40226 Federal Register / Vol. 63, No. 144 /Tuesday, July 28, 1998 / Proposed Rules

(e) The records of the mandatory

inspections required as a result of revising

the Life Limits Section of the ICA and the air

carrier’s continuous airworthiness

maintenance program as provided by

paragraph (a) of this AD shall be maintained

by FAA-certificated air carriers which have

an approved continuous airworthiness

maintenance program in accordance with the

record keeping system currently specified in

their manual required by sections 121.369 of

the Federal Aviation Regulations (14 CFR

121.369); or, in lieu of the record showing the

current status of each mandatory inspection

required by sections 121.380(a)(2)(vi) of the

Federal Aviation Regulations (14 CFR

121.380(a)(2)(vi)), certificated air carriers

may establish an approved alternate system

of record retention that provides a method for

preservation and retrieval of the maintenance

records that include the inspections resulting

from this AD, and include the policy and

procedures for implementing this alternate

method in the air carrier’s maintenance

manual required by sections 121.369 (c) of

the Federal Aviation Regulations (14 CFR

121.369 (c)); however, the alternate system

must be accepted by the appropriate PMI and

require the maintenance records be

maintained either indefinitely or until the

work is repeated.

Note 3: These record keeping requirements

apply only to the records used to document

the mandatory inspections required as a

result of revising the Life Limits Section of

the ICA as provided in paragraph (a) of this

AD, and do not alter or amend the record

keeping requirements for any other AD or

regulatory requirement.

Issued in Burlington, Massachusetts, on

July 16, 1998.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 98–19632 Filed 7–27–98; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–ANE–48–AD]

RIN 2120–AA64

Airworthiness Directives; Pratt &

Whitney JT8D–1, –1A, –1B, –7, –7A,

–7B, –9, –9A, –11, –15, –15A, –17,

–17A, –17R, and –17AR Series

Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This proposal would require

revisions to the Time Limits Section

(TLS) in the Pratt & Whitney (PW)

JT8D–1, –1A, –1B, –7, –7A, –7B, –9,

–9A, –11, –15, –15A, –17, –17A, –17R,

and –17AR Turbofan Engines Engine

Manual (EM) to include required

enhanced inspection of selected critical

life-limited parts at each piece-part

exposure. This proposal would also

require an air carrier’s approved

continuous airworthiness maintenance

program to incorporate these inspection

procedures. Air carriers with an

approved continuous airworthiness

maintenance program would be allowed

to either maintain the records showing

the current status of the inspections

using the record keeping system

specified in the air carrier’s

maintenance manual, or establish an

acceptable alternate method of record

keeping. This proposal is prompted by

an FAA study of in-service events

involving uncontained failures of

critical rotating engine parts which

indicated the need for improved

inspections. The improved inspections

are needed to identify those critical

rotating parts with conditions, that if

allowed to continue in service, could

result in uncontained failures. The

actions specified by this proposed AD

are intended to prevent critical lifelimited rotating engine part failure,

which could result in an uncontained

engine failure and damage to the

airplane.

DATES: Comments must be received by

October 26, 1998.

ADDRESSES: Submit comments in

triplicate to the FederalAviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

Attention: Rules Docket No. 98–ANE–

48–AD, 12 New England Executive Park,

Burlington, MA 01803-5299. Comments

may also be sent via the Internet using

the following address: ‘‘9-adengineprop@faa.dot.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.

FOR FURTHER INFORMATION CONTACT:

Christopher Spinney, Aerospace

Engineer, Engine Certification Office,

FAA, Engine and Propeller Directorate,

12 New England Executive Park,

Burlington, MA 01803–5299; telephone

(781) 238–7175, 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 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 98–ANE–48–AD.’’ 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

