Airworthiness Directives; AlliedSignal Inc. TFE731 Series Turbofan Engines

[Federal Register Volume 62, Number 44 (Thursday, March 6, 1997)]
[Rules and Regulations]
[Pages 10201-10202]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-5512]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-ANE-08; Amendment 39-9926; AD 97-04-03]
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. TFE731 series turbofan engines, that 
requires removal from service of certain first stage low pressure 
turbine (LPT) seal plates prior to accumulating the new, reduced cyclic 
life limit, and replacement with serviceable LPT seal plates. This 
amendment is prompted by a report that the machined LPT seal plate 
geometry did not meet the design intent due to drawing ambiguity. The 
actions specified by this AD are intended to prevent fatigue cracking 
and subsequent uncontained failure of an LPT seal plate.

DATES: Effective May 5, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 5, 1997.

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. TFE731 series 
turbofan engines was published in the Federal Register on July 10, 1996 
(61 FR 36310). That action proposed to require removing from service 
first stage LPT seal plates, Part Number (P/N) 3073552-2 and P/N 
3074053-1, prior to accumulating the new, reduced cyclic life limit of 
3,700 cycles since new (CSN), and replacement with serviceable parts. 
The actions would be required to be accomplished in accordance with 
AlliedSignal Inc. Service Bulletin (SB) No. TFE731-72-3573, dated 
August 15, 1995. AlliedSignal Inc. SB No. TFE731-72-3001, Service Life 
Limits of Critical Life Limited Components, Revision 42, dated July 17, 
1995, incorporates the new cyclic life limit of 3,700 CSN.
    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 added a new paragraph (c) to clarify that operators may seek FAA-
approval of modifications to the new life limits only through the 
alternative method of compliance procedure described in the AD. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule with this change.The FAA has determined that this 
change will neither increase the economic burden on any operator nor 
increase the scope of the AD.
    The FAA estimates that 268 engines installed on aircraft of U.S. 
registry will be affected by this AD, that it will take approximately 1 
work hour per engine to accomplish the required actions, and that the 
average labor rate is $60 per work hour. Required parts will cost 
approximately $5,000 per engine. Based on these figures, the total cost 
impact of the AD on U.S. operators is estimated to be $1,356,080.
    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 USC 106(g), 40113, 44701.


Sec. 39.13  [AMENDED]

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

97-04-03 AlliedSignal Inc.: Amendment 39-9926. Docket 96-ANE-08.

    Applicability: AlliedSignal Inc. Models TFE731-2A, -3C and -3CR 
series turbofan engines, with first stage low pressure turbine (LPT) 
seal plates, Part Number (P/N) 3073552-2 and P/N 3074053-1, 
installed on but not limited to the following aircraft: Cessna Model 
650 Citation III and Israel Aircraft Industries Model 1125 Westwind 
Astra aircraft.

    Note 1: This airworthiness directive (AD) applies to each engine 
identified in the preceding applicability provision, regardless

[[Page 10202]]

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 fatigue cracking and subsequent uncontained failure 
of a first stage LPT seal plate, accomplish the following:
    (a) Prior to accumulating 3,700 cycles since new (CSN) on LPT 
seal plates, P/Ns 3073552-2 and 3074053-1, remove from service these 
first LPT seal plates, and replace with serviceable parts, in 
accordance with the Accomplishment Instructions of AlliedSignal Inc. 
Service Bulletin (SB) No. TFE731-72-3573, dated August 15, 1995.
    (b) This action establishes a new, reduced cyclic life limit of 
3,700 CSN for first stage LPT seal plates, P/N 3073552-2 and P/N 
3074053-1.
    (c) Except as provided in paragraph (d) of this AD, no 
alternative replacement times may be approved for LPT seal plates, 
P/N 3073552-2 and 3074053-1.
    (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 2: 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 Inc. SB:

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            Document No.              Pages              Date           
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TFE731-72-3573.....................      1-6  August 15, 1995           
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    Total Pages: 6.
    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 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 May 5, 1997.

    Issued in Burlington, Massachusetts, on February 26, 1997.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 97-5512 Filed 3-5-97; 8:45 am]
BILLING CODE 4910-13-U

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