Document ID: FAA-2012-0492-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Model 747 Airplanes
Posted Date: 2012-05-31T04:00Z

[Federal Register Volume 77, Number 105 (Thursday, May 31, 2012)]
[Proposed Rules]
[Pages 32064-32069]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-13187]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0492; Directorate Identifier 2010-NM-126-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Model 747 Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to certain The Boeing Company Model 747 airplanes. 
The existing AD currently requires repetitive visual inspections around 
the bushings of the wing landing gear (WLG) beam outboard end fittings 
for corrosion, and rework if necessary; and ultrasonic inspections for 
cracks of the outboard end fittings of the WLG support beams, and 
rework if necessary. Since we issued that AD, there have been new 
reports of corrosion damage to the end fittings of the WLG support 
beams, and one report of subsequent cracking in the end fittings. This 
proposed AD would add airplanes and repetitive inspections of the 
outboard end fitting of the left and right WLG support beams for cracks 
and corrosion, and corrective actions if necessary. We are proposing 
this AD to detect and correct corrosion and subsequent cracking in the 
outboard end fittings, which could result in separation of the fitting 
and damage to adjacent flight control cables and hydraulic systems and 
consequent reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by July 16, 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 20590, 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, Washington 98124-2207; telephone 206-
544-5000, extension 1, fax 206-766-5680; email me.boecom@boeing.com; 
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, 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 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 (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Bill Ashforth, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: (425) 917-
6432; fax: (425) 917-6590; email: bill.ashforth@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-2012-0492; 
Directorate Identifier 2010-NM-126-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 July 7, 1989, we issued AD 89-15-07, amendment 39-6267 (54 FR 
30009, July 18, 1989), for certain Model 747 airplanes. That AD 
requires visual inspections around the bushings of the wing landing 
gear for corrosion, and repair if necessary, and ultrasonic inspections 
for cracks of the outboard end fittings of the WLG support beams, and 
overhaul if necessary. That AD resulted from a report of a fracture of 
the outboard end fitting of a left WLG beam. We issued that AD to 
prevent failure of the outboard end fitting of a WLG beam with possible 
damage to control cables or hydraulic lines in the area of the landing 
gear beam.

[[Page 32065]]

Actions Since Existing AD Was Issued

    Since we issued AD 89-15-07, amendment 39-6267 (54 FR 30009, July 
18, 1989), we have received new reports of corrosion damage to the end 
fittings of the WLG support beams, and one report of subsequent 
cracking in the end fittings. The end fittings are installed on the 
outboard ends of the WLG support beams, and they attach to gate 
fittings installed on the rear wing spars. There are two types of end 
fittings used--one is a two-piece end fitting installed in a ``back to 
back'' configuration; the other is a one-piece end fitting.
    Boeing Service Bulletin 747-57-2244, Revision 1, dated July 28, 
1988, was referred to in the existing AD for accomplishing the required 
actions on Model 747 airplanes having line numbers 1 through 695. The 
terminating action specified in that service bulletin involves 
replacing each of the end fitting lug bore and bolt hole bushings with 
new standard or oversize bushings which are installed with sealant to 
provide better corrosion prevention. That terminating action was 
incorporated into the design of replacement fittings used on production 
airplanes having line numbers 696 and subsequent.
    Although the terminating action seemed to work well on airplanes 
having line numbers 1 through 695, recent reports from operators of 
airplanes having line numbers 696 and subsequent revealed that the 
problem occurred again. Further investigation revealed that the 
corrosion started at the lug bore and bushing interface because 
moisture continued to develop in that area due to exposure of the end 
fittings to environmental conditions. Subsequently, cracks have 
occurred at the corroded areas of the end fittings; therefore, the 
terminating action in that service bulletin is no longer valid because 
the unsafe condition specified in the existing AD has not been 
corrected.

