preamble attached >>>
ADs updated daily at www.Tdata.com
2020-04-20 DE HAVILLAND AIRCRAFT OF CANADA LIMITED (TYPE CERTIFICATE PREVIOUSLY HELD BY BOMBARDIER, INC.):
Amendment 39-19857; Docket No. FAA-2019-0726; Product Identifier 2019-NM-102-AD.

(a) EFFECTIVE DATE

    This AD is effective May 4, 2020.

(b) AFFECTED ADS

    None.

(c) APPLICABILITY

    This AD applies to De Havilland Aircraft of Canada Limited Model DHC-8
    -400, -401, and -402 airplanes, certificated in any category, manufac-
    turer serial numbers 4001, 4003, and subsequent.

(d) SUBJECT

    Air Transport Association (ATA) of America Code 28, Fuel.

(e) REASON

    This AD was prompted  by reports of wear  on  fuel couplings,  bonding
    springs,  and  sleeves  as well  as fuel  tube end  ferrules and  fuel
    component end  ferrules. The  FAA is  issuing this  AD to address such
    wear, which could reduce the integrity of the electrical bonding paths
    through the fuel line and components, and ultimately lead to fuel tank
    ignition in the event of a lightning strike.

(f) COMPLIANCE

    Comply with this AD within the compliance times specified,  unless al-
    ready done.

(g) INITIAL INSPECTION COMPLIANCE TIMES

    For airplanes  having serial numbers 4001 and 4003 through 4575 inclu-
    sive that,  as of  the effective  date of  this AD,  have not done the
    actions  specified  in  Bombardier Service Bulletin 84-28-21:  At  the
    applicable times specified in paragraph  (g)(1) or (2) of this  AD, do
    the actions specified in paragraphs (h)(1) and (2) of this AD.

(1) For all airplanes except those identified  in paragraph (g)(2) of this
    AD: Within 6,000 flight hours  or 36 months,  whichever  occurs  first
    after the effective date of this AD.

(2) For airplanes with an original airworthiness certificate  or  original
    export certificate of airworthiness  issued on or after  the effective
    date of  this AD:  Within 6,000  flight hours  or 36 months, whichever
    occurs first after the date of issuance of the original  airworthiness
    certificate or the date of issuance of the original export certificate
    of airworthiness.

(h) REPETITIVE INSPECTIONS AND CORRECTIVE ACTIONS

    For airplanes  having serial numbers 4001 and 4003 through 4575 inclu-
    sive that,  as of  the effective  date of  this AD,  have not done the
    actions  specified  in  Bombardier Service Bulletin 84-28-21:  At  the
    applicable times specified in paragraph  (g)(1) or (2) of this  AD, do
    the actions specified in paragraphs (h)(1) and (2) of this AD.  Repeat
    the actions thereafter at intervals  not to exceed 6,000 flight  hours
    or 36 months, whichever occurs first.

(1) Do a detailed inspection of the clamshell coupling bonding wires, fuel
    couplings,  and  associated   sleeves  for  discrepancies   that  meet
    specified criteria, as identified in, and in accordance with paragraph
    3.B., "Procedure,"  of the  Accomplishment Instructions  of Bombardier
    Service Bulletin 84-28-20, Revision D, dated November 23, 2018. If any
    conditions  are found  meeting  the  criteria specified  in Bombardier
    Service Bulletin 84-28-20, Revision D, dated November 23, 2018, before
    further flight, replace affected parts with new couplings and  sleeves
    of  the  same  part   number,  in  accordance  with   paragraph  3.B.,
    "Procedure," of the Accomplishment Instructions of Bombardier  Service
    Bulletin 84-28-20, Revision D, dated November 23, 2018.

(2) Do a detailed inspection of the fuel tube end ferrules, fuel component
    end ferrules,  and ferrule  O-ring flanges  for damage  and wear,  and
    rework  (repair,  replace,  or blend,  as  applicable)  the parts,  in
    accordance  with paragraph  3.B., "Procedure,"  of the  Accomplishment
    Instructions  of  Bombardier Service  Bulletin  84-28-20,  Revision D,
    dated November 23, 2018.

