(a) COMMENTS DUE DATE

    The FAA must receive comments by August 26, 2019.

(b) AFFECTED ADS

    This AD replaces AD 2009-09-02, Amendment 39-15888 (74 FR 18121, April
    21, 2009) ("AD 2009-09-02").

(c) APPLICABILITY

    This AD applies to Bombardier,  Inc., Model DHC-8-400, -401, and  -402
    airplanes, certificated  in any  category, serial  numbers 4001, 4003,
    and  subsequent,  equipped  with  main  landing  gear  (MLG)   forward
    stabilizer brace part number (P/N) 46401-7.

(d) SUBJECT

    Air Transport Association (ATA) of America Code 32, Main landing gear.

(e) REASON

    This AD was prompted  by reports of failures  of the aft hinge  of the
    MLG forward stabilizer brace due to fatigue cracks. The FAA is issuing
    this AD to address failure of the stabilizer brace, which could result
    in the collapse of the MLG.

(f) COMPLIANCE

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

(g) RETAINED INSPECTION AND CORRECTIVE ACTIONS, WITH REVISED SERVICE INFO-
    RMATION AND REMOVED REPORTING REQUIREMENT

    This paragraph restates the requirements  of paragraph (f) of AD  2009
    -09-02,   with   new  service   information   and  removed   reporting
    requirement. Unless already done, do the following actions:

(1) At the applicable  time specified in paragraph  (g)(1)(i), (g)(1)(ii),
    (g)(1)(iii),  or  (g)(1)(iv)  of  this  AD:  Perform  non- destructive
    inspections for damage of the MLG forward stabilizer brace  assemblies
    P/N 46401-7, in accordance with Bombardier Repair Drawing  8/4-32-099,
    Issue 1, dated March 10, 2009, and Goodrich Service Concession Request
    026-09, Revision B, dated March 10, 2009; or Bombardier Repair Drawing
    8/4-32-099, Issue  4, dated  September 4,  2018, and  Goodrich Service
    Concession Request 026-09, Revision  H, dated August 29,  2018. Repeat
    the  inspection thereafter  at intervals  not to  exceed 2,000  flight
    cycles. As  of the  effective date  of this  AD, use Bombardier Repair
    Drawing 8/4-32-099,  Issue 4,  dated September  4, 2018,  and Goodrich
    Service Concession Request 026-09, Revision H, dated August 29,  2018,
    for the actions required by this paragraph.

(i) For airplanes with MLG forward stabilizer braces that have accumulated
    12,000 or more total  flight cycles as of  May 6, 2009 (the  effective
    date of AD 2009-09-02): Inspect  within 50 flight cycles after  May 6,
    2009.

(ii) For airplanes with MLG forward  stabilizer braces that  have accumul-
     ated 9,000 or  more total flight  cycles but fewer  than 12,000 total
     flight cycles as  of May 6,  2009 (the effective  date of AD  2009-09
     -02): Inspect before the accumulation of 12,050 total flight  cycles,
     or  within 500  flight cycles  after May  6, 2009,  whichever  occurs
     earlier.

(iii) For airplanes with MLG forward stabilizer braces that  have accumul-
      ated 4,500 or  more total flight  cycles but fewer  than 9,000 total
      flight cycles as of  May 6, 2009 (the  effective date of AD  2009-09
      -02): Inspect before the accumulation of 9,500 total flight  cycles,
      or within 1,500  flight cycles after  May 6, 2009,  whichever occurs
      earlier.

(iv) For airplanes with MLG forward  stabilizer braces that  have accumul-
     ated fewer  than 4,500  total flight  cycles as  of May  6, 2009 (the
     effective date of AD 2009-09-02): Inspect before the accumulation  of
     6,000 total flight cycles.

(2) If  any damage  is found  during any  inspection required by paragraph
    (g)(1) of this AD, before further flight, do all applicable corrective
    actions in accordance with Goodrich Service Concession Request 026-09,
    Revision  B,  dated March  10,  2009; or  Goodrich  Service Concession
    Request 026-09, Revision H, dated August 29, 2018; except as  provided
    by paragraphs (g)(3), (g)(4), (g)(5), and (g)(6) of this AD. As of the
    effective date  of this  AD, use  Goodrich Service  Concession Request
    026-09, Revision H, dated August 29, 2018, for the actions required by
    this paragraph.