Relevant Service Information

    Since the issuance of AD 89-15-07, amendment 39-6267 (54 FR 30009, 
July 18, 1989), Boeing has issued Alert Service Bulletin 747-57A2331, 
dated November 12, 2009. This new service information is applicable to 
Model 747 airplanes having line numbers 1 through 1419 inclusive, which 
includes airplanes on which the terminating action in AD 89-15-07 was 
done.
    We have reviewed Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009. This service bulletin describes procedures for 
repetitive detailed and ultrasonic inspections, as applicable, for 
cracks and corrosion of the end fittings of the left and right WLG 
support beams; and repetitive detailed inspections of the fillet seal 
for damage, as applicable. The service information describes necessary 
actions and options after accomplishing the inspections, depending on 
the findings and configurations. Those actions and options (including 
Options 1A and 1B) include the following:
     Repairing or changing each end fitting (by installing 
higher interference fit bushings on the end fitting), which is 
identified as ``Part 7'' of this service bulletin, may be done in lieu 
of the inspections described previously, but is necessary for findings 
of cracks or corrosion.
     Repetitively inspecting, as described previously, along 
with an additional inspection of the fillet seal for damage; and 
applying corrosion inhibiting compound or doing ``Part 7'' of this 
service bulletin, if necessary.
     Doing ``Post-Part 7 inspections,'' which involves actions 
similar to the inspections for cracks, corrosion, and damage described 
previously.
    The recommended compliance times follow:
     Detailed and ultrasonic inspections: The initial 
compliance time for these inspections depends on configuration, and is 
either (1) 8 years on the end fitting and 18 months after the date on 
this service bulletin (whichever is later); or (2) 10 years on the end 
fitting and 24 months after the date on this service bulletin 
(whichever is later). The repetitive interval also depends on 
configurations and findings, and ranges between 12 and 24 months.
     ``Part 7'' of this service bulletin: The initial 
compliance time is the later of 20,000 total flight cycles on an end 
fitting, and either 18 or 24 months (depending on configuration). The 
repetitive interval is either 13,000 or 16,000 flight cycles on an end 
fitting; depending on configuration.
     ``Post-Part 7'' inspections: The compliance time is 12 
years after the repair or change. The subsequent repetitive intervals 
range between 12 months and 36 months, depending on findings and 
configurations.
    For airplanes on which any crack, corrosion, or damage is found, 
the compliance time for ``Part 7'' or application of corrosion 
inhibitor is before further flight.

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 the same type design.

Proposed AD Requirements

    This proposed AD would retain certain requirements of the existing 
AD. This proposed AD would also add airplanes and require accomplishing 
the actions specified in the service information described previously.

Changes to Existing AD

    We have changed the applicability of AD 89-15-07, amendment 39-6267 
(54 FR 30009, July 18, 1989), in this proposed AD to identify model 
designations as published in the most recent type certificate data 
sheet for the affected models. We have also changed the legal name of 
the manufacturer as published in the most recent type certificate data 
sheet for the affected airplane models.
    This proposed AD would retain certain requirements of AD 89-15-07, 
amendment 39-6267 (54 FR 30009, July 18, 1989). Since AD 89-15-07 was 
issued, the AD format has been revised, and certain paragraphs have 
been rearranged. As a result, the corresponding paragraph identifiers 
have changed in this proposed AD, as listed in the following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
    Requirement in AD 89-15-07,
  Amendment 39-6267 (54 FR 30009,     Corresponding  requirement in this
           July 18, 1989)                        proposed AD
------------------------------------------------------------------------
            paragraph A                        paragraph (g)
            paragraph B                     paragraph (g)(1)
             paragraph C                    paragraph (g)(2)
            paragraph D                     paragraph (g)(3)
------------------------------------------------------------------------

    In addition, we have revised paragraph (g)(3) of this proposed AD 
(which was designated as paragraph D. in the existing AD) to require 
that if any corrosion is found after the effective date of this 
proposed AD, rework is required before further flight. We have reduced 
the compliance time to do the rework from ``within 12 months'' to 
``before further flight'' because extensive service history has shown 
that the deferral of known airplane damage such as cracks and corrosion 
has not provided an acceptable level of safety. Service history has 
shown that the extent of damage from unrepaired corrosion can not 
reliably be determined by inspection techniques. The damaged corroded 
material must first be removed and only then can the remaining material 
dimensions be accurately compared to the allowable damage limits. The 
extent of unrepaired corrosion damage can not be accurately

[[Page 32066]]

determined by current inspection methods. Further, the reliance for 
operation with known damage is predicated on the adjacent and 
associated structure being free from other damage during this time 
period, which has not been demonstrated by older airplanes.
    Depending on airplane configuration, the new proposed inspections 
would take between 1 and 4 work hours per airplane, at an average labor 
rate of $85 per work hour. Based on these figures, the estimated cost 
of the new inspections specified in this proposed AD for U.S. operators 
is between $14,705 and $58,820, or between $85 and $340 per airplane, 
per inspection cycle.

