[Federal Register Volume 75, Number 96 (Wednesday, May 19, 2010)]
[Proposed Rules]
[Pages 27969-27972]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-11905]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0481; Directorate Identifier 2009-NM-192-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model 737-100 and -
200 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Model 737-100 and -200 series airplanes. This proposed AD would
require repetitive inspections for cracking and damaged fasteners of
certain fuselage frames and stub beams, and corrective actions if
necessary. For certain airplanes, this proposed AD would also require
repetitive inspections for cracking of the inboard chord fastener hole
of the frame at body station 639, stringer S-16, and corrective actions
if necessary. For certain airplanes, this proposed AD would also
require an inspection to determine the edge margin of the lower chord.
For airplanes with a certain short edge margin, this proposed AD
requires repetitive inspections for cracking, and corrective actions if
necessary; replacing the lower chord terminates the repetitive
inspections. This proposed AD requires an eventual preventive
modification. For certain airplanes, doing the modification or a repair
would terminate the repetitive inspections for the repaired or modified
frame only. For airplanes on which the modification or repair is done
at certain body stations, this proposed AD would require repetitive
inspections for cracking of certain frame webs and inner and outer
chords, and corrective actions if necessary. For certain other
airplanes, this proposed AD requires a modification which includes
reinforcing the body frame inner chords, replacing the stub beam upper
chords and attach angles, and reinforcing the stub beam web. This
proposed AD results from reports of fatigue cracks at certain frame
sections, in addition to stub beam cracking, caused by high flight
cycle stresses from both pressurization and maneuver load. 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 result in rapid
decompression of the fuselage.
DATES: We must receive comments on this proposed AD by July 6, 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. 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-2010-0481;
Directorate Identifier 2009-NM-192-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 found at certain frame
sections, in addition to stub beam cracking, caused by high flight
cycle stresses from both pressurization and maneuver load. Numerous
cracks were found in the shear ties, webs, and inboard and outboard
chords of the overwing body frames and stub beams between body stations
559 and 639. Cracks were also found in the webs, attach angles, and the
upper and lower chords of the stub beams. There were reports of sheared
fasteners in the overwing body frames and stub beams in the same
location.
Fatigue cracking of certain fuselage frames and stub beams, if not
detected and corrected, and possible severed frames, 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 result in rapid decompression of the
fuselage.
Relevant Service Information
We have reviewed Boeing Service Bulletin 737-53-1061, Revision 4,
including Addendum, dated July 16, 1992. For airplanes on which a
repair (Part III) or preventive modification (Part II) has not been
done, the service bulletin describes procedures for
[[Page 27970]]
repetitive detailed inspections for cracks and damaged fasteners in the
circumferential frame and the stub beam at body stations 559, 578, 597,
616, and 639, and corrective actions if necessary. For Group 1-3
airplanes, the service bulletin describes procedures for repetitive
eddy current inspections for cracking of the inboard chord fastener
hole of the frame at body station 639, stringer S-16, and corrective
actions if necessary. For airplanes on which certain stub beam lower
chords were installed, the service bulletin describes procedures for an
inspection to determine if a short edge margin exists in the lower
chord and, for airplanes with a certain short edge margin, repetitive
inspections for cracking and corrective actions if necessary. For
airplanes on which either circumferential frame at body station 597 was
changed as given in Boeing Service Bulletin 737-53-1061, Revision 1,
dated December 16, 1983; Revision 2, dated April 18, 1986; or Revision
3, dated June 15, 1989; the service bulletin describes procedures for
repetitive detailed inspections for cracking of the frame.
This service bulletin also describes a preventive modification,
which would eliminate the need for the repetitive inspections. For
airplanes on which the modification or repair is done at body stations
616 and 639, the service bulletin describes procedures for repetitive
detailed inspections for cracking of the body station 616 and 639 frame
webs and inner and outer chords, near stringer S-16, and corrective
actions if necessary.
The corrective actions include doing a repair for any cracking and
damaged fasteners that are within the limits specified, replacing a
cracked component by installation of a preventive modification if the
cracks are outside the limits, and contacting Boeing for instructions
if cracks or damaged fasteners cannot be repaired in accordance with
the specified procedures or if the upper chord was replaced at a
certain location.
For Group 1-3 airplanes, the service bulletin describes procedures
for a modification, which includes reinforcing the body frame inner
chords, replacing the stub beam upper chords and attach angles, and
reinforcing the stub beam web at body stations 597, 616, and 639.
Related Rulemaking
We are in the process of issuing an AD that refers to Boeing Alert
Service Bulletin 737-53A1254, Revision 1, dated July 9, 2009, and is
related to this proposed AD. That service information applies to Model
737-200, -300, -400, and -500 series airplanes. During review of that
service information it was determined that the same unsafe condition
exists on earlier Boeing Model 737-100 and -200 series airplanes
identified in Boeing Service Bulletin 737-53-1061, Revision 4, dated
July 16, 1992, referred to in this proposed AD as the appropriate
source of service information for accomplishing the actions.
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 the Service Information.''
Differences Between the Proposed AD and the Service Information
Although the Accomplishment Instructions of Boeing Service Bulletin
737-53-1061, Revision 4, dated July 16, 1992, include a modification
for Group 4 airplanes (Model 737-200C airplanes), the applicability of
this proposed AD does not include those airplanes. This proposed AD is
applicable to passenger airplanes only.
The service bulletin also 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 Delegation Authorization (ODA) that we have
authorized to make those findings.
Costs of Compliance
We estimate that this proposed AD would affect 45 airplanes of U.S.
registry.
We estimate that it would take about 4 work-hours per product to
comply with the proposed inspections. The average labor rate is $85 per
work-hour. Based on these figures, we estimate the cost of this
proposed inspection to the U.S. operators to be $15,300, or $340 per
product, per inspection cycle.
We estimate that it would take about 288 work-hours per product to
comply with the proposed modification (for Group 1-3 airplanes). The
average labor rate is $85 per work-hour. Required parts would cost
about $58,742 per product. Based on these figures, we estimate the cost
of this proposed modification to the U.S. operators to be $83,222 per
product.
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:
[[Page 27971]]
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-2010-0481; Directorate Identifier
2009-NM-192-AD.
Comments Due Date
(a) We must receive comments by July 6, 2010.
Affected ADs
(b) None.
Applicability
(c) This AD applies to The Boeing Company Model 737-100 and -200
series airplanes, certificated in any category; line numbers 1
through 848 inclusive.
Subject
(d) Air Transport Association (ATA) of America Code 53:
Fuselage.
Unsafe Condition
(e) This AD results from reports of fatigue cracks at certain
frame sections, in addition to stub beam cracking, caused by high
flight cycle stresses from both pressurization and maneuver load.
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 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.
Inspections
(g) For airplanes on which a repair (Part III of the
Accomplishment Instructions of Boeing Service Bulletin 737-53-1061)
or preventive modification (Part II of the Accomplishment
Instructions of Boeing Service Bulletin 737-53-1061) has not been
done in accordance with Boeing Service Bulletin 737-53-1061 as of
the effective date of this AD: Before the accumulation of 15,000
total flight cycles or within 3,000 flight cycles after the
effective date of this AD, whichever occurs later, do the
inspections required by paragraphs (g)(1) and (g)(2) of this AD, in
accordance with the Accomplishment Instructions of Boeing Service
Bulletin 737-53-1061, Revision 4, dated July 16, 1992. Repeat the
inspection at the time specified, until the terminating action
required by paragraph (l) of this AD is done.
(1) Do a detailed inspection (Part I of the Accomplishment
Instructions of Boeing Service Bulletin 737-53-1061) for cracks and
damaged fasteners of the fuselage frames and stub beams. If no crack
or damaged fastener is found, repeat the inspection thereafter at
intervals not to exceed 4,500 flight cycles.
(2) Do an eddy current inspection (Part IV of the Accomplishment
Instructions of Boeing Service Bulletin 737-53-1061) for cracking of
the inboard chord fastener hole of the frame at body station 639,
stringer S-16. If no crack is found, repeat the inspection
thereafter at intervals not to exceed 15,000 flight cycles.
Note 1: Access and restoration instructions, as detailed in the
Accomplishment Instructions of Boeing Service Bulletin 737-53-1061,
Revision 4, dated July 16, 1992, are not required by this AD.
