[Federal Register Volume 80, Number 164 (Tuesday, August 25, 2015)]
[Proposed Rules]
[Pages 51488-51491]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-20853]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-3146; Directorate Identifier 2014-NM-249-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain The Boeing Company Model 777-200 series airplanes. This 
proposed AD was prompted by an evaluation by the design approval holder 
(DAH) indicating that the skin lap splices at certain stringers in 
certain fuselage sections are subject to widespread fatigue damage 
(WFD). This proposed AD would require inspections to detect cracking of 
fuselage skin lap splices in certain fuselage sections, and corrective 
actions if necessary; modification of left-side and right-side lap 
splices; and post-modification repetitive inspections for cracks in the 
modified lap splices, and corrective actions if necessary. We are 
proposing this AD to detect and correct fatigue cracking of the skin 
lap splices, and consequent risk of sudden decompression and the 
inability to sustain limit flight and pressure loads.

DATES: We must receive comments on this proposed AD by October 9, 2015.

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 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-2015-
3146.

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-2015-
3146; 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: Haytham Alaidy, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6573; fax: 
425-917-6590; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2015-3146; 
Directorate Identifier 2014-NM-249-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

    Structural fatigue damage is progressive. It begins as minute 
cracks, and those cracks grow under the action of repeated stresses. 
This can happen because of normal operational conditions and design 
attributes, or because of isolated situations or incidents such as 
material defects, poor fabrication quality, or corrosion pits, dings, 
or scratches. Fatigue damage can occur locally, in small areas or 
structural design details, or globally. Global fatigue damage is 
general degradation of large areas of structure with similar structural 
details and stress levels. Multiple-site damage is global damage that 
occurs in a large structural element such as a single rivet line of a 
lap splice joining two large skin panels. Global damage can also occur 
in multiple elements such as adjacent frames or stringers. Multiple-
site-damage and multiple-element-damage cracks are typically too small 
initially to be reliably detected with normal

[[Page 51489]]

inspection methods. Without intervention, these cracks will grow, and 
eventually compromise the structural integrity of the airplane, in a 
condition known as WFD. As an airplane ages, WFD will likely occur, and 
will certainly occur if the airplane is operated long enough without 
any intervention.
    The FAA's WFD final rule (75 FR 69746, November 15, 2010) became 
effective on January 14, 2011. The WFD rule requires certain actions to 
prevent structural failure due to WFD throughout the operational life 
of certain existing transport category airplanes and all of these 
airplanes that will be certificated in the future. For existing and 
future airplanes subject to the WFD rule, the rule requires that DAHs 
establish a limit of validity (LOV) of the engineering data that 
support the structural maintenance program. Operators affected by the 
WFD rule may not fly an airplane beyond its LOV, unless an extended LOV 
is approved.
    The WFD rule (75 FR 69746, November 15, 2010) does not require 
identifying and developing maintenance actions if the DAHs can show 
that such actions are not necessary to prevent WFD before the airplane 
reaches the LOV. Many LOVs, however, do depend on accomplishment of 
future maintenance actions. As stated in the WFD rule, any maintenance 
actions necessary to reach the LOV will be mandated by airworthiness 
directives through separate rulemaking actions.
    In the context of WFD, this action is necessary to enable DAHs to 
propose LOVs that allow operators the longest operational lives for 
their airplanes, and still ensure that WFD will not occur. This 
approach allows for an implementation strategy that provides 
flexibility to DAHs in determining the timing of service information 
development (with FAA approval), while providing operators with 
certainty regarding the LOV applicable to their airplanes.
    During Model 777 fatigue testing, skin cracks were found at the 
stringer S-14 lap splice. These cracks initiated at scribe lines that 
were made inadvertently in production when maskant was removed from the 
skin panels. This condition, if not corrected, could result in fatigue 
cracking of the skin lap splices, and consequent reduced structural 
integrity of the airplane and could cause sudden decompression and the 
inability to sustain limit flight and pressure loads.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 777-53A0052, dated 
October 10, 2014. The service bulletin describes procedures for 
inspections to detect cracking of fuselage skin lap splices and 
repairs, modification to the skin lap splices; and repetitive 
inspections for cracks in the modified lap splices and repairs. 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 NPRM.

