Document ID: FAA-2012-1068-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2012-10-10T04:00Z

[Federal Register Volume 77, Number 196 (Wednesday, October 10, 2012)]
[Proposed Rules]
[Pages 61542-61548]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-24809]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-1068; Directorate Identifier 2011-NM-073-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede two existing airworthiness directives 
(AD) that apply to certain The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes. The existing AD, for 
certain Model 737-100, -200, and -200C series airplanes currently 
requires repetitive inspections of the aft end of each inboard flap 
track of the wing outboard flap, and corrective actions, if necessary. 
The existing AD, for certain Model 737-100, -200, -200C, -300, -400, 
and -500 series airplanes requires repetitive inspections for cracks in 
the upper flange of the inboard track at the rear spar attachments of 
each outboard flap, and corrective action, if necessary. That AD also 
requires, for certain airplanes, repetitive inspections for 
discrepancies of the rear spar attachments and cracks in the upper 
flange of the inboard track at the rear spar attachment of each 
outboard flap, and eventual rework of the flap track assembly and rear 
spar attachments, including replacement of the flap track with a new 
track, if necessary. Since we issued those ADs, we have received 
reports that the work sequence and procedures used during track 
installation could also cause loose or cracked tracks. This proposed AD 
would require an inspection for damage and stop-drill repairs along the 
flap track; an inspection for damage, cracking, and stop-drill repairs 
along the track webs; and an inspection for damage of the flap track 
web and flanges, and corrective actions if necessary. This proposed AD 
would also require, for certain airplanes, an inspection for signs of 
movement between the tapered shim and anti-fret strip, installation of 
the anti-fret strip, and corrosion of the tapered shim and anti-fret 
strip; an inspection for signs of movement, cracks and corrosion where 
the track is attached to the wing rear spar; an inspection for cracking 
of the outboard edge of the track; an inspection for cracking of the 
inner edge of the track; and related investigative and corrective 
actions if necessary. This proposed AD would also require repetitive 
overhauls of the flap track and repetitive post-overhaul inspections 
and corrective actions if necessary; an inspection to determine the 
part number of the flap track assembly, and replacement of affected 
parts if necessary; and would also add airplanes to the applicability. 
We are proposing this AD to detect and correct cracking and damage in 
the flap track, which could cause loss of the outboard trailing edge 
flap and consequent reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by November 26, 
2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, 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: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, P. 
O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, 
extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. 
You may review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For 
information on

[[Page 61543]]

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 Management Facility 
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 Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6440; fax 
425-917-6590; email: nancy.marsh@faa.gov.

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-2012-1068; 
Directorate Identifier 2011-NM-073-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 because of 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

    On December 5, 2000, we issued AD 2000-25-07, Amendment 39-12041 
(65 FR 78913, December 18, 2000), for certain Model 737-100, -200, and 
-200C series airplanes. That AD requires repetitive inspections of the 
aft end of each inboard flap track of the wing outboard flap, and 
corrective actions, if necessary. That AD resulted from reports of 
cracking of the aft end of an inboard flap track of the wing outboard 
flap found on a Model 737-200 series airplane having improved flap 
tracks installed. The inner and outer webs of the track, as well as the 
upper and lower flanges, were severed. We issued that AD to detect and 
correct damage of the aft end of each flap track, which could result in 
loss of the outboard trailing edge flap and consequent loss of 
controllability of the airplane.
    On March 8, 2002, we issued AD 2002-05-07, Amendment 39-12675 (67 
FR 11891, March 18, 2002), for certain Model 737-100, -200, -200C, -
300, -400, and -500 series airplanes. That AD requires, for certain 
airplanes, repetitive inspections for discrepancies of the rear spar 
attachments and cracks in the upper flange of the inboard track at the 
rear spar attachment of each outboard flap, and eventual rework of the 
flap track assembly and rear spar attachments, including replacement of 
the flap track with a new track, if necessary. For certain airplanes, 
that AD requires repetitive inspections for cracks in the upper flange 
of the inboard flap tracks at the rear spar attachments, and corrective 
action, if necessary. That AD resulted from several reports of cracking 
of the inboard track of the outboard flap. We issued that AD to detect 
and correct discrepancies of the inboard tracks of the outboard flaps, 
which could result in loss of the outboard trailing edge flaps and 
consequent reduced controllability of the airplane.

