AD 2009-24-07
Recurring
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 737-600 | Airworthiness Directives; Boeing 737-600, -700, -700C, and -800 Series Airplanes |
Unsafe Condition
Damage to the protective finishes on the forward trunnion pins for the left and right main landing gear (MLG) may lead to stress corrosion cracking, which could result in fracture of the pins and consequent collapse of the MLG.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Repetitive lubrications of the right and left MLG forward trunnion pins are required. An inspection for discrepancies of the transition radius of the MLG forward trunnion pins is also required, with corrective actions if necessary. For certain airplanes, repetitive detailed inspections for finish damage, corrosion, pitting, and base metal scratches of the transition radius of the left and right MLG trunnion pins are required, with corrective action if necessary. Replacing or overhauling the trunnion pins terminates the AD requirements.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the compliance time specified in the AD, which corresponds to the normal scheduled maintenance for most affected operators.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 737-600, -700, -700C, and -800 series airplanes of U.S. registry.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, and -800 series airplanes. This AD requires repetitive lubrications of the right and left main landing gear (MLG) forward trunnion pins. This AD also requires an inspection for discrepancies of the transition radius of the MLG forward trunnion pins, and corrective actions if necessary. For certain airplanes, this AD also requires repetitive detailed inspections for discrepancies (including finish damage, corrosion, pitting, and base metal scratches) of the transition radius of the left and right MLG trunnion pins, and corrective action if necessary. Replacing or overhauling the trunnion pins terminates the actions required by this AD. This AD results from a report that the protective finishes on the forward trunnion pins for the left and right MLG might have been damaged during final assembly. We are issuing this AD to prevent stress corrosion cracking of the forward trunnion pins, which could result in fracture of the pins and consequent collapse of the MLG.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 74, Number 227 (Friday, November 27, 2009)]
[Rules and Regulations]
[Pages 62231-62233]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: E9-28171]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2009-0411; Directorate Identifier 2008-NM-190-AD;
Amendment 39-16095; AD 2009-24-07]
RIN 2120-AA64
Airworthiness Directives; Boeing 737-600, -700, -700C, and -800
Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: We are adopting a new airworthiness directive (AD) for certain
Boeing Model 737-600, -700, -700C, and -800 series airplanes. This AD
requires repetitive lubrications of the right and left main landing
gear (MLG) forward trunnion pins. This AD also requires an inspection
for discrepancies of the transition radius of the MLG forward trunnion
pins, and corrective actions if necessary. For certain airplanes, this
AD also requires repetitive detailed inspections for discrepancies
(including finish damage, corrosion, pitting, and base metal scratches)
of the transition radius of the left and right MLG trunnion pins, and
corrective action if necessary. Replacing or overhauling the trunnion
pins terminates the actions required by this AD. This AD results from a
report that the protective finishes on the forward trunnion pins for
the left and right MLG might have been damaged during final assembly.
We are issuing this AD to prevent stress corrosion cracking of the
forward trunnion pins, which could result in fracture of the pins and
consequent collapse of the MLG.
DATES: This AD is effective January 4, 2010.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of January 4,
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 <a href="/cdn-cgi/l/email-protection#7d1018531f12181e12103d1f121814131a531e1210"><span class="__cf_email__" data-cfemail="c8a5ade6aaa7adaba7a588aaa7ada1a6afe6aba7a5">[email protected]</span></a>;
Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
Examining the AD Docket
You may examine the AD docket on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a>; 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) 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: Nancy Marsh, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425)
917-6440; 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 Boeing Model 737-600, -700, -700C, and -800 series airplanes.
That NPRM was published in the Federal Register on May 5, 2009 (74 FR
20661). That NPRM proposed to require repetitive lubrications of the
right and left main landing gear (MLG) forward trunnion pins. That NPRM
also proposed to require an inspection for discrepancies of the
transition radius of the MLG forward trunnion pins, and corrective
actions if necessary. For certain airplanes, that NPRM also proposed to
require repetitive detailed inspections for discrepancies (including
finish damage, corrosion, pitting, and base metal scratches) of the
transition radius of the left and right MLG trunnion pins, and
corrective action if necessary. Replacing or overhauling the trunnion
pins would terminate the actions proposed by that NPRM.
Comments
We gave the public the opportunity to participate in developing
this AD. We considered the comments received from the commenters.
Support for the NPRM
Boeing and Alaska Airlines support the NPRM.
Request To Change Reference to Terminating Action in Paragraph (h) of
the Final Rule
Air Transport Association (ATA), on behalf of its member AirTran,
states that paragraph (h) of the NPRM should refer to paragraph (j) of
the NPRM instead of paragraph (i) of the NPRM as the optional
terminating action.