Regional Counsel, Attention: Rules

Docket No. 98–ANE–48–AD, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

A recent FAA study analyzing 15

years of accident data for transport

category airplanes identified several

failure mode root causes that can result

in serious safety hazards to transport

category airplanes. This study identified

uncontained failure of critical lifelimited rotating engine parts as the

leading engine-related safety hazard to

airplanes. Uncontained engine failures

have resulted from undetected cracks in

rotating parts that initiated and

propagated to failure. Cracks can

originate from causes such as

unintended excessive stress from the

original design, or they may initiate

from stresses induced from material

flaws, handling damage, or damage from

machining operations. The failure of

rotating parts can present a significant

safety hazard to the airplanes by release

of high energy fragments that could

injure passengers or crew by penetration

of the cabin, damage flight control

surfaces, sever flammable fluid lines, or

otherwise compromise the

airworthiness of the airplane.

Accordingly, the FAA has developed

an intervention strategy to significantly
Federal Register / Vol. 63, No. 144 /Tuesday, July 28, 1998 / Proposed Rules 40227

reduce uncontained engine failures.

This intervention strategy was

developed after consultation with

industry and will be used as a model for

future initiatives. This intervention

strategy is to conduct enhanced,

nondestructive inspections of front

compressor front hubs (fan hubs) and

second stage compressor disks which

could most likely result in a safety

hazard to the airplane in the event of a

hub or disk fracture. The need for

additional rule making is also being

considered by the FAA. Future ADs may

be issued introducing additional

intervention strategies to further reduce

or eliminate uncontained engine

failures.

Properly focused enhanced

inspections require identification of the

parts whose failure presents the highest

safety hazard to the airplane, identifying

the most critical features to inspect on

these parts, and utilizing inspection

procedures and techniques that improve

crack detection. The FAA, with close

cooperation of the engine

manufacturers, has completed a detailed

analysis that identifies the most safety

significant parts and features, and the

most appropriate inspection methods.

Critical life-limited high energy

rotating parts are currently subject to

some form of recommended crack

inspection when exposed during engine

maintenance or disassembly. As a result

of this AD, the inspections currently

recommended by the manufacturer will

become mandatory for those parts listed

in the compliance section. Furthermore,

the FAA intends that additional

mandatory enhanced inspections

resulting from this AD serve as an

adjunct to the existing inspections. The

FAA has determined that the enhanced

inspections will significantly improve

the probability of crack detection while

the parts are disassembled during

maintenance. All mandatory inspections

must be conducted in accordance with

detailed inspection procedures

prescribed in the manufacturer’s Engine

Manual.

Additionally, this AD allows for air

carriers operating under the provisions

of 14 CFR part 121 with an FAAapproved continuous airworthiness

maintenance program, and entities with

whom those air carriers make

arrangements to perform this

maintenance, to verify performance of

the enhanced inspections by retaining

the maintenance records that include

the inspections resulting from this AD,

provided that the records include the

date and signature of the person

performing the maintenance action.

These records must be retained with the

maintenance records of the part, engine

module, or engine until the task is

repeated. This will establish a method

of record preservation and retrieval

typical to those in existing continuous

airworthiness maintenance programs.

Instructions must be included in an air

carrier’s maintenance manual providing

procedures on how this record

preservation and retrieval system will

be implemented and integrated into the

air carrier’s record keeping system.

For engines or engine modules that

are approved for return to service by an

authorized FAA-certificated entity and

that are acquired by an operator after the

effective date of this AD, the mandatory

enhanced inspections need not be

accomplished until the next piece-part

opportunity. For example, there is no

need for an operator to disassemble to

piece-part level an engine or module

returned to service by an FAAcertificated facility simply because that

engine or module was previously

operated by an entity not required to

comply with this AD. Furthermore, the

FAA intends for operators to perform

the enhanced inspections of these parts

at the next piece-part opportunity

following the initial acquisition,

installation, and removal of the part

following the effective date of this AD.

For piece parts that have not been

approved for return to service prior to

the effective date of this AD, the FAA

does intend that the mandatory

enhanced inspections required by this

AD be performed before such parts are

approved for return to service. Piece

parts that have been approved for return

to service prior to the effective date of

this AD may be installed; however,

enhanced inspection will be required at

the next piece-part opportunity.