Actions Since Existing ADs 2000-25-07, Amendment 39-12041 (65 FR 78913, 
December 18, 2000); and 2002-05-07, Amendment 39-12675 (67 FR 11891, 
March 18, 2002); Were Issued

    Since we issued ADs 2000-25-07, Amendment 39-12041 (65 FR 78913, 
December 18, 2000); and 2002-05-07, Amendment 39-12675 (67 FR 11891, 
March 18, 2002); we have received reports that the work sequence and 
procedures used during track installation could also cause loose 
tracks, causing the track to move laterally at the rear spar joint when 
full torque is applied to the forward attach bolt, putting a side load 
on the inboard aft attach bolt. Because of friction caused by 
tightening to the specified torque value, the torque applied to the 
bolt is not sufficient to hold the track tight against the rear spar 
structure. Continued operation with a cracked or loose attachment at 
the rear spar could cause the track to break, which could result in the 
loss of the outboard trailing edge flap and consequent loss of 
controllability of the airplane.

Relevant Service Information

    We reviewed Boeing Service Bulletin 737-57A1271, Revision 3, dated 
February 13, 2012, for all Model 737-100, -200, -200C, -300, -400, and 
-500 series airplanes. This service information describes procedures 
for a detailed inspection for damage (cracks, nicks, corrosion pits, 
galling, pieces broken off) and stop-drill repairs along the full 
length of the upper and lower flanges of the flap track; a detailed 
inspection for damage, cracking, and stop-drill repairs along the full 
length of the track webs; an eddy current inspection for damage 
(including cracking) of the flap track web and flanges; and corrective 
actions if necessary. Corrective actions include repairing damage and 
replacing flap tracks.
    Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 
2012, also describes, for certain airplanes, procedures for a detailed 
inspection for signs of movement between the tapered shim and anti-fret 
strip installation of the anti-fret strip, and corrosion of the tapered 
shim and anti-fret strip; a detailed inspection for signs of movement, 
cracks and corrosion of the area where the track is attached to the 
wing rear spar; an eddy current inspection for cracking of the outboard 
edge of the track adjacent to the outboard attach bolt; an ultrasonic 
inspection for cracking of the inner edge of the track adjacent to the 
outboard attach bolt; and related investigative and corrective actions 
if necessary. The related investigative actions (which include 
disassembly of the flap track-to-wing attachment) include the following 
inspections.
     A detailed inspection of the anti-fret strip for signs 
that show the strip is loose or damaged and to determine if the anti-
fret strip is made of phenolic.
     A detailed inspection of the tapered shim for damage and 
corrosion, and to determine if the shim is made of laminated material 
and the shim width is less than 1.70 inches.
     A detailed inspection of the track in the area where it is 
fitted against the wing skin for corrosion on the surface and corrosion 
in the bolt holes.
     A detailed inspection of the bushing for corrosion.
     An eddy current inspection or magnetic particle inspection 
for cracking on the upper surface of the track flange adjacent to the 
inboard and outboard bolt holes.
     An eddy current inspection or magnetic particle inspection 
of the inboard and outboard bolt holes for cracking.
    The corrective actions include installing a new anti-fret strip, 
tapered shim, or bushing; removing or repairing corrosion; and removing 
damage and replacing the flap track.

[[Page 61544]]

    Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 
2012, also describes procedures for repetitive overhauls of the flap 
track and repetitive post-overhaul inspections and corrective actions 
if necessary.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs.

Proposed AD Requirements

    This proposed AD would retain all requirements of AD 2000-25-07, 
Amendment 39-12041 (65 FR 78913, December 18, 2000); and all 
requirements of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 
18, 2002). This proposed AD would require new inspections and overhauls 
of the flap track assembly. This proposed AD would also require 
accomplishing the actions specified in the service information 
described previously, except as discussed under ``Differences Between 
the AD and the Service Information.''

