in paragraph B.3. of
the MCAI includes the grace period for both the initial inspection and
the limitation sections of the AWLs. We have added paragraph (j)(4) of
this AD to address the compliance time for the limitation sections of
AWL 57-21-145 and AWL 57-21-155.

Request To Combine ``No Alternative Actions or Intervals'' Paragraphs

Air Wisconsin Airlines requested that we consider combining
paragraphs (h) and (k) of the proposed AD. The commenter asserted that
paragraph (h) of the proposed AD does not restate the requirement of
paragraph (f)(2) of AD 2008-24-14.
We do not agree to the request to combine paragraphs (h) and (k) of
this AD because the retained and new requirements are addressed
separately in this supersedure AD. Paragraph (h) of this AD restates
the requirements of paragraph (f)(2) of AD 2008-24-14, with a new
exception. Paragraph (h) of this AD applies to the retained action
required by paragraph (g) of this AD while paragraph (k) of this AD
applies to the new action required by paragraph (i) of this AD. We have
not changed this AD in this regard.

Request To Clarify Figure Reference

Air Wisconsin Airlines requested that we clarify the reference to
``the AWLs identified in figure 1 to paragraphs (i) and (o)'' in
paragraph (o) of the proposed AD. The commenter remarked that no AWLs
are specifically listed in paragraph (o) of the proposed AD.
We agree to clarify the figure reference in paragraph (o) of this
AD. The AWLs are specifically listed in figure 1, which is designated
``figure 1 to paragraphs (i)(1) and (o).'' Paragraphs (i)(1) and (o)
both reference that figure. As previously mentioned, OFR requires that
the designation of any figure in an AD must include all paragraphs in
which it is referenced, and the full designation is required in each
reference. The correct designation of the figure in question is
``figure 1 to paragraphs (i)(1) and (o),'' as referenced in paragraphs
(i)(1) and (o) of this AD. We have not changed this AD with regard to
figure designations.

Request To Revise Paragraph (l) of the Proposed AD

Air Wisconsin Airlines requested that we revise paragraph (l) of
the proposed AD to state that the compliance time for the limitation
section is at the applicable time specified in the applicable AWLs.
As stated previously, we have revised paragraph (l) of this AD to
specify the compliance times for the rework. We note that the
compliance times for the limitation sections are provided in paragraphs
(j)(2) and (j)(4) of this AD. If affected parts are removed and
replaced with MLG trunnion, part numbers 601R10068-5 and -6, the
inspection and limitation sections compliance times of the affected
AWLs start from the installation of the new part numbers 601R10068-5
and -6. After the part replacement, the inspections and limitation
sections of AWL 57-21-155 and AWL 57-21-161 still apply.

Clarification of Compliance Times

Where the compliance times for the repetitive inspections and life
limits specified in the TRs identified in figure 1 to paragraphs (i)(1)
and (o) of this AD specify ``landings,'' those compliance times are
based on the landings of the affected part. The compliance times for
the initial inspections are specified in paragraphs (j)(1) and (j)(3)
of this AD and those compliance times are based on flight cycles or
landings of the airplane. We have clarified the compliance times in
paragraphs (i) and (j)(3) of this AD.

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 has issued the following service information.
Bombardier Service Bulletin 601R-57-046, Revision C, dated
December 20, 2012, describes the cold working of fastener holes in the
MLG trunnion fitting, and related investigative and corrective actions.
Bombardier Service Bulletin 601R-57-047, Revision B, dated
October 2, 2012, describes the installation of forcemate bushings in
the MLG trunnion, and related investigative and corrective actions.
Bombardier Service Bulletin 601R-57-048, Revision C, dated
June 6, 2013, describes the cold working of holes on the web of the MLG
trunnion, and related investigative and corrective actions.
Bombardier has also issued the following temporary revisions (TRs),
which are distinct because they describe different AWL tasks that apply
to different Canadair part numbers.
Bombardier Maintenance Requirements Manual Temporary
Revision 2B-2237, dated June 19, 2014. This TR describes AWL task 57-
21-145, MLG Mounting Trunnion Fitting Assembly (Pre-SB 601R-57-047).
Bombardier Maintenance Requirements Manual Temporary
Revision 2B-2238, dated June 19, 2014. This TR describes AWL task 57-
21-161, MLG Mounting Trunnion Web at WS66 (Pre-SB 601R-57-046 or Pre-SB
601R-57-048).
Bombardier Maintenance Requirements Manual Temporary
Revision 2B-2239, dated June 19, 2014. This TR describes AWL task 57-
21-155, MLG Mounting Trunnion Fitting Assembly (Pre-SB 601R-57-046 or
Pre-SB 601R-57-048).
Bombardier Maintenance Requirements Manual Temporary
Revision 2B-2241, dated June 19, 2014. This TR describe AWL tasks 57-
21-162, MLG Mounting Trunnion Assembly; and 57-21-163, MLG Mounting
Trunnion Assembly.
Bombardier Maintenance Requirements Manual Temporary
Revision 2B-2242, dated June 19, 2014. This TR removes certain AWL
tasks.
Bombardier Maintenance Requirements Manual Temporary
Revision 2B-2246, dated November 7, 2014. This TR describes AWL tasks
57-21-162, MLG Mounting Trunnion Assembly; and 57-21-163, MLG Mounting
Trunnion Assembly.
This AD also requires Bombardier Temporary Revision 2B-2136, dated
May 1, 2008, to the Bombardier CL-600-2B19 Maintenance Requirements
Manual, Part 2, Appendix B--Airworthiness Limitations, which the
Director of the Federal Register approved for incorporation by
reference as of December 19, 2008 (73 FR 73785, December 4, 2008).
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 460 airplanes of U.S. registry. We
estimate the following costs to comply with this AD:

Estimated Costs for Required Actions

Action
Labor cost
Parts cost
Cost per product
Cost on U.S. operators
Retained actions from AD 2008-24-14 1 work-hour x $85 per hour = $85 $0 $85 $39,100
New actions Up to 178 work-hours x $85 per hour = Up to $15,130 38,928 Up to $54,058 Up to $24,866,680

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.
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. We do not control warranty coverage for affected
individuals. As a result, we have included all costs in our 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.
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)
2008-24-14, Amendment 39-15758 (73 FR 73785, December 4, 2008), and
adding the following new AD: