(a) COMMENTS DUE DATE

We must receive comments by June 4, 2012.

(b) AFFECTED ADS

This  AD  supersedes  AD  2011-23-08,  Amendment  39-16859  (76  FR 71241,
November 17, 2011).

(c) APPLICABILITY

This AD applies to Bombardier, Inc. Model CL-600-2B19 (Regional Jet Series
100 & 440)  airplanes, certificated in  any category, serial  numbers 7003
and subsequent.

(d) SUBJECT

Air Transport Association (ATA) of  America Code 29, Hydraulic Power;  32,
Landing Gear.

(e) REASON

This AD was prompted by  reports of on-ground hydraulic accumulator  screw
cap/end  cap  failure.  We  are issuing  this  AD  to  detect and  correct
hydraulic accumulator screw cap/end cap failure, which could result in the
loss of the associated hydraulic  system and high-energy impact damage  to
adjacent systems  and structure,  and consequent  loss of  control of  the
airplane.

(f) COMPLIANCE

You are responsible for having  the actions required by this  AD performed
within the  compliance times  specified, unless  the actions  have already
been done.

(g) RETAINED AIRPLANE FLIGHT  MANUAL (AFM) REVISION, WITH  REVISED SERVICE
    INFORMATION

This paragraph restates the revision required by paragraph (g) of AD  2010
-22-02, Amendment 39-16481 (75 FR  64636, October 20, 2010), with  revised
service information. Within 30 days after November 4, 2010 (the  effective
date  of  AD 2010-22-02,  Amendment  39-16481 (75  FR  64636, October  20,
2010)), revise  the Limitations  section, Normal  Procedures section,  and
Abnormal Procedures section of the  Canadair Regional Jet AFM, CSP  A-012,
by incorporating Canadair Regional  Jet Temporary Revision (TR)  RJ/186-1,
dated August 24,  2010, into the  applicable section of  Canadair Regional
Jet AFM,  CSP A-012.  Thereafter, except  as provided  by paragraph (p) of
this AD, no alternative actions specified in Canadair Regional Jet TR  RJ/
186-1, dated August 24, 2010, may be approved.

NOTE 1 TO PARAGRAPH (G) OF THIS AD: The  actions required by paragraph (g)
of this AD  may be done  by inserting a  copy of Canadair  Regional Jet TR
RJ/186-1,  dated  August 24,  2010,  into the  applicable  section of  the
Canadair Regional Jet AFM,  CSP A-012. When this  TR has been included  in
the general revisions of this  AFM, the general revisions may  be inserted
into this AFM, and this TR removed, provided that the relevant information
in the general revision is identical  to that in Canadair Regional Jet  TR
RJ/186-1, dated August 24, 2010.

(h) RETAINED  DEACTIVATION OF THE HYDRAULIC SYSTEM NO. 3 ACCUMULATOR, WITH
    REVISED SERVICE INFORMATION

This paragraph restates the deactivation  required by paragraph (h) of  AD
2010-22-02,  Amendment  39-16481 (75  FR  64636, October  20,  2010), with
revised service information.  Within 250 flight  cycles after November  4,
2010  (the  effective date  of  AD 2010-22-02),  deactivate  the hydraulic
system No. 3 accumulator, in accordance with Part A of the  Accomplishment
Instructions of Bombardier  Alert Service Bulletin  A601R-29-031, Revision
A, dated March 26, 2009. Doing  the removal of the hydraulic system  No. 3
accumulator in  paragraph (l)  of this  AD terminates  the requirements of
this paragraph. The actions in this paragraph apply to all accumulators in
hydraulic system No. 3.

(i) RETAINED  REMOVAL  OF THE  HYDRAULIC  SYSTEM  NO. 2  ACCUMULATOR, WITH
    REVISED SERVICE INFORMATION

This paragraph restates the removal  required by paragraph (i) of  AD 2010
-22-02, Amendment 39-16481 (75 FR  64636, October 20, 2010), with  revised
service information. Within 500 flight cycles after November 4, 2010  (the
effective  date  of AD  2010-22-02),  remove the  hydraulic  system No.  2
accumulator,  in  accordance  with  the  Accomplishment  Instructions   of
Bombardier Service Bulletin  601R-29- 032, Revision  A, dated January  26,
2010. The actions in this paragraph apply to all accumulators in hydraulic
system No. 2.