Changes to Existing ADs 2000-25-07 Amendment 39-12041 (65 FR 78913, 
December 18, 2000); and 2002-05-07 Amendment 39-12675 (67 FR 11891, 
March 18, 2002)

    Since ADs 2000-25-07 Amendment 39-12041 (65 FR 78913, December 18, 
2000); and 2002-05-07 Amendment 39-12675 (67 FR 11891, March 18, 2002); 
were issued, the AD format has been revised, and certain paragraphs 
have been re-arranged. As a result, the corresponding paragraph 
identifiers have changed in this proposed AD, as listed in the 
following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
   Requirement in previous ADs 2000-25-07
 Amendment 39-12041 (65 FR 78913, December    Corresponding  requirement
  18, 2000); and 2002-05-07 Amendment 39-        in this  proposed AD
    12675 (67 FR 11891, March 18, 2002)
------------------------------------------------------------------------
paragraph (a) of AD 2000-25-07, Amendment    paragraph (g).
 39-12041 (65 FR 78913, December 18, 2000).
paragraph (b) of AD 2000-25-07, Amendment    paragraph (i).
 39-12041 (65 FR 78913, December 18, 2000).
paragraph (a) of AD 2002-05-07, Amendment    paragraph (j).
 39-12675 (67 FR 11891, March 18, 2002).
paragraph (b) of AD 2002-05-07, Amendment    paragraph (l).
 39-12675 (67 FR 11891, March 18, 2002).
paragraph (c) of AD 2002-05-07, Amendment    paragraph (m).
 39-12675 (67 FR 11891, March 18, 2002).
paragraph (d) of AD 2002-05-07, Amendment    paragraph (n).
 39-12675 (67 FR 11891, March 18, 2002).
paragraph (e) of AD 2002-05-07, Amendment    paragraph (o).
 39-12675 (67 FR 11891, March 18, 2002).
------------------------------------------------------------------------

    The reference to ``the service bulletin'' in paragraph (e) of AD 
2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002) has been 
spelled out with the full citation, ``Boeing Service Bulletin 737-
57A1249, Revision 1, including Appendix A, dated June 1, 2000,'' in 
paragraph (o) of this proposed AD. Boeing Commercial Airplanes has 
received an Organization Designation Authorization (ODA). We have 
revised paragraphs (i) and (o) of this AD to delegate the authority to 
approve an alternative method of compliance for any repair required by 
this proposed AD to the Boeing Commercial Airplanes ODA rather than a 
Designated Engineering Representative (DER).
    Note 2 of AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 
18, 2000), has been changed to paragraph (h) of this proposed AD.
    Note 3 of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 
2002), has been changed to paragraph (k) of this proposed AD which 
provides credit for previous accomplishment of certain actions.
    We have also revised certain headings throughout this AD.

Differences Between the Proposed AD and the Service Information

    Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 
2012, specifies procedures to inspect for installation of an anti-fret 
strip but does not specify on-condition actions if the anti-fret strip 
is missing. If an anti-fret strip is not found installed, this proposed 
AD would require that the related investigative actions specified for 
anti-fret strips that have signs of damage or corrosion are done, and 
corrective actions if necessary, including making and installing a new 
anti-fret strip, are done in accordance with paragraph 3.B.5 of the 
Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, 
Revision 3, dated February 13, 2012.
    Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 
2012, specifies procedures to remove certain flap track assemblies if 
found. This proposed AD would require an inspection to determine the 
part number of the flap track assembly and replacement of affected 
parts if necessary.

Explanation of Change to Costs of Compliance

    Since issuance of AD 2002-05-07, Amendment 39-12041 (65 FR 78913, 
December 18, 2000), we have increased the labor rate used in the Costs 
of Compliance from $60 per work-hour to $85 per work-hour. The Costs of 
Compliance information, below, reflects this increase in the specified 
hourly labor rate.