Other Related Service Information

    Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, 
specifies concurrent accomplishment of an inspection of the fuselage 
skin for external scribe lines, skin cracks, and repair, which are 
described in Boeing Service Bulletin 777-53A0054, Revision 1, dated 
November 4, 2010. The actions described in Boeing Service Bulletin 777-
53A0054, Revision 1, dated November 4, 2010, are required by AD 2013-
07-11, Amendment 39-17415 (78 FR 22185, April 15, 2013); therefore, 
those actions are not required in this NPRM.
    Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, 
describes doing inspections for cracks in the skin of the stringer lap 
splices and repair, which are also described in Boeing Alert Service 
Bulletin 777-53A0043, dated November 9, 2011. The actions described in 
Boeing Alert Service Bulletin 777-53A0043, dated November 9, 2011, are 
required by AD 2012-14-03, Amendment 39-17117 (77 FR 42962, July 23, 
2012); therefore, those actions are not required in this NPRM.

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 require accomplishing the actions specified 
in the service information described previously, except as discussed 
under ``Differences Between this Proposed AD and the Service 
Information.'' Refer to Boeing Alert Service Bulletin 777-53A0052, 
dated October 10, 2014, for information on the procedures and 
compliance times.
    The phrase ``corrective actions'' is used in this proposed AD. 
``Corrective actions'' are actions that correct or address any 
condition found. Corrective actions in an AD could include, for 
example, repairs.

Explanation of Compliance Time

    The compliance time for the modification specified in this proposed 
AD for addressing WFD was established to ensure that discrepant 
structure is modified before WFD develops in airplanes. Standard 
inspection techniques cannot be relied on to detect WFD before it 
becomes a hazard to flight. We will not grant any extensions of the 
compliance time to complete any AD-mandated service bulletin related to 
WFD without extensive new data that would substantiate and clearly 
warrant such an extension.

Differences Between This Proposed AD and the Service Information

    The service bulletin specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this proposed AD 
would require repairing those conditions in one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

Explanation of ``RC (Required for Compliance)'' Steps in Service 
Information

    The FAA worked in conjunction with industry, under the 
Airworthiness Directive Implementation Aviation Rulemaking Committee 
(ARC), to enhance the AD system. One enhancement was a new process for 
annotating which steps in the service information are required for 
compliance with an AD. Differentiating these steps from other tasks in 
the service information is expected to improve an owner's/operator's 
understanding of crucial AD requirements and help provide consistent 
judgment in AD compliance. The steps identified as RC (required for 
compliance) in any service information identified previously have a 
direct effect on detecting, preventing, resolving, or eliminating an 
identified unsafe condition.
    For service information that contains steps that are labeled as 
Required for Compliance (RC), the following provisions apply: (1) 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

[[Page 51490]]

AD, and an AMOC is required for any deviations to RC steps, including 
substeps and identified figures; and (2) 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.

Costs of Compliance

    We estimate that this proposed AD affects 21 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Action                       Labor cost         Parts cost     Cost per product                     Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection and modification.........  2,713 work-hours x $85           $0  $230,605..............  $4,842,705.
                                       per hour = $230,605.
Post-modification inspection........  1,391 work-hours x $85            0  $118,235 per            $2,482,935 per inspection cycle.
                                       per hour = $118,235                  inspection cycle.
                                       per inspection cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this proposed 
AD.
    According to the manufacturer, some of the costs of this proposed 
AD may be covered under warranty, thereby reducing the cost impact on 
affected individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all available costs in our 
cost estimate.

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

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):

The Boeing Company: Docket No. FAA-2015-3146; Directorate Identifier 
2014-NM-249-AD.

(a) Comments Due Date

    We must receive comments by October 9, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200 series 
airplanes, certified in any category; as identified in Boeing Alert 
Service Bulletin 777-53A0052, dated October 10, 2014.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by an evaluation by the design approval 
holder (DAH) indicating that the skin lap splices at certain 
stringers in certain fuselage sections are subject to widespread 
fatigue damage (WFD). We are issuing this AD to detect and correct 
fatigue cracking of the skin lap splices, and consequent risk of 
sudden decompression and the inability to sustain limit flight and 
pressure loads.

