21898 Federal Register / Vol. 66, No. 85 / Wednesday, May 2, 2001 / Proposed Rules

uncontained engine failure, and damage to

the airplane, do the following:

(a) Remove fan rotor discs P/N’s 3072162–

All, 3072816–All, 3073436–All, 3073539–

All, and 3074529–All (where All denotes all

dash numbers), and replace with serviceable

fan rotor discs at next access to the fan rotor

disc, at the next scheduled fan rotor disc

inspection, or prior to December 31, 2002,

whichever occurs earliest. Fan rotor disc

replacement information is available in

Honeywell International Inc. Alert Service

Bulletin TFE731–A72–3668, dated October

25, 2000.

Definitions

(b) For the purpose of this AD, the

following definitions apply:

(1) Access to the fan rotor disc is whenever

the fan shaft is unstretched.

(2) A serviceable disc is a disc that does

not have a P/N listed in this AD.

Alternative Methods of Compliance

(c) 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

(LAACO). Operators shall submit their

request through an appropriate FAA

Principal Maintenance Inspector, who may

add comments and then send it to the

Manager, LAACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the LAACO.

Special Flight Permits

(d) Special flight permits may be issued in

accordance §§ 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 24, 2001.

Donald E. Plouffe,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 01–10890 Filed 5–1–01; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NE–61–AD]

RIN 2120–AA64

Airworthiness Directives; GE Aircraft

Engines CT7 Series Turboprop

Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: The Federal Aviation

Administration (FAA) proposes to adopt

a new airworthiness directive (AD) that

is applicable to GE Aircraft Engines (GE)

CT7 series turboprop engines. This

proposal would require removal of stage

2 turbine aft cooling plates of a certain

part number (P/N) and installation of

cooling plates of a new design. This

proposal is prompted by a report of a

stage 2 turbine aft cooling plate

cracking, resulting in an uncontained

engine failure. The actions specified by

the proposed AD are intended to

prevent stage 2 turbine aft cooling plate

cracking, which could result in

uncontained engine failure, and damage

to the airplane.

DATES: Comments must be received by

July 2, 2001.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

Attention: Rules Docket No. 2000–NE–

61–AD, 12 New England Executive Park,

Burlington, MA 01803–5299. Comments

may also be sent via the Internet using

the following address: 9-aneadcomment@faa.gov. Comments sent

via the Internet must contain the docket

number in the subject line. Comments

may be inspected at this location

between 8 a.m. and 4:30 p.m., Monday

through Friday, except Federal holidays.

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:

Barbara Caufield, Aerospace Engineer,

Engine Certification Office, FAA, Engine

and Propeller Directorate, 12 New

England Executive Park, Burlington, MA

01803–5299; telephone: (781) 238–7146;

fax: (781) 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 action 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 action

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 2000–NE–61–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. 2000–NE–61–AD, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

In July 1999, the FAA was made

aware of an uncontained failure of a GE

CT7–5 turboprop engine, caused by a

cracked stage 2 turbine aft cooling plate.

In February 2000, GE identified and

reported the root cause of the cooling

plate failure to the FAA. The failure was

due to micro-cracking at the cooling air

holes and a reduction in material

properties, caused during manufacture

by an excessive electro-discharge

machining (EDM) recast layer in the air

holes followed by inadequate abrasive

flow. GE has identified those cooling

plates manufactured by this method, as

P/N 6064T07P02, having the serial

number (SN) prefix of GFF. GE also has

reported that a few unaffected stage 2

turbine aft cooling plates, P/N

6064T07P02 having a SN prefix other

than GFF, are installed mainly on

engines in foreign military service. This

condition, if not corrected, could cause

cracking of the stage 2 turbine aft

cooling plate, resulting in an

uncontained engine failure, and damage

to the airplane.

FAA’s Determination of an Unsafe

Condition and Proposed Actions

Since an unsafe condition has been

identified that is likely to exist or

develop on other GE CT7 series

turboprop engines of the same type

design, the proposed AD would require

replacing affected stage 2 turbine aft

cooling plates with new design aft

cooling plates, P/N 6064T07P05, having

cooling holes made by conventional

drilling methods.

