```

[Federal Register Volume 80, Number 144 (Tuesday, July 28, 2015)]
[Rules and Regulations]
[Pages 44832-44835]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-18156]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-0778; Directorate Identifier 2014-NM-095-AD; 
Amendment 39-18220; AD 2015-15-11]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
The Boeing Company Model 747-100B, 747-100B SUD, 747-200B, 747-200C, 
747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series 
airplanes. This AD was prompted by reports of skin cracks and 
subsequent findings of hidden corrosion found on the mating surfaces 
between certain skin and stringers at circumferential skin splices. 
This AD requires general visual inspections of the fuselage skin at 
certain lower circumferential splices for the presence of existing 
external doublers, repetitive inspections of the fuselage skin, and 
related investigative and corrective actions if necessary. We are 
issuing this AD to detect and correct hidden corrosion due to 
compromised fillet seals, which can result in skin cracking and 
consequent loss of capability to support limit loads.

DATES: This AD is effective September 1, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of September 1, 
2015.

ADDRESSES: 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 view this 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. It is also 
available on the Internet at http://www.regulations.gov by searching 
for and locating Docket No. FAA-2014-0778.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2014-
0778; 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 AD, the regulatory evaluation, any comments received, and 
other information. The address for the Docket Office (phone: 800-647-
5527) is Docket Management Facility, 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: Bill Ashforth, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6432; fax: 425-917-6590; email: bill.ashforth@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to certain The Boeing Company 
Model 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 
747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. The 
NPRM published in the Federal Register on November 28, 2014 (79 FR 
70799). The NPRM was prompted by reports of skin cracks and subsequent 
findings of hidden corrosion found on the mating surfaces between 
certain skin and stringers at circumferential skin splices. The NPRM 
proposed to require general visual inspections of the fuselage skin at 
certain lower circumferential splices for the presence of existing 
external doublers, repetitive inspections of the fuselage skin, and 
related investigative and corrective actions if necessary. We are 
issuing this AD to detect and correct hidden corrosion due to 
compromised fillet seals, which can result in skin cracking and 
consequent loss of capability to support limit loads.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM (79 
FR 70799, November 28, 2014) and the FAA's response to each comment.

Concurrence With NPRM (79 FR 70799, November 28, 2014)

    United Airlines stated that it concurs with the proposed 
requirements specified in the NPRM (79 FR 70799, November 28, 2014).

[[Page 44833]]

Request To Clarify What Prompted the AD Action and Clarify the Unsafe 
Condition

    Boeing requested that we clarify the unsafe condition and revise 
various locations of the NPRM (79 FR 70799, November 28, 2014) to 
indicate that corrosion was discovered only after a skin crack was 
reported. Boeing explained the hidden corrosion between the skin and 
stringer was not visibly detectable and was discovered only after a 
skin crack was reported.
    We agree to revise the sentences that specify the unsafe condition 
and that specify what prompted the AD action. We have revised the 
SUMMARY of this final rule, as well as the Discussion and paragraph (e) 
of this AD, by adding the phrase ``hidden corrosion due to'' to the 
sentences that specify the unsafe condition, and by adding the phrase 
``skin cracks and subsequent findings of hidden'' to the sentences that 
discuss what prompted the AD action.

Request To Clarify Requirements Based on Presence of Doubler Repair

    Boeing requested that we revise paragraph (g) of the NPRM (79 FR 
70799, November 28, 2014) to clarify the proposed requirements for 
surface low frequency eddy current (LFEC) inspections for areas with 
and without repair doublers.
    We agree to revise paragraph (g) of this AD to clarify 
configurations of areas with and without repair doublers. We have 
revised paragraph (g)(1) and added new paragraph (g)(2) to this AD to 
specify configurations having ``an external repair doubler'' and where 
``no existing repair doubler'' exists.

Request To Add Required High Frequency Eddy Current (HFEC) Inspections

    Boeing requested that we revise paragraphs (g)(2) and (h)(2)(i) of 
the NPRM (79 FR 70799, November 28, 2014) by adding HFEC inspections as 
a required action.
    We disagree with specifying HFEC inspections as requested in this 
AD because this AD already requires compliance with all applicable 
``related investigative actions,'' which include applicable HFEC 
inspections. The terminology for the proposed AD requirements was 
addressed by the NPRM (79 FR 70799, November 28, 2014). Our standard 
practice is to specify actions that are related to the primary action 
and actions that further investigate the nature of any condition found 
as ``related investigative actions.'' No change has been made to this 
AD in this regard.

Request To Reference Correct Service Information

    UPS requested that the correct eddy current inspection procedure be 
referenced in the NPRM (79 FR 70799, November 28, 2014). UPS stated 
that Boeing Information Notice 747-53A2861 IN 01, dated April 24, 2014, 
was issued to inform operators that Paragraph 3.B, Part 2, Step 1, of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2861, dated April 1, 2014, should refer to ``747 Nondestructive test 
(NDT) Manual Part 6, 53-30-00, Procedure 5,'' instead of ``747 NDT 
Manual Part 6, 51-00-00, Procedure 8,'' as the correct inspection 
procedure of the fuselage skin. UPS stated that adding this information 
would prevent the need for requests for alternative methods of 
compliance (AMOCs) related to this error.
