This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents. Prices of

new books are listed in the first FEDERAL

REGISTER issue of each week.

Rules and Regulations Federal Register

37473

Vol. 65, No. 116

Thursday, June 15, 2000

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–ANE–66–AD; Amendment

39–11780; AD 2000–12–02]

RIN 2120–AA64

Airworthiness Directives; Pratt &

Whitney PW4000 Series Turbofan

Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to certain Pratt & Whitney

PW4000 Series Turbofan Engines, that

currently requires revisions to the Time

Limits Section of the manufacturer’s

Engine Manuals (EM’s) to include

required enhanced inspection of

selected critical life-limited parts at

each piece-part exposure. This action

adds additional critical life-limited parts

for enhanced inspection. This

amendment is prompted by additional

focused inspection procedures for other

critical life-limited rotating engine parts

that have been developed by the

manufacturer. The actions specified by

this AD are intended to prevent critical

life-limited rotating engine part failure,

which could result in an uncontained

engine failure and damage to the

airplane.

DATES: Effective September 13, 2000.

ADDRESSES: The rulemaking docket may

be examined at the Federal Aviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

12 New England Executive Park,

Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Peter White, Aerospace Engineer,

Engine Certification Office, FAA, Engine

and Propeller Directorate, 12 New

England Executive Park, Burlington, MA

01803–5299; telephone (781) 238–7128,

fax (781) 238–7199.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39)

by superseding (AD) 99–08–15,

Amendment 39–11121 (64 FR 17947),

that is applicable to certain Pratt &

Whitney series turbofan engine was

published in the Federal Register on

October 7, 1999 (64 FR 54582). The

original AD required enhanced

inspection of selected critical lifelimited rotating components in the fan

rotor at each piece-part exposure. This

amendment will require additional

enhanced inspections of selected critical

life-limited rotating components in the

HPT rotor at each piece-part exposure.

New Procedures and Parts

Since the issuance of that AD,

additional focused inspection

procedures for other critical life-limited

rotating engine parts have been

developed. The new parts are the:

• High Pressure Turbine (HPT) 1st

stage airseal—on certain models

• HPT 2nd stage airseal—on certain

models

• HPT 1st stage (front) hub

• HPT 2nd stage (rear) hub

This AD will require an air carrier’s

approved continuous airworthiness

maintenance program to incorporate

these inspection procedures, and will

revise the Time Limits Section of the

manufacturer’s Engine Manual.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

eleven comments received.

Length of Comment and Inspection

Periods

Two comments express concerns

regarding the length of the comment

period, and the length of the initial

compliance time allowed to incorporate

the manufacturer’s instructions into an

applicant’s maintenance plan. One

comment asks that the final rule not be

issued and the comment period

extended until after the manufacturer

publishes the new inspection

procedures in the manufacturer’s

manuals. Another comment asks that

the initial compliance time be extended

from 30 to 90 days to better

accommodate the manufacturer’s

planned manual change schedule.

The FAA does not agree. The FAA

believes that the nature and scope of the

added inspections will not be

significantly different from existing

inspections. In addition, the effective

date of this AD has been extended to 90

days after publication to allow time for

the specific procedures to be published.

Operators may submit comments on the

specific procedures once they are

published and the FAA will consider

extending the effective date further or

additional rulemaking, as necessary.

The extra time until the AD becomes

effective should also allow the

manufacturer to issue a manual

revision. The FAA does not believe,

however, that this final rule need be

delayed pending the publication of the

inspection procedures, or the initial

compliance time extended to

accommodate the manufacturer’s

manual revision cycle.

More Than One Engine Model Covered

by AD

One comment notes that engine

models covered by two different Type

Certificates are affected by this AD, and

feels that a separate AD should be

issued to cover the engine models

covered by each Type Certificate.

Another comment notes that, to avoid

confusion, the tables in proposed

paragraph (a) should be divided by

engine model. The comment points out

that as presently constructed the AD

requires information related to different

engine models to be incorporated into

all manuals. That could cause confusion

as information unrelated to a particular

engine model would appear in that

model’s manuals.

The FAA does not agree that products

covered by different type certificates

must be addressed with separate AD’s.

