[Federal Register Volume 81, Number 93 (Friday, May 13, 2016)]
[Proposed Rules]
[Pages 29813-29817]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-11173]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2016-6664; Directorate Identifier 2015-NM-177-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 supersede Airworthiness Directive (AD) 2012-16-
07, which applies to certain Boeing Model 737-500 series airplanes. AD
2012-16-07 currently requires inspections of the fuselage skin at the
chem-milled steps, and repair if necessary. Since we issued AD 2012-16-
07, an evaluation by the design approval holder (DAH) indicates that
the fuselage skin is subject to widespread fatigue damage (WFD), and we
have received reports of cracks at the chem-milled steps in the
fuselage skin. This proposed AD would add new fuselage skin inspections
for cracking, inspections to detect missing or loose fasteners and any
disbonding or cracking of bonded doublers, permanent repairs of time-
limited repairs, related investigative and corrective actions if
necessary, and skin panel replacement. We are proposing this AD to
detect and correct cracking on the aft lower lobe fuselage skins, which
could result in rapid decompression of the airplane.
DATES: We must receive comments on this proposed AD by June 27, 2016.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
[[Page 29814]]
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 NPRM, 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-2016-6664.
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-2016-
6664; 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: Wade Sullivan, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6430; 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 proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2016-6664;
Directorate Identifier 2015-NM-177-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
Fatigue damage can occur locally, in small areas or structural
design details, or globally, in widespread areas. Multiple-site damage
is widespread damage that occurs in a large structural element such as
a single rivet line of a lap splice joining two large skin panels.
Widespread 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. This condition is known as widespread fatigue damage. It is
associated with general degradation of large areas of structure with
similar structural details and stress levels. 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.
On July 31, 2012, we issued AD 2012-16-07, Amendment 39-17154 (77
FR 48423, August 14, 2012) (``AD 2012-16-07''), for certain The Boeing
Company Model 737-500 series airplanes. AD 2012-16-07 requires
inspections of the fuselage skin at the chem-milled steps, and repair
if necessary. AD 2012-16-07 resulted from reports of chem-milled steps
cracking on the aft lower lobe fuselage skins. We issued AD 2012-16-07
to detect and correct cracking on the aft lower lobe fuselage skins,
which could result in rapid decompression of the airplane.
Actions Since AD 2012-16-07 Was Issued
Since we issued AD 2012-16-07, an evaluation by the DAH indicates
that the lower lobe skin panels are subject to WFD, and we have
received reports of cracks at the chem-milled steps in the fuselage
skin.
Related Service Information Under 1 CFR Part 51
We reviewed Boeing Special Attention Service Bulletin 737-53-1315,
Revision 1, dated June 30, 2015. The service information describes
procedures for inspection and repair of the fuselage skin panels
between station 727 and station 1016, and between stringers S-14 and S-
25; and also describes procedures for skin panel replacement. 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.
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 designs.
[[Page 29815]]
Proposed AD Requirements
Although this proposed AD does not explicitly restate the
requirements of AD 2012-16-07, this proposed AD would retain all of the
requirements of AD 2012-16-07. Those requirements are referenced in the
service information identified previously, which, in turn, is
referenced in paragraphs (g) and (h) of this proposed AD.
This proposed AD would also require accomplishing the actions
specified in the service information described previously, except as
discussed under ``Differences Between This Proposed AD and the Service
Information.''
For information on the procedures and compliance times, see this
service information at http://www.regulations.gov by searching for and
locating Docket No. FAA-2016-6664.
The phrase ``related investigative actions'' is used in this
proposed AD. ``Related investigative actions'' are follow-on actions
that (1) are related to the primary actions, and (2) further
investigate the nature of any condition found. Related investigative
actions in an AD could include, for example, inspections.
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 This Proposed AD and the Service Information
Boeing Special Attention Service Bulletin 737-53-1315, Revision 1,
dated June 30, 2015, specifies to contact the manufacturer for
instructions on how to repair certain conditions and also to obtain
certain work instructions, but this proposed AD would require repairing
those conditions and also to obtain those work instructions 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 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 33 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
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Inspections [actions retained 23 work-hours x $85 $0 $1,955 per $64,515 per
from AD 2012[dash]16[dash]07]. per hour = $1,955 inspection cycle. inspection cycle.
per inspection
cycle.
Inspections [new proposed action] Up to 1,515 $0 Up to $128,775 per Up to $4,249,575
work[dash]hours x inspection cycle. per inspection
$85 per hour = cycle.
$128,775 per
inspection cycle.
Skin panel replacement [new 688 work[dash]hours $96,000 $154,480........... $5,097,840.
proposed action]. x $85 per hour =
$58,480.
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We estimate the following costs to do any necessary repairs that
would be required based on the results of the proposed inspection. We
have no way of determining the number of aircraft that might need these
repairs:
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Time-limited repair............ 24 work-hours x $85 [\1\] $2,040.\1\
per hour = $2,040.
Permanent repair............... 31 work-hours x $85 [\1\] $2,635.\1\
per hour = $2,635.
Permanent repair inspection.... 4 work-hours x $85 per [\1\] $340 \1\ per inspection cycle.
hour = $340 per
inspection cycle.
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[\1\] We have received no definitive data that would enable us to provide parts 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.
[[Page 29816]]
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)
2012-16-07, Amendment 39-17154 (77 FR 48423, August 14, 2012), and
adding the following new AD:
The Boeing Company: Docket No. FAA-2016-6664; Directorate Identifier
2015-NM-177-AD.
(a) Comments Due Date
The FAA must receive comments on this AD action by June 27,
2016.
(b) Affected ADs
This AD replaces AD 2012-16-07, Amendment 39-17154 (77 FR 48423,
August 14, 2012) (``AD 2012-16-07'').
(c) Applicability
This AD applies to all The Boeing Company Model 737-500 series
airplanes, certificated in any category.
(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) that indicates that the fuselage skin is subject to
widespread fatigue damage (WFD), and reports of cracks at the chem-
milled steps in the fuselage skin. We are issuing this AD to detect
and correct cracking on the aft lower lobe fuselage skins, which
could result in rapid decompression of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Inspections, Related Investigative and Corrective Actions
At the applicable times specified in table 1 of paragraph 1.E.,
``Compliance,'' of Boeing Special Attention Service Bulletin 737-53-
1315, Revision 1, dated June 30, 2015, except as required by
paragraphs (h)(1) and (h)(2) of this AD: Do the applicable
inspections to detect cracks in the fuselage skin panels; and do all
applicable related investigative and corrective actions; in
accordance with the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 737-53-1315, Revision 1, dated June 30,
2015, except as required by paragraphs (h)(3), (h)(4), and (h)(5) of
this AD. Do all applicable related investigative and corrective
actions before further flight. Repeat the applicable inspections
thereafter at the applicable intervals specified Boeing Special
Attention Service Bulletin 737-53-1315, Revision 1, dated June 30,
2015. Accomplishment of a repair in accordance with ``Part 3:
Repair'' of the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 737-53-1315, Revision 1, dated June 30,
2015, except as required by paragraph (h)(3) of this AD, is
terminating action for the repetitive inspections required by this
paragraph at the repaired locations only.
(h) Exceptions to Boeing Special Attention Service Bulletin 737-53-
1315, Revision 1, Dated June 30, 2015
(1) Where Boeing Special Attention Service Bulletin 737-53-1315,
Revision 1, dated June 30, 2015, specifies compliance times ``after
the Revision 1 date of this service bulletin,'' this AD requires
compliance within the specified compliance times after the effective
date of this AD.
(2) The Condition column of table 1 of Paragraph 1.E.,
``Compliance,'' of Boeing Special Attention Service Bulletin 737-53-
1315, Revision 1, dated June 30, 2015, refers to airplanes in
certain configurations as of the ``issue date of Revision 1 of this
service bulletin.'' However, this AD applies to airplanes in the
specified configurations ``as of the effective date of this AD.''
(3) Where Boeing Special Attention Service Bulletin 737-53-1315,
Revision 1, dated June 30, 2015, specifies contacting Boeing for
repair instructions or work instructions, before further flight,
repair or perform the work instructions using a method approved in
accordance with the procedures specified in paragraph (m) of this
AD, except as required by paragraph (h)(4) of this AD.
(4) For airplanes on which an operator has a record that a skin
panel was replaced with a production skin panel at or before 53,000
total flight cycles: At the applicable time for the next inspection
as specified in table 1 of paragraph 1.E., ``Compliance,'' Boeing
Special Attention Service Bulletin 737-53-1315, Revision 1, dated
June 30, 2015, except as provided by paragraphs (h)(1) and (h)(2) of
this AD: Perform inspections and applicable corrective actions using
a method approved in accordance with the procedures specified in
paragraph (m) of this AD.
(5) The Condition column of table 2 of Paragraph 1.E.,
``Compliance,'' of Boeing Special Attention Service Bulletin 737-53-
1315, Revision 1, dated June 30, 2015, refers to airplanes in
certain configurations as of the ``issue date of Revision 1 of this
service bulletin.'' However, this AD applies to airplanes in the
specified configurations regardless of when the time limited repair
is installed.
(i) Actions for Airplanes With a Time Limited Repair Installed
For airplanes with a time limited repair installed as specified
in Boeing Special Attention Service Bulletin 737-53-1315, dated July
29, 2011; or Boeing Special Attention Service Bulletin, Revision 1,
dated June 30, 2015: At the applicable times specified in table 2 of
paragraph 1.E., ``Compliance,'' of Boeing Special Attention Service
Bulletin 737-53-1315, Revision 1, dated June 30, 2015, except as
provided by paragraphs (h)(1) and (h)(5) of this AD: Do the actions
specified in paragraphs (i)(1) and (i)(2) of this AD.
(1) Do the applicable inspections to detect missing or loose
fasteners and any disbonding or cracking of bonded doublers; and do
all applicable related investigative and corrective actions; in
accordance with the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 737-53-1315, Revision 1, dated June 30,
2015, except as required by paragraph (h)(3) of this AD. Do all
applicable related investigative and corrective actions before
further flight. Repeat the applicable inspections thereafter at the
applicable intervals specified Boeing Special Attention Service
Bulletin 737-53-1315, Revision 1, dated June 30, 2015.
(2) Make the time limited repair permanent; and do all
applicable related investigative and corrective actions; in
accordance the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 737-53-1315, Revision 1, dated June 30,
2015, except as required by paragraph (h)(3) of this AD. Do all
applicable related investigative and corrective actions before
further flight. Accomplishing the permanent repair required by this
paragraph terminates the inspections required by paragraph (i)(1) of
this AD for the permanently repaired area only.
(j) Certain Post-Repair Inspections
For airplanes with a permanent repair installed as specified in
Boeing Special Attention Services Bulletin 737-53-1315, Revision 1,
dated June 30, 2015: At the applicable time specified in table 3 of
paragraph 1.E., ``Compliance,'' of Boeing Special Attention Service
Bulletin 737-53-1315, Revision 1, dated June 30, 2015, except as
provided by paragraph (h)(1) of this AD: Do an external low
frequency eddy current (LFEC) inspection for cracking of the skin at
the critical fastener row of the repair doubler; and do all
applicable corrective actions; in accordance the Accomplishment
Instructions of Boeing Special Attention Service Bulletin 737-53-
1315, Revision 1, dated June 30, 2015, except as required by
paragraph (h)(3) of this AD. Do all applicable corrective actions
before further flight. Repeat the LFEC
[[Page 29817]]
inspection thereafter at the applicable intervals specified Boeing
Special Attention Service Bulletin 737-53-1315, Revision 1, dated
June 30, 2015.
(k) Skin Panel Replacement
At the later of the times specified in paragraphs (k)(1) and
(k)(2) of this AD: Replace the applicable skin panels, and do all
applicable related investigative and corrective actions, in
accordance with the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 737-53-1315, Revision 1, dated June 30,
2015. Do all applicable related investigative and corrective actions
before further flight. Doing the skin panel replacement required by
this paragraph terminates the inspection requirements of paragraph
(g) of this AD for that skin panel only, provided the skin panel
replacement was done with a production skin panel after 53,000 total
flight cycles.
(1) Before 60,000 total flight cycles, but not at or before
53,000 total flight cycles.
(2) Within 6,000 flight cycles after the effective date of this
AD, but not at or before 53,000 total flight cycles.
(l) Credit for Previous Actions
This paragraph provides credit for the zone 1 actions required
by paragraph (g) of this AD, as described in Boeing Special
Attention Service Bulletin 737-53-1315, Revision 1, dated June 30,
2015, if the zone 1, 2, and 3 actions, as described in Boeing
Special Attention Service Bulletin 737-53-1315, dated July 29, 2011,
were performed before the effective date of this AD using Boeing
Special Attention Service Bulletin 737-53-1315, dated July 29, 2011,
except as required by paragraph (h)(4) of this AD. Boeing Special
Attention Bulletin 737-53-1315, dated July 29, 2011, was
incorporated by reference in AD 2012-16-07.
(m) 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 (n)(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, modification, or alteration 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. To be approved, the
repair method, modification deviation, or alteration deviation must
meet the certification basis of the airplane, and the approval must
specifically refer to this AD.
(4) AMOCs approved previously for AD 2012-16-07 are approved as
AMOCs for the corresponding provisions of paragraph (g) of this AD.
(n) Related Information
(1) For more information about this AD, contact Wade Sullivan,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6430; 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, 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 May 5, 2016.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2016-11173 Filed 5-12-16; 8:45 am]
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