[Federal Register: April 22, 2008 (Volume 73, Number 78)]
[Rules and Regulations]
[Page 21521-21523]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22ap08-2]
[[Page 21521]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-29065; Directorate Identifier 2007-NM-142-AD;
Amendment 39-15486; AD 2008-09-05]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 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 747 airplanes. This AD requires inspecting the trunnion
fork assembly of the wing landing gears to determine the part number
and serial number and to determine the category of the trunnion fork
assemblies. For certain airplanes, this AD also requires, if necessary,
various inspections to detect discrepancies of the trunnion fork
assemblies, related investigative/corrective actions, and a terminating
action. This AD results from a report of a fractured trunnion fork
assembly. We are issuing this AD to prevent a fractured trunnion fork
assembly, which could result in the collapse of a wing landing gear on
the ground and possible damage to hydraulic equipment and the aileron
and spoiler cables. Such damage could result in reduced controllability
of the airplane.
DATES: This AD is effective May 27, 2008.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of May 27,
2008.
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
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: Gary Oltman, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425)
917-6443; 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 747 airplanes. That NPRM was published in the
Federal Register on August 31, 2007 (72 FR 50282). That NPRM proposed
to require inspecting the trunnion fork assembly of the wing landing
gears to determine the part number and serial number and to determine
the category of the trunnion fork assemblies. For certain airplanes,
that NPRM also proposed to require, if necessary, various inspections
to detect discrepancies of the trunnion fork assemblies, related
investigative/corrective actions, and a terminating action.
Comments
We gave the public the opportunity to participate in developing
this AD. We considered the comments received from the three commenters.
Request To Revise Initial Compliance Time
Boeing requests that the compliance time specified in paragraph (g)
of the NPRM be revised from 18 months to either 18 months or within 18
months after the date of issuance of the original Standard Certificate
of Airworthiness or the original Export Certificate of Airworthiness,
whichever occurs later. Boeing states that operators of airplanes
delivered more than 18 months after the effective date of the AD will
be unable to comply with the requirements of paragraph (g) of the NPRM.
We do not agree. We have confirmed with Boeing that affected
airplanes currently in production are compliant with the requirements
of this AD. Therefore, for affected airplanes delivered after the
effective date of the AD, no additional time will be necessary to
comply with the requirements of paragraph (g) of this AD. We have made
no change to the compliance time specified in paragraph (g) of this AD
in this regard.
Requests To Allow Review of Maintenance or Delivery Records
Boeing and Lufthansa request that, for clarification purposes,
paragraph (g) of the NPRM be revised to allow review of maintenance or
delivery records instead of doing the proposed inspection. The
commenters note that such an alternative is specified in paragraphs 3.
and 4. of Part 1 of the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-32A2482. Boeing notes that we have included a
similar provision in other ADs.
We agree with the commenters to clarify paragraph (g) of this AD.
It was our intent that either the inspection or record review be done
in accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-32A2482. Therefore, we have revised paragraph (g)
of the AD accordingly.
Request To Allow a Magnetic-Particle Inspection
Boeing requests that we allow a magnetic-particle inspection in
accordance with Boeing Standard Operating Procedure Manual 20-20-01 as
an alternative to the high frequency eddy current inspection required
by paragraph (h)(1) of the NPRM. Boeing states that it intended the
HFEC inspection to be done ``in-situ'' by the operators. Boeing also
states that one operator intends to remove the trunnion forks from the
airplane and inspect them for cracks at an overhaul facility that has
magnetic-particle inspection capability. In addition, Boeing states
that it intends to add this option in the next revision of Boeing Alert
Service Bulletin 747-32A2482, if revised.
We partially agree. We acknowledge that a magnetic-particle
inspection may be done instead of an HFEC inspection; however, Boeing
has not completed developing procedures for a revised service bulletin.
We may consider approving the revised service bulletin as an
alternative method of compliance (AMOC) once it has been completed.
Paragraph (k) of this AD provides for operators' requests for approval
of an AMOC to address these unique circumstances. Therefore, we have
made no change to this AD in this regard.
Request To Include a Parts Installation Paragraph
Boeing requests that we add a parts installation paragraph to the
NPRM for Category A, B, C, or D trunnion fork assemblies that are
installed after the terminating action specified in Boeing Alert
Service Bulletin 747-32A2482 has been done (i.e., Part 5 of the
Accomplishment Instructions of the service bulletin). Boeing states
that such a paragraph will ensure that the actions specified in the
service bulletin are done on spare parts within the compliance times
mandated by the NPRM. Boeing is concerned about
[[Page 21522]]
landing gear parts being interchanged between airplanes.
We partially agree. We acknowledge that spare parts must be
addressed due to the interchangeability of landing gears. However, it
is not necessary to change the AD. The AD refers to Boeing Alert
Service Bulletin 747-32A2482 as the appropriate source of service
information for doing the required actions. Note (b) of Tables 4 (for
Categories A and C trunnion fork assemblies) and 5 (for Categories B
and D trunnion fork assemblies) of paragraph 1.E, ``Compliance,'' of
the service bulletin specifies that the following three types of
trunnion fork assemblies can be installed:
1. New trunnion fork assembly;
2. Category Not Affected trunnion fork assembly; or
3. Category B (Group 1 airplanes) or D (Group 2 airplanes) trunnion
fork assembly on which Part 3 or Part 4 of Boeing Alert Service
Bulletin 747-32A2482 has been done.
