[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
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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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.
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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
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Action Labor cost Parts cost Cost per product
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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