Airworthiness Directives; General Electric Company CF6-45A, CF6-50A, CF6-50C, and CF6-50E Series Turbofan Engines

[Federal Register Volume 70, Number 245 (Thursday, December 22, 2005)]
[Rules and Regulations]
[Pages 75933-75934]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-24341]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-22124; Directorate Identifier 2005-NE-21-AD; 
Amendment 39-14427; AD 2005-26-06]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-45A, CF6-
50A, CF6-50C, and CF6-50E Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
General Electric Company (GE) CF6-45A, CF6-50A, CF6-50C, and CF6-50E 
series turbofan engines. This AD requires removing from service pre-GE 
Service Bulletin (SB) No. CF6-50S/B 72-1268 configuration low pressure 
turbine (LPT) stage 2 interstage seal assemblies and stage 3 interstage 
seal assemblies. This AD also requires installing new or reworked 
configuration stage 2 interstage seal assemblies and stage 3 interstage 
seal assemblies. This AD results from reports of fan mid shaft 
separation, leading to separation of the LPT stage 1 disk, disk 
overspeed, and uncontained engine failure. We are issuing this AD to 
prevent uncontained engine failure and damage to the airplane.

DATES: This AD becomes effective January 26, 2006.

ADDRESSES: You can get the service information referenced in this AD 
from General Electric Company via Lockheed Martin Technology Services, 
10525 Chester Road, Suite C, Cincinnati, Ohio 45215, telephone (513) 
672-8400, fax (513) 672-8422.
    You may examine the AD docket on the Internet at http://dms.dot.gov 
or in Room PL-401 on the plaza level of the Nassif Building, 400 
Seventh Street, SW., Washington, DC.

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 (781) 238-
7192; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed airworthiness directive (AD). The proposed AD applies 
to GE CF6-45A, CF6-50A, CF6-50C, and CF6-50E series turbofan engines. 
We published the proposed AD in the Federal Register on August 19, 2005 
(70 FR 48660). That action proposed to require removing from service 
pre-GE SB No. CF6-50 S/B 72-1268 configuration LPT stage 2 interstage 
seal assemblies and stage 3 interstage seal assemblies. That action 
also proposed to require installing new or reworked configuration stage 
2 interstage seal assemblies and stage 3 interstage seal assemblies.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the Docket Management 
Facility Docket Office between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The Docket Office (telephone (800) 
647-5227) is located on the plaza level of the Department of 
Transportation Nassif Building at the street address stated in 
ADDRESSES. Comments will be available in the AD docket shortly after 
the DMS receives them.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the three comments received. 
The commenters support the proposal.

Conclusion

    We have carefully reviewed the available data, including the 
comments

[[Page 75934]]

received, and determined that air safety and the public interest 
require adopting the AD as proposed.

Costs of Compliance

    There are about 2,079 CF6-45A, CF6-50A, CF6-50C, and CF6-50E series 
turbofan engines of the affected design in the worldwide fleet. We 
estimate that 790 engines installed on airplanes of U.S. registry will 
be affected by this AD. We also estimate that it will take about 5 work 
hours per engine to rework the stage 2 interstage seal assembly and the 
stage 3 interstage seal assembly. The average labor rate is $65 per 
work hour. We estimate that 90% of the affected engines will have the 
parts reworked, and 10% will have new parts installed. A new stage 2 
interstage seal assembly and new stage 3 interstage seal assembly will 
cost about $26,758 per engine. Based on these figures, we estimate the 
total cost of the AD to U.S. operators to be $2,344,957.

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 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 at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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 adding the following new airworthiness 
directive:

2005-26-06 General Electric Company: Amendment 39-14427. Docket No. 
FAA-2005-22124; Directorate Identifier. 2005-NE-21-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective January 
26, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-45A, 
CF6-50A, CF6-50C, and CF6-50E series turbofan engines. These engines 
are installed on, but not limited to, Boeing DC10 and 747 series 
airplanes, and Airbus Industrie A300 series airplanes.

Unsafe Condition

    (d) This AD results from reports of fan mid shaft separation, 
leading to separation of the low pressure turbine (LPT) stage 1 
disk, disk overspeed, and uncontained engine failure. We are issuing 
this AD to prevent uncontained engine failure and damage to the 
airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next disassembly of the LPT stage 2 interstage 
seal assembly and stage 3 interstage seal assembly from the LPT 
stator after the effective date of this AD, but no later than 
December 31, 2010, unless the actions have already been done.

Stage 2 Interstage Seal Assemblies

    (f) Remove from service the pre-GE Service Bulletin (SB) No. 
CF6-50 72-1268 configuration LPT stage 2 interstage seal assembly.
    (g) Install a new or reworked configuration LPT stage 2 
interstage seal assembly, part number (P/N) 9198M81G05, 2092M13G01, 
2092M13G02, or 2092M13G03, or other FAA-approved equivalent part.
    (h) Information on reworking the pre-SB No. CF6-50 S/B 72-1268 
configuration stage 2 interstage seal assembly to the new 
configuration can be found in GE SB No. CF6-50 S/B 72-1268, dated 
December 16, 2004.

Stage 3 Interstage Seal Assemblies

    (i) Remove from service the pre-SB No. CF6-50 S/B 72-1268 
configuration stage 3 interstage seal assembly.
    (j) Install a new or reworked configuration LPT stage 3 
interstage seal assembly, P/N 9044M29G17 or 2092M14G01, or other 
FAA-approved equivalent part.
    (k) Information on reworking the pre-SB No. CF6-50 S/B 72-1268 
configuration stage 3 interstage seal assembly to the new 
configuration can be found in GE SB No. CF6-50 S/B 72-1268, dated 
December 16, 2004.

Prohibition of Pre-SB No. CF6-50 S/B 72-1268 Configurations

    (l) After the effective date of this AD, do not install pre-SB 
No. CF6-50 S/B 72-1268 configuration LPT stage 2 interstage seal 
assemblies or stage 3 interstage seal assemblies into any engine.

Alternative Methods of Compliance

    (m) 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.

Related Information

    (n) National Transportation Safety Board Safety Recommendation 
No. A-98-125, dated December 3, 1998, pertains to the subject of 
this AD.

Material Incorporated by Reference

    (o) None.

    Issued in Burlington, Massachusetts, on December 14, 2005.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 05-24341 Filed 12-21-05; 8:45 am]
BILLING CODE 4910-13-P

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