[Federal Register Volume 77, Number 84 (Tuesday, May 1, 2012)]
[Proposed Rules]
[Pages 25647-25649]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-10489]



[[Page 25647]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0424; Directorate Identifier 2011-NM-004-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 all 
The Boeing Company Model 777 airplanes. This proposed AD was prompted 
by heat damage and cracks at the pivot joint location of the main 
landing gear (MLG) inner cylinder/truck beam. This proposed AD would 
require repetitive lubrication of the MLG pivot joints; repetitive 
detailed inspections of the outer diameter chrome on the center axles 
of the MLG for chicken-wire cracks, corrosion, and chrome plate 
distress; repetitive magnetic particle inspections of the outer 
diameter chrome on the center axles of the MLG for cracks; and related 
investigative and corrective actions if necessary. We are proposing 
this AD to detect and correct cracking in the MLG center axle and shock 
strut inner cylinder lugs (pivot joint), which could result in fracture 
of the MLG pivot joint components and consequent collapse of the MLG.

DATES: We must receive comments on this proposed AD by June 15, 2012.

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, Washington 98124-2207; phone: 206-544-
5000, extension 1; fax: 206-766-5680; email: [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 (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: James Sutherland, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: 425-
917-6533; fax: 425-917-6590; email: [email protected].

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-2012-0424; 
Directorate Identifier 2011-NM-004-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 39 MLG center axles with cracks at the 
pivot joint location of the inner cylinder/truck beam. These cracks 
were found in areas common to the inner cylinder pivot bushings where 
heat damage had occurred. This heat damage and cracks are caused by MLG 
truck pitching motion during normal airplane operations. Heat damage or 
cracking in the MLG center axle and shock strut inner cylinder lugs 
(pivot joint) could result in fracture of the MLG pivot joint 
components and consequent collapse of the MLG.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 777-32A0082, dated 
December 9, 2010, which describes procedures for repetitive lubrication 
of the MLG pivot joints; repetitive detailed inspections of the outer 
diameter chrome on the center axles of the MLG for chicken-wire cracks, 
corrosion, and chrome plate distress; repetitive magnetic particle 
inspections of the outer diameter chrome on the center axles of the MLG 
for cracks; and related investigative and corrective actions if 
necessary.
    The related investigative actions include a detailed inspection of 
the inner diameters and flanges of the inner cylinder bushing for 
cracks, smearing of material into the lubrication grooves, bushing 
distress, and wear limits; a detailed inspection for corrosion of the 
inner cylinder lug face; a detailed inspection of the lug bore inner 
cylinder for cracks, corrosion, or bronze transfer; a detailed 
inspection of the lug bore face for corrosion or cracks; a penetrant 
inspection of the lug bore inner cylinder for corrosion; a magnetic 
particle inspection of the lug bore inner cylinder and face for cracks; 
and a local etch inspection of large parts of the lug bore inner 
cylinder for heat damage.
    The corrective actions include repairing the center axle or 
replacing it with a new, overhauled, or serviceable axle; and 
refinishing the lug bore and faces, and installing new bushings.
    Boeing Alert Service Bulletin 777-32A0082, dated December 9, 2010, 
specifies, for the lubrication, an initial compliance time of within 
120 days after the original issue date of that service bulletin, and a 
repetitive interval of 50 flight cycles or 25 days, whichever occurs 
later. That service bulletin also specifies, for the detailed and 
magnetic particle inspections, an initial compliance time between 1,825 
days after the issue date of the original Certificate of Airworthiness 
or Export Certificate of Airworthiness or since the last MLG overhaul, 
or within 1,125 days after the original issue date of this service 
bulletin, whichever is later; and 3,750 days after the issue date of 
the original Certificate of Airworthiness or Export Certificate of 
Airworthiness or since the last MLG overhaul, or within 375 days after 
the original issue date of this service bulletin, whichever is later; 
depending on the airplane configuration, lubrication schedule, and

[[Page 25648]]

inspection status. That service bulletin specifies a repetitive 
interval of 3,750 days for the detailed and magnetic particle 
inspections.
    We have reviewed Boeing Special Attention Service Bulletin 777-32-
0080, dated July 10, 2008; and Boeing Special Attention Service 
Bulletin 777-32-0080, Revision 1, dated April 16, 2009. Part 2 of the 
Accomplishment Instructions of these service bulletins describe 
procedures for a detailed inspection of the outer diameter chrome on 
the center axles of the MLG for chicken-wire cracks, corrosion, and 
chrome plate distress and a magnetic particle inspection of the outer 
diameter chrome on the center axles of the MLG for cracks.
    We have reviewed Boeing Service Bulletin 777-32A0085, dated April 
14, 2011. This service bulletin describes procedures for replacing the 
MLG left and right center axles with new, overhauled, or serviceable 
center axles, or changing the center axles by polishing to the new 
configuration; replacing the inner cylinder assemblies with new, 
overhauled, or serviceable inner cylinder assemblies; part marking the 
MLG components and assemblies; lubricating the pivot joint with new 
grease; and updating the maintenance program to do repetitive 
lubrication of the MLG pivot joints.

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 designs.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously.