Costs of Compliance

    We estimate that this proposed AD affects 570 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                       Parts                        Number of     Cost on U.S.
             Action                  Labor cost        cost      Cost per product   airplanes      operators
----------------------------------------------------------------------------------------------------------------
Detailed visual inspection       6 work-hours x             $0  $510.............         290  $147,900.
 [retained actions from           $85 per hour =
 existing AD 2000-25-07,          $510.
 Amendment 39-12041 (65 FR
 78913, December 18, 2000)].

[[Page 61545]]

 
Detailed visual, HFEC, and       4 work-hours x             $0  $340.............       1,100  $374,000.
 ultrasonic inspections           $85 per hour =
 [retained actions from           $340.
 existing AD 2002-05-07,
 Amendment 39[dash]12675 (67 FR
 11891, March 18, 2002)].
Detailed and eddy current        82 work-hours x            $0  $6,970 per                570  $3,972,900 per
 inspections [new proposed        $85 per hour =                 inspection cycle.              inspection
 actions].                        $6,970 per                                                    cycle.
                                  inspection cycle.
Overhaul [new proposed action].  70 work-hours x       $20,000  $25,950 per               570  $14,791,500 per
                                  $85 per hour =                 overhaul cycle.                overhaul cycle.
                                  5,950 per
                                  overhaul cycle.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for labor cost for repair, and parts cost for repair and 
replacement for the on-condition actions specified in this proposed AD. 
The labor cost of the replacement is $1,360 (16 work-hours x $85 per 
hour). We have no way of determining the number of aircraft that might 
need these repairs/replacements.

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 have 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 that the 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.

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 removing airworthiness directives 
(AD) 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000); 
and 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002); and 
adding the following new AD:

The Boeing Company: Docket No. FAA-2012-1068; Directorate Identifier 
2011-NM-073-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by November 26, 
2012.

(b) Affected ADs

    This AD supersedes ADs 2000-25-07, Amendment 39-12041 (65 FR 
78913, December 18, 2000); and 2002-05-07, Amendment 39-12675 (67 FR 
11891, March 18, 2002).

(c) Applicability

    This AD applies to all The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, certificated in any 
category.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by reports that the work sequence and 
procedures used during installation of replacement tracks installed 
in accordance with AD 2000-25-07, Amendment 39-12041 (65 FR 78913, 
December 18, 2000); or AD 2002-05-07, Amendment 39-12675 (67 FR 
11891, March 18, 2002); could cause loose or cracked tracks. We are 
issuing this AD to detect and correct cracking and damage in the 
flap track, which could cause loss of the outboard trailing edge 
flap and consequent reduced controllability of the airplane.

(f) Compliance

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

(g) Retained Repetitive Inspections

    This paragraph restates the inspection required by paragraph (a) 
of AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 
2000), with added references to a terminating action. For Model 737-
100, -200, and -200C series airplanes on which the left- or right-
hand inboard flap tracks of the wing outboard flap have a part 
number (P/N) listed in Table 1 of this AD: Do a detailed visual 
inspection to detect damage (corrosion, cracking) of the aft end of 
the left- and right-hand inboard flap tracks of the wing outboard 
flap, per Boeing All Operator Message (AOM) M-7200-00-01854, dated 
July 27, 2000, at the latest of the times specified in paragraphs 
(g)(1), (g)(2), and (g)(3) of this AD. Repeat the inspection 
thereafter at intervals not to exceed 1,200 flight cycles. 
Accomplishing the requirements of paragraph (p) of this AD 
terminates the requirements of this paragraph.

             Table 1--Boeing Flap Tracks Subject to This AD
------------------------------------------------------------------------
                         Name                               Part No.
------------------------------------------------------------------------
Boeing...............................................         65-46428-9
                                                             65-46428-15

[[Page 61546]]

 
                                                             65-46428-17
                                                             65-46428-19
                                                             65-46428-21
                                                             65-46428-23
                                                             65-46428-25
                                                             65-46428-27
                                                             65-46428-33
                                                             65-46428-35
------------------------------------------------------------------------

     (1) Within 30 days after January 2, 2001 (the effective date of 
AD 2000-25-07 Amendment 39-12041 (65 FR 78913, December 18, 2000)).
    (2) Within 1,200 flight cycles after the last documented 
inspection or overhaul of the aft end of each flap track.
    (3) Before the accumulation of 15,000 total flight cycles.

