[Federal Register Volume 77, Number 143 (Wednesday, July 25, 2012)]
[Proposed Rules]
[Pages 43547-43550]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-18147]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2012-0723; Directorate Identifier 2011-NM-137-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 737-600, -700, -700C, -800, and -900
series airplanes. This proposed AD was prompted by a report of cracks
found in the skin at body station (STA) 540 just below stringer S-22L
on a Model 737-700 series airplane. This proposed AD would require
repetitive detailed and high frequency eddy current inspections for
cracking of the skin around the eight fasteners common to the ends of
the STA 540 bulkhead chords between stringers S-22 and S-23, left and
right sides; and corrective actions and preventive modification if
necessary. We are proposing this AD to detect and correct fatigue
cracking in the skin, which can result in rapid decompression of the
cabin.
DATES: We must receive comments on this proposed AD by September 10,
2012.
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
[[Page 43548]]
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 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; 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: Alan Pohl, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax:
425-917-6590; email: [email protected].
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include ``Docket No. FAA-2012-0723;
Directorate Identifier 2011-NM-137-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
We received a report of cracks found in the skin at body station
(STA) 540 just below stringer S-22L on a Model 737-700 series airplane.
Subsequent investigation revealed that the design at the STA 540
bulkhead chords has insufficient load path where the chords meet
between stringers S-22 and S-23 on both the left and right sides of the
airplane. This condition, if not corrected, could result in fatigue
cracking in the skin, which can result in rapid decompression of the
cabin.
Relevant Service Information
We reviewed Boeing Special Attention Service Bulletin 737-53-1294,
dated March 31, 2011. The service information describes procedures for
repetitive detailed and high frequency eddy current (HFEC) inspections
for cracking of the skin around the eight fasteners common to the ends
of the STA 540 bulkhead chords between stringers S-22 and S-23, and
corrective actions and preventive modification if necessary. The
preventive modification includes doing an open-hole HFEC inspection for
cracking of the skin and STA 540 bulkhead chords, installing a new
chord splice plate, and repair if necessary. The corrective actions
include repairing cracking, and doing preventive modifications on any
side on which cracking is not found.
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 described previously, except as discussed
under ``Differences Between the Proposed AD and the Service
Information.''
Differences Between the Proposed AD and the Service Information
Boeing Special Attention Service Bulletin 737-53-1294, dated March
31, 2011, 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.
Clarification of Repetitive Inspections
The Repeat Interval column of table 1 of paragraph 1.E.,
``Compliance,'' of Boeing Special Attention Service Bulletin 737-53-
1294, dated March 31, 2011, specifies repetitive detailed and HFEC
inspections at intervals not to exceed 4,000 flight cycles, and the
Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-53-1294, dated March 31, 2011, specify repetitive detailed
inspections only. We have determined that doing both repetitive
detailed and HFEC inspections is necessary to address the unsafe
condition of this AD.
Clarification of Post-Repair Inspections
Paragraph (j), and Note 1 to paragraph (j), of this proposed AD
clarify that the post-repair inspections specified in Table 2 of
paragraph 1.E., ``Compliance,'' of Boeing Special Attention Service
Bulletin 737-53-1294, dated March 31, 2011, are not required by this
proposed AD.
Costs of Compliance
We estimate that this proposed AD affects 903 airplanes of U.S.
registry.
We estimate the following costs to comply with this proposed AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product Cost on U.S. operators
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Inspection (left and right 3 work-hours x $0 $255 per $230,265 per inspection cycle.
sides). $85 per hour = inspection
$255 per cycle.
inspection
cycle.
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We estimate the following costs to do any necessary repairs and
inspections 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:
[[Page 43549]]
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Preventive modification (each side). 6 work-hours x $85 per $894 $1,404.
hour = $510.
Skin repair (each side)............. 55 work-hours x $85 Up to $5,635 Up to $10,310.
per hour = $4,675.
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According to the manufacturer, some of the costs of this proposed
AD may be covered under warranty, thereby reducing the cost impact on
affected individuals. We do not control warranty coverage for affected
individuals. As a result, we have included all costs in our cost
estimate.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national Government and the States, or on the distribution
of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
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]
2. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive (AD):
The Boeing Company: Docket No. FAA-2012-0723; Directorate Identifier
2011-NM-137-AD.
(a) Comments Due Date
We must receive comments by September 10, 2012.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, and -900 series airplanes; certificated in any category;
as identified in Boeing Special Attention Service Bulletin 737-53-
1294, dated March 31, 2011.
(d) Subject
Joint Aircraft System Component (JASC)/Air Transport Association
(ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by a report of cracks found in the skin at
body station (STA) 540 just below stringer S-22L. We are issuing
this AD to detect and correct fatigue cracking in the skin, which
can result in rapid decompression of the cabin.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Inspection and Corrective Action
(1) Except as required by paragraphs (g)(2), (i)(2), (i)(3), and
(i)(4) of this AD, at the applicable time specified in table 1 of
paragraph 1.E. ``Compliance,'' of Boeing Special Attention Service
Bulletin 737-53-1294, dated March 31, 2011: Do detailed and high
frequency eddy current (HFEC) inspections of the skin for cracking
in the area around the eight fasteners securing the STA 540 bulkhead
chords between stringers S-22 and S-23, and do all applicable
corrective actions, in accordance with Parts 1, 2, 3, 4, and 5 of
the Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-53-1294, dated March 31, 2011, except as required by
paragraph (i)(1) of this AD. If no cracking is found, repeat the
detailed and HFEC inspections at the intervals specified in table 1
of paragraph 1.E., ``Compliance,'' of Boeing Special Attention
Service Bulletin 737-53-1294, dated March 31, 2011, except as
required by paragraph (g)(2) of this AD, until the optional
preventive modification specified in paragraph (h) of this AD is
done. Do all applicable corrective actions before further flight.
(2) For airplanes that have incorporated Boeing Business Jet
Lower Cabin Altitude Supplemental Type Certificate (STC) ST01697SE
(6,500 feet maximum cabin altitude in lieu of 8,000 feet), the
flight-cycle related compliance times are different from those
specified in Boeing Special Attention Service Bulletin 737-53-1294,
dated March 31, 2011. All initial compliance times specified in
total flight cycles or flight cycles must be reduced to half of
those specified in Boeing Special Attention Service Bulletin 737-53-
1294, dated March 31, 2011. All repetitive interval compliance times
specified in flight cycles must be reduced to one-quarter of those
specified in Boeing Special Attention Service Bulletin 737-53-1294,
dated March 31, 2011.
(h) Optional Preventive Modification
Accomplishing the preventive modification, including an HFEC
inspection for cracking of the skin and STA 540 bulkhead chords, and
all applicable repairs, in accordance with paragraph 3.B, Part 2 or
Part 4 (left side), and Part 3 or Part 5 (right side), of the
Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-53-1294, dated March 31, 2011, terminates the
inspection requirements of paragraph (g) of this AD for the side on
which the modification is done, except as required by paragraph
(i)(1) of this AD.
(i) Exceptions to Service Bulletin Specifications
(1) If any cracking is found during any inspection required by
this AD, and Boeing Special Attention Service Bulletin 737-53-1294,
dated March 31, 2011, specifies to contact Boeing for appropriate
action: Before further flight, repair using a method approved in
accordance with the procedures specified in paragraph (k) of this
AD.
[[Page 43550]]
(2) Where Boeing Special Attention Service Bulletin 737-53-1294,
dated March 31, 2011, specifies to do the action after the original
issue date of that service bulletin, this AD requires the compliance
time after the effective date of this AD.
(3) Where the Condition column of table 1 of paragraph 1.E.,
``Compliance,'' of Boeing Special Attention Service Bulletin 737-53-
1294, dated March 31, 2011, specifies a condition as of the original
issue date of that service bulletin, this AD specifies the condition
as of the effective date of this AD.
(4) Note 1 of paragraph 3.A. of the Accomplishment Instructions
of Boeing Special Attention Service Bulletin 737-53-1294, dated
March 31, 2011, is to be disregarded when accomplishing the actions
required by this AD.
(j) Post-Repair Inspections
The post-repair inspections, specified in Table 2 of paragraph
1.E., ``Compliance,'' of Boeing Special Attention Service Bulletin
737-53-1294, dated March 31, 2011, are not required by this AD.
Note 1 to paragraph (j) of this AD: The damage tolerance
inspections specified in Table 2 of paragraph 1.E., ``Compliance,''
of Boeing Special Attention Service Bulletin 737-53-1294, dated
March 31, 2011, may be used in support of compliance with Section
121.1109(c)(2) or 129.109(c)(2) of the Federal Aviation Regulations
(14 CFR 121.1109(c)(2) or 14 CFR 129.109(c)(2)). The corresponding
actions specified in the Accomplishment Instructions of Boeing
Special Attention Service Bulletin 737-53-1294, dated March 31,
2011, are not required by this AD.
(k) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Seattle 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, it may be emailed to: [email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(3) An AMOC that provides an acceptable level of safety may be
used for any repair required by this AD if it is approved by the
Boeing Commercial Airplanes Organization Designation Authorization
(ODA) that has been authorized by the Manager, Seattle Aircraft
Certification Office (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.
(l) Related Information
(1) For more information about this AD, contact Alan Pohl,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356;
phone: 425-917-6450; 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 review copies of the 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 July 17, 2012.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2012-18147 Filed 7-24-12; 8:45 am]
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