21896 Federal Register / Vol. 66, No. 85 / Wednesday, May 2, 2001 / Proposed Rules

TABLE 2.—PROHIBITED SPARE PARTS

Airbus model series airplane Part Part No.

(1) A300 B2 and B4 ................................................................ Sensor ................................................................................... 718–054–1

(2) A300 B2 and B4 ................................................................ Sensor ................................................................................... 718–557

(3) A300 B2 and B4 ................................................................ Sensor ................................................................................... 718–055–1

(4) A300 B2 and B4 ................................................................ Connector .............................................................................. 852510R8T33SN02

(5) A310 .................................................................................. Connector .............................................................................. E0052R10B6SNE

(6) A310 .................................................................................. Connector .............................................................................. E0052R12B10SNE

(7) A310 .................................................................................. Connector .............................................................................. E0052R14B19SNE

(8) A300–600 .......................................................................... Connector .............................................................................. E0052R14B19SNE

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,

International Branch, ANM–116, Transport

Airplane Directorate, FAA. Operators shall

submit their requests through an appropriate

FAA Principal Maintenance Inspector, who

may add comments and then send it to the

Manager, International Branch, ANM–116.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the International Branch,

ANM–116.

Special Flight Permits

(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.

Note 3: The subject of this AD is addressed

in French airworthiness directive 2000–481–

324(B), dated November 29, 2000.

Issued in Renton, Washington, on April 25,

2001.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 01–10940 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–53–AD]

RIN 2120–AA64

Airworthiness Directives; Honeywell

International Inc. TFE731–2, –3, and –4

Series Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: The Federal Aviation

Administration (FAA) proposes to

supersede two existing airworthiness

directives (ADs), applicable to

Honeywell International Inc. (formerly

AlliedSignal Inc. and Garrett Turbine

Engine Co.) TFE731–2, –3, and –4 series

turbofan engines. Those AD’s currently

require removing certain fan rotor discs

from service in accordance with a

drawdown schedule, and establishing

new fan rotor disc life limits. This

proposal would require stricter life

limits for certain fan rotor discs. This

proposal is prompted by the availability

of an improved fan rotor disc and by a

reduction in the probability of fan rotor

disc failure by terminating the life of the

older, high-stressed, fan rotor disc. The

actions specified in the proposed AD are

intended to prevent failure of the fan

disc due to fatigue cracking in the

dovetail slots, which could result in inflight engine shutdown, 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–

53–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.

The service information referenced in

the proposed rule may be obtained from

Honeywell Engines and Systems

(formerly AlliedSignal Inc. and Garrett

Turbine Engine Co.) Technical

Publications and Distribution, M/S

2101–201, P.O. Box 52170, Phoenix, AZ

85072–2170; telephone: (602) 365–2493

(General Aviation), (602) 365–5535

(Commercial Aviation), fax: (602) 365–

5577 (General Aviation), (602) 365–2832

(Commercial Aviation). 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

90712–4137; 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 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–53–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–53–AD, 12 New

Federal Register / Vol. 66, No. 85 / Wednesday, May 2, 2001 / Proposed Rules 21897

England Executive Park, Burlington, MA

01803–5299.