We agree that paragraph (h) of the NPRM should reference paragraph
(j) of the NPRM. We have changed this final rule accordingly.
Request To Clarify Service Information
ATA, on behalf of its member AirTran, states that Boeing Special
Attention Service Bulletin 737-32-1402, dated August 6, 2008 (the
source of service information cited in the NPRM), contains two errors.
AirTran notes a discrepancy between the part number cited in the
materials section of the service bulletin and the Work Instructions.
AirTran states that the section titled ``Parts and Materials Supplied
by the Operator'' of the service bulletin identifies BMS3-26 as
``grease--aircraft general purpose.'' However, AirTran notes that BMS3-
26 is a corrosion-inhibiting compound, and the work instructions for
the lubrication requirement identify Boeing specification BMS3-33 for
the grease. In addition, the materials section of the service bulletin
identifies MS20995NC32 (corrosion-resistant steel). AirTran requests
that we provide clarification regarding the correct safety wire to be
used for the trunnion pin installation to ensure consistent fleet
compliance.
[[Page 62232]]
We agree that the information on page 23 of Boeing Special
Attention Service Bulletin 737-32-1402, dated August 6, 2008, under the
heading ``Parts and Materials Supplied by the Operator'' contains
errors. However, this section of the service bulletin is not mandated
by the AD; therefore, no change to the AD is necessary. We have
requested that Boeing issue an information notice to clarify the intent
of the service bulletin. We have not changed the AD in this regard.
Request To Not Require the Use of Ultrachromate 300
Continental Airlines notes that Part 3 of the Accomplishment
Instructions of Boeing Special Attention Service Bulletin 737-32-1402,
dated August 6, 2008, specifies the use of Ultrachromate 300.
Continental Airlines states that this chemical is a known carcinogen
that requires special handling precautions and states that using this
chemical is better suited in a landing gear shop environment where
adequate safety precautions are in place. Furthermore, Continental
Airlines states there is a risk that using Ultrachromate 300 could
contaminate the surrounding landing gear structures. The commenter
requests that we revise the NPRM to require applying primer and paint
with repetitive lubrications as sufficient protection against
corrosion. The commenter notes that it has overhauled 64 landing gear
sets on Boeing Model 737-700 and -800 series airplanes, and has not
received any reports of corrosion findings on the transition radius of
the forward trunnion pins.
We disagree that applying primer and paint in combination with
repetitive lubrications provides sufficient protection against
corrosion for all affected airplanes. Ultrachromate 300 or equivalent
is used to ensure that the primer adheres properly. We agree that
appropriate precautions should be taken when handling Ultrachromate
300. The procedure for using Ultrachromate 300 was developed with
operator input during an all-operator meeting held in Seattle on
November 6, 2007. We have not changed this AD in this regard. Operators
who wish to use an alternative procedure may request approval of an
AMOC following the procedures outlined in paragraph (k) of this AD.
Request To Extend Compliance Time
Continental Airlines notes that Boeing currently has no forward
trunnion pins in stock, and the lead time for this part is 175 days.
Continental Airlines states that it is concerned that the
unavailability of parts could severely impact its ability to perform
the inspection within the proposed time limits.
We infer that Continental Airlines is requesting that we extend the
compliance time. We do not agree to extend the compliance time. In
developing an appropriate compliance time for this action, we
considered the urgency associated with the subject unsafe condition,
the availability of required parts, and the practical aspect of
accomplishing the required modification within a period of time that
corresponds to the normal scheduled maintenance for most affected
operators. According to the manufacturer, an ample number of required
parts will be available to modify the U.S. fleet within the proposed
compliance time. We have not changed this AD in this regard. However,
according to the provisions of paragraph (k) of the final rule, we may
approve requests to adjust the compliance time if the request includes
data that prove that the new compliance time would provide an
acceptable level of safety.
Request To Clarify Magnification Requirements
ATA, on behalf of its member AirTran, also states that Part I, step
5, of the Work Instructions of Boeing Special Attention Service
Bulletin 737-32-1402, dated August 6, 2008, allows for a range of
magnification from unaided to up to 10X magnification. AirTran
questions the reason for specifying a range of the magnification and
requests that we change the NPRM to require a specific level of
magnification to ensure consistent fleet compliance.
We do not agree to limit the choice provided by the service
bulletin. We have determined that using any of the magnification levels
specified in the service bulletin provides an adequate level of safety.
We have not changed the final rule in this regard.
Conclusion
We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
the AD with the change described previously. We also determined that
this change will not increase the economic burden on any operator or
increase the scope of the AD.
Costs of Compliance
We estimate that this AD affects 100 airplanes of U.S. registry.
The following table provides the estimated costs for U.S. operators to
comply with this AD.