Costs of Compliance

    We estimate that this proposed AD affects 160 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Lubrication of MLG pivot joints..  4 work-hours x $85               $0  $340 per             $54,400 per
                                    per hour = $340                      lubrication cycle.   lubrication cycle.
                                    per lubrication
                                    cycle.
Detailed and magnetic particle     39 work-hours x $85               0  $3,315 per           $530,400 per
 inspections.                       per hour = $3,315                    inspection cycle.    inspection cycle.
                                    per inspection
                                    cycle.
Inner cylinder lug bore            6 work-hours x $85                0  $510 per inspection  $81,600 per
 inspection.                        per hour = $510                      cycle.               inspection cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary repairs or 
replacements that would be required based on the results of the 
proposed inspections. We have no way of determining the number of 
aircraft that might need these repairs or replacements.

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
             Action                  Labor cost                Parts cost                 Cost per product
----------------------------------------------------------------------------------------------------------------
Replacing center axle..........  25 work-hours x     $54,030......................  $56,155.
                                  $85 per hour =
                                  $2,125.
Refinishing the lug bore and     12 work-hours x     Up to $3,526.................  Up to $4,546.
 faces, and installing new        $85 per hour =
 bushings.                        $1,020.
Replacing the inner cylinder     46 work-hours x     Up to $254,847...............  Up to $258,757.
 assembly.                        $85 per hour =
                                  $3,910.
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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

    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:

[[Page 25649]]

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 
airworthiness directive (AD):

The Boeing Company: Docket No. FAA-2012-0424; Directorate Identifier 
2011-NM-004-AD.

(a) Comments Due Date

    We must receive comments by June 15, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200, -200LR, -
300, -300ER, and 777F series airplanes, certificated in any 
category, as identified in Boeing Alert Service Bulletin 777-
32A0082, dated December 9, 2010.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 32, Landing Gear.

(e) Unsafe Condition

    This AD was prompted by heat damage and cracks at the pivot 
joint location of the main landing gear (MLG) cylinder/truck beam. 
We are issuing this AD to detect and correct cracking in the MLG 
center axle and shock strut inner cylinder lugs (pivot joint), which 
could result in fracture of the MLG pivot joint components and 
consequent collapse of the MLG.

(f) Compliance

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

(g) Repetitive Lubrication and Inspections

    At the applicable compliance times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 777-32A0082, dated 
December 9, 2010, except as provided by paragraph (i) of this AD: 
Lubricate the MLG pivot joints; do a detailed inspection of the 
outer diameter chrome on the center axles of the MLG for chicken-
wire cracks, corrosion, and chrome plate distress; do a magnetic 
particle inspection of the outer diameter chrome on the center axles 
of the MLG for cracks; and do all applicable related investigative 
and corrective actions; in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 777-32A0082, dated 
December 9, 2010. Repeat the lubrication and inspections thereafter 
at the applicable interval specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 777-32A0082, dated 
December 9, 2010. Do all applicable related investigative and 
corrective actions before further flight.

(h) Definition

    For the purposes of this AD, chicken-wire cracks are defined as 
cracks that occur when stress created in the chrome deposit during 
plating is relieved. The cracks are evident in the deposited chrome 
when viewed from a perpendicular plane as a pattern similar to 
chicken wire. Crack size can vary with plating conditions.

(i) Exception to Service Information

    Where Boeing Alert Service Bulletin 777-32A0082, dated December 
9, 2010, specifies a compliance time after the original issue date 
of that service bulletin, this AD requires compliance within the 
specified compliance time after the effective date of this AD.

(j) Optional Actions for Compliance With Paragraph (g) of This AD

    (1) Doing the detailed and magnetic particle inspections in 
accordance with Part 2 of the Accomplishment Instructions of Boeing 
Special Attention Service Bulletin 777-32-0080, dated July 10, 2008; 
or Boeing Special Attention Service Bulletin 777-32-0080, Revision 
1, dated April 16, 2009; is considered acceptable for compliance 
with the inspections of the center axle of the MLG required by 
paragraph (g) of this AD.
    (2) Replacing the MLG left and right center axles with new, 
overhauled, or serviceable center axles, or changing the center 
axles by polishing to the new configuration; replacing the inner 
cylinder assembly with new, overhauled, or serviceable inner 
cylinder assembly; part marking the MLG components and assemblies; 
and lubricating the pivot joint with new grease; and updating the 
maintenance program to repetitively lubricate the MLG pivot joints; 
in accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 777-32A0085, dated April 14, 2011; is considered acceptable 
for compliance with lubricating of the MLG pivot joints and 
inspecting the center axles of the MLG as required by paragraph (g) 
of this AD.

(k) Special Flight Permit

    Special flight permits may be issued in accordance with sections 
21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 
and 21.199) to operate the airplane to a location where the airplane 
can be modified (if the operator elects to do so), if the flight is 
operated as a non-revenue flight.

(l) 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 the Related Information 
section of this AD. Information may be emailed to: [email protected].
    (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 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. 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.

(m) Related Information

    (1) For more information about this AD, contact James 
Sutherland, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, 
Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., 
Renton, Washington 98057-3356; phone: 425-917-6533; fax: 425-917-
6590; email: [email protected].
    (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; phone: 206-
544-5000, extension 1; fax: 206-766-5680; email 
[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.

    Issued in Renton, Washington, on April 20, 2012.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-10489 Filed 4-30-12; 8:45 am]
BILLING CODE 4910-13-P