[Federal Register Volume 59, Number 86 (Thursday, May 5, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-9002]


[[Page Unknown]]

[Federal Register: May 5, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-ANE-04; Amendment 39-8877; AD 94-08-05]

 

Airworthiness Directives; General Electric Company CF6 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to General Electric Company (GE) CF6-45/-50 series turbofan 
engines, that requires installation of a fan stator case stiffening 
ring assembly, and a new stage one fan shroud. This amendment is 
prompted by a report of an uncontained stage one fan blade failure, 
which resulted in an inflight engine shutdown, and damage to the 
aircraft. The actions specified by this AD are intended to prevent an 
uncontained stage one fan blade failure, which can result in an 
inflight engine shutdown, and damage to the aircraft.

DATES: Effective July 5, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 5, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from General Electric Aircraft Engines, CF6 Distribution 
Clerk, Room 132, 111 Merchant Street, Cincinnati, OH 45246. This 
information may be examined at the Federal Aviation Administration 
(FAA), New England Region, Office of the Assistant Chief Counsel, 12 
New England Executive Park, Burlington, MA; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

FOR FURTHER INFORMATION CONTACT: Robert J. Ganley, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299, telephone (617) 
238-7138; fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to General Electric Company (GE) CF6-45/-50 series turbofan 
engines was published in the Federal Register on January 11, 1994 (59 
FR 1503). That action proposed to require installation of a fan stator 
case stiffening ring assembly and a new stage one fan shroud, which 
will result in reduced running clearances, and lower fan blade 
stresses. The compliance end date of December 31, 1996, ensures timely 
compliance without forced engine removals based on hardware 
availability. The actions would be required to be accomplished in 
accordance with GE CF6-50 Service Bulletin (SB) No. 72-573, Revision 5, 
dated September 15, 1981.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Two commenters support the rule as proposed.
    One commenter states that the compliance end-date of August 31, 
1995, in compliance paragraph (a) of the proposed rule should be 
extended to December 31, 1996, in order to avoid forced engine 
removals. The Federal Aviation Administration (FAA) concurs. The FAA 
has determined that flight safety will not be compromised by extending 
the compliance end-date to December 31, 1996. The final rule has been 
changed accordingly.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change described 
previously. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 67 GE CF6-45/-50 series turbofan engines of 
the affected design in the worldwide fleet. The FAA has been advised by 
the manufacturer that there are no engines on U.S. registered aircraft 
that would be affected by this AD. However, should an affected engine 
be imported on an aircraft and placed on the U.S. registry in the 
future, it would take approximately 48 work hours to accomplish the 
required actions, and that the average labor rate is $55 per work hour. 
Required parts will cost approximately $9,360 per engine. Based on 
these figures, the total cost impact of the AD is estimated to be 
$12,000 per engine.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-08-05 General Electric Company: Amendment 39-8877. Docket 93-ANE-
04.

    Applicability: General Electric Company (GE) CF6-45/-50 series 
turbofan engines installed on, but not limited to, Airbus A300 
series, Boeing 747 series, and McDonnell Douglas DC-10 series 
aircraft.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent an uncontained stage one fan blade failure, which can 
result in inflight engine shutdown, and damage to the aircraft, 
accomplish the following:
    (a) For engines that have not been modified in accordance with 
any revision level of GE CF6-50 Service Bulletin (SB) No. 72-573, 
prior to the effective date of this AD, install a fan stator case 
stiffening ring assembly and stage one fan shroud, in accordance 
with GE CF6-50 SB No. 72-573, Revision 5, dated September 15, 1981, 
by December 31, 1996.
    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Engine Certification Office. The 
request should be forwarded through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Engine Certification Office.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    (c) Special flight permits may be issued in accordance with FAR 
21.197 and 21.199 to operate the aircraft to a location where the 
requirements of this AD can be accomplished.
    (d) The modification shall be done in accordance with the 
following service bulletin:

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                       Document No.                             Pages          Revision             Date        
----------------------------------------------------------------------------------------------------------------
GE CF6-50 SB No. 72-573...................................            1-17               5  Sept. 15, 1981.     
    Total Pages: 17 ......................................                                                      
----------------------------------------------------------------------------------------------------------------

    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from General Electric Aircraft 
Engines, CF6 Distribution Clerk, Room 132, 111 Merchant Street, 
Cincinnati, OH 45246. Copies may be inspected at the FAA, New 
England Region, Office of the Assistant Chief Counsel, 12 New 
England Executive Park, Burlington, MA; or at the Office of the 
Federal Register, 800 North Capitol Street NW., suite 700, 
Washington, DC.
    (e) This amendment becomes effective on July 5, 1994.

    Issued in Burlington, Massachusetts, on April 5, 1994.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 94-9002 Filed 5-4-94; 8:45 am]
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