Difference Between the Proposed AD and the Service Information

    Operators should note that Conditions 6, 13, and 16 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 747-57A2331, 
dated November 12, 2009, specify a detailed inspection. However, the 
corresponding conditions in the Accomplishment Instructions of this 
service bulletin specify both detailed and high frequency eddy current 
(HFEC) inspections. We have confirmed with Boeing that its intent is 
that this service bulletin specify only a detailed inspection for those 
conditions.

Costs of Compliance

    We estimate that this proposed AD affects 173 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                  Cost per
            Action                Labor cost      Parts cost      product           Cost on U.S.  operators
----------------------------------------------------------------------------------------------------------------
Inspections [retained actions  10 work-hours x            $0  $850 per         $147,050 per inspection cycle.
 from existing AD 89-15-07,     $85 per hour =                 inspection
 amendment 39-6267 (54 FR       $850 per                       cycle.
 30009, July 18, 1989)].        inspection
                                cycle.
Inspections [new proposed      Up to 67 work-              0  Up to $5,695     Up to $985,235 per inspection
 action].                       hours x $85 per                per inspection   cycle, depending on
                                hour = $5,695                  cycle,           configuration.
                                per inspection                 depending on
                                cycle,                         configuration.
                                depending on
                                configuration.
----------------------------------------------------------------------------------------------------------------

     We estimate the following costs to do any necessary repairs/
replacements that would be required based on the results of the 
proposed inspection. We have no way of determining the number of 
aircraft that might need these repairs/replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
             Action                     Labor cost            Parts cost               Cost per product
----------------------------------------------------------------------------------------------------------------
Repair or replacement..........  Up to 71 work-hours x    Up to $26,436,     Up to $32,471, depending on
                                  $85 per hour = $6,035,   depending on       configuration.
                                  depending on             configuration.
                                  configuration.
----------------------------------------------------------------------------------------------------------------

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.

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 directive 
(AD) 89-15-07, Amendment 39-6267 (54 FR 30009, July 18, 1989), and 
adding the following new AD:

The Boeing Company: Docket No. FAA-2012-0492; Directorate Identifier 
2010-NM-126-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by July 16, 
2012.

[[Page 32067]]

(b) Affected ADs

    This AD supersedes AD 89-15-07, Amendment 39-6267 (54 FR 30009, 
July 18, 1989).

(c) Applicability

    This AD applies to The Boeing Company Model 747-100, 747-100B, 
747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-
400D, 747-400F, 747SR, and 747SP series airplanes; certificated in 
any category; as identified in Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by new reports of corrosion damage to the 
end fittings of the wing landing gear (WLG) support beams, and one 
report of subsequent cracking in the end fittings. We are issuing 
this AD to detect and correct corrosion and subsequent cracking in 
the outboard end fittings, which could result in separation of the 
fitting and damage to adjacent flight control cables and hydraulic 
systems and consequent 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) Retained Repetitive Inspections With Revised Compliance Times

