
[Federal Register Volume 78, Number 140 (Monday, July 22, 2013)]
[Proposed Rules]
[Pages 43839-43842]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-17412]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0625; Directorate Identifier 2013-NM-013-AD]
RIN 2120-AA64


Airworthiness Directives; the Boeing Company

AGENCY: Federal Aviation Administration (FAA), 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 series 
airplanes. The existing AD currently requires repetitive detailed 
inspections to detect cracking in certain fuselage upper deck tension 
ties, repair or modification of any cracked tension ties, and 
repetitive inspections of repaired and modified tension ties and repair 
or modification if necessary. The existing AD also provides for 
optional terminating action for the repetitive detailed inspections of 
tension ties that have not been repaired or modified. This proposed AD 
was prompted by an evaluation by the design approval holder indicating 
that the upper deck tension ties of the fuselage are subject to 
widespread fatigue damage. This proposed AD would retain the repetitive 
inspections, mandate the previously optional terminating modification, 
and add, for tension ties that have not been repaired or modified, 
repetitive inspections that must be done concurrently with the existing 
repetitive inspections. We are proposing this AD to prevent widespread 
fatigue damage of certain fuselage upper deck tension ties, which could 
result in reduced structural integrity of the airplane.

DATES: We must receive comments on this proposed AD by September 5, 
2013.

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 AD, contact Boeing 
Commercial Airplanes, Attention: Data & Services Management, P. O. Box 
3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, 
extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. 
You may review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Ave. 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 (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Nathan Weigand, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: (425) 917-
6428; fax: (425) 917-6590; email: nathan.p.weigand@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-2013-0625; 
Directorate Identifier 2013-NM-013-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 June 14, 1994, we issued AD 94-13-06, Amendment 39-8946 (59 FR 
32879, June 27, 1994), for certain Boeing Model 747 series airplanes. 
That AD requires inspections to detect cracking in certain fuselage 
upper deck tension ties, and repair or modification of any cracked 
tension ties. That AD resulted from reports of fatigue cracking in 
tension ties. We issued that AD to prevent failure of two or more 
tension ties and the resultant rapid decompression of the airplane.

Actions Since Existing AD (59 FR 32879, June 27, 1994) Was Issued

    AD 94-13-06, Amendment 39-8946 (59 FR 32879, June 27, 1994), 
provides a terminating modification as an option. We have determined 
that it is necessary to mandate this modification to adequately address 
the identified unsafe condition.
    We can better ensure long-term continued operational safety by 
design changes to remove the source of the problem, rather than by 
repetitive inspections. Long-term inspections may not provide the 
degree of safety necessary for the transport airplane fleet. This 
determination, along with a better understanding of the human factors 
associated with numerous continual inspections, has led us to consider 
placing less emphasis on inspections and more emphasis on

[[Page 43840]]

design improvements. The proposed modification requirement is 
consistent with these conditions.

WFD Program

    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 inspection methods. 
Without intervention, these cracks will grow, and eventually compromise 
the structural integrity of the airplane, in a condition known as 
widespread fatigue damage (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 design 
approval holders (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.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 747-53A2371, Revision 2, 
dated December 11, 2012. For information on the procedures and 
compliance times, see this service information at http://www.regulations.gov by searching for Docket No. FAA-2013-0625.

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

    Although this proposed AD does not explicitly restate the 
requirements of AD 94-13-06, Amendment 39-8946 (59 FR 32879, June 27, 
1994), this proposed AD would retain all of the requirements of AD 94-
13-06. Those requirements are referenced in the service information 
identified previously, which, in turn, is referenced in paragraphs (g) 
and (i) of this proposed AD. Paragraph (h) of this proposed AD would 
mandate the previously optional terminating modification for the 
inspections of tension ties that have not been repaired or modified. 
Paragraph (g) of this proposed AD would also add, for tension ties that 
have not been repaired or modified, repetitive high frequency eddy 
current inspections to be done concurrently with the existing detailed 
inspections specified in for tensions ties that have not been repaired 
or modified. This proposed AD would require accomplishing the actions 
specified in the service information described previously, except as 
discussed under ``Differences Between the Proposed AD and the Service 
Information.''
    In addition, 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.

Differences Between the Proposed AD and the Service Information

    Table 3 in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 747-53A2371, Revision 2, dated December 11, 2012, specifies 
repeating the detailed inspection for cracks in the tension ties; 
however, that inspection is incorrect. This section of the service 
information should specify a high frequency eddy current inspection 
(HFEC) inspection, as specified in the other related sections. 
Therefore, the inspection required by this proposed AD is an HFEC 
inspection, performed in accordance with Part 4 and Figure 8 of this 
service bulletin. This service information is being revised to specify 
the correct inspection type. This difference has been coordinated with 
Boeing.
    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 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.

Clarification of Applicability

    We have revised the applicability of existing AD 94-13-06, 
amendment 39-8946 (59 FR 32879, June 27, 1994), to identify model 
designations as published in the most recent type certificate data 
sheet for the affected models.