(h) Retained Definition

    This paragraph restates the definition specified by Note 2 of AD 
2000-25-07 Amendment 39-12041 (65 FR 78913, December 18, 2000). For 
the purposes of this AD, a detailed visual inspection is defined as: 
``An intensive visual examination of a specific structural area, 
system, installation, or assembly to detect damage, failure, or 
irregularity. Available lighting is normally supplemented with a 
direct source of good lighting at an intensity deemed appropriate by 
the inspector. Inspection aids such as a mirror, magnifying lenses, 
etc., may be used. Surface cleaning and elaborate access procedures 
may be required.''

(i) Retained Corrective Actions

    This paragraph restates the corrective actions required by 
paragraph (b) of AD 2000-25-07, Amendment 39-12041 (65 FR 78913, 
December 18, 2000), with added reference to organization designation 
authorization (ODA). If any damage (corrosion, cracking) is detected 
during any inspection required by paragraph (g) of this AD, before 
further flight, repair or rework the flap track per the ``Repair and 
Rework Instructions'' specified in Boeing AOM M-7200-00-01854, dated 
July 27, 2000. Where that AOM specifies that the manufacturer may be 
contacted for disposition of certain corrective actions (i.e., 
repair and/or rework of the flaps), this AD requires such repair 
and/or rework to be done per a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO), FAA; or per data 
meeting the type certification basis of the airplane approved by a 
Boeing Company designated engineering representative (DER) or the 
Boeing Commercial Airplanes ODA who has been authorized by the 
Manager, Seattle ACO, to make such findings. For a repair method to 
be approved by the ODA, the repair must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD. For a repair method to be approved by the Manager, Seattle ACO, 
as required by this paragraph, the Manager's approval letter must 
specifically reference this AD.

(j) Retained Initial Inspections

    This paragraph restates the initial inspection required by 
paragraph (a) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, 
March 18, 2002), with added references to terminating action. For 
Model 737-100, -200, and -200C series airplanes with line numbers 
(L/N) 1 through 869 inclusive, and those airplanes with L/Ns 870 
through 1585 inclusive, which either still have their original flap 
tracks or which have had the original flap tracks replaced with 
certain tracks as specified in Boeing Service Bulletin 737-57A1249, 
Revision 1, including Appendix A, dated June 1, 2000; except 
airplanes on which any replacement flap tracks were installed as 
specified in Boeing Service Bulletin 737-57-1203, dated November 15, 
1990, or production equivalent: Within 6 months after April 22, 2002 
(the effective date of AD 2002-05-07, Amendment 39-12675 (67 FR 
11891, March 18, 2002)), accomplish the requirements of paragraphs 
(j)(1) and (j)(2) of this AD, according to Boeing Service Bulletin 
737-57A1249, Revision 1, including Appendix A, dated June 1, 2000. 
Accomplishing the requirements of paragraph (p) of this AD 
terminates the requirements of this paragraph.
    (1) Perform a detailed visual inspection for discrepancies 
(e.g., corrosion, or missing, damaged, or migrated anti-fret strips 
and tapered shims) of the rear spar attachments of the flap tracks.
    (2) Perform detailed visual, high frequency eddy current (HFEC), 
and ultrasonic inspections for cracking in the upper flange of the 
inboard track of each outboard flap at the rear spar attachments.

(k) Retained Credit for Previous Actions

    This paragraph restates the credit for certain previously 
accomplished actions specified by Note 3 of AD 2002-05-07, Amendment 
39-12675 (67 FR 11891, March 18, 2002). This paragraph provides 
credit for the actions specified in paragraphs (j), (l), (m), and 
(n) of this AD, if those actions were performed before the effective 
date of this AD using Boeing Alert Service Bulletin 737-57A1249, 
including Appendix A, dated December 16, 1999.

