This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

21053

Vol. 60, No. 83

Monday, May 1, 1995

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95–ANE–21]

Airworthiness Directives; AlliedSignal

Engines LTS101 Series Turboshaft

Engines Installed on Eurocopter

France Model AS–350D and SA–366G1

Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD), applicable to

AlliedSignal Engines (formerly Textron

Lycoming) LTS101 series turboshaft

engines installed on Eurocopter France

(formerly Aerospatiale) Model AS–350D

and SA–366G1 helicopters. This

proposal would require incorporation of

design modifications to the power

turbine (PT) rotor. This proposal is

prompted by reports of PT disk failures

after No. 3 bearing failures. The actions

specified by the proposed AD are

intended to prevent an uncontained

engine failure due to a PT disk failure.

DATES: Comments must be received by

June 30, 1995.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No.

95–ANE–21, 12 New England Executive

Park, Burlington, MA 01803–5299.

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 Engines, 550 Main Street,

Stratford, CT 06497. This information

may be examined at the FAA, New

England Region, Office of the Assistant

Chief Counsel, 12 New England

Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Eugene Triozzi, Aerospace Engineer,

Engine Certification Office, FAA, Engine

and Propeller Directorate, 12 New

England Executive Park, Burlington, MA

01803–5299; telephone (617) 238–7148,

fax (617) 238–7199.

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 95–ANE–21.’’ 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

Assistant Chief Counsel, Attention:

Rules Docket No. 95–ANE–21, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

The Federal Aviation Administration

(FAA) has received reports of three

uncontained power turbine (PT) disk

failures on AlliedSignal Engines

(formerly Textron Lycoming) LTS101

series turboshaft engines. These PT disk

failures were caused by No. 3 bearing

failures, resulting in loss of rotor axial

location, aft movement of the PT rotor,

and PT shaft disengagement from the

gear train drive, subsequently unloading

the PT and causing rotor overspeed. The

disengagement further rendered the gear

train drive overspeed control

inoperative; therefore, the PT overspeed

progressed until disk failure. This

condition, if not corrected, could result

in an uncontained engine failure due to

a PT disk failure.

On October 28, 1994, AlliedSignal

Inc. purchased the turbine engine

product line of Textron Lycoming.

The FAA has reviewed and approved

the technical contents of Textron

Lycoming Service Bulletin (SB) No.

LTS101A–72–50–0134, Revision 1,

dated June 17, 1991, and SB No.

LTS101B–72–50–0128, Revision 1,

dated June 17, 1991, that describe

procedures for incorporation of design

modifications to the PT to enhance rotor

retention in the event of No. 3 bearing

failure.

At the present time, this proposed

airworthiness directive (AD) would

require only the PT rotor retention

modifications for AlliedSignal Engines

Model LTS101–600A2, –600A3, and

–750B2 engines. AlliedSignal Engines

and several airframe manufacturers have

developed electronic overspeed system

(EOS) modifications for other models of

the AlliedSignal Engines LTS101 series

turboshaft engines. These other

modifications address additional disk

failures precipitated by No. 4 bearing

failure, which in two cases led to power

pinion gear failure and PT shaft

disengagement from the power train

without loss of rotor axial location,

overspeed, and loss of PT overspeed

protection. In separate rulemaking, the

FAA will require these EOS

modifications for these other models.

Airworthiness directive 88–14–01,

applicable to all Textron Lycoming

LTS101 engines, requires repetitive

inspections and monitoring of the

lubrication system to prevent PT rotor

disk failures due to failure of either No.

3 or No. 4 bearings. Performing the PT

rotor and EOS modifications on these

other models would constitute

terminating action for the inspections

and monitoring required by AD 88–14–
21054 Federal Register / Vol. 60, No. 83 / Monday, May 1, 1995 / Proposed Rules

01. The FAA has requested that

AlliedSignal Engines and Eurocopter

France develop EOS modifications for

the AlliedSignal Engines LTS101

models addressed in this proposed AD.

When these modifications are available,

the FAA will require these

modifications in future rulemaking that

would constitute terminating action to

the inspection and monitoring

requirements of AD 88–14–01.

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

require incorporation of a modified PT

rotor retention system at the next shop

visit after the effective date of this AD,

but not later than April 30, 1996. The

FAA has determined that by that date

affected engines would have at least one

scheduled shop visit to incorporate

modifications. The actions would be

required to be accomplished in

accordance with the service bulletins

described previously.

The FAA estimates that 20 engines

installed on aircraft of U.S. registry

would be affected by this proposed AD,

that it would take approximately 10

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 $44,400 engine. Based on

these figures, the total cost impact of the

proposed AD on U.S. operators is

estimated to be $900,000.

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 ‘‘major rule’’ under Executive

Order 12291; (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. App. 1354(a), 1421

and 1423; 49 U.S.C. 106(g); and 14 CFR

11.89.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

AlliedSignal Engines: Docket No. 95–ANE–

21.

Applicability: AlliedSignal Engines

(formerly Textron Lycoming) Models

LTS101–600A2 and –600A3 turboshaft

engines installed on Eurocopter France

(formerly Aerospatiale) Model AS–350D

helicopters; and LTS101–750B2 turboshaft

engines installed on Eurocopter France

Model SA–366G1 helicopters.

Note: This 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 use the authority

provided in paragraph (b) to request approval

from the FAA. This approval may address

either no action, if the current configuration

eliminates the unsafe condition, or different

actions necessary to address the unsafe

condition described in this AD. Such a

request should include an assessment of the

effect of the changed configuration on the

unsafe condition addressed by this AD. In no

case does the presence of any modification,

alteration, or repair remove any engine from

the applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously.

To prevent an uncontained engine failure

due to power turbine (PT) disk failure,

accomplish the following:

(a) Incorporate improved PT rotor retention

system modifications in accordance with

Textron Lycoming Service Bulletin (SB) No.

LTS101A–72–50–0134, Revision 1, dated

June 17, 1991, or SB No. LTS101B–72–50–

0128, Revision 1, dated June 17, 1991, as

applicable, at the next shop visit after the

effective date of this airworthiness directive

(AD) when the PT rotor is removed, but not

later than April 30, 1996.

(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, Engine

Certification Office. The request should be

forwarded through an appropriate FAA

Maintenance Inspector, who may add

comments and then send it to the Manager,

Engine Certification Office.

Note: Information concerning the existence

of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(c) Special flight permits may be issued in

accordance with §§ 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

April 17, 1995.

James C. Jones,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 95–10594 Filed 4–28–95; 8:45 am]

BILLING CODE 4910–13–P

14 CFR Part 39

[Docket No. 95–NM–26–AD]

Airworthiness Directives; Boeing

Model 757 and 767 Series Airplanes

Equipped With Sundstrand Ram Air

Turbine (RAT)/Hydraulic Pumps

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain Boeing Model 757 and 767 series

airplanes. This proposal would require

replacement of the hydraulic pressure

transfer tube of the ram air turbine

(RAT) system with a new hose

assembly. This proposal is prompted by

reports that, during flight tests, the

hydraulic pressure transfer tube of the

RAT cracked when the RAT was

extended on a Model 767 series

airplane. The actions specified by the

proposed AD are intended to prevent

such cracking, which could result in the

loss of hydraulic fluid of the center

system and the inability of the RAT to

pressurize the center system; this

situation could lead to loss of all

hydraulic system power in the event

that power is lost in both engines.

DATES: Comments must be received by

June 26, 1995.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 95–NM–

26–AD, 1601 Lind Avenue, SW.,