(j) RETAINED  INITIAL AND  REPETITIVE ULTRASONIC  INSPECTIONS OF HYDRAULIC
    SYSTEM  NO. 1,  INBOARD BRAKE  AND OUTBOARD  BRAKE ACCUMULATORS,  WITH
    REVISED SERVICE INFORMATION

This paragraph restates the initial and repetitive ultrasonic  inspections
required by  paragraph (k)  of AD  2010-22-02, Amendment  39-16481 (75  FR
64636, October 20, 2010), with revised service information. For  hydraulic
system No. 1,  inboard brake and  outboard brake accumulators  having part
number (P/N) 601R75138-1 (08-60163-001 or 08-60163-002): At the applicable
compliance times specified in paragraph (k) of this AD, do the inspections
required  by  paragraphs  (j)(1)  and  (j)(2)  of  this  AD.  Repeat   the
inspections for each accumulator  having P/N 601R75138-1 (08-60163-001  or
08-60163- 002)  thereafter at  intervals not  to exceed  500 flight cycles
until  the  replacement  specified  in  this  paragraph  is  done  or  the
replacement specified in paragraph (m) of this AD is done. If any crack is
found,  before  further  flight,  replace  the  accumulator  with  a   new
accumulator having  P/N 601R75138-1  (08-60163-001 or  08-60163- 002)  and
having the letter "T" after the serial number on the identification plate,
in  accordance  with  the Accomplishment  Instructions  of  the applicable
service bulletin identified in table 1 or table 2 of this AD.

(1) Do an ultrasonic inspection for cracks on each accumulator, in accord-
    ance with Part B of the Accomplishment Instructions of the  applicable
    service bulletin identified in table 1 of this AD.

   TABLE 1--BOMBARDIER SERVICE INFORMATION FOR ACCUMULATOR INSPECTION
--------------------------------------------------------------------------
  ACCUMULATOR              DOCUMENT            REVISION     DATE
--------------------------------------------------------------------------
Hydraulic System  Bombardier Alert Service     B.......  May 11, 2010.
No. 1......       Bulletin A601R-29-029,
                  including Appendix A, dated
                  October 18, 2007.
Inboard and       Bombardier Alert Service     D.......  May 11, 2010.
Outboard Brake..  Bulletin A601R-32-103,
                  including Appendix A,
                  Revision A, dated October 18,
                  2007.
--------------------------------------------------------------------------

(2) Do an ultrasonic inspection for cracks on the screw cap, in accordance
    with  the  Accomplishment  Instructions  of  the  applicable   service
    bulletin identified in table 2 of this AD.

     TABLE 2--BOMBARDIER SERVICE INFORMATION FOR SCREW CAP INSPECTION
--------------------------------------------------------------------------
  ACCUMULATOR              DOCUMENT               REVISION     DATE
--------------------------------------------------------------------------
Hydraulic System  Bombardier Service Bulletin     A......  May 11, 2010.
No. 1......       601R-29-033, including
                  Appendix A, dated May 5, 2009.
Inboard and Out-  Bombardier Service Bulletin     A......  May 11, 2010.
board Brake..     601R-32-106, including
                  Appendix A.
--------------------------------------------------------------------------

(k) RETAINED  INITIAL AND  REPETITIVE ULTRASONIC  INSPECTIONS OF HYDRAULIC
    SYSTEM  NO. 1,  INBOARD BRAKE  AND OUTBOARD  BRAKE ACCUMULATORS,  WITH
    REVISED SERVICE INFORMATION

This paragraph restates the initial and repetitive ultrasonic  inspections
required by  paragraph (l)  of AD  2010-22-02, Amendment  39-16481 (75  FR
64636, October 20, 2010), with revised service information. For  hydraulic
system No.  1 inboard  brake, and  outboard brake  accumulators having P/N
601R75138-1 (08-60163-001 or 08-60163- 002): Do the inspections  specified
in paragraph (j) of  this AD at the  applicable time in paragraph  (k)(1),
(k)(2), and (k)(3) of this AD.