Costs of Compliance

    We estimate that this proposed AD affects 113 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

[[Page 43841]]



                                                 Estimated Costs
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                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Detailed inspections [retained     5 work-hours x $85               $0  $425 per inspection  $48,025 per
 action from existing AD 94-13-     per hour = $425.                     cycle.               inspection cycle.
 06, amendment 39-8946 (59 FR
 32879, June 27, 1994)].
Post-mod/repair inspections......  1 work-hour x $85                 0  $85................  $9,605.
                                    per hour = $85.
Modification [new proposed         Up to 112 work-                   0  Up to $9,520.......  Up to $1,075,760.
 action].                           hours x $85 per
                                    hour = up to
                                    $9,520.
----------------------------------------------------------------------------------------------------------------

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

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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 removing airworthiness directive (AD) 
94-13-06, Amendment 39-8946 (59 FR 32879, June 27, 1994), and adding 
the following new AD:

The Boeing Company: Docket No. FAA-2013-0625; Directorate Identifier 
2013-NM-013-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by September 5, 
2013.

(b) Affected ADs

    This AD supersedes AD 94-13-06, Amendment 39-8946 (59 FR 32879, 
June 27, 1994).

(c) Applicability

    This AD applies to The Boeing Company Model 747-100, 747-200B, 
and 747-200F series airplanes, certificated in any category, as 
listed in Boeing Alert Service Bulletin 747-53A2371, Revision 2, 
dated December 11, 2012.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by an evaluation by the design approval 
holder indicating that the upper deck tension ties of the fuselage 
are subject to widespread fatigue damage. We are issuing this AD to 
prevent widespread fatigue damage of certain fuselage upper deck 
tension ties, which could result in reduced structural integrity of 
the airplane.

(f) Compliance

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

(g) Inspections and Repair/Modification

    Except as required by paragraph (k)(3) of this AD, at the 
applicable time specified in Tables 1 and 3 of paragraph 1.E., 
``Compliance'' of Boeing Alert Service Bulletin 747-53A2371, 
Revision 2, dated December 11, 2012: Do detailed and surface high 
frequency eddy current (HFEC) inspections for cracks in the tension 
ties, as applicable, and do all applicable corrective actions, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2371, Revision 2, dated December 11, 2012, 
except as required by paragraph (k)(2) of this AD. The effective 
date of AD 94-13-06, Amendment 39-8946 (59 FR 32879, June 27, 1994) 
is July 27, 1994. Do all applicable corrective actions before 
further flight. Repeat the detailed and HFEC inspection thereafter 
at the time specified in paragraph 1.E., ``Compliance,'' of Boeing 
Alert Service Bulletin 747-53A2371, Revision 2, dated December 11, 
2012, except as specified in paragraph (k)(1) of this AD. Repair of 
a tension tie, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2371, Revision 2, dated 
December 11, 2012, except as required by paragraph (k)(2) of this 
AD, terminates the requirements of this paragraph for that tension 
tie only.

(h) Modification

    Except as provided by paragraph (k)(3) of this AD, at the 
applicable time specified in Table 3 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2371, 
Revision 2, dated December 11, 2012: Modify the tension ties, 
including doing an open-hole HFEC inspection for cracks before 
enlarging the hole, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2371, Revision 
2, dated December 11, 2012. Modification of the tension ties 
terminates the requirements of paragraph (g) of this AD. If any 
cracking is found, before further flight, do the repair using a 
method approved in accordance with the procedures specified in 
paragraph (l) of this AD.

[[Page 43842]]

(i) Post-Repair/Modification Inspections

    At the applicable time specified in Table 2 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2371, 
Revision 2, dated December 11, 2012: Do a detailed inspection of all 
repaired and modified tension ties, and do all applicable corrective 
actions, except as required by paragraph (k)(2) of this AD, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2371, Revision 2, dated December 11, 2012, 
except as required by paragraph (k)(2) of this AD. Repeat the 
inspection thereafter at the times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2371, 
Revision 2, dated December 11, 2012. Do all applicable corrective 
actions before further flight.

(j) Credit for Previous Actions

    This paragraph provides credit for the modification required by 
paragraphs (g) and (h) of this AD if that modification was done 
before the effective date of this AD using Boeing Service Bulletin 
747-53-2371, dated July 29, 1993; or Boeing Alert Service Bulletin 
747-53A2371, Revision 1, dated April 27, 1995; which are not 
incorporated by reference in this AD.

(k) Exception to Service Information

    (1) Where Row 2 of Table 3 of paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 747-53A2371, Revision 2, dated 
December 11, 2012, specifies repeating a ``detailed'' inspection, 
``as given in Part 4'' of this service information, the repetitive 
inspections required by this AD are ``HFEC'' inspections, done in 
accordance with Part 4 and Figure 8 of Boeing Alert Service Bulletin 
747-53A2371, Revision 2, dated December 11, 2012.
    (2) Where Boeing Alert Service Bulletin 747-53A2371, Revision 2, 
dated December 11, 2012, specifies contacting Boeing for repair 
instructions, or does not include repair instructions for a crack 
found in an area other than the aft tension tie area: Before further 
flight, do the repair using a method approved in accordance with the 
procedures specified in paragraph (l) of this AD.
    (3) Where Boeing Alert Service Bulletin 747-53A2371, Revision 2, 
dated December 11, 2012 specifies a compliance time of ``after the 
Revision 2 date of this service bulletin,'' this AD requires 
compliance within the specified compliance time after the effective 
date of this AD.

(l) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
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 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 94-13-06, Amendment 39-8946 (59 FR 
32879, June 27, 1994), are approved as AMOCs for the corresponding 
actions required by paragraphs (g), (h), and (i) of this AD.

(m) Related Information

    (1) For more information about this AD, contact Nathan Weigand, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 
98057-3356; phone: (425) 917-6428; fax: (425) 917-6590; email: 
nathan.p.weigand@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; 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 July 12, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-17412 Filed 7-19-13; 8:45 am]
BILLING CODE 4910-13-P