(i) OPTIONAL TERMINATING ACTION FOR REPETITIVE INSPECTIONS

    For airplanes  having serial numbers 4001 and 4003 through 4575 inclu-
    sive:  Doing a detailed inspection of the fuel tube end ferrules, fuel
    component  end ferrules,  and ferrule  O-ring flanges  for damage  and
    wear, and  reworking (repair,  replace, or  blend, as  applicable) the
    parts; and doing a retrofit (structural rework) of the fuel couplings,
    isolators,  and structural  provisions, in  accordance with  paragraph
    3.B., "Procedure,"  of the  Accomplishment Instructions  of Bombardier
    Service Bulletin 84-28-21, Revision C, dated July 13, 2018, terminates
    the inspections specified in paragraphs (h)(1) and (2) of this AD.

(j) ELECTRICAL BONDING CHECKS/DETAILED INSPECTION

    For airplanes having serial numbers 4001, 4003 through 4489 inclusive,
    and 4491 through 4575 inclusive that, as of the effective date of this
    AD, have done the actions specified  in Bombardier Service Bulletin 84
    -28-21, Revision  A, dated  September 29,  2017; and  airplanes having
    serial numbers 4576 through 4581 inclusive: Within 6,000 flight  hours
    or 36  months after  the effective  date of  this AD, whichever occurs
    first, do the actions specified in paragraph (j)(1) or (2) of this AD.

(1) Accomplish electrical bonding checks of all threaded couplings  on the
    inboard vent lines  in the left and right wings,  in  accordance  with
    paragraph 3.B.,  "Procedure,"  of the  Accomplishment Instructions  of
    Bombardier Service Bulletin 84-28-26,  Revision A,  dated November 29,
    2018.

(2) Do a detailed inspection of the fuel tube end ferrules, fuel component
    end ferrules, and ferrule O-ring flanges for damage and wear,  and re-
    work (repair, replace or blend, as applicable) the parts; and a retro-
    fit (structural rework) of the fuel couplings, isolators and structur-
    al provisions in accordance with paragraph 3.B.,  "Procedure,"  of the
    Accomplishment Instructions  of Bombardier  Service Bulletin 84-28-21,
    Revision C, dated July 13, 2018.

(k) MAINTENANCE OR INSPECTION PROGRAM REVISION

    Within 30 days after the effective date of this AD,  revise the exist-
    ing maintenance or inspection program,  as applicable,  to incorporate
    the  information  specified  in  Q400  Dash 8  (Bombardier)  Temporary
    Revision ALI-0192, dated April 24, 2018;  and Q400 Dash 8 (Bombardier)
    Temporary Revision ALI-0193, dated April 24, 2018. Except as specified
    in paragraph (l) of this AD, the initial compliance time for doing the
    tasks in Q400 Dash 8 (Bombardier)  Temporary Revision ALI-0192,  dated
    April 24, 2018,  is at the time specified  in Q400 Dash 8 (Bombardier)
    Temporary Revision ALI-0192, dated April 24, 2018,  or  within 30 days
    after the effective date of this AD, whichever occurs later.

(l) INITIAL COMPLIANCE TIME FOR TASK 284000-419

    The initial compliance time  for task 284000-419 is at the time speci-
    fied in paragraph (l)(1) or (2) of this AD, as applicable,  or  within
    30 days after the effective date of this AD, whichever occurs later.

(1) For airplanes having serial numbers 4001 and 4003 through 4575, inclu-
    sive: Within 18,000 flight hours or 108 months, whichever occurs first
    after the earliest date of embodiment  of Bombardier Service Bulletin
    84-28-21 on the airplane.

(2) For airplanes having serial numbers 4576 and subsequent: Within 18,000
    flight hours or 108 months,  whichever occurs first,  from the date of
    issuance of the original airworthiness certificate  or original export
    certificate of airworthiness.

(m) NO ALTERNATIVE ACTIONS, INTERVALS OR CRITICAL DESIGN CONFIGURATION CON
    -TROL LIMITATIONS (CDCCLS)

    After the existing maintenance  or inspection program has been revised
    as required by paragraph (k) of this AD, no alternative actions (e.g.,
    inspections), intervals,  or CDCCLs  may be  used unless  the actions,
    intervals,  and  CDCCLs  are  approved  as  an  alternative  method of
    compliance  (AMOC)  in  accordance with  the  procedures  specified in
    paragraph (p)(1) of this AD.

(n) NO REPORTING REQUIREMENT

    Although Bombardier Service Bulletin 84-28-20 Revision D, dated Novem-
    ber 23, 2018,  specifies to submit certain information to the manufac-
    turer, this AD does not include that requirement.

