[Federal Register Volume 79, Number 74 (Thursday, April 17, 2014)]
[Proposed Rules]
[Pages 21655-21658]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-08730]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-0232; Directorate Identifier 2013-NM-100-AD]
RIN 2120-AA64


Airworthiness Directives; the Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain the Boeing Company Model DC-9-10, DC-9-20, DC-9-30, DC-9-40, 
and DC-9-50 series airplanes. This proposed AD was prompted by an 
evaluation by the design approval holder (DAH) indicating that the 
bulkhead dome tees, which connect the bulkhead web to the fuselage, are 
subject to widespread fatigue damage (WFD). This proposed AD would 
require repetitive inspections of the improved ventral aft pressure 
bulkhead tees and replacement if necessary. We are proposing this AD to 
detect and correct fatigue cracking of the bulkhead dome tees, which 
could result in reduced structural integrity and rapid decompression of 
the airplane.

DATES: We must receive comments on this proposed AD by June 2, 2014.

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, 
3855 Lakewood Boulevard, MC D800-0019, Long Beach, CA 90846-0001; 
telephone 206-544-5000, extension 2; fax 206-766-5683; 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.

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-
0232; 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: Eric Schrieber, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-
627-5348; fax: 562-627-5210; 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-2014-0232; 
Directorate Identifier 2013-NM-100-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 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

[[Page 21656]]

timing of service information development (with FAA approval), while 
providing operators with certainty regarding the LOV applicable to 
their airplanes.
    This AD was prompted by an evaluation by the DAH indicating that 
the improved (shot-peened) ventral aft pressure bulkhead dome tees, 
which connect the bulkhead web to the fuselage, are subject to WFD. No 
new improved (shot-peened) tees have been found cracked to date, but it 
has been determined that these improved tees could crack before the 
airplane's limit of validity is reached. This condition, if not 
corrected, could result in reduced structural integrity and rapid 
decompression of the airplane.

Relevant Service Information

    We reviewed McDonnell Douglas Alert Service Bulletin A53-232, 
Revision 2, dated April 28, 1995. For information on the procedures and 
compliance times, see this service information at http://www.regulations.gov by searching for Docket No. FAA-2014-0232.

FAA's Determination

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

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information identified previously, except as discussed 
under ``Differences Between the Proposed AD and the Service 
Information.''

Differences Between This Proposed AD and the Service Information

    McDonnell Douglas Alert Service Bulletin A53-232, Revision 2, dated 
April 28, 1995, did not specify compliance times for inspections of the 
new improved (shot-peened) tees. We have determined that the compliance 
time specified in this proposed AD adequately addresses the unsafe 
condition. This difference has been coordinated with The Boeing 
Company.
    Although McDonnell Douglas Alert Service Bulletin A53-232, Revision 
2, dated April 28, 1995, describes inspection procedures for the 
original design tees, the inspection procedures also apply to the 
improved (shot-peened) tees specified in this AD.
    Although McDonnell Douglas Alert Service Bulletin A53-232, Revision 
2, dated April 28, 1995, notes that replacing all six aft pressure 
bulkhead tee sections with new improved tee sections terminates the 
repetitive inspection requirements, this proposed AD does not allow 
that terminating action because the new improved tee could crack before 
the airplane's limit of validity is reached.
    Although Table 1 of Figure 4, and paragraph 3, ``Material 
Information,'' of McDonnell Douglas Alert Service Bulletin A53-232, 
Revision 2, dated April 28, 1995, specify tee part numbers of 
SR09530056-3, SR09530056-5, SR09530056-6, SR09530056-7, SR09530056-8, 
SR09530056-9, 5910163-387, 5910163-389, 5910163-391, 5910163-392, 
5910163-393, or 5910163-394, the complete lists of part numbers are 
listed in paragraphs (h) and (k) of this proposed AD.
    These differences have been coordinated with The Boeing Company.

Related Rulemaking

    AD 96-16-04, Amendment 39-9704 (61 FR 39860, July 31, 1996) 
requires repetitive inspections of the original tee in accordance with 
McDonnell Douglas Alert Service Bulletin A53-232, Revision 2, dated 
April 28, 1995, whether or not the original tee was replaced. AD 96-16-
04 did not address WFD and, therefore, allowed replacement of the tee 
with a new improved tee as a terminating action for repetitive 
inspections.

Explanation of Compliance Time

    The compliance time for the replacement specified in this proposed 
AD for addressing WFD was established to ensure that discrepant 
structure is replaced 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.

Costs of Compliance

    We estimate that this proposed AD affects 48 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
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                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspection.......................  Up to 148                        $0  Up to $12,580 per    Up to $603,840 per
                                    work[dash]hours x                    inspection cycle.    inspection cycle.
                                    $85 per hour =
                                    $12,580 per
                                    inspection cycle.
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    We estimate the following costs to do any necessary 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 replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replacement..................................  4,000 work-hours x $85 per hour         $26,000         $366,000
                                                = $340,000.
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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

[[Page 21657]]

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-2014-0232; Directorate Identifier 
2013-NM-100-AD.

(a) Comments Due Date

    We must receive comments by June 2, 2014.

(b) Affected ADs

    This AD affects certain requirements of AD 96-16-04, Amendment 
39-9704 (61 FR 39860, July 31, 1996).

(c) Applicability

    This AD applies to The Boeing Company Model DC-9-11, DC-9-12, 
DC-9-13, DC-9-14, DC-9-15, and DC-9-15F airplanes; Model DC-9-21 
airplanes; Model DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-
33F, DC-9-34, DC-9-34F, and DC-9-32F (C-9A, C-9B) airplanes; Model 
DC-9-41 airplanes; and Model DC-9-51 airplanes; certificated in any 
category; equipped with a ventral aft pressure bulkhead.

(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 improved (shot-peened) ventral aft 
pressure bulkhead dome tees, which connect the bulkhead web to the 
fuselage, are subject to widespread fatigue damage (WFD). We are 
issuing this AD to detect and correct fatigue cracking of the 
improved (shot-peened) ventral aft pressure bulkhead dome tees 
connecting the bulkhead web to the fuselage, which could result in 
reduced structural integrity and rapid decompression of the 
airplane.

(f) Compliance

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

(g) Definitions

    (1) For the purposes of this AD, the term ``original tee 
section'' refers to the original (non-peened) ventral aft pressure 
bulkhead web to fuselage skin attach tee sections.
    (2) For the purposes of this AD, the term ``improved tee 
section'' refers to improved (shot peened) ventral aft pressure 
bulkhead web to fuselage skin attach tee sections.

(h) Inspections

    For airplanes on which an improved tee section having P/N 
5910130-389, 5910130-391, 5910130-392, 5910130-393, 5910130-394, 
5910130-387, SR09530001-19, SR09530001-21, SR09530001-22, 
SR09530001-23, SR09530001-24, SR09530001-25, SR09530001-35, 
SR09530001-29, SR09530001-30, SR09530001-31, SR09530001-32, 
SR09530001-33, SR09530056-3, SR09530056-5, SR09530056-6, SR09530056-
7, SR09530056-8, SR09530056-9, SR09530056-19, SR09530056-21, 
SR09530056-22, SR09530056-23, SR09530056-24, or SR09530056-25, is 
installed: At the applicable time specified in paragraph (i)(1) or 
(i)(2) of this AD, do general visual and low frequency eddy current 
inspections (Option I), or high and low frequency eddy current 
inspections (Option II), for cracking of the improved tee sections, 
in accordance with the Accomplishment Instructions of McDonnell 
Douglas Alert Service Bulletin A53-232, Revision 2, dated April 28, 
1995.

(i) Compliance Times

    (1) For Option I and Option II inspections specified in 
paragraph (h) of this AD: If the time of installation of an improved 
tee section having a part number listed in paragraph (h) of this AD, 
is known, do the initial inspection required by paragraph (h) of 
this AD within 70,000 flight cycles after installation of the 
improved tee section, or within 1,500 flight cycles after the 
effective date of this AD, whichever occurs later.
    (2) For Option I and Option II inspections specified in 
paragraph (h) of this AD: If the time of installation of an improved 
tee section having a part number listed in paragraph (h) of this AD, 
is not known, do the initial inspection required by paragraph (h) of 
this AD before the accumulation of 105,000 total flight cycles on 
the airplane or within 1,500 flight cycles after the effective date 
of this AD, whichever occurs later.

(j) Repetitive Inspections

    If no cracking is found during the inspection required by 
paragraph (h) of this AD: Do the actions specified in paragraph 
(j)(1) or (j)(2) of this AD, as applicable, in accordance with the 
Accomplishment Instructions of McDonnell Douglas Alert Service 
Bulletin A53-232, Revision 2, dated April 28, 1995.
    (1) For Option I: If Option I was used for the inspection 
required by paragraph (h) of this AD, repeat the inspections 
specified in paragraphs (j)(1)(i), (j)(1)(ii), and (j)(1)(iii) of 
this AD at the intervals specified in paragraphs (j)(1)(i), 
(j)(1)(ii), and (j)(1)(iii) of this AD.
    (i) Repeat the low frequency eddy current inspection for 
cracking of side areas above the floor between longerons L7 and L17 
on the fuselage, at intervals not to exceed 1,500 flight cycles.
    (ii) Repeat the general visual inspection for cracking of the 
top and lower areas from longeron L7 left side to longeron L7 right 
side, and lower fuselage longeron L17 to longeron L20 on the left 
and right sides, at intervals not to exceed 1,500 flight cycles.
    (iii) Repeat the general visual inspection for cracking of the 
bottom areas from longeron L20 left side to longeron L20 right side, 
at intervals not to exceed 3,500 flight cycles.
    (2) For Option II: If Option II was used for the inspection 
required by paragraph (h) of this AD, repeat the high and low 
frequency eddy current inspection for cracking around the entire 
periphery of the fuselage on the forward side of the bulkhead, at 
intervals not to exceed 2,500 flight cycles.

(k) Corrective Actions and Post-Replacement Inspections

    If any cracking is found during any inspection required by 
paragraph (h) or (j) of this AD: Before further pressurized flight, 
replace each cracked tee section with an airworthy tee section 
having a part number listed in paragraph (h) of this AD, or with an 
original tee section having P/N 5910130-47, 5910130-51, 5910130-53, 
5910130-54, 5910130-55, or 5910130-56, in accordance with the 
Accomplishment Instructions of McDonnell Douglas Alert Service 
Bulletin A53-232, Revision 2, dated April 28, 1995.

[[Page 21658]]

    (1) If the tee section is replaced with an improved tee section 
listed in paragraph (h) of this AD, prior to the accumulation of 
70,000 flight cycles after installation, inspect the tee section in 
accordance with paragraph (h) of this AD and do all applicable 
corrective actions and repetitive inspections in accordance with and 
at the times specified in paragraphs (j) and (k) of this AD.
    (2) If the tee section is replaced with an original tee section 
listed in paragraph (k) of this AD, prior to the accumulation of 
35,000 flight cycles after installation, inspect the tee section in 
accordance with paragraph (h) of this AD and do all applicable 
corrective actions and repetitive inspections in accordance with and 
at the times specified in paragraphs (j) and (k) of this AD.

(l) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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 (m)(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, Los Angeles ACO, to 
make those findings. For a repair method to be approved, the repair 
must meet the certification basis of the airplane, and 14 CFR 
25.571, Amendment 45, and the approval must specifically refer to 
this AD.

(m) Related Information

    (1) For more information about this AD, contact Eric Schrieber, 
Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles 
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
CA 90712-4137; phone: 562-627-5348; fax: 562-627-5210; email: 
[email protected].
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
3855 Lakewood Boulevard, MC D800-0019, Long Beach, CA 90846-0001; 
telephone 206-544-5000, extension 2; fax 206-766-5683; 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 April 7, 2014.
John P. Piccola,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-08730 Filed 4-16-14; 8:45 am]
BILLING CODE 4910-13-P