(1) For any accumulator not having the letter "T" after the serial  number
    on the identification plate and with more than 4,500 flight cycles  on
    the accumulator as of November 4, 2010 (the effective date of AD  2010
    -22-02, Amendment 39-16481 (75  FR 64636, October 20,  2010)): Inspect
    within 500 flight cycles after November 4, 2010 (the effective date of
    AD 2010-22-02).

(2) For any accumulator not having the letter "T" after the serial  number
    on the identification  plate and with  4,500 flight cycles  or less on
    the accumulator as of November 4, 2010 (the effective date of AD  2010
    -22-02, Amendment 39-16481 (75  FR 64636, October 20,  2010)): Inspect
    prior to the accumulation of 5,000 flight cycles on the accumulator.

(3) If it is not possible  to determine the flight cycles accumulated  for
    any accumulator not having the  letter "T" after the serial  number on
    the  identification  plate:  Inspect within  500  flight  cycles after
    November 4, 2010 (the effective  date of AD 2010- 22-02,  Amendment 39
    -16481 (75 FR 64636, October 20, 2010)).

NOTE  2 TO  PARAGRAPH (J)  OF THIS  AD: For  any  accumulator  having  P/N
601R75138-1 (08-60163-001 or  08-60163-002) and the  letter "T" after  the
serial number  on the  identification plate,  or if  the accumulator  part
number is not listed in paragraph (j) of this AD, the inspection specified
in paragraph (j) of this AD is not required.

TABLE 3--BOMBARDIER CREDIT SERVICE INFORMATION FOR ACCUMULATOR INSPECTION
--------------------------------------------------------------------------
                DOCUMENT                  REVISION          DATE
--------------------------------------------------------------------------
Bombardier Alert Service Bulletin A601R-  ..........  October 18, 2007.
29-029.
Bombardier Alert Service Bulletin A601R-  A.........  November 12, 2009.
29-029.
Bombardier Alert Service Bulletin A601R-  ..........  November 21, 2006.
32-103.
Bombardier Alert Service Bulletin A601R-  A.........  March 7, 2007.
32-103.
Bombardier Alert Service Bulletin A601R-  B.........  October 18, 2007.
32-103.
Bombardier Alert Service Bulletin A601R-  C.........  February 26, 2009.
32-103.
--------------------------------------------------------------------------

 TABLE 4--BOMBARDIER CREDIT SERVICE INFORMATION FOR SCREW CAP INSPECTION
--------------------------------------------------------------------------
                 DOCUMENT                               DATE
--------------------------------------------------------------------------
    Bombardier Service Bulletin 601R-29-033..       May 5, 2009.
    Bombardier Service Bulletin 601R-32-106..       May 5, 2009.
--------------------------------------------------------------------------

(l) RETAINED REMOVAL  OF THE HYDRAULIC  SYSTEM NO. 3  ACCUMULATOR, WITH NO
    NEW SERVICE INFORMATION

This paragraph restates the removal  required by paragraph (o) of  AD 2011
-23-08, Amendment 39-16859 (76 FR 71241, November 17, 2011), with  reduced
compliance  time  for  paragraph  (n)  of  this  AD,  and  no  new service
information.  Within  1,000 flight  cycles  after December  22,  2011 (the
effective  date  of AD  2011-23-08),  remove the  hydraulic  system No.  3
accumulator, in accordance with Part B of the Accomplishment  Instructions
of Bombardier Alert Service Bulletin A601R-29-031, Revision A, dated March
26, 2009. Doing the action  in this paragraph terminates the  requirements
of paragraph (h) of this AD.