Federal Register / Vol. 66, No. 85 / Wednesday, May 2, 2001 / Proposed Rules 21899

Economic Impact

There are approximately 564 engines

of the affected design in the worldwide

fleet. The FAA estimates that 180

engines installed on airplanes of U.S.

registry would be affected by this

proposed AD, that it would take

approximately 0.5 work hour per engine

to accomplish the proposed actions, and

that the average labor rate is $60 per

work hour. Required aft cooling plates

would cost approximately $15,282 per

engine. Based on these figures, the total

cost impact of the proposed AD on U.S.

operators is estimated to be $2,756,160.

The manufacturer has stated that it may

provide the new design aft cooling plate

at no cost to operators, and that if the

aft cooling plate is replaced at the next

engine or hot section module overhaul

shop visit, no additional labor costs will

be incurred.

Regulatory Impact

This proposed rule does not have

federalism implications, as defined in

Executive Order 13132, because it

would not have a substantial direct

effect 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.

Accordingly, the FAA has not consulted

with state authorities prior to

publication of this proposed rule.

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

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.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

GE Aircraft Engines: Docket No. 2000–NE–

61–AD.

Applicability: This airworthiness directive

(AD) is applicable to GE Aircraft Engines

(GE) CT7 Models CT7–5A2, –5A3, –7A, and

–7A1 turboprop engines, installed on but not

limited to Construcciones Aeronauticas, SA

CN–235 series and SAAB Aircraft AB SF340

series airplanes.

Note 1: 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 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

Compliance is required at the next overall

of the engine or hot section module, or

within 8,000 cycles after the effective date of

this AD, whichever occurs first, unless

already done.

To prevent stage 2 turbine aft cooling plate

cracking, which could result in an

uncontained engine failure and damage to

the airplane, do the following:

(a) Replace stage 2 aft cooling plate

P/N 6064T07P02 with stage 2 aft cooling

plate P/N 6064T07P05.

(b) After the effective date of this AD, do

not install any stage 2 aft cooling plate P/N

6064T07P02.

Alternative Methods of Compliance

(c) 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 (ECO). Operators shall

submit their request through an appropriate

FAA Principal Maintenance Inspector, who

may add comments and then send it to the

Manager, ECO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the ECO.

Special Flight Permits

(d) Special flight permits may be issued in

accordance §§ 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 24, 2001.

Donald E. Plouffe,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 01–10889 Filed 5–1–01; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Coast Guard

33 CFR Part 164

[USCG–2001–8826]

RIN 2115–AG09

Electronic Chart Display and

Information Systems for Commercial

Vessels

AGENCY: Coast Guard, DOT.

ACTION: Advance notice of proposed

rulemaking.

SUMMARY: The Coast Guard proposes to

amend its regulations to allow

commercial vessels to use as their

primary means of navigation in U.S.

waters an electronic charting and

navigation system that meets the

Electronic Charting Display and

Information System (ECDIS) standard of

the International Maritime Organization

(IMO). Allowing commercial vessels to

use modern electronic charting

technology may reduce the potential for

human error by providing a continuous

update of a vessel’s position for the

mariner. To obtain information needed

to amend this rule, the Coast Guard asks

for comments from the public on the

questions listed in this document.

DATES: Comments and related material

must reach the Docket Management

Facility on or before July 2, 2001.

ADDRESSES: To make sure your

comments and related material are not

entered more than once in the docket,

please submit them by only one of the

following means:

(1) By mail to the Docket Management

Facility (USCG 2001–8826), U.S.

Department of Transportation, room PL–

401, 400 Seventh Street SW.,

Washington, DC 20590–0001.

(2) By delivery to room PL–401 on the

Plaza level of the Nassif Building, 400

Seventh Street SW., Washington, DC,

between 9 a.m. and 5 p.m., Monday

through Friday, except Federal holidays.

The telephone number is (202) 366–

9329.

(3) By fax to the Docket Management

Facility at (202) 493–2251.