[Federal Register Volume 59, Number 234 (Wednesday, December 7, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-28110]


[[Page Unknown]]

[Federal Register: December 7, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-ANE-39; Amendment 39-9066; AD 94-23-04]

 

Airworthiness Directives; Garrett Turbine Engine Company ATF3 
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 Garrett Turbine Engine Company ATF3 series turbofan 
engines, that requires a one-time inspection for cracks of the curvic 
and bore area of the high pressure turbine (HPT) rotor assembly disk, 
and replacement, if necessary, with a serviceable disk. This amendment 
is prompted by several reports of cracks discovered during routine 
inspections of HPT rotor assembly disks. The actions specified by this 
AD are intended to prevent an uncontained failure of the HPT rotor 
assembly disk.

DATES: Effective on February 6, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 6, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from AlliedSignal Propulsion Engines, Aviation Services 
Division, Data Distribution, Dept. 64-3/2102-1M, P.O. Box 29003, 
Phoenix, AZ 85038-9003. 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: Joseph Costa, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, FAA, Transport Airplane 
Directorate, 3229 East Spring Street, Long Beach, CA 90806-2425; 
telephone (310) 988-5246; fax (310) 988-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to Garrett Turbine Engine Company 
Model ATF3-6 and -6A turbofan engines was published in the Federal 
Register on February 11, 1994 (59 FR 6603). That action proposed to 
require a one-time inspection for cracks of the curvic and bore area of 
high pressure turbine (HPT) rotor assembly disks listed by serial 
number in Table 1 of Allied-Signal Aerospace Company, Garrett Engine 
Division, Alert Service Bulletin (ASB) No. ATF3-A72-6184, Revision 1, 
dated January 11, 1993.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the Federal Aviation Administration's (FAA) determination 
of the cost to the public. The FAA has determined that air safety and 
the public interest require the adoption of the rule as proposed.
    There are approximately 75 Garrett Turbine Engine Company Model 
ATF3-6 and -6A turbofan engines of the affected design in the worldwide 
fleet. The FAA estimates that 2 engines installed on aircraft of U.S. 
registry will be affected by this AD, that it will take approximately 
220 work hours per engine to accomplish the required actions, and that 
the average labor rate is $55 per work hour. Based on these figures, 
the total cost impact of the AD on U.S. operators is estimated to be 
$24,200.
    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 part 39 of 
the Federal Aviation Regulations (14 CFR part 39) 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:

94-23-04  Garrett Turbine Engine Company: Amendment 39-9066. Docket 
93-ANE-39.

    Applicability: Garrett Turbine Engine Company Model ATF3-6 and -
6A turbofan engines equipped with high pressure turbine (HPT) rotor 
assembly disk, Part Number (P/N) 3001765-1 and -2, listed by serial 
numbers in Table 1 of Allied-Signal Aerospace Company, Garrett 
Engine Division, Alert Service Bulletin (ASB) No. ATF3-A72-6184, 
Revision 1, dated January 11, 1993. These engines are installed on 
but not limited to Dassault Aviation Falcon Jet Falcon Series G 
(Falcon 20G/HU-25) and Mystere-Falcon 200 aircraft.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent an uncontained failure of the HPT rotor assembly 
disk, accomplish the following:
    (a) For engines with 1550 or more HPT rotor assembly disk cycles 
since new (CSN) on the effective date of this AD, perform a one-time 
inspection for cracks of the curvic and bore area of the HPT rotor 
assembly disk, and replace if necessary, with a serviceable disk, in 
accordance with Allied-Signal Aerospace Company, Garrett Engine 
Division, ASB No. ATF3-A72-6184, Revision 1, dated January 11, 1993, 
within 50 cycles in service (CIS) after the effective date of this 
AD.
    (b) For engines with less than 1550 HPT rotor assembly disk CSN 
on the effective date of this AD, perform a one-time inspection for 
cracks of the curvic and bore area of the HPT rotor assembly disk, 
and replace if necessary, with a serviceable disk, in accordance 
with Allied-Signal Aerospace Company, Garrett Engine Division, ASB 
No. ATF3-A72-6184, Revision 1, dated January 11, 1993, within 300 
CIS after the effective date of this AD, or prior to accumulating 
1600 CSN, whichever occurs first.
    (c) 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, Los Angeles Aircraft 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, Los Angeles Aircraft Certification Office.

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

    (d) 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 aircraft to a location where 
the requirements of this AD can be accomplished.
    (e) The inspection, and replacement, if necessary, shall be done 
in accordance with the following alert service bulletin:

------------------------------------------------------------------------
          Document No.            Pages   Revision          Date        
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Allied-Signal Aerospace              1-6         1  Jan. 11, 1993.      
 Company, Garrett Engine                                                
 Division, ASB No. ATF3-A72-                                            
 6184.                                                                  
Total Pages: 6.                                                         
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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 AlliedSignal Propulsion Engines, 
Aviation Services Division, Data Distribution, Dept. 64-3/2102-1M, 
P.O. Box 29003, Phoenix, AZ 85038-9003. 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.
    (f) This amendment becomes effective on February 6, 1995.

    Issued in Burlington, Massachusetts, on November 3, 1994.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 94-28110 Filed 12-06-94; 8:45 am]
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