(l) Retained Repetitive Inspections

    This paragraph restates the repetitive inspections required by 
paragraph (b) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, 
March 18, 2002). For airplanes subject to the requirements of 
paragraph (j) of this AD: If no discrepancy is found during any 
inspection required by paragraph (j) of this AD, thereafter, repeat 
the inspections specified in paragraph (j) of this AD at intervals 
not to exceed 9 months, until the actions required by paragraph (m) 
or (p) of this AD have been accomplished.

(m) Retained Rework

    This paragraph restates the rework required by paragraph (c) of 
AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). For 
airplanes subject to the requirements of paragraph (j) of this AD: 
At the applicable time specified in paragraph (m)(1) or (m)(2) of 
this AD, accomplish rework of the flap track assembly and aft flap 
track attachments (including removal of the flap track; a detailed 
visual inspection for a missing, damaged, or migrated anti-fret 
strip and tapered shim of the rear spar attachments of the flap 
track; replacement of the anti-fret strip with a new aluminum anti-
fret strip (or installation of an aluminum strip if no strip is 
installed), as applicable; replacement of the tapered shim with a 
new shim (or installation of a shim if no shim is installed); eddy 
current and ultrasonic inspections for fatigue cracking of the flap 
tracks; a detailed visual inspection for corrosion of the flap 
tracks; and rework of attachment holes), including replacement of 
the flap tracks, as applicable, by accomplishing all actions 
specified in Part II of the Accomplishment Instructions of Boeing 
Service Bulletin 737-57A1249, Revision 1, including Appendix A, 
dated June 1, 2000. Do these actions according to the Accomplishment 
Instructions of Boeing Service Bulletin 737-57A1249, Revision 1, 
including Appendix A, dated June 1, 2000, except as provided by 
paragraph (o) of this AD. Accomplishment of the actions required by 
this paragraph terminates the repetitive inspections required by 
paragraph (l) of this AD. Accomplishing the requirements of 
paragraph (p) of this AD terminates the requirements of this 
paragraph.
    (1) If no discrepancy is found during any inspection required by 
paragraph (j) or (l) of this AD: Do the rework within 24 months 
after April 22, 2002 (the effective date of AD 2002-05-07, Amendment 
39-12675 (67 FR 11891, March 18, 2002).
    (2) If any discrepancy is found during any inspection required 
by paragraph (j) or (l) of this AD: Do the rework prior to further 
flight.

(n) Retained Repetitive Inspections

    This paragraph restates the repetitive inspections required by 
paragraph (d) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, 
March 18, 2002). For Model 737-100, -200, -200C, -300, -400, and -
500 series airplanes, except airplanes on which any replacement flap 
tracks were installed as specified in Boeing Service Bulletin 737-
57-1203, dated November 15, 1990, or production equivalent: At the 
applicable time specified in paragraph (n)(1) or (n)(2) of this AD, 
and thereafter at least every 24 months, perform detailed visual, 
HFEC, and ultrasonic inspections for cracking in the upper flange of 
the inboard track of each outboard flap at the rear spar 
attachments, according to Part I of the Accomplishment Instructions 
of Boeing Service Bulletin 737-57A1249, Revision 1, including 
Appendix A, dated June 1, 2000. Accomplishing the requirements of 
paragraph (p) of this AD terminates the requirements of this 
paragraph.
    (1) For airplanes subject to paragraph (m) of this AD, do the 
inspections within 10 years after accomplishment of the rework 
according to paragraph (m) of this AD.
    (2) For airplanes other than those identified in paragraph 
(n)(1) of this AD, do the inspections within 10 years since the 
airplane's date of manufacture, or within 6 months after April 22, 
2002 (the effective date of AD 2002-05-07, Amendment 39-

[[Page 61547]]

12675 (67 FR 11891, March 18, 2002), whichever occurs later.

