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PROPOSED AD BOMBARDIER, INC.: Docket No. FAA-2012-0142; Directorate Identifier 2010-NM-275-AD.
(a) COMMENTS DUE DATE

We must receive comments by May 4, 2012.

(b) AFFECTED ADS

None.

(c) APPLICABILITY

This  AD applies  to the  airplanes identified  in  paragraphs  (c)(1) and
(c)(2) of this AD, certificated in any category.

(1) Bombardier, Inc.  Model CL-600-2C10 (Regional  Jet Series 700,  701, &
    702)  airplanes,  with  serial   number  (S/N)  10003  through   10314
    inclusive.

(2) Bombardier, Inc.  Model CL-600-2D15 (Regional  Jet Series 705) and CL-
    600-2D24  (Regional Jet Series 900) airplanes, with S/N 15001  through
    15259 inclusive.

(d) SUBJECT

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

(e) REASON

This AD was prompted by  reports of failures of a  hydraulic accumulator's
screw-cap/end cap while on the ground that resulted in loss of use of that
hydraulic system and in high-energy impact damage to adjacent systems  and
structures. We are issuing this AD  to prevent loss of use of  a hydraulic
system, which could result in reduced controllability 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) INSPECTION FOR PART NUMBERS (P/NS)

At the applicable time specified in paragraphs (g)(1), (g)(2), and  (g)(3)
of this AD,  inspect the hydraulic  accumulators in the  hydraulic systems
No. 1, No. 2,  and No. 3, and  the inboard and outboard  brake systems, to
determine  the  part  number  of the  accumulator.  A  review  of airplane
maintenance records is acceptable in  lieu of this inspection if  the part
number of the accumulator can be conclusively determined from that review.

(1) For an accumulator with more than 4,500 total flight cycles as of  the
    effective date of this AD, inspect that accumulator within 500  flight
    cycles after the effective date of this AD.

(2) For an accumulator  with 4,500 or less  total flight cycles as  of the
    effective date  of this  AD, inspect  that accumulator  before it  has
    accumulated 5,000 total flight cycles.

(3) If it is not possible to determine the total flight cycles accumulated
    on an accumulator, inspect  that accumulator within 500  flight cycles
    after the effective date of this AD.

(h) INSPECTION FOR LETTER DESIGNATION AFTER THE SERIAL NUMBER

If,  during  an  inspection  required by  paragraph  (g)  of  this AD,  an
accumulator having  P/N 900096-1  (for hydraulic  systems No.  1 and No. 2
accumulators), 900097-1 (for  hydraulic system No.  3 accumulator), or  08
-60204-001 (for inboard and outboard brake accumulators) is found, at  the
applicable time specified in paragraphs (g)(1), (g)(2), and (g)(3) of this
AD,  do  an  inspection  of  the  identification  plate  on  the hydraulic
accumulator to determine if an "M" (for hydraulic system accumulators)  or
a "T"  (for brake  system accumulators)  follows the  serial number on the
identification  plate.  A  review  of  airplane  maintenance  records   is
acceptable in lieu of this inspection if the part number and the letter of
the accumulator can be conclusively determined from that review.

Note 1 to paragraphs (h), (i), (k), (l)(2), and (m): The letter "M"  after
the  serial  number   on  the  identification   plate  is  applicable   to
accumulators, P/Ns 900096-1 and 900097-1, on hydraulic systems No. 1,  No.
2, and No. 3. The letter "T" after the serial number on the identification
plate  is applicable  to accumulators,  P/ N  08-60204-001, on  the  brake
system.

(i) INITIAL ULTRASONIC  INSPECTIONS OF HYDRAULIC  SYSTEM NO. 1,  HYDRAULIC
    SYSTEM NO.  2, HYDRAULIC  SYSTEM NO.  3, INBOARD  BRAKE, AND  OUTBOARD
    BRAKE ACCUMULATORS

If,  during any  inspection required  by  paragraph  (h) of  this AD,  any
accumulator without the letter "M" (for hydraulic system accumulators)  or
a "T" (for brake system accumulators) after the serial number is found, at
the applicable time  specified in paragraph  (g)(1), (g)(2), or  (g)(3) of
this  AD:  Do an  ultrasonic  inspection of  the  inner shoulders  of  the
accumulator  screw-cap for  cracking, in  accordance  with  Part B  of the
Accomplishment Instructions of the applicable Bombardier service  bulletin
identified in paragraphs (i)(1), (i)(2), and (i)(3) of this AD, and at the
internal threads of the screw-caps, in accordance with the  Accomplishment
Instructions of the applicable  Bombardier service bulletin identified  in
paragraphs (i)(4), (i)(5), and (i)(6) of this AD.