    This paragraph restates the requirements of paragraphs A., B., 
C., and D., of AD 89-15-07, Amendment 39-6267 (54 FR 30009, July 18, 
1989): For airplanes identified in Boeing Service Bulletin 747-57-
2244, Revision 1, dated July 28, 1988: Prior to the accumulation of 
30,000 flight hours or 8 years in service, whichever occurs first; 
or within the next 14 months after August 22, 1989 (the effective 
date of AD 89-15-07); whichever occurs later; visually inspect 
around the fitting lug bushings at the wing landing gear (WLG) beam 
outboard end fittings for corrosion, and ultrasonically inspect the 
WLG beam outboard end fittings for cracks, in accordance with Boeing 
Service Bulletin 747-57-2244, Revision 1, dated July 28, 1988. 
Accomplishing the initial inspections required by paragraph (j) of 
this AD terminates the inspections required by this paragraph.
    (1) If no cracking or corrosion is found, repeat the inspections 
at intervals not to exceed 18 months until paragraph (j) of this AD 
has been accomplished.
    (2) If cracking is found, prior to further flight, remove the 
WLG beam outboard fitting, and rework, in accordance with Boeing 
Service Bulletin 747-57-2244, Revision 1, dated July 28, 1988.
    (3) If only corrosion is found, within the next 12 months, 
rework in accordance with Boeing Service Bulletin 747-57-2244, 
Revision 1, dated July 28, 1988. The ultrasonic inspections for 
cracks required by paragraph (g) of this AD must be accomplished at 
intervals not to exceed 6 months until the rework is accomplished. 
For any corrosion that is found after the effective date of this AD, 
the rework must be done before further flight.

(h) Retained Terminating Action

    This paragraph restates the requirements of paragraph E., of AD 
89-15-07, Amendment 39-6267 (54 FR 30009, July 18, 1989): 
Terminating action for the inspections required by paragraph (g) of 
this AD consists of rework of the WLG beam outboard fittings, in 
accordance with Boeing Service Bulletin 747-57-2244, Revision 1, 
dated July 28, 1988.

(i) New Compliance Times for This AD

    For all the actions identified in paragraphs (j) through (t) of 
this AD, do the actions at the applicable time specified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009. Where paragraph 1.E., 
``Compliance'' of this service bulletin specifies a compliance time 
relative to the original issue date of the service bulletin, this AD 
requires compliance within the specified compliance time after the 
effective date of this AD.

(j) New Repetitive Inspections for Groups 1 Through 5 Airplanes

    For Groups 1 through 3 airplanes, Configurations 1 and 2; and 
Groups 4 and 5 airplanes: Do detailed and ultrasonic inspections of 
the end fittings for cracks and corrosion, in accordance with Part 1 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009.

(k) New Inspections for No Crack or Corrosion Findings for Groups 1 
Through 5 Airplanes

    If no crack or corrosion is found during any inspection required 
by paragraph (j) of this AD, do either of the actions required by 
paragraph (k)(1) or (k)(2) of this AD.
    (1) Repeat the detailed and ultrasonic inspections of the end 
fittings for cracks and corrosion, in accordance with Part 1 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.
    (2) Do a detailed inspection of the end fittings for fillet seal 
damage and for cracks and corrosion, in accordance with Part 2 of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009.
    (i) If no fillet seal damage, crack, or corrosion is found: 
Repeat the inspection required by paragraph (k)(2) of this AD.
    (ii) If any fillet seal damage is found, but no crack or 
corrosion is found: Remove the fillet seal, and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 2 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (A) If any crack or corrosion is found: Repair or change the end 
fitting, in accordance with paragraph (l) of this AD.
    (B) If no crack or corrosion is found: Apply corrosion 
inhibiting compound on each end fitting, in accordance with Part 2 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009; and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 3 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (1) If no crack or corrosion is found: Apply corrosion 
inhibiting compound on each end fitting, in accordance with Part 3 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009, and thereafter repeat the 
inspections required by paragraph (k)(2)(ii)(B) of this AD.
    (2) If any crack or corrosion is found: Repair or change the end 
fitting, in accordance with paragraph (l) of this AD.

(l) New Repair for Crack or Corrosion Findings for Groups 1 Through 5 
Airplanes

    If any crack or corrosion is found during any inspection 
required by paragraph (j) or (k) of this AD: Repair or change the 
end fitting, in accordance with Part 7 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009. After accomplishing the repair or change in 
accordance with Part 7 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009, do the 
applicable actions required by paragraph (j) of this AD.