(m) RETAINED REPLACEMENT OF THE HYDRAULIC SYSTEM NO. 1, INBOARD BRAKE  AND
    OUTBOARD BRAKE ACCUMULATORS, WITH NO NEW SERVICE INFORMATION

This paragraph restates  the replacement required  by paragraph (p)  of AD
2011-23-08,  Amendment 39-16859  (76 FR  71241, November  17, 2011),  with
reduced compliance time for paragraph (o)  of this AD, and no new  service
information. Within 4,000  flight cycles or  24 months after  December 22,
2011  (the effective  date of  AD 2011-23-  08), whichever  occurs  first,
replace  any  hydraulic system  No.  1, inboard  brake  or outboard  brake
accumulator having P/N 601R75138-1 (08-60163-001 or 08-60163-002), with  a
new accumulator having P/N  601R75139-1 (11093-4), in accordance  with the
Accomplishment Instructions of the applicable service bulletin  identified
in table 5 of this AD.  Doing the action in this paragraph  terminates the
requirement  for the  inspections in  paragraph (j)  of this  AD for  that
accumulator. As  of December  22, 2011  (the effective  date of AD 2011-23
-08), use only Bombardier Service Bulletin 601R-29-035, Revision A,  dated
December 8, 2010; or Bombardier Service Bulletin 601R-32-107, Revision  B,
dated December 8, 2010; as applicable.

   TABLE 5--BOMBARDIER SERVICE INFORMATION FOR ACCUMULATOR REPLACEMENT
--------------------------------------------------------------------------
   ACCUMULATOR            DOCUMENT          REVISION       DATE
--------------------------------------------------------------------------
Hydraulic System    Bombardier Service
No. 1........       Bulletin 601R-29-035..  ........   May 11, 2010.

Hydraulic System    Bombardier Service
No. 1........       Bulletin 601R-29-035..  A.......   December 8, 2010.

Inboard and Out-    Bombardier Service
board Brake....     Bulletin 601R-32-107..  A.......   June 17, 2010.

Inboard and Out-    Bombardier Service
board Brake....     Bulletin 601R-32-107..  B.......   December 8, 2010.
--------------------------------------------------------------------------

(n) RETAINED  ACTION  FOR AIRPLANES ON  WHICH BOMBARDIER  SERVICE BULLETIN
    601R-29-035,  DATED  MAY 11,  2010,  IS DONE  AND  REDUCER HAVING  P/N
    MS21916D8-6 IS INSTALLED, WITH NO NEW SERVICE INFORMATION

This paragraph restates  the action required  by paragraph (q)  of AD 2011
-23-08, Amendment 39-16859 (76 FR 71241, November 17, 2011), with  reduced
compliance  time  for  paragraph  (n)  of  this  AD,  and  no  new service
information. For  airplanes on  which Bombardier  Service Bulletin 601R-29
-035, dated May 11, 2010, is  done, and reducer having P/N MS21916D8-6  is
installed: At  the later  of the  times specified  in paragraph  (n)(1) or
(n)(2) of this AD: Replace the reducer of the hydraulic system No. 1  with
a new reducer,  in accordance with  Part B of  Bombardier Service Bulletin
601R-29-035, Revision A, dated December 8, 2010.

(1) Within 1,200 flight  cycles or 8 months  after December 22, 2011  (the
    effective  date of  AD 2011-23-08,  Amendment 39-16859  (76 FR  71241,
    November 17, 2011)), whichever occurs first.

(2) Within 60 days after the effective date of this AD.

(o) CREDIT FOR PREVIOUS ACTIONS

(1) This paragraph provides  credit for deactivating the  hydraulic system
    No. 3 accumulator,  as required by  paragraph (h) of  this AD, if  the
    deactivation was performed before November 4, 2010 (the effective date
    of AD 2010-22-02, Amendment 39-16481 (75 FR 64636, October 20,  2010))
    using Bombardier Alert  Service Bulletin A601R-29-031,  dated December
    23, 2008.

(2) This paragraph provides credit for removing the hydraulic system No. 2
    accumulator as required  by paragraph (i)  of this AD,  if the removal
    was performed before November 4,  2010 (the effective date of  AD 2010
    -22-02,  Amendment 39-16481  (75 FR  64636, October  20, 2010))  using
    Bombardier Service Bulletin 601R-29-032, dated November 12, 2009.