(f) Compliance

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

(g) Inspections and Corrective Actions

    Except as provided by paragraph (h)(1) of this AD, at the 
applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014: 
Do Part 1, inspection ``A,'' of the modification area for cracks; 
Part 2, inspection ``B,'' of the modification area for cracks; and 
Part 3, inspection ``C,'' of the modification area for scribe lines 
and cracks; as applicable; and do all applicable corrective actions; 
in accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 777-53A0052, dated October 10, 2014, except as 
provided by paragraph (h)(2) of this AD. Do all applicable 
corrective actions before further flight.
    (1) Inspection ``A'' includes an external phased array 
ultrasonic inspection for cracks in the lower/overlapped skin of the 
stringer S-14 left and right (L/R) lap splices between fuselage 
station 655 and station 1434, and an open hole high frequency eddy 
current (HFEC) inspection for skin cracks at the upper and lower 
fastener rows of the stringer lap splices.
    (2) Inspection ``B'' includes the inspections specified in 
paragraphs (g)(2)(i) through (g)(2)(iv) of this AD.
    (i) A detailed inspection for cracks of any skin panel common to 
a stringer lap splice

[[Page 51491]]

between fuselage station 655 and station 1434 that has a scribe line 
0.001 inch or deeper.
    (ii) Either an ultrasonic inspection or a surface HFEC 
inspection for cracks (depending on the location of the scribe 
line(s)) of any skin panel common to a stringer lap splice between 
fuselage station 655 and station 1434 that has a scribe line 0.001 
inch or deeper.
    (iii) An external phased array ultrasonic inspection for cracks 
in the lower/overlapped skin of the stringer S-14L/R lap splices 
between fuselage station 655 and station 1434.
    (iv) An open hole HFEC inspection for skin cracks at the upper 
and lower fastener rows of the stringer lap splices.
    (3) Inspection ``C'' includes the inspections for scribe lines 
and cracks specified in paragraphs (g)(3)(i), (g)(3)(ii), and 
(g)(3)(iii) of this AD on stringer S-14L/R lap splice between 
fuselage station 655 and station 1434 on both sides of the airplane.
    (i) A detailed inspection for scribe lines. If any scribe line 
is found during the inspection required by this paragraph, the 
actions include the inspections specified in paragraphs (g)(3)(i)(A) 
and (g)(3)(i)(B) of this AD.
    (A) A detailed inspection for cracks of the scribe line area(s).
    (B) Either an ultrasonic inspection or a surface HFEC inspection 
for cracks (depending on the location of the scribe line(s)).
    (ii) An external phased array ultrasonic inspection for cracks 
in the lower/overlapped skin of the stringer lap splices between 
fuselage station 655 and station 1434.
    (iii) An open hole HFEC inspection for skin cracks at the upper 
and lower fastener rows of the stringer S-14L/R lap splices.

(h) Exceptions to Service Information Specifications

    (1) Where Paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 777-53A0052, dated October 10, 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) If, during accomplishment of any inspection required by this 
AD, any condition is found for which Boeing Alert Service Bulletin 
777-53A0052, dated October 10, 2014, specifies to contact Boeing for 
special repair instructions or supplemental instructions for the 
modification, and specifies that action as ``RC'' (Required for 
Compliance): Before further flight, do the repair or modification 
using a method approved in accordance with the procedures specified 
in paragraph (k) of this AD.

(i) Lap Splice Modification

    At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 777-53A0052, dated 
October 10, 2014: Do the left-side and right-side lap splice 
modification, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 777-53A0052, dated October 10, 2014, 
except as provided by paragraph (h)(2) of this AD.

(j) Post-Modification Inspections and Corrective Action

    At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 777-53A0052, dated 
October 10, 2014: Do a post-modification internal surface HFEC 
inspection for skin cracks in the modified lap splices on both sides 
of the airplane; and do all applicable corrective actions; in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 777-53A0052, dated October 10, 2014, except as 
provided by paragraph (h)(2) of this AD. Do all applicable 
corrective actions before further flight. Repeat the inspection of 
the modified lap splices thereafter at the applicable intervals 
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 777-53A0052, dated October 10, 2014.

(k) 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 (l)(1) of this AD. 
Information may be emailed to: [email protected].
    (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) Except as required by paragraph (h)(2) of this AD: For 
service information that contains steps that are labeled as Required 
for Compliance (RC), the provisions of paragraphs (k)(4)(i) and 
(k)(4)(ii) apply.
    (i) 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.
    (ii) 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.

(l) Related Information

    (1) For more information about this AD, contact Haytham Alaidy, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6573; 
fax: 425-917-6590; email: [email protected].
    (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 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.

    Issued in Renton, Washington, on August 17, 2015.
Kevin Hull,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-20853 Filed 8-24-15; 8:45 am]
 BILLING CODE 4910-13-P