(o) Retained Repair Instructions and Exception to Procedures in Service 
Information

    This paragraph restates the repair instructions and exception to 
procedures required by paragraph (e) of AD 2002-05-07, Amendment 39-
12675 (67 FR 11891, March 18, 2002). If any discrepancy is found 
during any action required by paragraph (j), (l), or (m) of this AD, 
and Boeing Service Bulletin 737-57A1249, Revision 1, including 
Appendix A, dated June 1, 2000, specifies to contact Boeing for 
appropriate action; or if any discrepancy is found during 
inspections according to paragraph (n) of this AD: Prior to further 
flight, repair according to a method approved by the Manager, 
Seattle ACO, FAA; or according to data meeting the type 
certification basis of the airplane approved by a Boeing Company DER 
or ODA who has been authorized by the Manager, Seattle ACO, to make 
such findings. For a repair method to be approved by the ODA, the 
repair must meet the certification basis of the airplane, and the 
approval must specifically refer to this AD. For a repair method to 
be approved by the Manager, Seattle ACO, as required by this 
paragraph, the approval letter must specifically reference this AD.

(p) New Inspection of Flap Track Web and Flanges

    For all airplanes: At the times specified in paragraph (q) of 
this AD: Do the inspections specified in paragraphs (p)(1), (p)(2), 
(p)(3), and (p)(4) of this AD, and do all applicable corrective 
actions, in accordance with paragraph 3.B.3. of the Accomplishment 
Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, 
dated February 13, 2012, except as required by paragraphs (r) and 
(v) of this AD. Performing these inspections terminates the 
requirements of paragraphs (g), (j) and (n) of this AD. Do all 
applicable corrective actions before further flight.
    (1) Detailed inspection for damage (cracks, nicks, corrosion 
pits, galling, pieces broken off) and stop-drill repairs along the 
full length of the upper and lower flanges of the flap track.
    (2) Detailed inspection for damage, cracking, and stop-drill 
repairs along the full length of the track webs.
    (3) Eddy current inspection for damage (including cracking) of 
the flap track web and flanges.
    (4) Inspection to determine the part number of the flap track 
assembly.

(q) New Compliance Time

    At the latest of the applicable times specified in paragraphs 
(q)(1), (q)(2), and (q)(3) of this AD, do the actions required by 
paragraph (p) of this AD.
    (1) Within 96 months since the flap track was new or overhauled, 
or prior to the accumulation of 15,000 flight cycles on the flap 
track since new or overhauled; whichever occurs first.
    (2) Within 180 days after the effective date of this AD.
    (3) Within 24 months after the most recent inspection was 
performed in accordance with Part 1 of the Accomplishment 
Instructions of Boeing Service Bulletin 737-57A1249, including 
Appendix A, dated December 16, 1999; or Revision 1, including 
appendix A, dated June 1, 2000.

(r) Replacement

    If, during any inspection required by paragraph (p) of this AD, 
any flap track assembly having P/N 65-46428-31 or 65-46428-33 is 
found, before further flight, replace the flap track assembly with a 
new or serviceable flap track assembly, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, 
Revision 3, dated February 13, 2012, except as required by paragraph 
(v) of this AD.

(s) New Inspections of Flap-to-Wing Attachment if Repairs Are Done or 
if No Damage Is Found in Flap Track Web and Flanges

    For airplanes on which no damage is found in the flanges or the 
Web during any inspection required by paragraph (p) of this AD; and 
for airplanes on which a repair is done during any corrective action 
required by (p) of this AD; before further flight, do the 
inspections specified in paragraphs (s)(1) through (s)(4) of this 
AD, and do all applicable related investigative and corrective 
actions, in accordance with paragraphs 3.B.4 and 3.B.5 of the 
Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, 
Revision 3, dated February 13, 2012, except as required by paragraph 
(v) of this AD. If, during the inspection required by paragraph 
(s)(1) of this AD, an anti-fret strip is not found installed, before 
further flight, do the related investigative actions specified in 
Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 
2012, for an anti-fret strip that has signs of damage or corrosion 
and do all applicable corrective actions, including making and 
installing a new anti-fret strip, in accordance with paragraph 3.B.5 
of the Accomplishment Instructions of Boeing Service Bulletin 737-
57A1271, Revision 3, dated February 13, 2012, except as required by 
paragraph (v) of this AD. Do all applicable related investigative 
and corrective actions before further flight.
    (1) Detailed inspection for signs of movement between the 
tapered shim and anti-fret strip, installation of the anti-fret 
strip, and corrosion of the tapered shim and anti-fret strip.
    (2) Detailed inspection for signs of movement, cracks and 
corrosion of the area where the track is attached to the wing rear 
spar.
    (3) High frequency eddy current inspection for cracking of the 
outboard edge of the track adjacent to the outboard attach bolt.
    (4) Ultrasonic inspection for cracking of the inner edge of the 
track adjacent to the outboard attach bolt.