    We find that clarification is needed. To clarify this information, 
we have added a new exception to include the correct source of service 
information for this inspection. New paragraph (i)(3) of this AD refers 
to ``747 NDT Manual Part 6, 53-30-00, Procedure 5,'' as the appropriate 
source of service information for the eddy current inspection of the 
fuselage skin. We have also added a reference to paragraph (i)(3) of 
this AD in paragraphs (g) and (h) of this AD.

Request To Exclude Location From Required Inspections

    UPS requested that the NPRM (79 FR 70799, November 28, 2014) be 
revised to exclude a certain location from the inspection requirements, 
or that the proposed AD provide an inspection procedure that is 
adequate for that location. UPS stated that Boeing Alert Service 
Bulletin 747-53A2861, dated April 1, 2014, specifies that external 
surface LFEC inspections for corrosion of the fuselage skin be done 
using ``747 NDT Manual Part 6, 51-00-00, Procedure 5 or Procedure 12,'' 
which are appropriate for skins with a specified thickness. UPS stated 
Table 2 of Appendix C of Boeing Alert Service Bulletin 747-53A2861, 
dated April 1, 2014, contains an error. Skin panels having part number 
65B23792-XX are chem milled with a thickness that exceeds the 
specification listed in Table 2 of Appendix C of Boeing Alert Service 
Bulletin 747-53A2861, dated April 1, 2014. Therefore, the NDT 
procedures are not valid for those skin panels at this location. UPS 
stated that since action is identified as ``Required for Compliance,'' 
by Boeing Alert Service Bulletin 747-53A2861, dated April 1, 2014, no 
deviations are allowed without AMOC approval.
    We disagree with the request. Agreeing with the request would delay 
the issuance of the AD and we find that delaying this action would be 
inappropriate in light of the identified unsafe condition. Boeing is 
aware of the discrepancy with the NDI instructions, and is actively 
working on a global AMOC for operators to correct the error by means of 
a validated procedure. Operators have the option of proposing their own 
procedure in accordance with paragraph (j) of this AD.
    Since chem milling affects the ability to accomplish Boeing Alert 
Service Bulletin 747-53A2861, dated April 1, 2014, and the corrective 
action is not clear in the service information, we have added an 
exception to new paragraph (i)(4) of this AD to specify where Paragraph 
3.B, Part 3, Step 1, of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2861, dated April 1, 2014, specifies doing 
external surface LFEC inspections in accordance with ``747 NDT Manual 
Part 6, 51-00-00, Procedure 5 or Procedure 12,'' and the skin panels 
are chem milled with a thickness that exceeds the specification listed 
in Table 2 of Appendix C of Boeing Alert Service Bulletin 747-53A2861, 
dated April 1, 2014, this AD requires using an AMOC per paragraph (j) 
of this AD. We have added a reference to paragraph (i)(4) of this AD in 
paragraphs (g) and (h) of this AD. Operators may request approval of an 
AMOC under the provisions of paragraph (j) of this AD, for procedures 
that would help them meet the NDT test requirements.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (79 FR 70799, November 28, 2014) for correcting the unsafe 
condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (79 FR 70799, November 28, 2014).
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 747-53A2861, dated April 
1,

[[Page 44834]]

2014. The service information describes procedures for inspections of 
the fuselage skin at certain lower circumferential splices for the 
presence of existing external doublers, inspections of the fuselage 
skin for cracking and corrosion, and corrective actions. 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 of this final rule.

Costs of Compliance

    We estimate that this AD affects 165 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                    Labor cost         Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspection......................  Up to 121 work-                  $0   Up to $10,285......  Up to $1,697,025.
                                   hours x $85 per
                                   hour = $10,285.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this AD.

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

    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) Is not a ``significant rule'' under 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.

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

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2015-15-11 The Boeing Company: Amendment 39-18220; Docket No. FAA-
2014-0778; Directorate Identifier 2014-NM-095-AD.

(a) Effective Date

    This AD is effective September 1, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 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-
53A2861, dated April 1, 2014.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of skin cracks and subsequent 
findings of hidden corrosion found on the mating surfaces between 
certain skin and stringers at circumferential skin splices. We are 
issuing this AD to detect and correct hidden corrosion due to 
compromised fillet seals, which can result in skin cracking and 
consequent loss of capability to support limit loads.

(f) Compliance

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

(g) Inspections and Repair for Group 1 Airplanes

    For airplanes identified as Group 1 in Boeing Alert Service 
Bulletin 747-53A2861, dated April 1, 2014: At the applicable times 
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 747-53A2861, dated April 1, 2014, except as provided by 
paragraph (i)(1) of this AD, do external general visual inspections 
for the presence of external doublers on the fuselage skin, and do 
the applicable actions specified in paragraphs (g)(1) and (g)(2) of 
this AD, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2861, dated April 1, 2014, 
except as required by paragraphs (i)(2), (i)(3), and (i)(4) of this 
AD. Do all applicable repetitive inspections of the fuselage skin 
thereafter at the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2861, dated 
April 1, 2014.