Operators may do those actions in accordance with their maintenance
practices.
(h) For airplanes on which the body station 597 frame was
changed as of the effective date of this AD, in accordance with the
Accomplishment Instructions of Boeing Service Bulletin 737-53-1061,
dated May 28, 1982; Revision 1, dated December 16, 1983; Revision 2,
dated April 18, 1986; or Revision 3, dated June 15, 1989: Within
3,000 flight cycles after the effective date of this AD, do a
detailed inspection for cracking of the frame, in accordance with
the Accomplishment Instructions of Boeing Service Bulletin 737-53-
1061, Revision 4, dated July 16, 1992. Repeat the detailed
inspection thereafter at intervals not to exceed 4,500 flight
cycles. Installation of new radius fillers in accordance with the
Accomplishment Instructions of Boeing Service Bulletin 737-53-1061,
Revision 4, dated July 16, 1992, terminates the inspections required
by this paragraph.
(i) For airplanes on which a stub beam lower chord with \1/4\-
inch diameter fasteners at body station 597 is installed as of the
effective date of this AD, in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 737-53-1061, Revision 1,
dated December 16, 1983; Revision 2, dated April 18, 1986; or
Revision 3, dated June 15, 1989: Within 3,000 flight cycles after
the effective date of this AD, do a detailed inspection for short
edge margins. If the short edge margin is determined to be less than
1.5D (diameter), before further flight, do a detailed inspection for
cracking of the stub beam lower chords, in accordance with Boeing
Service Bulletin 737-53-1061, Revision 4, dated July 16, 1992.
Repeat the detailed inspection thereafter at intervals not to exceed
4,500 flight cycles, if the edge margin is less than 1.5D. If the
edge margin is greater than or equal to 1.5D, no further action is
required by this paragraph. Replacing the lower chord in accordance
with Boeing Service Bulletin 737-53-1061, Revision 4, dated July 16,
1992, terminates the repetitive inspections specified in this
paragraph.
Corrective Actions
(j) Except as required by paragraph (k) of this AD, if any crack
or damaged fastener is found during any inspection required by this
AD, before further flight, repair if cracking and damaged fasteners
are within the specified limits, or do a preventive modification if
cracking or damaged fasteners are outside the specified limits, in
accordance with the Accomplishment Instructions of Boeing Service
Bulletin 737-53-1061, Revision 4, dated July 16, 1992.
Exception to Service Information
(k) Where Boeing Service Bulletin 737-53-1061, Revision 4, dated
July 16, 1992, specifies to contact Boeing for repair instructions:
Before further flight, repair using a method approved in accordance
with the procedures specified in paragraph (n) of this AD.
Terminating Action (Preventive Modification) for Certain Inspections
(l) Before the accumulation of 75,000 total flight cycles: Do
the preventive modification in accordance with Part II, or repair in
accordance with Part III, of the Accomplishment Instructions of
Boeing Service Bulletin 737-53-1061, Revision 4, dated July 16,
1992. The modification or repair terminates the repetitive
inspection requirements of this AD for the repaired or modified
frame only, except as required by paragraph (m) of this AD.
Post-Modification or Repair Inspections
(m) For airplanes on which a repair or modification at body
station 616 or 639 is done: Within 24,000 flight cycles after doing
the repair or modification, or within 3,000 flight cycles after the
effective date of this AD, whichever occurs later, do a detailed
inspection for cracking of the BS 616 and 639 frame webs, inner
chord, and outer chord near stringer S-16, in accordance with Boeing
Service Bulletin 737-53-1061, Revision 4, dated July 16, 1992.
(1) If no cracking is found, repeat the inspection thereafter at
intervals not to exceed 4,500 flight cycles.
(2) If any cracking is found, before further flight, repair the
cracking using a method approved in accordance with the procedures
specified in paragraph (n) of this AD.
Alternative Methods of Compliance (AMOCs)
(n)(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 the
[[Page 27972]]
Boeing Commercial Airplanes Organization Delegation 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 May 5, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-11905 Filed 5-18-10; 8:45 am]
BILLING CODE 4910-13-P