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

31566

Vol. 66, No. 113

Tuesday, June 12, 2001

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NE–32–AD]

RIN 2120–AA64

Airworthiness Directives; Honeywell

International, Inc. (formerly

AlliedSignal, Inc. and Textron

Lycoming), T5313B, T5317 Series, and

T53 Series Turboshaft 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 Honeywell

International, Inc., (formerly

AlliedSignal, Inc., and Textron

Lycoming) T5313B series, T5317 series,

and former military T53 series,

turboshaft engines having certain serial

number centrifugal compressor

impellers, installed. This proposal

would require for T5313B series and

T5317 series engines, initial and

repetitive inspections of those

compressor impellers, if installed. This

proposal would also require for T53

series engines, a revised operating cycle

count (prorate) for those compressor

impellers if installed, and initial and

repetitive inspections, with eventual

compressor impeller replacement. In

addition, this proposal would require

the marking of those compressor

impellers. This proposal is prompted by

a report from the supplier that four

centrifugal compressor impellers may

have been inadvertently misidentified.

The actions specified by the proposed

AD are intended to prevent premature

failure of the impellers from being

operated beyond their design service

life, which could result in an

uncontained engine failure, in-flight

shutdown, or damage to the helicopter.

DATES: Comments must be received by

August 13, 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–

32-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 8:00 a.m. and 4:30 p.m.,

Monday through Friday, except Federal

holidays. The service information

referenced in this proposed rule may be

obtained from Honeywell International,

Inc. (formerly AlliedSignal, Inc. and

Textron Lycoming), 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:

Robert Baitoo, Aerospace Engineer, Los

Angeles Aircraft Certification Office

(ACO), FAA, Transport Airplane

Directorate, 3960 Paramount Blvd.,

Lakewood, CA 90712–4137; telephone:

(562) 627–5245; 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–32–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–32–AD, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

The manufacturer recently notified

the FAA of four centrifugal compressor

impellers, serial numbers 83317, 83327,

83328, and 83330, that may have been

inadvertently misidentified. These

impellers are installed in Honeywell

International, Inc. (formerly

AlliedSignal, Inc., and Textron

Lycoming) T5313B series, T5317 series,

and T53 series turboshaft engines. This

misidentification allows these impellers

to be operated beyond their design

service life. This proposal would require

for T5313B series and T5317 series

engines, initial and repetitive

inspections of those compressor

impellers, if installed. This proposal

would also require for T53 series

engines, a revised operating cycle count

(prorate) for those four centrifugal

compressor impellers if installed, and

initial and repetitive inspections, with

replacement within 300 operating hours

or six calendar months, whichever

occurs first, after the effective date of

this AD. In addition, this proposal

would require the marking of those four

compressor impellers. The actions

specified in this AD are intended to

prevent premature failure of the

impellers from being operated beyond

their design service life, which could

result in an uncontained engine failure,

in-flight shutdown, or damage to the

helicopter.

Federal Register / Vol. 66, No. 113 / Tuesday, June 12, 2001 / Proposed Rules 31567

Manufacturer’s Service Information

The FAA has reviewed and approved

the technical contents of Honeywell

International, Inc. Service Bulletins

(SB’s) T5313B/17–0020, Revision 5,

dated March 31, 2001, T53–L–13B–

0020, Revision 2, dated April 25, 2001,

T53–L–13B/D–0020, Revision 1, dated

April 25, 2001, and T53-L–703–0020,

Revision 1, dated April 25, 2001, that

describe procedures for conducting a

revised centrifugal compressor impeller

operating cycle count (prorate). The

FAA has also reviewed and approved

the technical contents of Textron

Lycoming SB T5313B/17–0052,

Revision 2, dated December 16, 1993,

AlliedSignal, Inc. SB’s T53–L–13B–

0108, Revision 1, dated November 22,

1999, T53–L–13B/D–0108, Revision 1,

dated November 22, 1999, and T53–L–

703–0108, Revision 1, dated November

22, 1999, that describe procedures for

visual and fluorescent penetrant

inspections of centrifugal compressor

impellers.