    (1) For each affected area with an external repair doubler: 
Before further flight, do a surface low frequency eddy current 
(LFEC) inspection for skin cracks of the external lower lobe repair 
doubler, and do all applicable related investigative and corrective 
actions. Do all applicable related investigative and corrective 
actions before further flight.
    (2) For any affected area with no external repair doubler: 
Before further flight, do a surface LFEC inspection for corrosion of 
the external lower lobe skin surface, and do all applicable related 
investigative and corrective actions. Do all applicable related 
investigative and corrective actions before further flight.

(h) Inspections and Repair for Group 2 Airplanes

    For airplanes identified as Group 2 in Boeing Alert Service 
Bulletin 747-53A2861, dated April 1, 2014: At the applicable times 
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 747-53A2861, dated April 1, 2014, except as provided by 
paragraph (i)(1) of this AD, do external general visual inspections 
for the presence of

[[Page 44835]]

external doublers on the fuselage skin, and do the applicable 
actions specified in paragraphs (h)(1) and (h)(2) of this AD, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2861, dated April 1, 2014, except as 
required by paragraphs (i)(2), (i)(3), and (i)(4) of this AD.
    (1) For affected areas with any existing repair doubler: Before 
further flight, do inspections and applicable repairs using a method 
approved in accordance with the procedures specified by paragraph 
(j) of this AD.
    (2) For affected areas with no existing repair doubler, do the 
applicable actions specified in paragraph (h)(2)(i) and (h)(2)(ii) 
of this AD.
    (i) Before further flight, do a surface LFEC inspection for 
corrosion of the external lower lobe doubler, a surface LFEC 
inspection for skin cracks of the external lower lobe doubler, a 
detailed inspection for cracks of the external lower lobe skin, and 
do all applicable related investigative and corrective actions. Do 
all applicable related investigative and corrective actions before 
further flight.
    (ii) Do all applicable repetitive inspections of the fuselage 
skin thereafter at the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2861, dated 
April 1, 2014.

(i) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Service Bulletin 747-53A2861, dated April 
1, 2014, specifies a compliance time ``after the original issue date 
of this service bulletin,'' this AD requires compliance within the 
specified compliance time after the effective date of this AD.
    (2) Although Boeing Alert Service Bulletin 747-53A2861, dated 
April 1, 2014, specifies to contact Boeing for repair data, and 
specifies that action as ``RC'' (Required for Compliance), this AD 
requires repair before further flight using a method approved in 
accordance with the procedures specified in paragraph (j) of this 
AD.
    (3) Where Paragraph 3.B, Part 2, Step 1, of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2861, dated 
April 1, 2014, incorrectly identifies ``747 NDT Manual Part 6, 51-
00-00, Procedure 8,'' associated with the LFEC inspection for skin 
cracks of the external lower lobe repair doubler, the correct 
reference is ``747 NDT Manual Part 6, 53-30-00, Procedure 5.''
    (4) Where Paragraph 3.B, Part 3, Step 1, of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2861, dated 
April 1, 2014, specifies doing external surface LFEC inspections in 
accordance with ``747 NDT Manual Part 6, 51-00-00, Procedure 5 or 
Procedure 12,'' and the skin panels are chem milled with a thickness 
that exceeds the specification listed in Table 2 of Appendix C of 
Boeing Alert Service Bulletin 747-53A2861, dated April 1, 2014, this 
AD requires using a method approved in accordance with the 
procedures specified in paragraph (j) of this AD.

(j) 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 paragraph (k) 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) Except as required by paragraph (i) of this AD: Some steps 
in the Work Instructions are labeled as Required for Compliance 
(RC). If this service bulletin is mandated by an AD, then the steps 
labeled as RC, including substeps under an RC step and any figures 
identified in an RC step, must be done to comply with the AD. An 
AMOC is required for any deviations to RC steps, including substeps 
and identified figures. Steps not labeled as RC may be deviated from 
using accepted methods in accordance with the operator's maintenance 
or inspection program without obtaining approval of an AMOC, 
provided the RC steps, including substeps and identified figures, 
can still be done as specified, and the airplane can be put back in 
an airworthy condition.
    (4) 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.

(k) Related Information

    For more information about this AD, contact Bill Ashforth, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6432; fax: 425-917-6590; email: 
bill.ashforth@faa.gov.

(l) 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 the AD specifies otherwise.
    (i) Boeing Alert Service Bulletin 747-53A2861, dated April 1, 
2014.
    (ii) Reserved.
    (3) 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.
    (4) You may view this service information at 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.
    (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, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on July 16, 2015.
Suzanne Masterson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-18156 Filed 7-27-15; 8:45 am]
BILLING CODE 4910-13-P
```