The FAA often includes products

covered by different type designs in a

single AD. When the same unsafe

condition exists or is likely to develop

on products covered by different type

designs, a single AD covering all the

affected products works more efficiently

than duplicating the same corrective

action into multiple AD’s. The single

AD should place no undue burden on

operators, and may actually simplify

administrative responsibilities by

reducing the number of AD’s required to

be tracked. This AD applies to engines

covered by three Type Certificates.

37474 Federal Register / Vol. 65, No. 116 / Thursday, June 15, 2000 / Rules and Regulations

The FAA does agree, however, that

the tables in paragraph (a) should be

separated by engine model. Paragraph

(a) will be changed to include a

provision that only the table that applies

to a particular engine model should be

incorporated into that engine model’s

manual. This will eliminate the

potential confusion in having

information not applicable to that

engine in its manual.

HPC Parts Included in the Proposed

Rule

Two comments question the need for

this AD noting that the lower risk

associated with HPC disk failures make

the inclusion of HPC parts in the

enhanced inspection program

unnecessary.

The FAA partially agrees. The failure

of an HPC disk with a full webbed bore

configuration such as the PW4000 poses

a hazard to the aircraft due to the energy

associated with these large, heavy,

rapidly spinning components. While the

risk factors for HPC failures are

somewhat lower than those associated

with HPT and fan failures, the FAA

feels this could be due to several factors,

which will need to be evaluated. Until

further studies have been completed,

the FAA will eliminate the HPC parts

from the enhanced inspection program

for these engine models. The FAA will

continue to review and evaluate the data

and will take appropriate action when

this review is completed.

Part Numbers Used To Identify Parts To

Be Inspected

One comment notes that the use of

specific part numbers (P/N’s) to identify

the parts needing enhanced inspection

raises concerns. The comment notes that

the use of part numbers places

additional undue burden on operators

who must keep track of the manual

changes to ensure consistency with P/

N’s, and creates a need for downstream

revisions to the AD as additional part

number disks are introduced into

service.

The FAA concurs. During the process

of preparing this rule, the FAA

considered utilizing the term ‘‘ALL’’

rather than specific part numbers, but

not all part numbers associated with a

specific part need enhanced inspection.

For example, HPT airseals from various

engine models may or may not need

enhanced inspection, depending on the

configuration of the part. Only those

parts that are likely to hazard the

aircraft by their failure are included in

the enhanced inspection program.

Therefore, the ‘‘ALL’’ terminology could

not be used consistently across engine

models. However, in response to

another comment the FAA is changing

the structure of this AD to separate the

tables by engine model. With that

change each table may use the term

‘‘ALL’’ and eliminate the need for

specific P/N’s.

Discussion Section Changed From

Original NPRM

One comment notes that the preamble

published with this Notice of Proposed

Rulemaking (NRPM) did not include the

same guidelines concerning required

enhanced inspections as the preamble

for the NPRM published for the current

AD. The comment asks that the FAA

add those guidelines to the final rule.

The FAA does not agree. The

inspection program established by the

current AD has not been changed. The

NPRM proposed to add additional parts

to the list of parts that must be

inspected, but does not change how air

carriers must manage the inspection

program. Future AD’s may be issued to

introduce additional intervention

strategies in order to further reduce

uncontained engine failures. These may

include AD’s to add new parts to the list

of parts to be inspected. The inspection

program established by the current AD

will remain unchanged unless

specifically changed in a future

proposal.

Manual References Should Include

Revision Level and Issue Date

Two comments note that the proposed

rule does not reference a specific

revision level or issue date of the Clean,

Inspect and Repair (CIR) manual. The

comments express concern that without

a specific manual revision referenced

operators will not know if the FAA

expects compliance with future

revisions to the manual, which may be

issued without notice and public

comment. For that reason, the

comments suggest that the manual

references in paragraph (a) include a

revision level and issue date.

The FAA disagrees. Unlike the typical

incorporation by reference, this AD does

not require inspections to be

accomplished ‘‘in accordance with’’ a

specific service document or manual.

This AD requires changes to the

Airworthiness Limitations Section

(ALS) of the Instructions for Continued

Airworthiness (ICA), and to air carrier

operator’s maintenance plans, in order

to include mandatory inspections. Once

included in the ALS, the enhanced

inspections become operational limits

that must be followed. The

manufacturer will update the sections of

their manuals to incorporate the

inspections, and those changes, as well

as any future changes, will be

coordinated with the FAA. It is not the

intent of this AD, however, to mandate

the use of any specific manual revision,

but only to require the accomplishment

of an enhanced inspection. If the FAA

should find it necessary to mandate

compliance with a specific future

revision of the manual, then the FAA

will undertake a new rulemaking action

and provide notice and an opportunity

for comment.