(3) For airplanes on which step 24. of Goodrich Service Concession Request
    026-09, Revision B, dated March 10, 2009, has been done: Within  1,200
    flight cycles after May 6, 2009 (the effective date of AD 2009-09-02),
    rework the MLG forward stabilizer  brace, and except for airplanes  on
    which the rework has been done, within 600 flight cycles after May  6,
    2009, do  a detailed  visual inspection  for damage  of the stabilizer
    brace  apex  lugs,  in  accordance  with  Goodrich  Service Concession
    Request 026-09, Revision B, dated March 10, 2009; or Goodrich  Service
    Concession Request 026-09, Revision H,  dated August 29, 2018. If  any
    damage  is  found, repair  before  further flight  in  accordance with
    Section C of Goodrich  Service Concession Request 026-09,  Revision B,
    dated March  10, 2009;  or Section  C of  Goodrich Service  Concession
    Request 026-09, Revision H, dated August 29, 2018. As of the effective
    date  of  this AD,  use  Goodrich Service  Concession  Request 026-09,
    Revision H, dated  August 29, 2018,  for the actions  required by this
    paragraph.

(4) At the applicable  time specified in paragraph  (g)(4)(i), (g)(4)(ii),
    or  (g)(4)(iii)  of  this AD,  replace  the  forward stabilizer  brace
    assembly, in accordance with  Goodrich Service Concession Request  026
    -09, Revision B, dated March 10, 2009; or Goodrich Service  Concession
    Request 026-09, Revision H, dated August 29, 2018. As of the effective
    date  of  this AD,  use  Goodrich Service  Concession  Request 026-09,
    Revision H, dated  August 29, 2018,  for the actions  required by this
    paragraph.

(i) For  airplanes  on  which  cracking  is  found  during  any inspection
    required by this AD, and  the cracking exceeds the limit  specified in
    paragraph  (g)(4)(i)(A) or  (g)(4)(i)(B) of  this AD,  as  applicable:
    Replace the assembly before further flight.

(A) For cracking  found before the  effective date of  this AD: The  limit
    specified in Section C of Goodrich Service Concession Request  026-09,
    Revision B, dated March 10, 2009.

(B) For  cracking found  on or  after the  effective date  of this AD: The
    limit  specified  in  Section  C  or  Section  D  of  Goodrich Service
    Concession Request 026-09, Revision H, dated August 29, 2018.

(ii) For airplanes on which any cracking is found after the rework specif-
     ied  in  Section C  of  Goodrich Service  Concession  Request 026-09,
     Revision  B, dated  March 10,  2009; or  specified  in  Section C  or
     Section D of Goodrich Service  Concession Request 026-09, Revision H,
     dated August 29, 2018: Replace the assembly before further flight.

(iii) For  airplanes  on  which  no cracking  is  found after  the  rework
      specified in Section  C of Goodrich  Service Concession Request  026
      -09, Revision B, dated March 10, 2009; or specified in Section C  or
      Section D of Goodrich Service Concession Request 026-09, Revision H,
      dated  August 29,  2018: Replace  the assembly  within 2,700  flight
      cycles after doing the rework.

(5) If foreign  object damage is  found during any  inspection required by
    this AD, or if  damage is found to  a forward stabilizer brace  lug or
    stop  bracket  retention  hole apex  bushing,  before  further flight,
    repair 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.

(6) If any crack is found during the visual inspection under 10X magnific-
    ation,  repair  before  further flight,  in  accordance  with Goodrich
    Service Concession Request 026-09,  Revision B, dated March  10, 2009;
    or  Goodrich  Service  Concession Request  026-09,  Revision  H, dated
    August 29, 2018.  As of the  effective date of  this AD, use  Goodrich
    Service Concession Request 026-09, Revision H, dated August 29,  2018,
    for the actions required by this paragraph.