(o) CREDIT FOR PREVIOUS ACTIONS

(1) This paragraph provides credit for the actions required  by paragraphs
    (h)(1) and (2) of this AD, if those actions were performed before  the
    effective date of this AD  using the service information specified  in
    paragraph (o)(1)(i), (ii), or (iii) of this AD.

(i) Bombardier Service Bulletin 84-28-20,  Revision A,  dated December 14,
    2016.

(ii) Bombardier Service Bulletin 84-28-20, Revision B,  dated February 13,
     2017.

(iii) Bombardier Service Bulletin 84-28-20,  Revision C,  dated  April 28,
      2017.

(2) For the airplane having serial number 4164,  this  paragraph  provides
    credit for the initial inspections required  by paragraphs (h)(1)  and
    (2) of this AD,  if those actions were performed  before the effective
    date of this AD using Bombardier Service Bulletin 84-28-20, dated Sep-
    tember 30, 2016.

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

(i) Bombardier Service Bulletin 84-28-21, dated August 31, 2017.

(ii) Bombardier Service Bulletin 84-28-21, Revision A, dated September 29,
     2017.

(iii) Bombardier Service Bulletin 84-28-21 Revision B, dated June 8, 2018.

(4) This paragraph provides credit  for the actions required  by paragraph
    (j)(1) of this AD if those actions were performed before the effective
    date of  this  AD  using  Bombardier Service Bulletin 84-28-26,  dated
    August 14, 2018.

(5) This paragraph provides credit  for the actions required  by paragraph
    (j)(2) of this AD if those actions were performed before the effective
    date of this AD using Bombardier Service Bulletin 84-28-21, Revision B
    dated June 8, 2018.

(6) For airplanes having serial numbers 4001, 4003 through 4489 inclusive,
    and 4491 through 4575 inclusive,  and that are post Bombardier Service
    Bulletin 84-28-21 Revision A, dated September 29, 2017: This paragraph
    provides credit  for the actions required  by paragraph (j) of this AD
    if those actions were performed prior to the effective date of this AD
    using the service information specified in paragraph (o)(6)(i) or (ii)
    of this AD.

(i) Bombardier Modification Summary Package  (ModSum)  IS4Q2800032,  dated
    February 1, 2018.

(ii) Any airworthiness limitation change request (ACR) specified in figure
     1 to paragraph (o)(6)(ii) of this AD.

                   FIGURE 1 TO PARAGRAPH (O)(6)(II)  ACRS
                   _______________________________________
                       ACR NUMBER          DATED
                   _______________________________________
                       400-072         January 24, 2018
                       400-073         January 23, 2018
                       400-074         January 24, 2018
                       400-077         February 27, 2018
                       400-078         March 21, 2018
                       400-079         April 18, 2018
                       400-080         April 30, 2018
                       400-081         May 4, 2018
                       400-082         May 4, 2018
                       400-083         June 4, 2018
                       400-084         May 18, 2018
                   _______________________________________

(p) OTHER FAA AD PROVISIONS

    The following provisions also apply to this AD:

(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
    instructions   from   a  manufacturer,   the   instructions  must   be
    accomplished using  a method  approved by  the Manager,  New York  ACO
    Branch,  FAA;  or  Transport  Canada  Civil  Aviation  (TCCA);  or  De
    Havilland   Aircraft  of   Canada  Limited's   TCCA  Design   Approval
    Organization (DAO). If approved by the DAO, the approval must  include
    the DAO-authorized signature.

(q) RELATED INFORMATION

(1) Refer   to   Mandatory  Continuing  Airworthiness  Information  (MCAI)
    Canadian  Airworthiness Directive  CF-2017-04R2,  dated  September 25,
    2018, for related information. This MCAI may be found in the AD docket
    on the internet  at https://www.regulations.gov  by searching for  and
    locating Docket No. FAA-2019-0726.

(2) For more information about this AD,  contact  Joseph Catanzaro,  Aero-
    space Engineer,  Airframe and Propulsion Section,  FAA,  New York  ACO
    Branch,  1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone
    516-228-7366; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

(3) Service information  identified in this AD that is not incorporated by
    reference is available at the addresses specified in paragraphs (r)(3)
    and (4) 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.

(i) Bombardier Service Bulletin 84-28-20,  Revision D,  dated November 23,
    2018.

(ii) Bombardier Service Bulletin 84-28-21 Revision C, dated July 13, 2018.

(iii) Bombardier Service Bulletin 84-28-26, Revision A, dated November 29,
      2018.