Table--Estimated Costs
----------------------------------------------------------------------------------------------------------------
Average Number of
Work labor U.S.-
Action hours rate per Parts Cost per product registered Fleet cost
hour airplanes
----------------------------------------------------------------------------------------------------------------
Repetitive lubrication......... 1 $80 $0 $80.............. 100 $8,000.
Inspections.................... 8 80 0 $640 per 100 $64,000 per
inspection cycle. inspection
cycle.
----------------------------------------------------------------------------------------------------------------
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
[[Page 62233]]
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:
2009-24-07 Boeing: Amendment 39-16095. Docket No. FAA-2009-0411;
Directorate Identifier 2008-NM-190-AD.
Effective Date
(a) This airworthiness directive (AD) is effective January 4,
2010.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 737-600, -700, -700C, and -
800 series airplanes, certificated in any category; as identified in
Boeing Special Attention Service Bulletin 737-32-1402, dated August
6, 2008.
Subject
(d) Air Transport Association (ATA) of America Code 32: Landing
gear.
Unsafe Condition
(e) This AD results from a report indicating that the protective
finishes on the main landing gear (MLG) forward trunnion pins might
have been damaged during final assembly. We are issuing this AD to
prevent stress corrosion cracking of the forward trunnion pins,
which could result in fracture of the pins and consequent collapse
of the MLG.
Compliance
(f) Comply with this AD within the compliance times specified,
unless already done.
Lubrication
(g) Within 30 days after the effective date of this AD:
Lubricate the left and right MLG forward trunnion pins in accordance
with the Accomplishment Instructions of Boeing Special Attention
Service Bulletin 737-32-1402, dated August 6, 2008. Repeat the
lubrication at intervals not to exceed 30 days until all applicable
requirements of paragraph (h) of this AD have been accomplished.
Inspection and Corrective Actions
(h) Within 60 months after the date of issuance of the original
airworthiness certificate or date of issuance of the original export
certificate of airworthiness, or within 6 months after the effective
date of this AD, whichever occurs later: Except as provided by
paragraph (j) of this AD, do a detailed inspection for discrepancies
(including finish damage, corrosion, pitting, and base metal
scratches) of the transition radius of the left and right MLG
trunnion pins, in accordance with the Accomplishment Instructions of
Boeing Special Attention Service Bulletin 737-32-1402, dated August
6, 2008. Except as provided by paragraph (j) of this AD, at the
times specified in paragraph 1.E., ``Compliance,'' of the service
bulletin, do all applicable repetitive inspections and corrective
actions, in accordance with the service bulletin. Accomplishing the
detailed inspections (initial and repetitive) and all applicable
corrective actions specified in this paragraph terminates the
repetitive lubrication requirements of paragraph (g) of this AD.
No Report Required
(i) Although Boeing Special Attention Service Bulletin 737-32-
1402, dated August 6, 2008, specifies to send inspection reports to
the manufacturer, this AD does not include that requirement.
Optional Terminating Action
(j) Overhauling or replacing a trunnion pin in accordance with
the Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-32-1402, dated August 6, 2008, ends the repetitive
lubrication requirements of paragraph (g) of this AD, and the
actions required by paragraph (h) of this AD, for that pin.
Alternative Methods of Compliance (AMOCs)
(k)(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: Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S,
FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6440; fax (425) 917-6590. Or, e-mail
information to <a href="/cdn-cgi/l/email-protection#6e57432f2023433d0b0f1a1a020b432f2d21432f23212d433c0b1f1b0b1d1a1d2e080f0f40090118"><span class="__cf_email__" data-cfemail="83baaec2cdceaed0e6e2f7f7efe6aec2c0ccaec2ceccc0aed1e6f2f6e6f0f7f0c3e5e2e2ade4ecf5">[email protected]</span></a>.
(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
Delegation Option Authorization Organization who 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 and the approval must specifically refer to this AD.
Material Incorporated by Reference
(l) You must use Boeing Special Attention Service Bulletin 737-
32-1402, dated August 6, 2008, to do the actions required by this
AD, unless the AD specifies otherwise. If you accomplish the
optional terminating action specified in this AD, you must use
Boeing Special Attention Service Bulletin 737-32-1402, dated August
6, 2008, to do those actions, 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
<a href="/cdn-cgi/l/email-protection#85e8e0abe7eae0e6eae8c5e7eae0ecebe2abe6eae8"><span class="__cf_email__" data-cfemail="e48981ca868b81878b89a4868b818d8a83ca878b89">[email protected]</span></a>; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
(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 or 425-227-1152.
(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: <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
Issued in Renton, Washington, on November 12, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E9-28171 Filed 11-25-09; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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