[Federal Register Volume 64, Number 74 (Monday, April 19, 1999)]
[Proposed Rules]
[Pages 19096-19097]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-9657]



[[Page 19096]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-51-AD]


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 to revise an existing airworthiness 
directive (AD), applicable to AlliedSignal Inc. TFE731 series turbofan 
engines, that currently requires the installation of an improved 
flexible (flex) fuel tube. This action would clarify that installation 
of the improved flex fuel tube and that the use of a clamp on the 
original rigid fuel tube are optional for engines installed on Learjet 
35, 36, and 55 series airplanes. This proposal is prompted by confusion 
from operators regarding the applicability of these Learjet engine 
installations. 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 May 19, 1999.

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 NPRM's

    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 August 3, 1998, the Federal Aviation Administration (FAA) issued 
AD 98-17-01, Amendment 39-10703 (63 FR 42691, August 11, 1998), to 
require installation of an improved flexible (flex) fuel tube. That 
action was prompted by reports of fuel leaks from a cracked fuel tube 
in engines that have already installed a clamp assembly in accordance 
with a superseded AD. That condition, if not corrected, could result in 
cracking of the fuel tube and the subsequent leakage of fuel on or 
around electrical components, which can cause an engine fire.
    Since the issuance of that AD, the FAA has received reports from 
operators expressing confusion as to the applicability of engines 
installed on Learjet 35, 36, and 55 series airplanes. That AD did 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 airplanes. 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, and AlliedSignal Inc. SB No. TFE731-73-3107, 
Revision 4, dated April 20, 1994, that describes procedures for 
installing a clamp assembly on the rigid 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 revise AD 98-17-01 to clarify that the installation 
of the improved flex fuel tube and the use of a clamp on the original 
rigid fuel tube are optional for engines installed on Learjet 35, 36, 
and 55 series airplanes.
    As this revision is merely a clarification, there would be no 
additional economic impact on operators. In addition, this revision 
corrects the docket number for this AD, which appears as ``98-ANE-36-
AD'' in the current AD. The correct docket number for this AD is ``97-
ANE-51-AD.''
    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) 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

[[Page 19097]]

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 39-10703 (63 FR 
42691, August 11, 1998), and by adding a new airworthiness directive, 
to read as follows:

AlliedSignal Inc.: Docket 97-ANE-51-AD. Revises AD 98-17-01, 
Amendment 39-10703.

    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 airplanes: 
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 (c) 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) Except for engines installed on Learjet 35, 36, and 55 
airplanes, 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 airplanes, 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 airplanes 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) For engines installed on Learjet 35, 36, and 55, the 
improved flex tube and the clamp assembly installed on the original 
rigid fuel tube are optional. If the clamp assembly is used, install 
the clamp assembly in accordance with the Accomplishment 
Instructions of AlliedSignal Inc. SB No. TFE731-73-3107, Revision 4, 
dated April 20, 1994.
    (c) An alternative method of compliance or adjustment of the 
initial 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 AD, 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 airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Burlington, Massachusetts, on April 12, 1999.
Ronald L. Vavruska,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-9657 Filed 4-16-99; 8:45 am]
BILLING CODE 4910-13-P