Airworthiness Directives; General Electric Company CF6 Series Turbofan Engines

[Federal Register Volume 71, Number 116 (Friday, June 16, 2006)]
[Rules and Regulations]
[Pages 34807-34808]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-5426]



[[Page 34807]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-10-AD; Amendment 39-14650; AD 2006-12-24]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) for General Electric Company (GE) CF6-45/-50 series turbofan 
engines. That AD currently requires an initial and repetitive on-wing 
visual inspection of the side links of the five-link forward mount 
assembly for cracks, and replacement of the side links and pylon 
attachment bolts and inspection of the fail-safe bolt and platform lug 
if the side links are cracked. That AD also requires a shop-level 
refurbishment of the side links as a terminating action to the on-wing 
inspection program. This ad requires inspecting and refurbishing the 
side link at every exposure of the side link. This AD also requires the 
same actions on certain part number side links installed on CF6-80A 
turbofan engines. This AD results from a report of a cracked side link. 
We are issuing this AD to prevent failure of the side links and 
possible engine separation from the airplane.

DATES: This AD becomes effective July 21, 2006. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of July 21, 2006.

ADDRESSES: You can get the service information identified in this AD 
from General Electric Aircraft Engines, CF6 Distribution Clerk, Room 
132, 111 Merchant Street, Cincinnati, OH 45246.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA. You may examine the service information, at the FAA, 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Karen Curtis, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (617) 238-
7192; fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to GE CF6-45/-50 series 
turbofan engines. We published the proposed AD in the Federal Register 
on December 12, 2005 (70 FR 73391). That action proposed to require 
inspecting and refurbishing the side links of the five-link forward 
mount assembly at every exposure of the side link. That action also 
proposed to require the same actions on certain part number side links 
installed on CF6-80A turbofan engines.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Definition of Exposure

    One commenter proposes that the definition of exposure be revised 
as follows: `` * * * removal of one or more bolts attaching the side 
links to the fan frame front HPC case or removal of the bolt attaching 
the side link to the mount platform while the engine is not 
installed.'' This commenter believes that the definition of exposure 
used in the proposed AD will create an undue burden on line maintenance 
operations, and will eliminate any on-wing maintenance on the link and 
associated hardware. They also believe the proposed definition will 
force operators to replace the link assembly even for bolt removal to 
facilitate other maintenance and unrelated minor discrepancies. We do 
not agree that the definition of exposure should be relaxed to 
facilitate on-wing maintenance. The opportunity for coating distress of 
the links occurs each time a bolt is removed, regardless of where or 
when the removal occurs. This definition of exposure protects against 
coating distress that can lead to stress corrosion cracking of the 
links. We did not change the AD.

Threshold Since Last Refurbishment

    One commenter requests that a threshold since the last 
refurbishment be allowed and that exposure be further defined to allow 
for staggering of serviceable assemblies within a prescribed threshold 
since last refurbishment. This commenter believes that there may be 
instances where an operator staggers a serviceable mount assembly from 
one engine to another, without that assembly going into the shop. We do 
not agree that a threshold since the last refurbishment should be 
allowed to facilitate staggering of serviceable assemblies. The 
opportunity for coating distress occurs each time a side link bolt is 
removed, regardless of when the last refurbishment may have occurred. 
As noted above, this definition of exposure protects against coating 
distress that can lead to stress corrosion cracking of the links. We 
did not change the AD.

Clarification of Previous On-wing Inspection Requirement

    One commenter requests clarification of the previous on-wing 
inspection requirement. This commenter notes that the original AD 
required an on-wing visual inspection and the proposed rule does not. 
They asked if this was intentional or an oversight. Although the 
proposed rule did not clearly state that the previous on-wing 
inspection requirement was being replaced by a shop-level inspection, 
the FAA's actions are intentional. The accomplishment instructions in 
the referenced service bulletins include fluorescent particle 
inspection or magnetic particle inspection as part of the refurbishment 
process required at each exposure. Experience proves that these in-shop 
inspections are more effective in detecting distress in the links than 
the previous on-wing visual inspection requirement. The requirement for 
refurbishment at each exposure in this final rule will prevent stress 
corrosion cracking of the links. We did not change the AD.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD as proposed.

Costs of Compliance

    We estimate that this AD will affect 195 engines installed on U.S. 
registered airplanes per year. We also estimate that it will take 8.0 
workhours per engine to perform the actions, and that the average labor 
rate is $65 per workhour. This AD does not require parts. Based on 
these figures, we estimate the total cost of this AD to U.S. operators 
to be $101,400 per year.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I,

[[Page 34808]]

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 have determined that 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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 95-ANE-10-AD'' in your request.

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 Federal Aviation Administration 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 removing Amendment 39-9346 (60 FR 
46758, September 8, 1995) and by adding a new airworthiness directive, 
Amendment 39-14650, to read as follows:

2006-12-24 General Electric Company: Amendment 39-14650. Docket No. 
95-ANE-10-AD.

Effective Date

    (a) This AD becomes effective July 21, 2006.

Affected ADs

    (b) This AD supersedes AD 95-17-15, Amendment 39-9346.

Applicability

    (c) This AD applies to General Electric (GE) CF6-45/-50 and CF6-
80A turbofan engines with left-hand side links part numbers (P/Ns) 
9204M94P01, 9204M94P03, and 9346M99P01, and right-hand side links, 
P/Ns 9204M94P02, 9204M94P04, and 9346M99P02, installed on the five-
link forward engine mount assembly (also known as Configuration 2). 
These engines are installed on, but not limited to, Boeing DC10-15, 
DC10-30, 767, and 747 series airplanes and Airbus Industrie A300 and 
A310 series airplanes.

Unsafe Condition

    (d) This AD results from a report of a cracked side link. We are 
issuing this AD to prevent failure of the side links and possible 
engine separation from the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at every exposure of the side link.

Inspecting and Refurbishing the Side Links

    (f) Inspect and refurbish each side link at every exposure of 
the side links. Use the following GE Aircraft Engines (GEAE) service 
bulletins (SBs):
    (1) For CF6-45/-50 series engines, use 3.A. through 3.E. of the 
Accomplishment Instructions of GEAE SB CF6-50 S/B 72-1255, dated 
January 26, 2005.
    (2) For CF6-80A series engines, use 3.A. through 3.E. of the 
Accomplishment Instructions of GEAE SB CF6-80A S/B 72-0797, dated 
January 26, 2005.

Definition of Exposure of Side Link

    (g) A side link is exposed when one or more bolts that attach 
the side links to the fan frame--front high pressure compressor case 
are removed, or when the bolt attaching the side link to the mount 
platform is removed.

Alternative Methods of Compliance

    (h) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

    (i) You must use General Electric Aircraft Engines Service 
Bulletins CF6-50 S/B 72-1255, dated January 26, 2005, and CF6-80A S/
B 72-0797, dated January 26, 2005 to perform the actions required by 
this AD. The Director of the Federal Register approved the 
incorporation by reference of these service bulletins in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51. You can get a copy of this 
service information from General Electric Aircraft Engines, CF6 
Distribution Clerk, Room 132, 111 Merchant Street, Cincinnati, OH 
45246, or at the Office of the Federal Register, 800 North Capitol 
Street, NW., Suite 700, Washington, DC.

Related Information

    (j) None.

    Issued in Burlington, Massachusetts, on June 8, 2006.
Thomas Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 06-5426 Filed 6-15-06; 8:45 am]
BILLING CODE 4910-13-P

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