Proposed Actions

Since an unsafe condition has been

identified that is likely to exist or

develop on other engines of the same

type design registered in the United

States, this AD is being issued to

prevent premature failure of the

impellers from being operated beyond

their design service life, which could

result in an uncontained engine failure,

in-flight shutdown, or damage to the

helicopter. The actions would be

required to be accomplished in

accordance with compliance

requirements contained in this proposed

rule.

Economic Impact

The FAA estimates there are

approximately four Honeywell

International, Inc., (formerly

AlliedSignal, Inc., and Textron

Lycoming) T5313B series, T5317 series,

and former military T53 series

turboshaft engines having the

misidentified centrifugal compressor

impellers, that are installed on

helicopters of U.S. registry. The FAA

also estimates that it would take

approximately eight work hours per

engine to accomplish the inspection,

and that the average labor rate is $60 per

work hour. No additional work hour

cost would be incurred if the centrifugal

compressor impeller is replaced during

normal engine disassembly. The

prorated cost of a replacement

compressor impeller is estimated to be

$20,000. Based on these figures, the

total labor cost impact of the proposed

AD on U.S. operators is estimated to be

$21,920.

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:

Honeywell International, Inc. Docket 2000–

NE–32–AD.

Applicability

This airworthiness directive (AD) is

applicable to Honeywell International, Inc.,

(formerly AlliedSignal, Inc., and Textron

Lycoming) T5313B series, T5317 series, and

former military T53 series, turboshaft engines

with centrifugal compressor impellers having

serial numbers (SN’s) 83317, 83327, 83328,

or 83330 installed. These engines are

installed on, but not limited to Bell

Helicopter Textron 204, 205, and 209 series,

and Kaman K–1200 series helicopters, and

the following surplus military helicopters

that have been certified in accordance with

sections 21.25 or 21.27 of the Federal

Aviation Regulations (14 CFR 21.25 or 21.27):

Bell Helicopter Textron manufactured AH–1,

UH–1, and SW–204/205 (UH–1) series.

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 (i) 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 accomplished previously.

Life limits

(a) When conducting a revised centrifugal

compressor impeller operating cycle count

on impellers having SN’s 83317, 83327,

83328, or 83330, consider these impellers to

be centrifugal compressor impeller P/N 1–

100–078–07. The life limit must use the

value as if these centrifugal compressor

impellers are P/N 1–100–078–07.

Revised Operating Cycle Count (Prorate) for

T53 engines

(b) For former military T53 series engines,

within 25 operating cycles or 7 calendar

days, whichever occurs first, after the

effective date of this airworthiness directive

(AD), perform the following:

(1) Conduct a revised centrifugal

compressor impeller operating cycle count

(prorate) in accordance with paragraph 2.E.of

the Honeywell International, Inc. Service

Bulletin (SB) that applies to the engine, from

the following list:

(i) For T53–L–13B series engines, use SB

T53–L–13B–0020, Revision 2, dated April 25,

2001.

(ii) For T53–L–13B/D engines, use SB T53–

L–13B/D–0020, Revision 1, dated April 25,

2001.

(iii) For T53–L–703 engines, use SB T53–

L–703–0020, Revision 1, dated April 25,

2001.

(2) Remove from service centrifugal

compressor impellers with SN’s 83317,

83327, 83328, or 83330, that exceed their

new life limit as calculated in accordance

with paragraph (b)(1) of this AD.

Impeller Marking

(c) At the next access to the centrifugal

compressor impeller, mark the impeller by

vibropeening a line over the -14 suffix, and

vibropeen a -07 suffix immediately following

the -14. Use the following vibropeening

parameters:

31568 Federal Register / Vol. 66, No. 113 / Tuesday, June 12, 2001 / Proposed Rules

(1) Vibropeen to a depth of 0.001–0.006

inch.