(1) For hydraulic system No.  1, and hydraulic system No.  2 accumulators:
    Bombardier  Alert Service  Bulletin A670BA-29-011,  Revision A,  dated
    July 27, 2010, including Appendix A, Revision A, dated  July 26, 2010.

(2) For hydraulic system No. 3 accumulators: Bombardier Alert Service Bul-
    letin A670BA-29-012, including Appendix A, Revision A, dated July  27,
    2010.

(3) For  inboard brake,  outboard brake  accumulators: Bombardier  Service
    Bulletin A670BA-32-021,  Revision C,  dated July  27, 2010,  including
    Appendix A, Revision A, dated October 18, 2007.

(4) For hydraulic system  No. 1 accumulators: Bombardier  Service Bulletin
    670BA-29-013, Revision A, dated  July 27, 2010, including  Appendix A,
    dated January 29, 2010.

(5) For hydraulic system  No. 2 accumulators: Bombardier  Service Bulletin
    670BA-29-013, Revision A, dated  July 27, 2010, including  Appendix A,
    dated January 29, 2010.

(6) For  inboard brake,  outboard brake  accumulators: Bombardier  Service
    Bulletin  670BA-32-026, Revision  A, dated  July 27,  2010,  including
    Appendix A, dated January 29, 2010.

(j) NO CRACKING FOUND DURING ACCOMPLISHMENT OF PARAGRAPH (I) OF THIS AD

If no cracking is found  during the inspections required by  paragraph (i)
of this AD, do the actions required by paragraph (l) of this AD.

(k) ANY CRACKING FOUND DURING ACCOMPLISHMENT OF PARAGRAPH (I) OF THIS AD

If any cracking is found during the inspections required by paragraph  (i)
of this  AD, before  further flight,  replace the  accumulator with  a new
accumulator containing  the letter  "M" or  "T", as  applicable, after the
serial  number  on  the  identification  plate,  in  accordance  with  the
Accomplishment Instructions of the applicable service bulletin  identified
in paragraphs (i)(1) through (i)(6) of this AD, or replace the accumulator
with a new accumulator as specified in paragraphs (k)(1) through (k)(3) of
this AD, as applicable.

(1) For any cracked hydraulic system  No. 1 or No. 2 accumulator,  replace
    the cracked accumulator with a new  accumulator, P/N 900121-1, in acc-
    ordance  with the  Accomplishment Instructions  of Bombardier  Service
    Bulletin 670BA-29-014, dated December 22, 2010.

(2) For  any cracked  hydraulic  system No.  3  accumulator,  replace  the
    cracked  accumulator  with  a   new  accumulator,  P/N  900122-1,   in
    accordance with the replacement specified in paragraph (o) of this AD.

(3) For any cracked inboard  brake or outboard brake accumulator  replaced
    the  cracked  accumulator with  a  new accumulator,  P/N  90006691, in
    accordance with the replacement specified in paragraph (p) of this AD.

(l) REPETITIVE ULTRASONIC INSPECTIONS OF HYDRAULIC SYSTEM NO. 1, HYDRAULIC
    SYSTEM NO.  2, HYDRAULIC  SYSTEM NO.  3, INBOARD  BRAKE, AND  OUTBOARD
    BRAKE ACCUMULATORS

For each accumulator on which no cracking was found during any  inspection
required by paragraph (i) of this  AD, within 500 flight cycles after  the
previous ultrasonic inspection, inspect the accumulator in accordance with
paragraph (i) of this AD.

(1) If no cracking is found,  do the actions required by paragraph  (l) of
    this AD and  repeat thereafter at  intervals not to  exceed 500 flight
    cycles.

(2) If any cracking is found, before further flight, replace  the accumul-
    ator  with a  new accumulator  containing the  letter "M"  or "T",  as
    applicable, after the  serial number on  the identification plate,  in
    accordance  with  the Accomplishment  Instructions  of the  applicable
    service bulletin  identified in  paragraphs (i)(1)  through (i)(6)  of
    this  AD,  or  replace  the  accumulator  with  a  new  accumulator as
    specified in  paragraphs (k)(1),  (k)(2), and  (k)(3) of  this AD,  as
    applicable.

