[Federal Register Volume 63, Number 35 (Monday, February 23, 1998)]
[Proposed Rules]
[Pages 8885-8886]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-4406]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-51-AD]
RIN 2120-AA64


Airworthiness Directives; AlliedSignal Inc. TFE731 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to AlliedSignal Inc. TFE731 
series turbofan engines, that currently requires the installation of a 
clamp assembly to support the rigid fuel tube. This action would 
require installation of an improved flexible (flex) fuel tube. This 
proposal is prompted by reports of fuel leaks from a cracked fuel tube 
in engines that have already installed a clamp assembly in accordance 
with the current AD. The actions specified by the proposed AD are 
intended to prevent cracking of the fuel tube and the subsequent 
leakage of fuel on or around electrical components, which can cause an 
engine fire.

DATES: Comments must be received by April 24, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 97-ANE-51-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ad-
[email protected]''. Comments sent via the Internet must contain 
the docket number in the subject line. Comments may be inspected at 
this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, 
except Federal holidays.
    The service information referenced in the proposed rule 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 
FAA, New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Joseph Costa, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, FAA, Transport Airplane 
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712; telephone (562) 
627-5246, fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-ANE-51-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-ANE-51-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On June 3, 1993, the Federal Aviation Administration (FAA) issued 
airworthiness directive AD 93-10-10, Amendment 39-8589 (58 FR 32835, 
June 14, 1993), applicable to Allied-Signal Aerospace Company, Garrett 
Engine Division (now AlliedSignal Inc.) TFE731 series turbofan engines, 
to require the installation of a clamp assembly to support the fuel 
line. Installation of the clamp assembly was to minimize excessive 
vibration and possible cracking of the fuel line due to starter 
generator bearing failure. That action was prompted by reports of fuel 
lines cracking and failing, resulting in inflight engine shutdowns and 
fuel spillage on and around electrical components in the engine 
accessory gearbox area. That condition, if not corrected, could result 
in a cracked fuel tube and the subsequent leakage of fuel on and around 
electrical components, which can cause an engine fire.
    Since the issuance of that AD, the FAA has received an additional 
11 reports of continued cracking of the rigid fuel tube in engines that 
have already installed a clamp assembly in accordance with the current 
AD. Eighteen of 19 tube failures which occurred before and after the 
implementation of AD 93-10-10 resulted from starter generator bearing 
failures. This AD does not affect the AlliedSignal engine Model TFE731-
2-2B and engine series TFE731-3A and -3AR installed on Learjet Models 
35, 36, and 55 because starter generators are not used on these 
aircraft. In addition, for this application, there have been no 
reported fuel line failures.
    The FAA has reviewed and approved the technical contents of 
AlliedSignal Inc. Alert Service Bulletin (ASB) No. TFE731-A73-3128, 
dated February 26, 1997, and AlliedSignal Inc. ASB No. TFE731-A73-3132, 
dated April 9, 1997, that describe procedures for installing an 
improved flex fuel tube.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 93-10-10 and require the installation of 
an improved flex fuel tube.
    There are approximately 3,325 engines of the affected design in the 
worldwide fleet. The FAA estimates that 2,319 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD, that 
it would take approximately 2.0 work hours per engine to accomplish the 
proposed actions, and that the average labor rate is $60 per work hour. 
Required parts would cost approximately $300 per engine. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $973,980.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1)

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is not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under the DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 
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 copy of the draft regulatory evaluation 
prepared for this action is contained in the Rules Docket. A copy of it 
may be obtained by contacting the Rules Docket at the location provided 
under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-8589 (58 FR 
32835, June 14, 1993) and by adding a new airworthiness directive to 
read as follows:

AlliedSignal Inc.: Docket No. 97-ANE-51-AD. Supersedes AD 93-10-10, 
Amendment 39-8589.

    Applicability: AlliedSignal Inc. (formerly Allied-Signal 
Aerospace Company, Garrett Engine Division and Garrett Turbine 
Engine Co.) TFE731-2, -3, and -4 series turbofan engines with fuel 
tubes, part numbers (P/Ns) 3071051-1, 3073729-1, or 3072886-1, 
installed. These engines are installed on but not limited to the 
following aircraft: Avions Marcel Dassault Falcon 10, 50, and 100 
series; Cessna Model 650, Citation III, VI, and VII; Learjet 31 
(M31) 35, 36 and 55 series, Raytheon British Aerospace HS-125 
series; and Sabreliner NA-265-65.

    Note 1: 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 (b) 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 cracked fuel tubes and the subsequent leakage of fuel on 
and around electrical components, which can cause an engine fire, 
accomplish the following:
    (a) Within 160 hours time in service (TIS) after the effective 
date of this AD, or prior to December 20, 1999, whichever occurs 
first, install an improved flexible fuel tube, as follows:
    (1) For engines installed on Cessna aircraft, install in 
accordance with the Accomplishment Instructions of AlliedSignal Inc. 
Alert Service Bulletin (ASB) No. TFE731-A73-3132, dated April 9, 
1997.
    (2) For engines installed on all other aircraft except for the 
Learjet 35, 36 and 55 series, install in accordance with the 
Accomplishment Instructions of AlliedSignal Inc. ASB No. TFE731-A73-
3128, dated February 26, 1997.
    (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, Los Angeles Aircraft Certification 
Office. Operators shall submit their requests 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.

    (c) 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.

    Issued in Burlington, Massachusetts, on February 11, 1998.
James C. Jones,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 98-4406 Filed 2-20-98; 8:45 am]
BILLING CODE 4910-13-U