Once the compliance threshold has been reached for doing the
terminating action required by this AD, operators are prohibited under
14 CFR 39.3 from replacing a trunnion fork assembly with an assembly
other than one identified in note (b) of Tables 4 and 5. Therefore, we
have made no change to the final rule in this regard.
Request To Correct Typographical Errors
Boeing requests that the categories specified in the first column
in Table 1 of the NPRM be corrected to match those specified in Tables
4 and 5 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service
Bulletin 747-32A2482. Boeing states that ``Categories A and D'' should
be ``Categories A and C'' in paragraph (h)(1) of Table 1, and
``Categories B and C'' should be ``Categories B and D'' in paragraph
(h)(2) of Table 1.
We agree that two typographical errors appear in Table 1 of the
NPRM. It was our intent to align the categories of Table 1 with those
in Tables 4 and 5 of paragraph 1.E., ``Compliance,'' of Boeing Alert
Service Bulletin 747-32A2482. Therefore, we have revised this AD
accordingly.
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 changes described previously. We also determined that
these changes will not increase the economic burden on any operator or
increase the scope of the AD.
Costs of Compliance
There are about 1,055 airplanes of the affected design in the
worldwide fleet. This AD affects about 215 airplanes of U.S. registry.
The required inspection for part number, serial number, and category
takes about 1 work hour per airplane, at an average labor rate of $80
per work hour. Based on these figures, the estimated cost of the
inspection required by this AD for U.S. operators is $17,200, or $80
per airplane.
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 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:
2008-09-05 Boeing: Amendment 39-15486. Docket No. FAA-2007-29065;
Directorate Identifier 2007-NM-142-AD.
Effective Date
(a) This airworthiness directive (AD) is effective May 27, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-
400F, 747SR, and 747SP series airplanes, certificated in any
category; as identified in Boeing Alert Service Bulletin 747-
32A2482, dated June 14, 2007.
Unsafe Condition
(d) This AD results from a report of a fractured trunnion fork
assembly. We are issuing this AD to prevent a fractured trunnion
fork assembly, which could result in the collapse of a wing landing
gear on the ground and possible damage to hydraulic equipment and
the aileron and spoiler cables. Such damage could result in reduced
controllability of the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Service Bulletin
(f) The term ``service bulletin,'' as used in this AD, means
Boeing Alert Service Bulletin 747-32A2482, dated June 14, 2007.
Initial Inspection for Part Number, Serial Number, and Category
(g) Within 18 months after the effective date of this AD,
inspect the pad-up area on the forward upper inboard surface of the
trunnion fork assembly of both the left and right wing landing gears
to determine the part number and serial number and to determine the
category of the trunnion fork assemblies. A review of airplane
maintenance or delivery records is acceptable instead of the
inspection if the part number and serial number of the installed
fork assembly can be conclusively determined from that review. Do
the actions in accordance with the Accomplishment Instructions of
the service bulletin.
[[Page 21523]]
Follow-On Actions for Category A, B, C, or D Trunnion Fork Assemblies
(h) If any part number and serial number identified as Category
A, B, C, or D in Tables 2 and 3 of paragraph 1.E., ``Compliance,''
of the service bulletin is found installed during the inspection
required by paragraph (g) of this AD: At the applicable compliance
time(s) listed in Table 4 or 5 of paragraph 1.E., ``Compliance,'' of
the service bulletin, except as provided by paragraph (i) of this
AD, do the applicable action(s) in Table 1 of this AD and applicable
related investigative/corrective actions, in accordance with the
Accomplishment Instructions of the service bulletin.
Table 1.--Requirements for Category A, B, C, or D Trunnion Fork Assemblies
----------------------------------------------------------------------------------------------------------------
For-- Do-- And-- Or--
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(1) Categories A and C trunnion A detailed inspection for An ultrasonic inspection Do the terminating
fork assemblies. damage to the protective to determine the wall action (Part 5).
finish and for corrosion thickness in the area
of the trunnion fork forward of the outer
assembly and a high cylinder attach lugs in
frequency eddy current 8 zones, and a hardness
(HFEC) inspection to measurement if
detect cracks (Part 2). applicable (Part 3).
(2) Categories B and D trunnion An ultrasonic inspection None.................... None.
fork assemblies. to determine the wall
thickness in the area
forward of the outer
cylinder attach lugs in
8 zones, and a hardness
measurement (Part 3).
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(i) Where paragraph 1.E., ``Compliance,'' of the service
bulletin specifies a compliance time after the date on the service
bulletin, this AD requires compliance within the specified
compliance time after the effective date of this AD.
Terminating Action
(j) Replacing the trunnion fork assembly of the wing landing
gear with a trunnion fork assembly identified in Part 5 of the
Accomplishment Instructions of the service bulletin, in accordance
with and at the applicable time specified in Table 4 or 5 of
paragraph 1.E., ``Compliance,'' of the service bulletin, constitutes
terminating action for the requirements of this AD for that side
only.
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 in
accordance with the procedures found in 14 CFR 39.19.
(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 appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
Material Incorporated by Reference
(l) You must use Boeing Alert Service Bulletin 747-32A2482,
dated June 14, 2007, to do the actions required by this AD, 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, P.O. Box 3707, Seattle, Washington
98124-2207.
(3) You may review copies of the service information
incorporated by reference at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 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 April 14, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-8530 Filed 4-21-08; 8:45 am]
BILLING CODE 4910-13-P