
[Federal Register Volume 80, Number 251 (Thursday, December 31, 2015)]
[Proposed Rules]
[Pages 81795-81797]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-32850]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-8133; Directorate Identifier 2015-NM-101-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company 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 The Boeing Company Model 737-600, -700, -700C, -800, -900, and 
-900ER series airplanes. This proposed AD was prompted by reports of 
heavy corrosion and chrome damage on the forward and aft trunnion pin 
assemblies of the right and left main landing gears (MLGs). This 
proposed AD would require repetitive lubrication of the forward and aft 
trunnion pin assemblies of the right and left MLGs; repetitive 
inspections of these assemblies for corrosion and chrome damage, and 
related investigative and corrective actions if necessary; and the 
installation of new or modified trunnion pin assembly components, which 
would terminate the repetitive lubrication and repetitive inspections. 
We are proposing this AD to detect and correct heavy corrosion and 
chrome damage on the forward and aft trunnion pin assemblies of the 
right and left MLGs, which could result in cracking of these assemblies 
and collapse of the MLGs.

DATES: We must receive comments on this proposed AD by February 16, 
2016.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, 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: Deliver to Mail address above 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, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view this referenced service information 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, WA. For information on the availability of this material at the 
FAA, call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
8133.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
8133; 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 (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Alan Pohl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax: 
425-917-6590; email: alan.pohl@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2015-8133; 
Directorate Identifier 2015-NM-101-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 received reports of heavy corrosion and chrome damage of the 
forward and aft trunnion pin assemblies of the right and left main MLGs 
on Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes. Investigation revealed that the lubrication between the 
forward and aft trunnion pin assemblies and the outer cylinder assembly 
bushings and the lubrication of the aft trunnion bearing ball was not 
sufficient to prevent wear and corrosion. It was also determined that 
the clearances between the forward and aft trunnion pin cross bolt 
bushings and the cross bolts could affect the rate of wear and 
corrosion of the MLG trunnion pin assemblies. Corrosion and chrome 
damage of the forward and aft trunnion pin assemblies of the right and 
left main MLGs, if not corrected, could result in cracking of these 
assemblies and collapse of the MLGs.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Special Attention Service Bulletin 737-32-1448, 
Revision 1, dated May 29, 2015. The service information describes 
procedures for lubricating the forward and aft trunnion pin assemblies 
on the left and right MLGs, inspecting the forward and aft trunnion pin 
assemblies

[[Page 81796]]

for corrosion or damage, and performing corrective actions. In 
addition, the service information describes procedures for installing a 
new forward trunnion pin housing assembly, seal, and retainer 
configuration. This service information is reasonably available because 
the interested parties have access to it through their normal course of 
business or by the means identified in the ADDRESSES section of this 
NPRM.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously, except as discussed 
under ``Differences Between this Proposed AD and the Service 
Information.'' For information on the procedures and compliance times, 
see this service information at http://regulations.gov by searching for 
and locating Docket No. FAA-2015-8133.
    The phrase ``related investigative actions'' is used in this 
proposed AD. ``Related investigative actions'' are follow-on actions 
that (1) are related to the primary actions, and (2) further 
investigate the nature of any condition found. Related investigative 
actions in an AD could include, for example, inspections.
    The phrase ``corrective actions'' is used in this proposed AD. 
``Corrective actions'' are actions that correct or address any 
condition found. Corrective actions in an AD could include, for 
example, repairs.

Costs of Compliance

    We estimate that this proposed AD affects 1,023 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
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                                                                              Cost per          Cost on U.S.
              Action                      Labor cost         Parts cost        product           operators
----------------------------------------------------------------------------------------------------------------
Lubrication.......................  2 work-hours x $85                 $0            $170  $173,190, per
                                     per hour = $170, per                                   lubrication cycle
                                     lubrication cycle.                                     (1,023 airplanes).
Inspection (Groups 1 and 2,         51 work-hours x $85                 0           4,335  $4,282,980, per
 Configuration 1 airplanes).         per hour = $4,335,                                     inspection cycle
                                     per inspection cycle.                                  (988 airplanes).
Inspection (Group 3 airplanes)....  93 work-hours x $85                 0           7,905  $276,675, per
                                     per hour = $7,905,                                     inspection cycle (35
                                     per inspection cycle.                                  airplanes).
Replacement/overhaul (Groups 1 and  84 work-hours x $85                 0           7,140  7,054,320 (988
 2).                                 per hour = $7,140.                                     airplanes).
Replacement/overhaul (Group 3       86 work-hours x $85                 0           7,310  $255,850 (35
 airplanes).                         per hour = $7,310.                                     airplanes).
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    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this proposed 
AD.

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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

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

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 airworthiness 
directive (AD):

The Boeing Company: Docket No. FAA-2015-8133; Directorate Identifier 
2015-NM-101-AD.

(a) Comments Due Date

    We must receive comments by February 16, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to certain The Boeing Company Model 737-600, -
700, -700C, -800, -900, and -900ER series airplanes, certificated in 
any category, as identified in Boeing Special Attention Service 
Bulletin 737-32-1448, Revision 1, dated May 29, 2015.

(d) Subject

    Air Transport Association (ATA) of America Code 32, Landing 
Gear.