Discussion

On May 22, 1986, the FAA issued AD

86–11–05, Amendment 39–5325 (51 FR

2025, June 4, 1986), and on August 26,

1996, the FAA issued AD 96–18–13,

Amendment 39–9737 (61 FR 47806,

September 11, 1996). These AD’s

require removing certain fan rotor discs

from service in accordance with

drawdown schedules based on the fan

rotor disc’s accumulated cycles-sincenew (CSN). These AD’s also establish

new fan rotor disc life cycle limits at

4,100 CSN or 4,600 CSN, depending on

the respective disc part number. That

action was prompted after additional

analyses revealed that stress levels in

the dovetail slots of the affected fan

rotor discs were higher than initially

calculated. The requirements of that AD

are intended to prevent failure of the fan

disc due to fatigue cracking in the

dovetail slots, resulting in in-flight

engine shutdown, uncontained engine

failure, and damage to the airplane. In

addition, to further reduce the

probability of a fatigue failure and

separation of in-service fan rotor discs,

the FAA issued AD 96–05–03,

Amendment 39–9529 (61 FR 10881,

March 18, 1996) and AD 96–04–01,

Amendment 39–9512 (61 FR 7690,

February 29, 1996), which require initial

and repetitive eddy current inspections

of the dovetail slots. Within the past ten

years, 400 fan discs have been removed

from service for unacceptable eddy

current inspection indications. Service

experience has shown that the crack

detection capability of this eddy current

inspection procedure remains between

80–90 percent. Since AD 86–11–05, AD

96–18–13, AD 96–05–03, and AD 96–

04–01 were issued, the FAA has

determined that approximately 1,400

affected fan rotor discs remain in

service, and has concluded that an

accelerated removal schedule of affected

fan rotor discs at next access or prior to

December 31, 2002, is necessary to

further reduce the probability of fan

rotor disc failures.

Manufacturer’s Service Information

The FAA has reviewed and approved

the technical contents of Honeywell

International Inc. Alert Service Bulletin

TFE731–A72–3668, dated October 25,

2000, that describes fan rotor disc

replacement procedures, and references

other documents for instructions on

replacement, with the redesigned fan

rotor discs.

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 Honeywell

International Inc. (formerly AlliedSignal

Inc. and Garrett Turbine Engine Co.)

TFE731–2, –3, and –4 series turbofan

engines of this same type design, the

proposed AD would require replacing

fan rotor discs part numbers (P/N’s)

3072162–All, 3072816–All, 3073436–

All, 3073539–All, and 3074529–All

(where All denotes all dash numbers).

Economic impact

There are approximately 1,400

engines with affected discs in the

worldwide fleet. The FAA estimates that

1,100 engines installed on aircraft of

U.S. registry would be affected by this

proposed AD. The FAA also estimates

that it would take approximately one

work hour per engine to accomplish the

proposed action during a normally

scheduled fan rotor disc removal period,

and approximately six work hours per

engine to accomplish the proposed

action during an unscheduled fan rotor

disc removal period, and that the

average labor rate is $60 per work hour.

Required parts would cost

approximately $20,400 per engine.

Based on these figures, the total cost

impact of the proposed AD on U.S.

operators is estimated to be $22,509,000.

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 (FAA) 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

removing Amendment 39–5325 (51 FR

2025, June 4, 1986) and Amendment

39–9737, (61 FR 47806, September 11,

1996) and by adding a new

airworthiness directive, to read as

follows:

Honeywell International Inc.: Docket No.

2000–NE–53–AD. Supersedes AD 86–

11–05, Amendment 39–5325 and AD 96–

18–13, Amendment 39–9737.

Applicability: This airworthiness directive

(AD) is applicable to Honeywell International

Inc. (formerly AlliedSignal Inc. and Garrett

Turbine Engine Co.) TFE731–2, –3, and –4

series turbofan engines, with fan rotor discs

part numbers (P/N’s) 3072162–All, 3072816–

All, 3073436–All, 3073539–All, and

3074529–All (where All denotes all dash

numbers). These engines are installed on, but

not limited to, Avions Marcel Dassault

Falcon 10, 50, and 100 series; Learjet 31, 35,

36, and 55 series; Lockheed-Georgia 1329–23

and –25 series; Israel Aircraft Industries 1124

series and 1125 Westwind series; Cessna

Model 650, Citations III, VI, and VII;

Raytheon British Aerospace HS–125 series;

and Sabreliner NA–265–65 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 with this AD is required as

indicated, unless already done.

To prevent failure of the fan disc due to

fatigue cracking in the dovetail slots, which

could result in in-flight engine shutdown,

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.