[Federal Register Volume 75, Number 88 (Friday, May 7, 2010)]
[Proposed Rules]
[Pages 25124-25127]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-10902]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0437; Directorate Identifier 2009-NM-130-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model 737-200, -300,
-400, and -500 Series 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 Model 737-200, -300, -400, and -500 series airplanes. This
proposed AD would require repetitive inspections for cracking of
certain fuselage frames and stub beams, and corrective actions if
necessary. This proposed AD also provides for an optional repair, which
would terminate the repetitive inspections. For airplanes on which a
certain repair is done, this proposed AD would also require repetitive
inspections for cracking of certain fuselage frames and stub beams, and
corrective actions if necessary. This proposed AD results from reports
of the detection of fatigue cracks at certain frame sections, in
addition to stub beam cracking, caused by high flight cycle stresses
from both pressurization and maneuver loads. We are proposing this AD
to detect and correct fatigue cracking of certain fuselage frames and
stub beams and possible severed frames, which could result in reduced
structural integrity of the frames. This reduced structural integrity
can increase loading in the fuselage skin, which will accelerate skin
crack growth and could result in rapid decompression of the fuselage.
DATES: We must receive comments on this proposed AD by June 21, 2010.
ADDRESSES: You may send comments 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: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m.
[[Page 25125]]
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,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1, fax 206-766-5680; e-mail [email protected];
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.
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 (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Wayne Lockett, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425)
917-6447; fax (425) 917-6590.
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-2010-0437;
Directorate Identifier 2009-NM-130-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 have received reports of fatigue cracks at certain frame
sections, in addition to stub beam cracking. The fatigue cracking is
caused by high flight cycle stresses from both pressurization and
maneuver loads. Reduced structural integrity of the frames can increase
loading in the fuselage skin, which will accelerate skin crack growth
and could result in rapid decompression of the fuselage.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 737-53A1254,
Revision 1, dated July 9, 2009. The service bulletin describes
procedures for, among other actions, repetitive detailed inspections
for cracks in the body station (BS) 616 and BS 639 frame webs, inner
chord, and outer chord, and the stub beam, and corrective actions if
necessary. The corrective actions include repair of any cracking before
further flight. The procedures also recommend contacting Boeing for
repair instructions for certain cracking and repairing before further
flight.
As an option to the detailed inspection, the service bulletin
describes procedures for a high frequency eddy current (HFEC)
inspection for cracks in the same areas, and repair of any crack found.
The service bulletin also describes procedures for doing a detailed
inspection of the inner chord along the length of the repair and around
the fastener heads if a repair or preventative modification exists on
the inner chord below the floor that prevents the accomplishment of the
detailed or HFEC inspection in that area.
For airplanes on which a certain repair is done, the service
bulletin describes procedures for repetitive detailed or HFEC
inspections for cracking of the replacement frame section (frame webs,
inner chord, and outer chord), and contacting Boeing for repair
instructions if any crack is found, and repairing before further
flight.
FAA's Determination and Requirements of This Proposed AD
We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
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 Boeing Alert Service Bulletin
737-53A1254, Revision 1, dated July 9, 2009.''
Differences Between the Proposed AD and Boeing Alert Service Bulletin
737-53A1254, Revision 1, Dated July 9, 2009
Although the service bulletin specifies economic inspections and
repairs of BS 597 and BS 601 frames, this proposed AD would not require
those inspections and repairs.
Although the service bulletin does not address accomplishing the
inspections for airplanes on which fewer than 15,000 total flight
cycles have been accumulated, this proposed AD would require the
inspections on those airplanes.
The service bulletin specifies to contact the manufacturer for
instructions on repairing cracks, but this proposed AD would require
repairing cracks in one of the following ways:
Using 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) that we have
authorized to make those findings.
Costs of Compliance
We estimate that this proposed AD would affect 635 airplanes of
U.S. registry. The following table provides the estimated costs for
U.S. operators to comply with this proposed AD.
Estimated Costs
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Number of U.S.-
Action Work hours Average labor Cost per product registered Fleet cost
rate per hour airplanes
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BS 616 and BS 639 inspection/ 15 $85 $1,275, per 635 $809,625 per inspection cycle.
lower frame and stub beam. inspection cycle.
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[[Page 25126]]
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), and
3. 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.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.
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 AD:
The Boeing Company: Docket No. FAA-2010-0437; Directorate Identifier
2009-NM-130-AD.
Comments Due Date
(a) We must receive comments by June 21, 2010.
Affected ADs
(b) None.
Applicability
(c) This AD applies to The Boeing Company Model 737-200, -300, -
400, and -500 series airplanes, certificated in any category; as
identified in Boeing Alert Service Bulletin 737-53A1254, Revision 1,
dated July 9, 2009.
Subject
(d) Air Transport Association (ATA) of America Code 53:
Fuselage.
Unsafe Condition
(e) This AD results from the detection of fatigue cracks at
certain frame sections, in addition to stub beam cracking, caused by
high flight cycle stresses from both pressurization and maneuver
loads. The Federal Aviation Administration is issuing this AD to
detect and correct fatigue cracking of certain fuselage frames and
stub beams and possible severed frames, which could result in
reduced structural integrity of the frames. This reduced structural
integrity can increase loading in the fuselage skin, which will
accelerate skin crack growth and could result in rapid decompression
of the fuselage.