[[Page 81797]]

(e) Unsafe Condition

    This AD was prompted by reports of heavy corrosion and chrome 
damage of the forward and aft trunnion pin assemblies of the right 
and left main landing gears (MLG). We are issuing this AD to detect 
and correct heavy corrosion and chrome damage of the forward and aft 
trunnion pin assemblies of the right and left MLGs, which could 
result in cracking of these assemblies and collapse of the MLGs.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Repetitive Lubrication of MLG Trunnion Pin Assemblies

    For airplanes in Groups 1 and 2, Configuration 1, and airplanes 
in Group 3, as identified in Boeing Special Attention Service 
Bulletin 737-32-1448, Revision 1, dated May 29, 2015: Except as 
required by paragraph (k) of this AD, at the applicable time 
specified in Table 1 or Table 2 of paragraph 1.E., ``Compliance,'' 
of Boeing Special Attention Service Bulletin 737-32-1448, Revision 
1, dated May 29, 2015, lubricate the forward and aft trunnion pin 
assemblies of the left and right MLGs, in accordance with Work 
Package 1 of the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-32-1448, Revision 1, dated May 29, 
2015. Repeat the lubrication thereafter at intervals not to exceed 
those specified in paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 737-32-1448, Revision 1, dated May 29, 
2015. Accomplishment of paragraph (i) of this AD terminates the 
repetitive lubrication required by this paragraph.

(h) Repetitive Inspections, Corrective Actions, and Lubrication

    For airplanes in Groups 1 and 2, Configuration 1, and airplanes 
in Group 3, as identified in Boeing Special Attention Service 
Bulletin 737-32-1448, Revision 1, dated May 29, 2015: Except as 
required by paragraph (k) of this AD, at the applicable time 
specified in Table 1 or Table 2 of paragraph 1.E., ``Compliance,'' 
of Boeing Special Attention Service Bulletin 737-32-1448, Revision 
1, dated May 29, 2015, do a general visual inspection of the left 
and right MLGs at the forward and aft trunnion pin locations and the 
visible surfaces of the forward and aft trunnion pin assemblies for 
signs of corrosion or chrome plating damage and lubricate the 
forward and aft trunnion pin assemblies, in accordance with Work 
Package 2 of the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-32-1448, Revision 1, dated May 29, 
2015. Repeat the general visual inspections thereafter at intervals 
not to exceed those specified in paragraph 1.E., ``Compliance,'' of 
Boeing Special Attention Service Bulletin 737-32-1448, Revision 1, 
dated May 29, 2015. If any discrepancy is found during any 
inspection required by this paragraph, before further flight, do all 
applicable related investigative and corrective actions in 
accordance with Work Package 2 of the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 737 32-1448, Revision 1, 
dated May 29, 2015. Accomplishment of the actions required by 
paragraph (i) of this AD terminates the repetitive inspections 
required by this paragraph.

(i) Modification of MLG Trunnion Pin Assemblies

    For airplanes in Groups 1 and 2, Configuration 1, and airplanes 
in Group 3, as identified in Boeing Special Attention Service 
Bulletin 737-32-1448, Revision 1, dated May 29, 2015: Except as 
required by paragraph (k) of this AD, at the applicable time 
specified in Table 1 or Table 2 of paragraph 1.E., ``Compliance,'' 
of Boeing Special Attention Service Bulletin 737-32-1448, Revision 
1, dated May 29, 2015, modify and lubricate the left and right MLG 
trunnion pin assemblies, and do all applicable related investigative 
and corrective actions, in accordance with Work Package 3 of the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-32-1448, Revision 1, dated May 29, 2015. Accomplishment 
of the actions in Work Package 3 of the Accomplishment Instructions 
of Boeing Special Attention Service Bulletin 737-32-1448, Revision 
1, dated May 29, 2015, terminates the repetitive lubrication 
required by paragraph (g) of this AD and the repetitive inspections 
required by paragraph (h) of this AD.

(j) Replacement of MLG Forward Trunnion Pin Housing Assembly Seal and 
Retainer

    For airplanes in Groups 1 and 2, Configuration 2, as identified 
in Boeing Special Attention Service Bulletin 737-32-1448, Revision 
1, dated May 29, 2015: At the applicable time specified in Table 3, 
paragraph 1.E., ``Compliance,'' of Boeing Special Attention Service 
Bulletin 737-32-1448, Revision 1, dated May 29, 2015, replace the 
seal, retainer, and support ring assembly with a new seal and 
retainer configuration, install the forward trunnion pin assembly 
into the housing assembly, and lubricate the forward and aft 
trunnion pin assemblies for the left and right MLGs, in accordance 
with Work Package 4 of the Accomplishment Instructions of Boeing 
Special Attention Service Bulletin 737-32-1448, Revision 1, dated 
May 29, 2015.

(k) Exception to Service Information Specification

    Where paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 737-32-1448, Revision 1, dated May 29, 
2015, specifies a compliance time ``from the original issue date on 
this service bulletin,'' this AD requires compliance within the 
specified compliance time ``after the effective date of this AD.''

(l) Credit for Previous Actions

    This paragraph provides credit for the requirements of paragraph 
(g) of this AD, if those actions were performed before the effective 
date of this AD using Boeing Special Attention Service Bulletin 737-
32-1448, dated May 19, 2011, which is not incorporated by reference 
in this AD.

(m) Alternative Methods of Compliance (AMOCs)

    (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. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in paragraph (n) of this AD. 
Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO to make those findings. To be approved, the 
repair method, modification deviation, or alteration deviation must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.

(n) Related Information

    (1) For more information about this AD, contact Alan Pohl, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; 
phone: 425-917-6450; fax: 425-917-6590; email: alan.pohl@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view this referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, WA. For information on the availability of this 
material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on December 21, 2015.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-32850 Filed 12-30-15; 8:45 am]
 BILLING CODE 4910-13-P