(3) This paragraph provides credit for an ultrasonic inspection for cracks
    as required by paragraph (j) of this AD, if the ultrasonic  inspection
    was performed before November 4,  2010 (the effective date of  AD 2010
    -22-02, Amendment 39-16481 (75 FR 64636, October 20, 2010)), using the
    applicable service bulletin identified in  table 3 of this AD,  or the
    applicable service bulletin identified in table 4 of this AD.

(4) This paragraph provides credit for removing the hydraulic system No. 3
    accumulator as required  by paragraph (l)  of this AD,  if the removal
    was performed before December 22, 2011 (the effective date of AD  2011
    -23-08, Amendment 39-16859  (76 FR 71241,  November 17, 2011)),  using
    Bombardier  Alert Service  Bulletin A601R-29-031,  dated December  23,
    2008.

(5) This  paragraph provides  credit for  replacing any  inboard brake  or
    outboard brake accumulator as required by paragraph (m) of this AD, if
    the replacement was performed before December 22, 2011 (the  effective
    date of AD 2011-23-08, Amendment  39-16859 (76 FR 71241, November  17,
    2011)), using Bombardier Service Bulletin 601R- 32-107, dated May  11,
    2010.

(p) OTHER FAA AD PROVISIONS

The following provisions also apply to this AD:

(1) ALTERNATIVE METHODS OF COMPLIANCE (AMOCS): The Manager, New  York Air-
    craft Certification Office, (ACO), ANE-170, 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 NYACO, send it  to
    ATTN: Program  Manager, Continuing  Operational Safety,  FAA, New York
    ACO,  1600  Stewart  Avenue,  Suite  410,  Westbury,  New  York 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. The AMOC approval
    letter must specifically reference this AD. AMOCs approved  previously
    in accordance  with AD  2010-22-02, Amendment  39-16481 (75  FR 64636,
    October  20,  2010),  are  approved  as  AMOCs  for  the corresponding
    provisions of this AD. AMOCs approved previously in accordance with AD
    2011-23-08, Amendment 39- 16859 (76 FR 71241, November 17, 2011),  are
    approved as AMOCs for the corresponding provisions of this AD.

(2) AIRWORTHY PRODUCT: For any requirement in this AD to obtain corrective
    actions from a manufacturer or other source, use these actions if they
    are FAA-approved.  Corrective actions  are considered  FAA-approved if
    they are approved by the State of Design Authority (or their delegated
    agent). You are required to assure the product is airworthy before  it
    is returned to service.

(q) RELATED INFORMATION

Refer to MCAI Canadian Airworthiness Directive CF-2010-24, dated August 3,
2010; and the  service bulletins specified  in paragraphs (q)(1),  (q)(2),
(q)(3), (q)(4), (q)(5), (q)(6), (q)(7), (q)(8), and (q)(9) of this AD; for
related information.

(1) Canadair Regional  Jet Temporary Revision  RJ/186-1, dated August  24,
    2010, to the Canadair Regional Jet  Airplane Flight Manual, CSP A-012.

(2) Bombardier Alert Service Bulletin A601R-29-029, Revision B, dated  May
    11, 2010, including Appendix A, dated October 18, 2007.

(3) Bombardier  Alert  Service  Bulletin  A601R-29-031, Revision  A, dated
    March 26, 2009.

(4) Bombardier Alert Service Bulletin A601R-32-103, Revision D, dated  May
    11, 2010, including Appendix A, Revision A, dated October 18, 2007.

(5) Bombardier Service Bulletin 601R-29-032, Revision A, dated January 26,
    2010.

(6) Bombardier  Service Bulletin  601R-29-033, Revision  A, dated  May 11,
    2010, including Appendix A, dated May 5, 2009.

(7) Bombardier Service Bulletin 601R-29-035, Revision A, dated December 8,
    2010.

(8) Bombardier Service Bulletin 601R-32-106, Revision A, including Append-
    ix A, dated May 11, 2010.

(9) Bombardier Service Bulletin 601R-32-107, Revision B, dated December 8,
    2010.

Issued in Renton, Washington, on  April 11, 2012. John P.  Piccola, Acting
Manager, Transport Airplane Directorate, Aircraft Certification Service.

DATES: We must receive comments on this proposed AD by June 4, 2012.