[Federal Register Volume 61, Number 177 (Wednesday, September 11, 1996)]
[Rules and Regulations]
[Pages 47806-47808]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22772]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-ANE-55; Amendment 39-9737; AD 96-18-13]
RIN 2120-AA64


Airworthiness Directives; AlliedSignal Inc. TFE731 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 AlliedSignal Inc. (formerly Garrett Engine Division) 
TFE731 series turbofan engines, that requires removing certain fan 
rotor disks from service in accordance with a drawdown schedule, and 
would establish new fan rotor disk life limits. This amendment is 
prompted after additional analyses revealed that stress levels in the 
fan rotor disk dovetail slots for the applicable engine models are 
higher than initially calculated. The actions specified by this AD are 
intended to prevent uncontained failure of the fan rotor disk due to 
fatigue cracking in the dovetail slots, which can result in inflight 
engine shutdowns, severe secondary damage, and fan rotor assembly 
separation from the engine.

DATES: Effective November 12, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 12, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from AlliedSignal Aerospace, Attn: Data Distribution, M/S 64-
3/2101-201, P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (602) 
365-2493, fax (602) 365-5577. 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, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone 
(310) 627-5246; fax (310) 627-5210.

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 AlliedSignal Inc. (formerly 
Garrett Engine Division) TFE731 series turbofan engines was published 
in the Federal Register on March 22, 1996 (61 FR 11790). That action 
proposed to require removing certain fan rotor disks from service in 
accordance with a drawdown schedule and would establish new fan rotor 
disk life limits in accordance with AlliedSignal Engines Alert Service 
Bulletin (ASB) No. TFE731-A72-3569, dated May 31, 1995, and ASB No. 
TFE731-A72-3570, dated May 31, 1995.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's 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 5,000 engines of the affected design in the 
worldwide fleet. The FAA estimates that 2,500 engines installed on 
aircraft of U.S. registry will be affected by this AD, that it will 
take approximately 16 work hours per engine to accomplish the required 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the total cost impact of the AD on U.S. operators is 
estimated to be $2,400,000.
    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

[[Page 47807]]

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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

96-18-13 AlliedSignal Inc.: Amendment 39-9737. Docket 95-ANE-55.

    Applicability: AlliedSignal Inc. (formerly Garrett Engine 
Division) Models TFE731-2, -2A, -3, -3A, -3AR, -3B, -3BR, -3C, -3CR, 
-3D, -3DR, -3R, and -4R turbofan engines, installed on, but not 
limited to the following aircraft: Avions Marcel Dassault Falcon 10, 
50, 100 series; Learjet 31, 35, 36, and 55 series; Lockheed-Georgia 
1329-23 and -25 series; Israel Aircraft Industries 1124 series and 
1125 Westwind series; Cessna Model 650, Citations III, VI, and VII; 
Raytheon British Aerospace HS-125 series; and Sabreliner NA-265-65.

    Note: This airworthiness directive (AD) applies to each engine 
identified in the preceding applicability provision, regardless of 
whether it has been modified, altered, or repaired in the area 
subject to the requirements of this AD. For engines that have been 
modified, altered, or repaired so that the performance of the 
requirements of this AD is affected, the owner/operator must request 
approval for an alternative method of compliance in accordance with 
paragraph (d) of this AD. The request should include an assessment 
of the effect of the modification, alteration, or repair on the 
unsafe condition addressed by this AD; and, if the unsafe condition 
has not been eliminated, the request should include specific 
proposed actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent uncontained failure of the fan rotor disk due to 
fatigue cracking in the dovetail slots, which can result in inflight 
engine shutdowns, severe secondary damage, and fan rotor assembly 
separation from the engine, accomplish the following:
    (a) For engines equipped with fan rotor disks, part numbers (P/
N's) 3072162-5, 3073436-5, 3073539-(All), and 3074529-(All), where 
(All) denotes any dash number, remove fan rotor disks from service 
and install a serviceable disk in accordance with the Accomplishment 
Instructions of AlliedSignal Engines Alert Service Bulletin (ASB) 
No. TFE731-A72-3569, dated May 31, 1995, as required by the 
following schedule:

------------------------------------------------------------------------
                                             Required fan rotor disk    
 Fan rotor disk cycles since new (CSN)       retirement (remove from    
    on the effective date of this AD                 service)           
------------------------------------------------------------------------
3,600 or less..........................  Not to exceed the new life     
                                          limit of 4,100 CSN.           
3,601 to 5,500.........................  Within the next 500 cycles     
                                          after the effective date of   
                                          this AD or prior to reaching  
                                          5,700 CSN, whichever occurs   
                                          first.                        
5,501 or greater.......................  Within the next 200 cycles     
                                          after the effective date of   
                                          this AD, not to exceed 7,100  
                                          CSN.                          
------------------------------------------------------------------------

    (b) For engines equipped with fan rotor disks, P/N 3072816-
(All), where (All) denotes any dash number, remove fan rotor disks 
from service and install a serviceable disk in accordance with 
Accomplishment Instructions of AlliedSignal Engines ASB No. TFE731-
A72-3570, dated May 31, 1995, as required by the following schedule:

------------------------------------------------------------------------
                                             Required fan rotor disk    
  Fan rotor disk CSN on the effective        retirement (remove from    
            date of this AD                          service)           
------------------------------------------------------------------------
3,850 or less..........................  Not to exceed the new life     
                                          limit of 4,600 CSN.           
3,851 to 6,000.........................  Within the next 750 cycles     
                                          after the effective date of   
                                          this AD, or prior to reaching 
                                          6,500 CSN, whichever occurs   
                                          first.                        
6,001 or greater.......................  Within the next 500 cycles     
                                          after the effective date of   
                                          this AD, not to exceed 10,000 
                                          CSN.                          
------------------------------------------------------------------------

    (c) A serviceable part is one that has not exceeded the life 
limits established by this AD.
    (d) 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.

    (e) 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.
    (f) The actions required by this AD shall be done in accordance 
with the following AlliedSignal Engines ASBs:

----------------------------------------------------------------------------------------------------------------
              Document No.                    Pages                 Revision                      Date          
----------------------------------------------------------------------------------------------------------------
TFE731-A72-3569........................             1-8  Original                       May 31, 1995.           
Total Pages: 8.                          ..............  .............................  ........................
TFE731-A72-3570........................             1-8  Original                       May 31, 1995.           
Total Pages: 8.                                                                                                 
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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 Aerospace, Attn: Data 
Distribution, M/S 64-3/2101-201, P.O. Box

[[Page 47808]]

29003, Phoenix, AZ 85038-9003; telephone (602) 365-2493, fax (602) 
365-5577. 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.
    (g) This amendment becomes effective on November 12, 1996.

    Issued in Burlington, Massachusetts, on August 26, 1996.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 96-22772 Filed 9-10-96; 8:45 am]
BILLING CODE 4910-13-U