(2) Do not vibropeen within 0.30 inch of

corners, fillets, or sharp edges.

Definition

(d) For the purpose of this AD, access to

the centrifugal compressor impeller is

defined as whenever the turboshaft engine is

disassembled sufficiently as specified by the

applicable maintenance manual, to expose

the compressor impeller for marking in

accordance with paragraph (c) of this AD.

Inspection of Impellers on T5313B and

T5317 Series Engines

(e) For T5313B and T5317 series engines,

inspect centrifugal compressor impellers

having SN’s 83317, 83327, 83328, or 83330,

for cracks in accordance with the

Accomplishment Instructions of Textron

Lycoming SB No. T5313B/17–0052, Revision

2, dated December 16, 1993, as follows:

(1) For those centrifugal compressor

impellers installed on AlliedSignal, Inc.

Model T5313B engines, accomplish the

following:

(i) For centrifugal compressor impellers

with equal to or greater than 4,600 cycles in

service (CIS) on the effective date of this AD,

initially inspect within 200 CIS after the

effective date of this AD.

(ii) For those centrifugal compressor

impellers with less than 4,600 CIS on the

effective date of this AD, initially inspect no

later than 4,800 CIS.

(2) For those centrifugal compressor

impellers installed on AlliedSignal, Inc.

T5317 series engines, accomplish the

following:

(i) For those centrifugal compressor

impellers with equal to or greater than 3,500

CIS on the effective date of this AD, initially

inspect within 200 CIS after the effective date

of this AD.

(ii) For those centrifugal compressor

impellers with less than 3,500 CIS on the

effective date of this AD, initially inspect no

later than 3,700 CIS.

(3) Centrifugal compressor impellers found

cracked in accordance with the

Accomplishment Instructions of Textron

Lycoming SB No. T5313B/17–0052, Revision

2, dated December 16, 1993, must be

removed from service and replaced with a

serviceable part that does not exceed the life

limit.

(4) If no cracks are detected, perform

repetitive inspections of the centrifugal

compressor impellers at intervals not to

exceed 500 CIS since last inspection in

accordance with the Accomplishment

Instructions of Textron Lycoming SB No.

T5313B/17–0052, Revision 2, dated

December 16, 1993.

Inspection of Impellers on T53–L–13B Series

Engines

(f) For T53–L–13B/D series engines with

centrifugal compressor impellers having SN’s

83317, 83327, 83328, or 83330, perform the

following:

(1) Within 25 operating hours from the

effective date of this AD, inspect the

centrifugal compressor impeller for cracks

using the revised cycle count (prorate)

required by paragraph (b)(1) of this AD, in

accordance with Accomplishment

Instructions of AlliedSignal, Inc. SB No. T53-

L–13B–0108, Revision 1, dated November 22,

1999.

(2) If cracks are detected, then prior to

further flight, replace centrifugal compressor

impellers found cracked in accordance with

the Accomplishment Instructions of

AlliedSignal, Inc. SB No. T53–L–13B–0108,

Revision 1, dated November 22, 1999, and

replace with a centrifugal compressor

impeller P/N 1–100–078–13/–14.

(3) If no cracks are detected, perform

repetitive inspections of the centrifugal

compressor impellers at intervals not to

exceed 100 operating hours since last

inspection in accordance with the

Accomplishment Instructions of

AlliedSignal, Inc. SB No. T53–L–13B–0108,

Revision 1, dated November 22, 1999.

(4) Within 300 operating hours or 6

calendar months, whichever occurs first,

after the effective date of this AD, replace

centrifugal compressor impellers having SN’s

83317, 83327, 83328, or 83330, with a

centrifugal compressor impeller P/N 1–100–

078–13/–14. Replacement of centrifugal

compressor impellers having SN’s 83317,

83327, 83328, or 83330, with a centrifugal

compressor impeller P/N 1–100–078–13/–14

constitutes terminating action for the

inspection requirements of paragraphs (f)(1)

and (f)(3) of this AD.