This proposal would require, within

the next 30 days after the effective date

of this AD, revisions to the Time Limits

Section (TLS) of the PW JT8D–1, –1A,

–1B, –7, –7A, –7B, –9, –9A, –11, –15,

–15A, –17, –17A, –17R, and –17AR

Turbofan Engines EM, and, for air

carriers, the approved continuous

airworthiness maintenance program.

PW, the manufacturer of JT8D–1, –1A,

–1B, –7, –7A, –7B, –9, –9A, –11, –15,

–15A, –17, –17A, –17R, and –17AR

series turbofan engines, used on 14 CFR

part 25 airplanes has provided the FAA

with a detailed proposal that identifies

and prioritizes the critical life-limited

rotating engine parts with the highest

potential to hazard the airplane in the

event of failure, along with instructions

for enhanced, focused inspection

methods. The enhanced inspections

resulting from this AD will be

conducted at piece-part opportunity, as

defined below in the compliance

section, rather than specific time

inspection intervals.

There are approximately 11,278

engines of the affected design in the

worldwide fleet. The FAA estimates that

5,821 engines installed on airplanes of

U.S. registry would be affected by this

proposed AD, that it would take

approximately 7 work hours per engine

to accomplish the proposed actions. The

average labor rate is $60 per work hour.

Based on these figures, the total cost

impact of the proposed AD on U.S.

operators is estimated to be $2,444,820.

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

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:

Pratt & Whitney: Docket 98–ANE–48–AD.
40228 Federal Register / Vol. 63, No. 144 /Tuesday, July 28, 1998 / Proposed Rules

Applicability: Pratt & Whitney (PW) JT8D–

1, –1A, –1B, –7, –7A, –7B, –9, –9A, –11, –15,

–15A, –17, –17A, –17R, and –17AR series

turbofan engines, installed on but not limited

to Boeing 727 and 737 series and McDonnell

Douglas DC–9 series aircraft.

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 critical life-limited rotating

engine part failure, which could result in an

uncontained engine failure and damage to

the airplane, accomplish the following:

(a) Within the next 30 days after the

effective date of this AD, revise the Time

Limits Section (TLS) of the Pratt & Whitney

(PW) JT8D–1, –1A, –1B, –7, –7A, –7B, –9,

–9A, –11, –15, –15A, –17, –17A, –17R, and

–17AR Turbofan Engines Engine Manual

(EM), part number 481672, and for air carrier

operations revise the approved continuous

airworthiness maintenance program, by

adding the following:

‘‘6. Critical Life Limited Part Inspection

A. Inspection Requirements:

(1) This section has the definitions for

individual engine piece parts and the

inspection procedures which are necessary

when these parts are removed from the

engine.

(2) It is necessary to do the inspection

procedures of the piece parts in paragraph B

when:

(a) The part is removed from the engine

and disassembled to the level specified in

paragraph B and—

(b) The part has accumulated more than

100 cycles since the last piece part

inspection, provided that the part was not

damaged by or related to the cause for it’s

removal from the engine.

(3) The inspections specified in this

section do not replace or make not necessary

other recommended inspections for these

parts or other parts.

B. Parts Requiring Inspection

Note: Piece part is defined as any of the

listed parts with all the blades removed.

Engine manual

description Section Inspection

Hub (Disk), 1st

Stage Compressor:

491201 ......... 72–33–31 –XX,–02,–03

496501 ......... 72–33–31 –XX,–02,–03

504101 ......... 72–33–31 –XX,–02,–03

Engine manual

description Section Inspection

515201 ......... 72–33–31 –XX,–02,–03

594301 ......... 72–33–31 –XX,–02,–03

640501 ......... 72–33–31 –XX,–02,–03

640601 ......... 72–33–31 –XX,–02,–03

743301 ......... 72–33–31 –XX,–02,–03

749701 ......... 72–33–31 –XX,–02,–03

749801 ......... 72–33–31 –XX,–02,–03

750001 ......... 72–33–31 –XX,–02,–03

750101 ......... 72–33–31 –XX,–02,–03

778901 ......... 72–33–31 –XX,–02,–03

791401 ......... 72–33–31 –XX,–02,–03

791501 ......... 72–33–31 –XX,–02,–03

791601 ......... 72–33–31 –XX,–02,–03

791701 ......... 72–33–31 –XX,–02,–03

791801 ......... 72–33–31 –XX,–02,–03

806001 ......... 72–33–31 –XX,–02,–03

806101 ......... 72–33–31 –XX,–02,–03

817401 ......... 72–33–31 –XX,–02,–03

844401 ......... 72–33–31 –XX,–02,–03

845401 ......... 72–33–31 –XX,–02,–03

848001 ......... 72–33–31 –XX,–02,–03

848101 ......... 72–33–31 –XX,–02,–03

Disk, 2nd

Stage

Compressor.

72–33–31 –XX,–02,–03

482502 ......... 72–33–33 –XX

502502 ......... 72–33–33 –XX

520602 ......... 72–33–33 –XX

570302 ......... 72–33–33 –XX

570402 ......... 72–33–33 –XX

678202 ......... 72–33–33 –XX

730202 ......... 72–33–33 –XX

730302 ......... 72–33–33 –XX

730402 ......... 72–33–33 –XX

740502 ......... 72–33–33 –XX

745702 ......... 72–33–33 –XX

745902 ......... 72–33–33 –XX

746002 ......... 72–33–33 –XX

746802 ......... 72–33–33 –XX

760402 ......... 72–33–33 –XX

760502 ......... 72–33–33 –XX

807502 ......... 72–33–33 –XX

5002402–01 72–33–33 –XX

790832 (Disk

assembly).

72–33–33 –XX’’

(b) Except as provided in paragraph (c) of

this AD, and notwithstanding contrary

provisions in section 43.16 of the Federal

Aviation Regulations (14 CFR 43.16), these

mandatory inspections shall be performed

only in accordance with the Time Limits

section in the EM.

(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 Engine Certification

Office. Operators shall submit their requests

through an appropriate FAA Principal

Maintenance Inspector (PMI), who may add

comments and then send it to the Engine

Certification Office.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

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.

(e) The records of the mandatory

inspections required as a result of revising

the Time Limits section in the EM and the

air carrier’s continuous airworthiness

maintenance program as provided by

paragraph (a) of this AD shall be maintained

by FAA-certificated air carriers which have

an approved continuous airworthiness

maintenance program in accordance with the

record keeping system currently specified in

their manual required by sections 121.369 of

the Federal Aviation Regulations (14 CFR

121.369); or, in lieu of the record showing the

current status of each mandatory inspection

required by sections 121.380(a)(2)(vi) of the

Federal Aviation Regulations (14 CFR

121.380(a)(2)(vi)), certificated air carriers

may establish an approved alternate system

of record retention that provides a method for

preservation and retrieval of the maintenance

records that include the inspections resulting

from this AD, and include the policy and

procedures for implementing this alternate

method in the air carrier’s maintenance

manual required by sections 121.369 (c) of

the Federal Aviation Regulations (14 CFR

121.369 (c)); however, the alternate system

must be accepted by the appropriate PMI and

require the maintenance records be

maintained either indefinitely or until the

work is repeated.

Note 3: These record keeping requirements

apply only to the records used to document

the mandatory inspections required as a

result of revising Chapter 05–11–00, titled

Time Limits, in the EM as provided in

paragraph (a) of this AD, and do not alter or

amend the record keeping requirements for

any other AD or regulatory requirement.

Issued in Burlington, Massachusetts, on

July 16, 1998.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 98–19633 Filed 7–27–98; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 71

[Airspace Docket No. 98–ACE–23]

Proposed Establishment of Class E

Airspace; Guthrie, IA

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking.

SUMMARY: This document proposes to

establish Class E airspace area at

Guthrie County Regional Airport,

Guthrie, IA. The FAA has developed

Global Positioning System (GPS)