(iv) Bombardier Q400 Dash 8 (Bombardier) Temporary Revision ALI-0192 dated
     April 24, 2018.

(v) Q400 Dash 8 (Bombardier) Temporary Revision ALI-0193,  dated April 24,
    2018.

(3) For service information  identified in this AD,  contact  De Havilland
    Aircraft of Canada Limited,  Q-Series Technical Help Desk, 123 Garratt
    Boulevard, Toronto, Ontario M3K 1Y5, Canada;  telephone  416-375-4000;
    fax   416-375-4539;   email  thd@dehavilland.com;   internet  https://
    dehavilland.com.

(4) 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.

(5) 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,  email
    fedreg.legal@nara.gov,  or  go  to:  https://www.archives.gov/federal-
    register/cfr/ibr-locations.html.

Issued on March 1, 2020.  Lance T. Gant, Director, Compliance & Airworthi-
ness Division, Aircraft Certification Service.

FOR FURTHER INFORMATION CONTACT: Joseph Catanzaro, Aerospace Engineer, Air
-frame and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart Ave-
nue, Suite 410, Westbury, NY 11590;  telephone 516-228-7366;  fax 516-794-
5531; email 9-avs-nyaco-cos@faa.gov.
PREAMBLE 

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0726; Product Identifier 2019-NM-102-AD; Amendment
39-19857; AD 2020-04-20]
RIN 2120-AA64

Airworthiness Directives; De Havilland Aircraft of Canada Limited
(Type Certificate Previously Held by Bombardier, Inc.) Airplanes

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

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain De Havilland Aircraft of Canada Limited Model DHC-8-400 series
airplanes. This AD was prompted by reports of wear on fuel couplings,
bonding springs, and sleeves as well as fuel tube end ferrules and fuel
component end ferrules. This AD requires repetitive inspections of
certain parts for discrepancies that meet specified criteria, and
replacement as necessary; repetitive inspections of certain parts for
damage and wear, and rework of parts; and electrical bonding checks of
certain couplings. This AD also requires revising the existing
maintenance or inspection program, as applicable, to incorporate new or
more restrictive airworthiness limitations. For certain airplanes, this
AD allows a modification that would terminate the repetitive
inspections. The FAA is issuing this AD to address the unsafe condition
on these products.

DATES: This AD is effective May 4, 2020.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of May 4, 2020.

ADDRESSES: For service information identified in this final rule,
contact De Havilland Aircraft of Canada Limited, Q-Series Technical
Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada;
telephone 416-375-4000; fax 416-375-4539; email thd@dehavilland.com;
internet https://dehavilland.com. 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. It is also available on the internet at https://www.
regulations.gov by searching for and locating Docket No. FAA-2019-0726.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.
gov by searching for and locating Docket No. FAA-2019-
0726; 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 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: Joseph Catanzaro, Aerospace Engineer,
Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7366; fax 516-
794-5531; email 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2017-04R2, dated
September 25, 2018 (also referred to as the Mandatory Continuing
Airworthiness Information, or ``the MCAI''), to correct an unsafe
condition for certain De Havilland Aircraft of Canada Limited Model
DHC-8-400 series airplanes. You may examine the MCAI in the AD docket
on the internet at https://www.regulations.gov by searching for and
locating Docket No. FAA-2019-0726.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain De Havilland
Aircraft of Canada Limited Model DHC-8-400 series airplanes. The NPRM
published in the Federal Register on October 30, 2019 (84 FR 58066).
The NPRM was prompted by reports of wear on fuel couplings, bonding
springs, and sleeves as well as fuel tube end ferrules and fuel
component end ferrules. The NPRM proposed to require repetitive
inspections of certain parts for discrepancies that meet specified
criteria, and replacement as necessary; repetitive inspections of
certain parts for damage and wear, and rework of parts; and electrical
bonding checks of certain couplings. The NPRM also proposed to require
revising the existing maintenance or inspection program, as applicable,
to incorporate new or more restrictive airworthiness limitations. For
certain airplanes, the NPRM proposed to allow a modification that would
terminate the repetitive inspections. The FAA is issuing this AD to
address wear on fuel couplings, bonding springs, and sleeves as well as
fuel tube end ferrules and fuel component end ferrules, which could
reduce the integrity of the electrical bonding paths through the fuel
line and components, and ultimately lead to fuel tank ignition in the
event of a lightning strike. See the MCAI for additional background
information.