(m) New Repetitive Inspections and Corrective Actions for Group 6 
Airplanes

    For Group 6 airplanes: Do a detailed inspection of the end 
fittings for fillet seal damage and for cracks and corrosion, in 
accordance with Part 1 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (1) If no fillet seal damage, crack, or corrosion is found: Do 
the detailed inspection of the end fittings for fillet seal damage 
and for cracks and corrosion, in accordance with Part 2 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.
    (i) If no fillet seal damage, crack, or corrosion is found: 
Repeat the detailed inspection required by paragraph (m)(1) of this 
AD.
    (ii) If any fillet seal damage is found, but no crack or 
corrosion is found: Remove the fillet seal, and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 2 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (A) If any crack or corrosion is found: Repair or change the end 
fitting, in accordance with paragraph (n) of this AD.
    (B) If no crack or corrosion is found: Apply corrosion 
inhibiting compound on each end fitting, in accordance with Part 2 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009; and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part

[[Page 32068]]

3 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-57A2331, dated November 12, 2009.
    (1) If any crack or corrosion is found: Repair or change the end 
fitting, in accordance with paragraph (n) of this AD.
    (2) If no crack or corrosion is found: Apply corrosion 
inhibiting compound, in accordance with Part 3 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009, and thereafter repeat the inspections required by 
paragraph (m)(1)(ii)(B) of this AD.
    (2) If any fillet seal damage is found, but no crack or 
corrosion is found: Remove the fillet seal, and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 1 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (i) If any crack or corrosion is found: Repair or change the end 
fitting, in accordance with paragraph (n) of this AD.
    (ii) If no crack or corrosion is found: Apply corrosion 
inhibiting compound on each end fitting, in accordance with Part 1 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009; and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 3 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (A) If any crack or corrosion is found: Repair or change the end 
fitting, in accordance with paragraph (n) of this AD.
    (B) If no crack or corrosion is found: Apply corrosion 
inhibiting compound, in accordance with Part 3 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009, and thereafter repeat the inspections required by 
paragraph (m)(2)(ii) of this AD.

(n) New Repair for Group 6 Airplanes

    If any crack or corrosion is found during any inspection 
required by paragraph (m) of this AD: Repair or change the end 
fitting, in accordance with Part 7 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009. After accomplishing the repair or change in 
accordance with Part 7 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009, do the 
applicable actions required by paragraph (m) of this AD.

(o) New Optional Terminating Action for Part 1, Part 2, and Part 3 
Inspections

    In lieu of doing Part 1, Part 2, or Part 3 inspections required 
by this AD: Repair or change the end fitting, in accordance with 
Part 7 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-57A2331, dated November 12, 2009. After accomplishing 
the repair or change in accordance with Part 7 of Boeing Alert 
Service Bulletin 747-57A2331, dated November 12, 2009, do the 
applicable actions required by paragraphs (p) and (r) of this AD. 
Doing the repair or change terminates the Part 1, 2, or 3 
inspections for that part only of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-57A2331, dated November 12, 2009.

(p) New Follow-On End Fitting Inspection for Groups 1 Through 5 
Airplanes

    For Groups 1 through 5 airplanes on which the repair or change 
specified in Part 7 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009, has 
been done: Do detailed and ultrasonic inspections of the end 
fittings for cracks and corrosion, in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009. If no crack or corrosion is found, 
do the actions required by either paragraph (p)(1) or (p)(2) of this 
AD.
    (1) Repeat the detailed and ultrasonic inspections of the end 
fittings for cracks and corrosion required by paragraph (p) of this 
AD.
    (2) Do a detailed inspection of each end fitting for fillet seal 
damage, cracks, and corrosion, in accordance with Part 5 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.
    (i) If no fillet seal damage, crack, or corrosion is found: 
Repeat the inspection required by paragraph (p)(2) of this AD.
    (ii) If any fillet seal damage is found, but no crack or 
corrosion is found: Remove the fillet seal, and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 5 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (A) If any crack or corrosion is found: Repair or change the end 
fitting, as required by paragraph (q) of this AD.
    (B) If no crack or corrosion is found: Apply corrosion 
inhibiting compound on each end fitting, in accordance with Part 5 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009; and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 6 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (1) If any crack or corrosion is found: Repair or change the end 
fitting, as required by paragraph (q) of this AD.
    (2) If no crack or corrosion is found: Apply corrosion 
inhibiting compound, in accordance with Part 6 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009; and repeat the detailed and HFEC inspections of 
each end fitting for cracks and corrosion, in accordance with Part 6 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009.