(7) Before the accumulation of  6,000 total flight cycles on  the MLG for-
    ward stabilizer braces, or within  600 flight hours after May  6, 2009
    (the effective date  of AD 2009-09-02),  whichever occurs later:  Do a
    detailed visual inspection for cracking of both MLG forward stabilizer
    braces  and  do  all  applicable  liquid  penetrant  inspections   for
    cracking, in accordance with Bombardier Q400 All Operator Message 338,
    dated February 23, 2009. Repeat the inspection thereafter at intervals
    not to exceed 600  flight hours. If any  cracking is found during  any
    inspection required by this paragraph, repair before further flight in
    accordance with Bombardier Repair  Drawing 8/4-32-099, Issue 1,  dated
    March  10,  2009,  and  Goodrich  Service  Concession  Request 026-09,
    Revision B, dated March 10, 2009; or Bombardier Repair Drawing  8/4-32
    -099,  Issue  4,  dated  September  4,  2018,  and  Goodrich   Service
    Concession Request 026-09,  Revision H, dated  August 29, 2018.  As of
    the effective date  of this AD,  use Bombardier Repair  Drawing 8/4-32
    -099,  Issue  4,  dated  September  4,  2018,  and  Goodrich   Service
    Concession  Request  026-09, Revision  H,  dated August  29,  2018, to
    repair  cracking  found  during   any  inspection  required  by   this
    paragraph.

(h) NEW REQUIREMENT OF THIS AD: INSTALLATION OF ELBOW RESTRICTOR

    Within 2,000 flight hours or  12 months, whichever occurs first,  from
    the effective date of this AD: Install an elbow restrictor, P/N  46610
    -1, in accordance with  the Accomplishment Instructions of  Bombardier
    Service Bulletin 84-32-69, Revision C, dated January 20, 2011.

(i) TERMINATING ACTIONS

(1) Installation of  an elbow restrictor  as required by  paragraph (h) of
    this  AD   terminates  the   repetitive  inspection   requirements  of
    paragraphs (g)(1) and (g)(7) of this AD.

(2) Installation of  an elbow restrictor  as required by  paragraph (h) of
    this AD  terminates the  replacement of  the forward  stabilizer brace
    assembly requirement of paragraph (g)(4)(iii) of this AD.

(j) NEW REQUIREMENT OF THIS AD: REVISED  REPETITIVE INSPECTIONS OF THE MLG
    FORWARD STABILIZER BRACE

(1) Within  2,000  flight  cycles  after  the  installation  specified  in
    paragraph (h)  of this  AD, or  within 12  months after  the effective
    date, whichever  occurs later,  do the  non-destructive inspection, in
    accordance with Bombardier Repair  Drawing 8/4-32-099, Issue 4,  dated
    September 4,  2018, and  Goodrich Service  Concession Request  026-09,
    Revision  H,  dated  August  29,  2018.  Thereafter,  repeat  the non-
    destructive inspection  at the times  specified in paragraph (j)(2) of
    this AD.

(2) Repeat the non-destructive inspection required in paragraph (j)(1)  of
    this AD at the applicable intervals specified in paragraphs (j)(2)(i),
    (j)(2)(ii), and (j)(2)(iii) of this AD.

(i) For  forward stabilizer  braces, P/N  46401-7, that  have not  had any
    required  rework done,  as specified  in Goodrich  Service  Concession
    Request  026-09,  Section C  or  D, and  have  had Bombardier  Service
    Bulletin   84-32-69   or   Bombardier   Service   Bulletin    84-32-76
    incorporated: Do  the non-destructive  inspection at  intervals not to
    exceed 6,000 flight cycles.

(ii) For forward stabilizer braces,  P/N 46401-7, that have been  reworked
     in  accordance  with  Goodrich  Service  Concession  Request  026-09,
     Section   D, and  have had  Bombardier Service  Bulletin 84-32-69  or
     Bombardier  Service  Bulletin  84-32-76  incorporated:  Do  the   non
     -destructive  inspection  at  intervals not  to  exceed  6,000 flight
     cycles.