(m) REPLACEMENT OF HYDRAULIC SYSTEM NO. 1 AND NO. 2 ACCUMULATORS

For airplanes  on which  a hydraulic  system No.  1 or  No. 2  accumulator
having P/N  900096-1 without  the letter  "M" after  the serial  number is
installed:  At  the applicable  time  specified in  paragraphs  (m)(1) and
(m)(2) of  this AD,  replace the  accumulator with  a new  one having  P/N
900096-1  with the  letter "M"  after the  serial number;  or  having  P/N
900121-1, in accordance with the Accomplishment Instructions of Bombardier
Service Bulletin 670BA-29- 014, dated December 22, 2010.

(1) For an accumulator with more than 19,500 total flight cycles as of the
    effective date of this AD, replace that accumulator within 500  flight
    cycles  after accomplishing  the most  recent  inspection  required by
    paragraph (i) or (l) of this AD.

(2) For an accumulator with 19,500  or less total flight cycles as  of the
    effective date  of this  AD, replace  that accumulator  before it  has
    accumulated 20,000 total flight cycles.

(3) If it is not possible to determine the total flight cycles accumulated
    on an accumulator, replace  that accumulator within 500  flight cycles
    after accomplishing the most recent ultrasonic inspection required  by
    paragraph (i) or (l) of this AD.

(n) HYDRAULIC SYSTEM SAFE LIFE LIMIT INTRODUCTION

Within 60 days after the effective date or this AD, revise the maintenance
program to include a  safe life limit for  the hydraulic system No.  1 and
No. 2 accumulators, P/N 900096-1, by incorporating Tasks  29-11-11-000-801
and 29-11-11-400-801  of Section  1.3, Safe  Life Components,  of Part  2,
Airworthiness Limitations, of the Bombardier CL-600-2C10, CL-600-2D15,  CL
-600-2D24,  CL-600-2E25  Maintenance   Requirements  Manual,  CSP   B-053,
Revision 11, dated October 20, 2010.

(o) REPLACEMENT OF HYDRAULIC SYSTEM NO. 3 ACCUMULATOR

Within 4,000 flight cycles or 24  months after the effective date of  this
AD, whichever occurs first, replace any hydraulic system No. 3 accumulator
having  P/N  900097-1  with  a new  accumulator  having  P/N  900122-1, in
accordance  with  the Accomplishment  Instructions  of Bombardier  Service
Bulletin 670BA-29-015, dated December 22, 2010.

(p) REPLACEMENT OF INBOARD OR OUTBOARD BRAKE SYSTEM ACCUMULATORS

Within 4,000 flight cycles or 24  months after the effective date of  this
AD, whichever occurs first, replace  any inboard or outboard brake  system
accumulator  having P/N  08-60204-001 with  a new  accumulator having  P/N
90006691, in accordance with the Accomplishment Instructions of Bombardier
Service Bulletin 670BA-32- 028, dated December 22, 2010.

(q) CREDIT FOR  ACTIONS ACCOMPLISHED IN  ACCORDANCE WITH PREVIOUS  SERVICE
    INFORMATION

(1) Actions done before the effective date of this AD using Part B of  the
    Accomplishment  Instructions  of   the  Bombardier  service   bulletin
    identified   in   paragraph   (q)(1)(i),   (q)(1)(ii),    (q)(1)(iii),
    (q)(1)(iv), or (q)(1)(v) of this AD is acceptable for compliance  with
    the corresponding requirements of this AD.

(i) Bombardier  Alert Service  Bulletin A670BA-29-011,  dated October  18,
    2007.

(ii) Bombardier  Alert  Service  Bulletin  A670BA-29-012, dated  March 13,
     2008.

(iii) Bombardier Alert Service Bulletin A670BA-32-021, dated November  21,
      2006.

(iv) Bombardier  Alert Service  Bulletin A670BA-32-021,  Revision A, dated
     March 7, 2007.

(v) Bombardier  Alert Service  Bulletin A670BA-32-021,  Revision B,  dated
    October 18, 2007.

(2) Actions done before the  effective date  of this AD  using the Accomp-
    lishment  Instructions  of Bombardier  Service  Bulletin 670BA-29-013,
    dated January 29, 2010; or  670BA-32-026, dated January 29, 2010;  are
    acceptable for compliance with the corresponding requirements of  this
    AD.

