[Federal Register Volume 75, Number 170 (Thursday, September 2, 2010)]
[Rules and Regulations]
[Pages 53843-53846]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-20491]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0481; Directorate Identifier 2009-NM-192-AD; 
Amendment 39-16406; AD 2010-17-14]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Model 737-100 and -
200 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Model 737-100 and -200 series airplanes. This AD requires repetitive 
inspections for cracking and damaged fasteners of certain fuselage 
frames and stub beams, and corrective actions if necessary. For certain 
airplanes, this AD also requires 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 AD also requires an inspection to determine the edge 
margin of the lower chord. For airplanes with a certain short edge 
margin, this AD requires repetitive inspections for cracking, and 
corrective actions if necessary; replacing the lower chord terminates 
the repetitive inspections. This AD requires an eventual preventive 
modification. For certain airplanes, doing the modification or a repair 
terminates 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 AD requires repetitive inspections for 
cracking of certain frame webs and inner and outer chords, and 
corrective actions if necessary. For certain other airplanes, this 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 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 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.

DATES: This AD is effective October 7, 2010.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of October 7, 
2010.

ADDRESSES: For service information identified in this 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.

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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527)

[[Page 53844]]

is the Document Management Facility, U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue, SE., Washington, DC 20590.

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: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
certain Model 737-100 and -200 series airplanes. That NPRM was 
published in the Federal Register on May 19, 2010 (75 FR 27969). That 
NPRM proposed to require repetitive inspections for cracking and 
damaged fasteners of certain fuselage frames and stub beams, and 
corrective actions if necessary. For certain airplanes, that NPRM also 
proposed to 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, that NPRM 
also proposed to require an inspection to determine the edge margin of 
the lower chord. For airplanes with a certain short edge margin, that 
NPRM proposed to require repetitive inspections for cracking, and 
corrective actions if necessary; replacing the lower chord would 
terminate the repetitive inspections. That NPRM proposed to require 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, that NPRM 
proposed to require repetitive inspections for cracking of certain 
frame webs and inner and outer chords, and corrective actions if 
necessary. For certain other airplanes, that NPRM proposed to require 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comment received. Boeing supports the NPRM.

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting the 
AD as proposed.

Costs of Compliance

    We estimate that this AD affects 45 airplanes of U.S. registry.
    We estimate that it will take about 4 work-hours per product to 
comply with the required inspections. The average labor rate is $85 per 
work-hour. Based on these figures, we estimate the cost of this 
inspection to the U.S. operators to be $15,300, or $340 per product, 
per inspection cycle.
    We estimate that it will take about 288 work-hours per product to 
comply with the required modification (for Group 1-3 airplanes). The 
average labor rate is $85 per work-hour. Required parts cost about 
$58,742 per product. Based on these figures, we estimate the cost of 
this 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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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 adding the following new AD:

2010-17-14 The Boeing Company: Amendment 39-16406. Docket No. FAA-
2010-0481; Directorate Identifier 2009-NM-192-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective October 7, 
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.

[[Page 53845]]

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, Revision 4, 
dated July 16, 1992) 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, Revision 4, 
dated July 16, 1992) 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 body station 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 
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.

Material Incorporated by Reference

    (o) You must use Boeing Service Bulletin 737-53-1061, Revision 
4, including Addendum, dated July 16, 1992; as applicable; to do the 
actions required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this 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.
    (3) You may review copies of the 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.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.


[[Page 53846]]


    Issued in Renton, Washington, on August 11, 2010.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-20491 Filed 9-1-10; 8:45 am]
BILLING CODE 4910-13-P