(iii) For forward stabilizer braces, P/N 46401-7, that have been  reworked
      in  accordance  with  Goodrich  Service  Concession  Request 026-09,
      Section  C,  and have  had Bombardier  Service Bulletin  84-32-69 or
      Bombardier  Service  Bulletin  84-32-76  incorporated:  Do  the  non
      -destructive  inspection at  intervals  not  to exceed  3,000 flight
      cycles.

(k) ACCEPTABLE METHOD OF COMPLIANCE FOR PARAGRAPH (H) OF THIS AD

    Replacing the standard elbow fitting  at the retract port of  the lock
    actuator  with  a new  custom  elbow fitting  in  accordance with  the
    Accomplishment Instructions of  Bombardier Service Bulletin  84-32-76,
    Revision  B,  dated  August  1,  2018,  is  an  acceptable  method  of
    compliance for the installation required by  paragraph (h) of this AD.

(l) CREDIT FOR PREVIOUS ACTIONS

(1) This paragraph provides credit  for actions required by paragraph  (h)
    of this AD, if those actions were performed before the effective  date
    of  this  AD using  the  service information  in  paragraph (l)(1)(i),
    (l)(1)(ii), or (l)(1)(iii) of this AD.

(i) Bombardier Service Bulletin 84-32-69, dated June 30, 2009.

(ii) Bombardier Service  Bulletin 84-32-69, Revision  A, dated August  19,
     2009.

(iii) Bombardier  Service Bulletin  84-32-69, Revision  B, dated September
      17, 2009.

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

(i) Bombardier Repair Drawing 8/4-32-099,  Issue 1, dated March 10,  2009,
    and  Goodrich Service  Concession  Request  026-09, Revision  B, dated
    March 10, 2009.

(ii) Bombardier Repair Drawing 8/4-32-099, Issue 2, dated April 20,  2009,
     and Goodrich  Service Concession  Request 026-09,  Revision C,  dated
     April 17, 2009.

(iii) Bombardier  Repair Drawing  8/4-32-099, Issue  3, dated  December 3,
      2009, and  Goodrich Service  Concession Request  026-09, Revision D,
      dated November 27, 2009.

(3) This paragraph provides credit for actions performed using the  method
    of compliance specified in paragraph (k) of this AD, if those  actions
    were performed before the effective date of this AD using the  service
    information in paragraph (l)(3)(i) or (l)(3)(ii) of this AD.

(i) Bombardier Service Bulletin 84-32-76, dated May 20, 2010.

(ii) Bombardier  Service  Bulletin 84-32-76,  Revision A,  dated June  19,
     2014.

(m) 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. AMOCs approved previously in accordance with AD  2009
    -09-02 are  approved as  AMOCs for  the corresponding  requirements in
    paragraph (g) 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.

(n) RELATED INFORMATION

(1) Refer  to   Mandatory  Continuing  Airworthiness  Information   (MCAI)
    Canadian AD CF-2009-11R2, dated May 31, 2018, 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-2019-0479.

(2) For more information about this AD, contact Andrea Jimenez,  Aerospace
    Engineer, Airframe and Mechanical  Systems Section, FAA, New  York ACO
    Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;  telephone
    516-228-7330; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

(3) For  service information  identified in  this AD,  contact Bombardier,
    Inc., Q-Series  Technical Help  Desk, 123  Garratt Boulevard, Toronto,
    Ontario  M3K 1Y5,  Canada; telephone  416-375-4000; fax  416-375-4539;
    email            thd.qseries@aero.bombardier.com;             internet
    http://www.bombardier.com. For Goodrich service information identified
    in this NPRM, contact Collins Aerospace, 1400 South Service Road West,
    Oakville, Ontario  L6L 5Y7,  Canada; telephone:  905-827-7777. 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.

Issued in Des Moines, Washington, on June 26, 2019. Dionne Palermo, Acting
Director, System Oversight Division, Aircraft Certification Service.

DATES: The FAA  must receive comments  on this proposed  AD by August  26,
2019.