Comments

The FAA gave the public the opportunity to participate in
developing this final rule. The following presents the comment received
on the NPRM and the FAA's response to the comment.

Request To Refer to Different Temporary Revisions (TRs)

Horizon Air requested that paragraph (k) of the proposed AD be
revised to refer to TR ALI-0192 and TR ALI-0193. The commenter
suggested that the proposed AD contains typographical errors in
referring to TR ALI-00AS and TR ALI-00AT.
The FAA agrees to clarify. Paragraph (k) of the proposed AD
requires incorporating ``the information specified in Q400 Dash 8
(Bombardier) Temporary Revision ALI-00AS, dated April 24, 2018; and
Q400 Dash 8 (Bombardier) Temporary Revision ALI-00AT, dated April 24,
2018.'' TCCA notified the FAA that TR ALI-00AS and TR ALI-00AT are
temporary placeholder identifiers for TR ALI-0192 and TR ALI-0193. These
temporary placeholder identifiers are used until the finalized TRs are
provided new numerical identifiers. The FAA has confirmed that the
information specified in these TRs is the same as the information
specified in the TRs mentioned by the commenter. For these reasons,
this AD has been revised to specify TR ALI-0192 and TR ALI-0193.

Explanation of Change to Introductory Text to Paragraph (h) of This AD

We have revised the introductory text to paragraph (h) of this AD
to clarify that the actions apply to the same airplanes as those
identified in the introductory text to paragraph (g) of this AD.

Conclusion

The FAA reviewed the relevant data, considered the comment
received, and determined that air safety and the public interest
require adopting this final rule with the changes described previously
and minor editorial changes. The FAA has 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.
The FAA 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 Service Bulletin 84-28-20, Revision D, dated
November 23, 2018. This service information describes procedures for
repetitive detailed inspections of the clamshell coupling bonding
wires, fuel couplings, and associated sleeves for discrepancies (wear
and damage, including discoloration, worn coating, scuffing and
grooves) that meet specified criteria, and replacement. This service
information also describes procedures for repetitive detailed
inspections for damage and wear of the fuel tube end ferrules, fuel
component end ferrules, and ferrule O-ring flanges, and rework of
parts.
Bombardier has also issued Service Bulletin 84-28-21, Revision C,
dated July 13, 2018. This service information describes procedures for
a detailed inspection for damage and wear of the fuel tube end
ferrules, fuel component end ferrules, and ferrule O-ring flanges;
rework (repair, replacement, or blending, as applicable) of parts; and
a retrofit (structural rework) of the fuel couplings, isolators, and
structural provisions.
Bombardier has also issued Service Bulletin 84-28-26, Revision A,
dated November 29, 2018. This service information describes procedures
for electrical bonding checks of all threaded couplings on the inboard
vent lines in the left and right wings.
Bombardier has also issued Q400 Dash 8 (Bombardier) Temporary
Revision ALI-0192, dated April 24, 2018; and Q400 Dash 8 (Bombardier)
Temporary Revision ALI-0193, dated April 24, 2018. This service
information describes airworthiness limitations for fuel tank systems.
These documents are distinct since they describe different
airworthiness limitations.
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

The FAA estimates that this AD affects 52 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs for Required Actions *

Labor cost
Parts cost
Cost per product
Cost on U.S. operators
268 work-hours x $85 per hour = $22,780
$0
$22,780
$1,184,560

* Table does not include estimated costs for revising the maintenance or inspection
program.

The FAA has determined that revising the maintenance or inspection
program takes an average of 90 work-hours per operator, although this
number may vary from operator to operator. In the past, the FAA has
estimated that this action takes 1 work-hour per airplane. Since
operators incorporate maintenance or inspection program changes for
their affected fleet(s), the FAA has determined that a per-operator
estimate is more accurate than a per-airplane estimate. Therefore, the
FAA estimates the total cost per operator to be $7,650 (90 work-hours x
$85 per work-hour).

Estimated Costs for Optional Actions

Labor cost
Parts cost
Cost per product
525 work-hours x $85 per hour = $44,625
$20,906
$65,531

The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of any
required or optional actions. The FAA has no way of determining the
number of aircraft that might need these on-condition actions:

Estimated Costs of On-Condition Actions

Labor cost
Parts cost
Cost per product
174 work-hours x $85 per hour = $14,790
$16,767
$31,557

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.
The FAA is 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

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) Will not affect intrastate aviation in Alaska, and
(3) 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 adding the following new airworthiness
directive (AD):