(t) New Overhaul

    Within 10,000 flight cycles on the flap track or 48 months, 
whichever occurs first after accomplishing the inspection required 
by paragraph (p) of this AD: Do an overhaul of the flap track, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 737-57A1271, Revision 3, dated February 13, 2012, except as 
required by paragraph (v) of this AD. Repeat the overhaul thereafter 
at intervals not to exceed 20,000 flight cycles on the flap track or 
96 months, whichever occurs first.

(u) New Post Overhaul Inspections

    For airplanes on which any overhaul required by paragraph (t) of 
this AD is done: Do the inspections specified in paragraph (p) of 
this AD within 10,000 flight cycles on the flap track or 48 months 
after the most recent overhaul, whichever occurs first. Repeat the 
inspections specified in paragraph (p) of this AD thereafter at 
intervals not to exceed 10,000 flight cycles on the flap track or 48 
months, whichever occurs first; except if an overhaul required by 
paragraph (t) of this AD is done, do the next inspection within 
10,000 flight cycles or 48 months, whichever occurs first, after the 
overhaul.

(v) Service Information Exception

    Where Boeing Service Bulletin 737-57A1271, Revision 3, dated 
February 13, 2012, specifies to contact Boeing for appropriate 
action: Before further flight, repair using a method approved in 
accordance with the procedures specified in paragraph (y) of this 
AD.

(w) New Parts Installation Prohibition

    As of the effective date of this AD, no person may install a 
flap track assembly, P/N 65-46428-31 or 65-46428-33, on any 
airplane.

(x) Credit for Previous Actions

    This paragraph provides credit for the actions specified in 
paragraphs (p) through (t) of this AD, if those actions were 
performed before the effective date of this AD, using the service 
bulletins specified in paragraph (x)(1), (x)(2), or (x)(3) of this 
AD.
    (1) Boeing Alert Service Bulletin 737-57A1271, dated September 
11, 2003, which is not incorporated by reference.
    (2) Boeing Service Bulletin 737-57A1217, Revision 1, dated July 
30, 2008, which is not incorporated by reference.
    (3) Boeing Service Bulletin 737-51A1217, Revision 2, dated 
January 17, 2011, which is not incorporated by reference.

(y) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO, 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 the attention of the person identified in the 
Related Information section of this AD. Information may be emailed 
to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) 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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD if it is approved by The

[[Page 61548]]

Boeing Commercial Airplanes ODA that has been authorized by the 
Manager, Seattle ACO to make those findings. For a repair method to 
be approved, the repair must meet the certification basis of the 
airplane, and the approval must specifically refer to this AD.
    (4) AMOCs approved previously in accordance with ADs 2000-25-07, 
Amendment 39-12041 (65 FR 78913, December 18, 2000); and 2002-05-07, 
Amendment 39-12675 (67 FR 11891, March 18, 2002); are approved as 
AMOCs for the corresponding requirements of this AD.

(z) Related Information

    (1) For more information about this AD, contact Nancy Marsh, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; 
phone: 425-917-6440; fax: 425-917-6590; email: nancy.marsh@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced 
service information at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, WA. For information on the availability of 
this material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on September 27, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-24809 Filed 10-9-12; 8:45 am]
BILLING CODE 4910-13-P