Inspection of Impellers on T53–L–13B/D

Series Engines

(g) For T53–L–13B/D series engines with

centrifugal compressor impellers having SN’s

83317, 83327, 83328, or 83330, perform the

following:

(1) Within 25 operating hours from the

effective date of this AD, inspect the

centrifugal compressor impeller for cracks

using the revised cycle count (prorate)

required by paragraph (b)(1) of this AD, in

accordance with Accomplishment

Instructions of AlliedSignal, Inc. SB No.

T53–L–13B/D–0108, Revision 1, dated

November 22, 1999.

(2) If cracks are detected, then prior to

further flight, replace centrifugal compressor

impellers found cracked in accordance with

the Accomplishment Instructions of

AlliedSignal, Inc. SB No. T53–L–13B/D–

0108, Revision 1, dated November 22, 1999,

and replace with a centrifugal compressor

impeller P/N 1–100–078–13/–14.

(3) If no cracks are detected, perform

repetitive inspections of the centrifugal

compressor impellers at intervals not to

exceed 100 operating hours since last

inspection in accordance with the

Accomplishment Instructions of

AlliedSignal, Inc. SB No. T53–L–13B/D–

0108, Revision 1, dated November 22, 1999.

(4) Within 300 operating hours or 6

calendar months, whichever occurs first,

after the effective date of this AD, replace

centrifugal compressor impellers having SN’s

83317, 83327, 83328, or 83330, with a

centrifugal compressor impeller P/N 1–100–

078–13/–14. Replacement of centrifugal

compressor impellers having SN’s 83317,

83327, 83328, or 83330, with a centrifugal

compressor impeller P/N 1–100–078–13/–14

constitutes terminating action for the

inspection requirements of paragraphs (g)(1)

and (g)(3) of this AD.

Inspection of Impellers on T53–L–703

Engines

(h) For T53–L–703 series engines with

centrifugal compressor impellers having SN’s

83317, 83327, 83328, or 83330, perform the

following:

(1) Within 25 operating hours from the

effective date of this AD, inspect the

centrifugal compressor impeller for cracks

using the revised cycle count (prorate)

required by paragraph (b)(1) of this AD, in

accordance with Accomplishment

Instructions of AlliedSignal, Inc. SB No.

T53–L–703–0108, Revision 1, dated

November 22, 1999.

(2) If cracks are detected, then prior to

further flight, replace centrifugal compressor

impellers found cracked in accordance with

the Accomplishment Instructions of

AlliedSignal, Inc. SB No. T53–L–703–0108,

Revision 1, dated November 22, 1999, and

replace with a centrifugal compressor

impeller part number (P/N) 1–100–078–13/–

14.

(3) If no cracks are detected, perform

repetitive inspections of the centrifugal

compressor impellers at intervals not to

exceed 100 operating hours since last

inspection in accordance with the

Accomplishment Instructions of

AlliedSignal, Inc. SB No. T53–L–703–0108,

Revision 1, dated November 22, 1999.

(4) Within 300 operating hours or 6

calendar months, whichever occurs first,

after the effective date of this AD, replace

centrifugal compressor impellers having SN’s

83317, 83327, 83328, or 83330, with a

centrifugal compressor impeller P/N 1–100–

078–13/–14. Replacement of centrifugal

compressor impellers having SN’s 83317,

83327, 83328, or 83330, with a centrifugal

compressor impeller P/N 1–100–078–13/–14

constitutes terminating action for the

inspection requirements of paragraphs (h)(1)

and (h)(3) of this AD.

Alternative Methods of Compliance

(i) 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 (ACO).

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 ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

Special Flight Permits

(j) 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 helicopter

to a location where the requirements of this

AD can be accomplished.

Federal Register / Vol. 66, No. 113 / Tuesday, June 12, 2001 / Proposed Rules 31569

Issued in Burlington, Massachusetts, on

June 4, 2001.