(r) TERMINATING ACTIONS

Accomplishing the actions required by paragraphs (m), (n), (o), and (p) of
this AD terminates the requirements of this AD for the accumulator at that
location only.

(s) 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, 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 manager  of the
    ACO, 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.

(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.

(t) RELATED INFORMATION

Refer to  MCAI Canadian  Airworthiness Directive  CF-2010-35R1, dated June
28,  2011, and  the service  information identified  in paragraphs  (t)(1)
through (t)(9) of this AD, for related information.

(1) Bombardier  Alert Service  Bulletin A670BA-29-011,  Revision A,  dated
    July 27, 2010, including Appendix A, Revision A, dated  July 26, 2010.

(2) Bombardier Alert Service Bulletin A670BA-29-012, including Appendix A,
    Revision A, dated July 27, 2010.

(3) Bombardier Service Bulletin A670BA-32-021, Revision C, dated July  27,
    2010, including Appendix A, Revision A, dated October 18, 2007.

(4) Bombardier Service Bulletin  670BA-29-013, Revision A, dated  July 27,
    2010, including Appendix A, dated January 29, 2010.

(5) Bombardier Service Bulletin  670BA-32-026, Revision A, dated  July 27,
    2010, including Appendix A, dated January 29, 2010.

(6) Bombardier Service Bulletin 670BA-29-014, dated December 22, 2010.

(7) Bombardier Service Bulletin 670BA-29-015, dated December 22, 2010.

(8) Bombardier Service Bulletin 670BA-32-028, dated December 22, 2010.

(9) Tasks 29-11-11-000-801 and 29-11-11-400-801 of Section 1.3, Safe  Life
    Components, of  Part 2,  Airworthiness Limitations,  of the Bombardier
    CL-600-2C10,   CL-600-2D15,   CL-600-2D24,   CL-600-2E25   Maintenance
    Requirements Manual, CSP B-053, Revision 11, dated October 20, 2010.

Issued in  Renton, Washington,  on January  26, 2012.  Kalene C. Yanamura,
Acting  Manager,  Transport Airplane  Directorate,  Aircraft Certification
Service.

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


14 CFR Part 39

[Docket No. FAA-2012-0142; Directorate Identifier 2010-NM-275-AD]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY:
We propose to adopt a new airworthiness directive (AD) for
certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700,
701, & 702), CL-600-2D15 (Regional Jet Series 705), and CL-600-2D24
(Regional Jet Series 900) airplanes. This proposed AD was prompted by
reports of failures of a hydraulic accumulator's screw-cap/end cap
while on the ground that resulted in loss of use of that hydraulic
system and in high-energy impact damage to adjacent systems and
structures. This proposed AD would require an inspection for part
numbers; repetitive inspections for any cracking of certain hydraulic
system accumulators, and replacement, if necessary; and revising the
maintenance program to include a life limit for certain hydraulic
system accumulators. We are proposing this AD to prevent loss of use of
a hydraulic system, which could result in reduced controllability of
the airplane.

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

ADDRESSES:
You may send comments by any of the following methods:

Federal eRulemaking Portal: Go to http://www.regulations.gov.
Follow the instructions for submitting comments.

Fax: (202) 493-2251.

Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590.

Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.

For service information identified in this proposed AD, contact
Bombardier, Inc., 400 C[ocirc]te-Vertu Road West, Dorval, Qu[eacute]bec
H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-7401; email
thd.crj@aero.bombardier.com; Internet http://www.bombardier.com. You
may review copies of the referenced service information at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton,
Washington. For information on the availability of this material at the
FAA, call 425-227-1221.

Examining the AD Docket


You may examine the AD docket on the Internet at http://www.regulations.gov;
or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Operations office (telephone (800) 647-5527) is
in the ADDRESSES section. Comments will be available in the AD docket
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Cesar Gomez, Aerospace Engineer,
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New
York 11590; telephone (516) 228-7318; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited


We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include "Docket No. FAA-2012-0142;
Directorate Identifier 2010-NM-275-AD" at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD based on those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,
including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.

Discussion


The Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2010-35R1, dated June 28, 2011 (referred to after this as "the
MCAI"), to correct an unsafe condition for the specified products. The
MCAI states:

Seven cases of on-ground hydraulic accumulator screw cap/end cap
failure have been experienced on CL-600-2B19 aeroplanes resulting in
loss of the associated hydraulic system and high-energy impact
damage to adjacent systems and structure. The lowest number of
flight cycles accumulated at the time of failure, to date, has been
6,991 flight cycles.

