Airworthiness Directives; Boeing 737-600, -700, -700C, and -800 Series Airplanes

[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 [www.gpo.gov]
[FR Doc No: E9-28171]


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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.

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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 [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) 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.
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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 [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 
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 
[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 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: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    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

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