Francis A. Favara,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 01–14672 Filed 6–11–01; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NE–62–AD]

RIN 2120–AA64

Airworthiness Directives; General

Electric Company GE90 Series

Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: The Federal Aviation

Administration (FAA) proposes to

supersede an existing airworthiness

directive (AD), applicable to certain

General Electric Company (GE) GE90

series turbofan engines. That AD

currently requires inspecting and

purging the P3B and Ps3 lines and

associated fittings and ports of moisture.

This proposal would allow the

installation of improved hardware as

terminating action to requirements of

the AD, and remove the GE90–92B

engine model from the AD applicability.

This proposal is prompted by the recent

FAA approval of redesigned P3B and

Ps3 sense lines, and the removal of the

GE90–92B engine from the applicability.

The actions described in this proposal

are intended to prevent loss of thrust

control due to corruption of the P3B and

Ps3 signals to the FADEC, which if it

occurs in a critical phase of flight, could

result in loss of airplane control.

DATES: Comments must be received by

August 13, 2001.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

Attention: Rules Docket No. 99-NE–62-

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 8:00 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 General Electric

Company via Lockheed Martin

Technology Services, 10525 Chester

Road, Suite C, Cincinnati, OH 45215;

telephone: (513) 672–8400, fax: (513)

672–8422. 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: John

E. Golinski, Aerospace Engineer, Engine

Certification Office, FAA, Engine and

Propeller Directorate, 12 New England

Executive Park, Burlington, MA 01803–

5299; telephone: (781) 238–7135; 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 to the address

specified above. All communications

received on or before the closing date

for comments, specified above, will be

considered before we take 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 sent

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 send a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 99–NE–62–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. 99–NE–62–AD, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

On December 29, 1999, the FAA

issued AD 99–27–15, Amendment 39–

11496 (65 FR 692, January 6, 2000), to

require visually inspecting P3B and Ps3

sense lines and FADEC P3B and Ps3

sensing ports and fittings, cleaning P3B

and Ps3 fittings and sensing ports,

purging the P3B and Ps3 systems of

moisture, and, if necessary, blending of

high metal, nicks, burrs, or scratches on

P3B and Ps3 fitting threads. That action

was prompted by seven reports of loss

of thrust control due to corruption of the

signals to the FADEC caused by water

freezing in the Ps3 sensing system. That

condition, if not corrected, could result

in loss of thrust control due to

corruption of the P3B and Ps3 signals to

the FADEC, which if it occurs in a

critical phase of flight, could result in

loss of airplane control. Since that AD

was issued, improved hardware has

been introduced as terminating action to

the visual inspections, cleanings,

purging, and blending of metal. Also,

alternative methods of compliance

approved for AD 99–27–15 are

incorporated as conventional methods

of compliance in this proposal. Also, the

GE90–92B engine model has been

removed from the AD applicability. The

FAA recently removed the GE90–92B

engine from the type certificate at the

request of GE.

Service Information

The FAA has reviewed and approved

the technical contents of GE Alert

Service Bulletin (ASB) GE90 73–A0060,

Revision 3, dated September 14, 2000,

that describes procedures for:

• Visually inspecting P3B and Ps3

sense lines and FADEC sensing ports

and fittings.

• Cleaning P3B and Ps3 fittings and

sensor ports, purging the P3B and Ps3

systems of moisture.

• Blending of high metal, nicks,

burrs, or scratches on Ps3 and P3B

fitting threads.

The FAA has also reviewed and

approved the technical contents of GE

Service Bulletin (SB) GE90 S/B 75–

0031, Revision 3, dated March 30, 2001,

that describes procedures for replacing

existing P3B and Ps3 lines and related

brackets and clamping with redesigned

hardware.

Differences Between ASB, SB, and

Proposal

This proposal contains provisions for

initial actions and GE ASB GE90 73–

A0060, Revision 3, dated September 14,

2000, assumes that all operators have

completed the initial actions based on

field reports. If, however, operators have

already accomplished the required

initial actions, they need not repeat

those actions, but may proceed directly

to accomplishing the repetitive actions,