Although there have been no failures to date on any CL-600-2C10,
CL-600-2D15 or CL-600-2D24 aeroplanes, similar accumulators to those
installed on the CL-600-2B19, are installed. The part numbers (P/Ns)
of the accumulators installed on CL-600-2C10, CL-600-2D15 and CL-
600-2D24 aeroplanes are 900096-1 (Hydraulic System No. 1 and
Hydraulic System No. 2 accumulators), 900097-1 (Hydraulic System No.
3 accumulator) and 08-60204-001 (Inboard Brake and Outboard Brake
accumulators).

A detailed analysis of the calculated line of trajectory of a
failed screw cap/end cap for each of the accumulators has been
conducted, resulting in the identification of
several areas where systems and/or structural components could
potentially be damaged. Although all of the failures to date have
occurred on the ground, an in-flight failure affecting such
components could potentially have an adverse effect on the
controllability of the aeroplane.

This [Canadian] directive gives instructions to conduct [an
inspection to determine if certain hydraulic accumulators are
installed and, if necessary,] repetitive ultrasonic inspections [for
cracking] of the Hydraulic System No. 1, Hydraulic System No. 2,
Hydraulic System No. 3, Inboard Brake and Outboard Brake
accumulators, P/Ns 900096-1, 900097-1, and 08-60204-001, that are
not identified by the letter "M" or "T" after the S/N [serial
number] on the identification plate.
* * * * *
Required actions include revising the maintenance program to
include a life limit for certain accumulators, and for airplanes on
which cracking is found during an ultrasonic inspection, replacing the
accumulator with a new accumulator containing the letter "M" or
"T", as applicable, after the serial number on the identification
plate or with a new accumulator with a different part number, and
eventual replacement of certain accumulators with new accumulators. You
may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information


Bombardier has issued the following service information.

Bombardier Alert Service Bulletin A670BA-29-011, Revision
A, dated July 27, 2010, including Appendix A, Revision A, dated July
26, 2010.

Bombardier Alert Service Bulletin A670BA-29-012, including
Appendix A, Revision A, dated July 27, 2010.

Bombardier Service Bulletin A670BA-32-021, Revision C,
dated July 27, 2010, including Appendix A, Revision A, dated October
18, 2007.

Bombardier Service Bulletin 670BA-29-013, Revision A,
dated July 27, 2010, including Appendix A, dated January 29, 2010.

Bombardier Service Bulletin 670BA-32-026, Revision A,
dated July 27, 2010, including Appendix A, dated January 29, 2010.

Bombardier Service Bulletin 670BA-29-014, dated December
22, 2010.

Bombardier Service Bulletin 670BA-29-015, dated December
22, 2010.

Bombardier Service Bulletin 670BA-32-028, dated December
22, 2010.

Tasks 29-11-11-000-801 and 29-11-11-400-801 of Section
1.3, Safe Life Components, of Part 2, Airworthiness Limitations, of the
Bombardier CL-600-2C10, CL-600-2D15, CL-600-2D24, CL-600-2E25
Maintenance Requirements Manual, CSP B-053, Revision 11, dated October
20, 2010.

The actions described in this service information are intended to
correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD


This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to our bilateral agreement with the State of Design Authority, we have
been notified of the unsafe condition described in the MCAI and service
information referenced above. We are proposing this AD because we
evaluated all pertinent information and determined an unsafe condition
exists and is likely to exist or develop on other products of the same
type design.

Costs of Compliance


Based on the service information, we estimate that this proposed AD
would affect about 389 products of U.S. registry. We also estimate that
it would take up to 21 work-hours per product to comply with the basic
requirements of this proposed AD. The average labor rate is $85 per
work-hour. Required parts would cost about $8,988 per product. Where
the service information lists required parts costs that are covered
under warranty, we have assumed that there will be no charge for these
parts. As we do not control warranty coverage for affected parties,
some parties may incur costs higher than estimated here. Based on these
figures, we estimate the cost of the proposed AD on U.S. operators to
be up to $4,190,697, or $10,773 per product, per inspection cycle.

In addition, we estimate that any necessary follow-on actions would
take up to 7 work-hours and require parts costing $8,988, for a cost of
$9,583 per product. We have no way of determining the number of
products that may need these actions.

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.

Regulatory Findings

We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:

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.

We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39


Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment


Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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 adding the following new AD: