[Federal Register Volume 84, Number 62 (Monday, April 1, 2019)]
[Proposed Rules]
[Pages 12143-12146]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-06031]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-0187; Product Identifier 2018-NM-172-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) 2005-20-
01, which applies to all The Boeing Company Model 737-100, -200, -200C,
-300, -400, and -500 series airplanes. AD 2005-20-01 requires
repetitive inspections of the vertical stiffeners at left buttock line
(LBL) and right buttock line (RBL) 6.15 for cracks; and replacement of
both stiffeners with new, improved stiffeners if any stiffener is found
cracked. Since we issued AD
[[Page 12144]]
2005-20-01, we have received reports of cracks found in the left and
right side keel beam upper chords when replacing vertical stiffeners.
In addition, we have determined that the replacement stiffener
installation degraded the fault current bonding path and could
introduce an ignition source in the fuel tank in the event of an
electrical hot short or a lightning strike. This proposed AD would
require, depending on airplane configuration, replacing the vertical
stiffeners at LBL and RBL 6.15 on the rear spar of the wing center
section, installing angle and bonding jumpers, installing brackets,
applying sealant, and applying paint. We are proposing this AD to
address the unsafe condition on these products.
DATES: We must receive comments on this proposed AD by May 16, 2019.
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 NPRM, contact Boeing
Commercial Airplanes, Attention: Contractual & Data Services (C&DS),
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600;
telephone 562-797-1717; internet https://www.myboeingfleet.com. You may
view this service information at the FAA, Transport Standards Branch,
2200 South 216th St., Des Moines, WA. For information on the
availability of this material at the FAA, call 206-231-3195. It is also
available on the internet at http://www.regulations.gov by searching
for and locating Docket No. FAA-2019-0187.
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-2019-
0187; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this NPRM, the regulatory evaluation, any comments received, and other
information. The street address for Docket Operations (phone: 800-647-
5527) is in the ADDRESSES section. Comments will be available in the AD
docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Galib Abumeri, Aerospace Engineer,
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5324; 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-2019-0187;
Product Identifier 2018-NM-172-AD'' at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this NPRM. We will consider all
comments received by the closing date and may amend this NPRM 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
We issued AD 2005-20-01, Amendment 39-14294 (70 FR 56358, September
27, 2005) (``AD 2005-20-01''), for all The Boeing Company Model 737-
100, -200, -200C, -300, -400, and -500 series airplanes. AD 2005-20-01
requires repetitive inspections of the vertical stiffeners at LBL and
RBL 6.15 for cracks; and replacement of both stiffeners with new,
improved stiffeners if any stiffener is found cracked. AD 2005-20-01
also allows replacement of both stiffeners at LBL and RBL 6.15 with
new, improved stiffeners, which terminates the repetitive inspections.
AD 2005-20-01 resulted from reports of cracks in the aft vertical
stiffeners at LBL and RBL 6.15 on the rear spar of the wing center
section. We issued AD 2005-20-01 to address cracks in the vertical
stiffeners at LBL and RBL 6.15, which could result in damage to the
keel beam structure and consequently reduce the capability of the
airplane to sustain flight loads.
Actions Since AD 2005-20-01 Was Issued
Since we issued AD 2005-20-01, Boeing discovered that the
replacement stiffener installation had degraded fault current bonding
because the existing rivets (which provide an inherent bond path for
fault currents and ground returns) had been replaced with non-
conductive finish K-code fasteners in transition fit holes. The
replacement fasteners are not adequate in maintaining required fault
current bonding path and could introduce an ignition source in the fuel
tank in the event of an electrical hot short or a lightning strike.
In addition to the above described electrical bonding issues, we
received a report of cracks in the left side and right side keel beam
upper chords when the aft vertical stiffeners were replaced. Boeing
determined that the actual stresses on aft vertical stiffeners at LBL
and RBL 6.15 exceed those used to design the structure and can cause
fatigue cracks in the stiffeners. If the aft vertical stiffeners have
cracks or are severed, the fatigue damage may extend into the adjacent
keel beam structure and could reduce the limit load capability of the
keel beam structure. Boeing has determined the inspections described in
Boeing Alert Service Bulletin 737-57A1269, dated December 4, 2003; and
Revision 1, dated September 16, 2004; do not provide sufficient
inspection intervals for timely crack detection in the aft vertical
stiffeners. AD 2005-20-01 requires the actions specified in Boeing
Alert Service Bulletin 737-57A1269, dated December 4, 2003; and
Revision 1, dated September 16, 2004. As a result, Boeing issued Alert
Service Bulletin 737-57A1339 RB, dated April 16, 2018, which describes
procedures for inspecting the vertical stiffeners and keel beam upper
chord structures. AD 2018-10-12, Amendment 39-19288 (83 FR 23775, May
23, 2018) (``AD 2018-10-12'') requires the actions specified in Boeing
Alert Service Bulletin 737-57A1339 RB, dated April 16, 2018. After we
issued AD 2018-10-12, Boeing issued Boeing Alert Service Bulletin 737-
57A1269, Revision 2, dated October 11, 2018, which provides procedures
for replacing the vertical stiffeners with new, improved stiffeners.
Accomplishment of the vertical stiffener replacements at LBL and
RBL 6.15, described in Boeing Alert Service Bulletin 737-57A1269,
Revision 2, dated October 11, 2018, as specified in paragraph (g) of
this proposed AD, eliminates the need to do the stiffener inspection
described in Boeing Alert Service Bulletin 737-57A1339 RB, dated April
16, 2018.
Related Service Information Under 1 CFR Part 51
We reviewed Boeing Alert Service Bulletin 737-57A1269, Revision 2,
[[Page 12145]]
dated October 11, 2018. This service information describes procedures
for replacing the vertical stiffeners at LBL and RBL 6.15 on the wing
center section rear spar with new, improved stiffeners, installing
angle and bonding jumpers, installing brackets, applying sealant, and
applying paint.
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 design.
Proposed AD Requirements
This proposed AD would retain none of the requirements of AD 2005-
20-01. 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,'' and except for any differences identified as exceptions
in the regulatory text of this proposed AD. For certain airplanes,
replacing the vertical stiffeners with new, improved stiffeners, would
terminate the need for the repetitive inspections required by AD 2018-
10-12. 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-2019-0187.
Differences Between This Proposed AD and the Service Information
Boeing Alert Service Bulletin 737-57A1269, Revision 2, dated
October 11, 2018, specifies, for certain airplanes, to do a concurrent
action consisting of a final one-time surface high frequency eddy
current inspection of the keel beam upper chord and general visual
inspection of the angle at LBL 6.50 and RBL 6.50, and all related
applicable actions, as specified in Boeing Alert Requirements Bulletin
737-57A1339 RB, dated April 16, 2018. We have determined that action is
already mandated by AD 2018-10-12. All requirements of AD 2018-10-12
remain in effect.
Costs of Compliance
We estimate that this proposed AD affects 171 airplanes of U.S.
registry. We estimate the following costs to comply with this proposed
AD:
Estimated Costs
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Parts
Action Labor cost cost Cost per product Cost on U.S. operators
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Stiffener replacement, angle Up to 257 work- $14,730 Up to $36,575............ Up to $6,254,325.
and bonding jumper hours x $85 per
installation, bracket hour = $21,845.
installation, and sealant
and paint application.
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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
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.
This proposed AD is issued in accordance with authority delegated
by the Executive Director, Aircraft Certification Service, as
authorized by FAA Order 8000.51C. In accordance with that order,
issuance of ADs is normally a function of the Compliance and
Airworthiness Division, but during this transition period, the
Executive Director has delegated the authority to issue ADs applicable
to transport category airplanes and associated appliances to the
Director of the System Oversight Division.
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)
2005-20-01, Amendment 39-14294 (70 FR 56358, September 27, 2005), and
adding the following new AD:
The Boeing Company: Docket No. FAA-2019-0187; Product Identifier
2018-NM-172-AD.
(a) Comments Due Date
The FAA must receive comments on this AD action by May 16, 2019.
(b) Affected ADs
This AD replaces AD 2005-20-01, Amendment 39-14294 (70 FR 56358,
[[Page 12146]]
September 27, 2005) (``AD 2005-20-01''). This AD terminates certain
requirements of AD 2018-10-12, Amendment 39-19288 (83 FR 23775, May
23, 2018) (``AD 2018-10-12'').
(c) Applicability
This AD applies to all The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, certificated in any
category.
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by reports of cracks in the aft vertical
stiffeners at left buttock line (LBL) and right buttock line (RBL)
6.15 on the rear spar of the wing center section and of cracks found
in the left and right side keel upper chords when replacing vertical
stiffeners. This AD was also prompted by possible degradation of the
fault current bonding path due to the replacement vertical stiffener
installation. We are issuing this AD to address cracks in vertical
stiffeners at LBL and RBL 6.15, which could result in damage to the
keel beam structure and consequently reduce the capability of the
airplane to sustain flight loads. We are also issuing this AD to
address a potential ignition source in the fuel tank due to
insufficient bonding, which could lead to a fuel tank explosion and
subsequent loss of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions for Group 1 and 3 Through 8 Airplanes
For airplanes identified as Group 1 and 3 through 8 in Boeing
Alert Service Bulletin 737-57A1269, Revision 2, dated October 11,
2018: Except as specified by paragraph (j) of this AD, at the
applicable times specified in paragraph 1.E., ``Compliance,'' of
Boeing Alert Service Bulletin 737-57A1269, Revision 2, dated October
11, 2018, do all applicable actions, identified in, and in
accordance with, the Accomplishment Instructions of Boeing Alert
Service Bulletin 737-57A1269, Revision 2, dated October 11, 2018.
Depending on the airplane configuration, applicable actions include
replacing the vertical stiffeners at LBL and RBL 6.15 on the rear
spar of the wing center section, installing angle and bonding
jumpers, installing brackets, applying sealant, and applying paint.
(h) Required Actions for Group 2 Airplanes
For airplanes identified as Group 2 in Boeing Alert Service
Bulletin 737-57A1269, Revision 2, dated October 11, 2018: Within 120
days after the effective date of this AD, do actions to correct the
unsafe condition, using a method approved in accordance with the
procedures specified in paragraph (l) of this AD.
(i) Terminating Action for Repetitive Inspections of Aft Vertical
Stiffener Required by AD 2018-10-12
Accomplishment of the stiffener replacement required by
paragraph (g) of this AD terminates only the repetitive inspections
of the aft vertical stiffeners required by paragraph (h) of AD 2018-
10-12 for that airplane only. All other requirements of paragraph
(h) of AD 2018-10-12 remain in effect.
(j) Exceptions to Service Information Specifications
(1) For purposes of determining compliance with the requirements
of this AD: Where Boeing Alert Service Bulletin 737-57A1269,
Revision 2, dated October 11, 2018, uses the phrase ``the Revision 2
date of this service bulletin,'' this AD requires using ``the
effective date of this AD.''
(2) Where Boeing Alert Service Bulletin 737-57A1269, Revision 2,
dated October 11, 2018, specifies contacting Boeing for repair
instructions: This AD requires doing the repair before further
flight using a method approved in accordance with the procedures
specified in paragraph (l) of this AD.
(k) Credit for Previous Actions
This paragraph provides credit only for the stiffener
replacement required by paragraph (g) of this AD, if those actions
were performed before the effective date of this AD using the
service information identified in paragraph (k)(1) or (k)(2) of this
AD.
(1) Boeing Alert Service Bulletin 737-57A1269, dated December 4,
2003, which is not incorporated by reference in this AD.
(2) Boeing Alert Service Bulletin 737-57A1269, Revision 1, dated
September 16, 2004, which was incorporated by reference in AD 2005-
20-01.
(l) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Los Angeles ACO Branch, 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 certification office, 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, 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, Los Angeles ACO Branch, FAA, 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.
(m) Related Information
(1) For more information about this AD, contact Galib Abumeri,
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch,
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5324; fax: 562-627-5210; email: [email protected].
(2) For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Contractual & Data Services
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; internet https://www.myboeingfleet.com. You may view this referenced service
information at the FAA, Transport Standards Branch, 2200 South 216th
St., Des Moines, WA. For information on the availability of this
material at the FAA, call 206-231-3195.
Issued in Des Moines, Washington, on March 22, 2019.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification
Service.
[FR Doc. 2019-06031 Filed 3-29-19; 8:45 am]
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