Compliance
(f) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Repetitive Inspections and Corrective Actions
(g) At the applicable time specified in paragraph (g)(1),
(g)(2), or (g)(3) of this AD: Do a detailed or high frequency eddy
current (HFEC) inspection for cracking of body station (BS) 616 and
BS 639 frame webs, inner chord, and outer chord, and the stub beams;
and do all applicable related investigative and corrective actions;
by accomplishing all the actions specified in Part 1 of the
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1254, Revision 1, dated July 9, 2009, except as specified in
paragraphs (i) and (j) of this AD. Do all applicable related
investigative and corrective actions before further flight.
Thereafter, repeat the inspection at intervals not to exceed 4,500
flight cycles since accomplishing the detailed inspection or at
intervals not to exceed 9,000 flight cycles since accomplishing the
HFEC inspection, as applicable.
(1) For airplanes on which no inspection of the BS 616 and BS
639 frames specified in Boeing Alert Service Bulletin 737-53A1254,
dated February 17, 2005, has been done as of the effective date of
this AD, and that have accumulated fewer than 55,000 total flight
cycles as of the effective date of this AD: Inspect within 3,000
flight cycles after the effective date of this AD, or before the
accumulation of 56,500 total flight cycles, whichever occurs first.
(2) For airplanes on which no inspection of the BS 616 and BS
639 frames specified in Boeing Alert Service Bulletin 737-53A1254,
dated February 17, 2005, has been done as of the effective date of
this AD, and that have accumulated 55,000 or more total flight
cycles as of the effective date of this AD: Inspect within 1,500
flight cycles after the effective date of this AD.
(3) For airplanes on which a detailed or HFEC inspection of the
BS 616 and BS 639 frames, specified in Boeing Alert Service Bulletin
737-53A1254, dated February 17, 2005, has been done as of the
effective date of this AD: Inspect at the later of the times
specified in paragraphs (g)(3)(i) and (g)(3)(ii) of this AD.
(i) Within 3,000 flight cycles after the effective date of this
AD.
(ii) Within 4,500 flight cycles after the previous inspection
done in accordance with Boeing Alert Service Bulletin 737-53A1254,
dated February 17, 2005.
Post-Repair Repetitive Inspections and Corrective Actions
(h) For airplanes on which the repair specified in Part 4 of the
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1254, Revision 1, dated July 9, 2009, has been done: At the
applicable time specified in paragraphs (h)(1) and (h)(2) of this
AD, do a detailed or HFEC inspection for cracking of the replacement
frame section (frame webs, inner chord, and outer chord); and do all
applicable related investigative and corrective actions; by
accomplishing all the actions specified in Part 1 of the
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1254, Revision 1, dated July 9, 2009, except as specified in
paragraphs (i) and (j) of this AD. Do all applicable related
investigative and corrective actions before further flight.
Thereafter, repeat the inspection at intervals not to exceed 4,500
flight cycles since accomplishing the detailed inspection or at
intervals not to exceed 9,000 flight cycles since accomplishing the
HFEC inspection, as applicable.
(1) For airplanes on which a partial frame splice repair at BS
616 or BS 639 has been done, and the inner chord and web have been
cold-worked: Inspect within 44,000 flight cycles after the repair
has been done.
(2) For airplanes on which a partial frame splice repair at BS
616 or BS 639 has been done, and the inner chord and web have not
been cold-worked: Inspect within 29,000 flight cycles after that
repair has been done.
Alternative Inspection of Repaired or Modified Area
(i) For airplanes on which a repair or preventative modification
exists on the inner chord below the floor which prevents the
accomplishment of the detailed or HFEC inspection in that area as
required by paragraph (g) of this AD: In lieu of inspecting that
area, do a detailed inspection of the
[[Page 25127]]
inner chord along the length of the repair and around the fastener
heads in accordance with Part 1 of the Accomplishment Instructions
of Boeing Alert Service Bulletin 737-53A1254, Revision 1, dated July
9, 2009.
Exceptions to Service Information
(j) Where Boeing Alert Service Bulletin 737-53A1254, Revision 1,
dated July 9, 2009, specifies to contact Boeing for repair
instructions and repair: Before further flight, repair the cracking
using a method approved in accordance with the procedures specified
in paragraph (m) of this AD.
(k) Although Boeing Alert Service Bulletin 737-53A1254, Revision
1, dated July 9, 2009, specifies to submit information to the
manufacturer, this AD does not include that requirement.
Terminating Action
(l) Doing the repair specified in Part 4 of Boeing Alert Service
Bulletin 737-53A1254, Revision 1, dated July 9, 2009, terminates the
repetitive inspection requirements of paragraph (g) of this AD for
the repaired frame only.
Alternative Methods of Compliance (AMOCs)
(m)(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. Send information to
ATTN: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-120S,
FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW.,
Renton, Washington 98057-3356; telephone (425) 917-6447; fax (425)
917-6590. Or, e-mail information to [email protected].
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, or lacking a
principal inspector, your local Flight Standards District Office.
The AMOC approval letter must specifically reference this AD.
(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 an
Authorized Representative for the Boeing Commercial Airplanes
Organization Designation Authorization (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.
Issued in Renton, Washington, on April 28, 2010.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-10902 Filed 5-6-10; 8:45 am]
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