(q) New Repair for Groups 1 Through 5 Airplanes

    If any crack or corrosion is found during any inspection 
required by paragraph (p) of this AD: Repair or change the end 
fitting, in accordance with Part 7 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009. After accomplishing the repair or change in 
accordance with Part 7 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009, do the 
applicable actions required by paragraphs (p) of this AD.

(r) New Follow-On End Fitting Inspection for Group 6 Airplanes

    For Group 6 airplanes on which the repair or change specified in 
Part 7 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-57A2331, dated November 12, 2009, has been done: Do a 
detailed inspection of the end fittings for fillet seal damage, 
cracks, and corrosion, in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.
    (1) If no fillet seal damage, crack, or corrosion is found: Do a 
detailed inspection of each end fitting for fillet seal damage, 
cracks, and corrosion, in accordance with Part 5 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.
    (i) If no fillet seal damage, crack, or corrosion is found: 
Repeat the inspection required by paragraph (r)(1) of this AD.
    (ii) If any fillet seal damage is found, but no crack or 
corrosion is found: Do detailed and HFEC inspections of each end 
fitting for cracks and corrosion, in accordance with Part 5 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.
    (A) If any crack or corrosion is found: Repair or change the end 
fitting as required by paragraph (s) of this AD.
    (B) If no crack or corrosion is found: Apply corrosion 
inhibiting compound on each end fitting, in accordance with Part 5 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009; and repeat the detailed and 
HFEC inspections of each end fitting for cracks and corrosion, in 
accordance with Part 6 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (1) If any crack or corrosion is found: Repair or change the end 
fitting, in accordance with Part 7 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009.
    (2) If no crack or corrosion is found: Apply corrosion 
inhibiting compound, in accordance with Part 6 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009; and repeat the detailed and HFEC inspections of 
each end fitting for cracks and corrosion, in accordance with Part 6 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009.
    (2) If any fillet seal damage is found, but no crack or 
corrosion is found: Do detailed and HFEC inspections of each end 
fitting for cracks and corrosion, in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2331, dated November 12, 2009.

[[Page 32069]]

    (i) If any crack or corrosion is found: Repair or change the end 
fitting, as required by paragraph (s) of this AD.
    (ii) If no crack or corrosion is found: Apply corrosion 
inhibiting compound on each end fitting, in accordance with Part 4 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009, and do detailed and HFEC 
inspections of each end fitting for cracks and corrosion, in 
accordance with Part 6 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-57A2331, dated November 12, 2009.
    (A) If any crack or corrosion is found: Repair or change the end 
fitting, as required by paragraph (s) of this AD.
    (B) If no crack or corrosion is found: Apply corrosion 
inhibiting compound, in accordance with Part 6 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009; and repeat the detailed and HFEC inspections of 
each end fitting for cracks and corrosion, in accordance with Part 6 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-57A2331, dated November 12, 2009.

(s) New Repair for Group 6 Airplanes

    If any crack or corrosion is found during any inspection 
required by paragraph (r) of this AD: Repair or change the end 
fitting, in accordance with Part 7 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009.

(t) New Optional Action for Part 4, Part 5, and Part 6 Inspections

    In lieu of doing Part 4, Part 5, or Part 6 inspections required 
by this AD: Repair or change the end fitting, in accordance with 
Part 7 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-57A2331, dated November 12, 2009. After accomplishing 
the repair or change in accordance with Part 7 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2331, dated 
November 12, 2009, do the applicable actions required by paragraphs 
(p) and (r) of this AD.

(u) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (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 
Boeing Commercial Airplanes Organization Designation Authorization 
(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 for AD 89-15-07, Amendment 39-6267 (54 FR 
30009, July 18, 1989), are approved as AMOCs for the corresponding 
requirements of this AD.

(v) Related Information

    (1) For more information about this AD, contact Bill Ashforth, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 
98057-3356; phone: (425) 917-6432; fax: (425) 917-6590; email: 
bill.ashforth@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, Washington 98124-2207; telephone 
206-544-5000, extension 1, fax 206-766-5680; email 
me.boecom@boeing.com; 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, 
Washington. For information on the availability of this material at 
the FAA, call 425-227-1221.

    Issued in Renton, Washington, on May 18, 2012.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-13187 Filed 5-30-12; 8:45 am]
BILLING CODE 4910-13-P