Other Corrections

One comment notes that the table in

proposed paragraph (a) lists CIR manual

51A357 as the manual to use when

inspecting HPT first stage hub, P/N

50L761, while that part is only found in

CIR manual 51A750. The FAA agrees,

and will make that correction in the

final rule.

One comment points out that detail

HPT 1st stage disk P/N 51L901 is

referenced in the manufacturer’s parts

catalog, but is not referenced in the

corresponding CIR. The FAA agrees.

However, the corresponding assembly

P/N is called out in the CIR. The ‘‘ALL’’

reference now utilized in the AD

eliminates any issues arising from the

Detail versus Assembly P/N reference

issue. In addition, the FAA has added

the definition of ‘‘piece-part

opportunity’’ to (a)(2) to clarify that the

disks must be inspected when torn

down to either the piece part or part

assembly P/N level where the

inspection can still be accomplished.

One comment notes that paragraph (e)

of the proposed rule contains the phrase

‘‘of this chapter’’ following a reference

to § 121.369 (c) of the Federal Aviation

Regulations [14 CFR 121.369 (c)]. The

comment asks that this phrase be

deleted in the interest of clarity. The

FAA agrees, and will make that

correction the final rule.

Engines Affected by the Ruling

One commenter notes the PW4098,

PW4090D and PW4090–3 models are

not affected by the AD, and questions

why they are excluded from the rule.

The FAA partially agrees. The PW4098

and PW4090D fan hardware were

included in the NPRM, and an

explanation for this inclusion is

provided in the NPRM. Coincident with

the inclusion of this hardware, these

two models were included in the

Applicability statement. The PW4090–3

engine model was certified at a later

date, and was not included in the

NPRM. The final rule will be modified

to include the PW4090–3 engine model

in the Applicability section for

completeness, as were the PW4098 and

PW4090D.

Federal Register / Vol. 65, No. 116 / Thursday, June 15, 2000 / Rules and Regulations 37475

Economic Analysis

No comments were received on the

economic analysis contained in the

proposed rules. The FAA has

determined that the annual cost of

complying with this AD does not create

a significant economic impact on small

entities.

After careful review of the available

data, including the comments noted

above, the FAA has determined that air

safety and the public interest require the

adoption of the rule with the changes

described previously. The FAA has

determined that these changes will

neither increase the economic burden

on any operator nor increase the scope

of the AD.

Regulatory Impact

This final rule does not have

federalism implications, as defined in

Executive Order 13132, because it does

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

final rule.

For the reasons discussed above, I

certify that this action (1) is not a

‘‘significant regulatory action’’ under

Executive Order 12866; (2) is not a

‘‘significant rule’’ under DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979); and (3)

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 final evaluation has

been prepared for this action and it is

contained in the Rules Docket. A copy

of it may be obtained from 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.

Adoption of the Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration amends 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 39–11121 (64 FR

17947, April 13, 1999), and by adding

a new airworthiness directive, to read as

follows:

2000–12–02 Pratt & Whitney: Amendment

39–11780. Docket No. 98–ANE–66–AD.

Supersedes AD 99–08–15, Amendment

39–11121.

Applicability: Pratt & Whitney (PW) Model

PW4050, PW4052, PW4056, PW4060,

PW4060A, PW4060C, PW4062, PW4152,

PW4156, PW4156A, PW4158, PW4160,

PW4460, PW4462, PW4168, PW4168A,

PW4164, PW4074, PW4074D, PW4077,

PW4077D, PW4084, PW4084D, PW4090,

PW4090D, PW4090–3 and PW4098 turbofan

engines, installed on but not limited to

Airbus A300, A310, and A330 series, Boeing

747, 767, and 777 series, and McDonnell

Douglas MD–11 series airplanes.

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:

Inspections

(a) Within the next 30 days after the

effective date of this AD, revise the Time

Limits Section of the manufacturer’s Engine

Manual (EM), Part Numbers (P/Ns) 50A605,

50A443, 51A342, 50A822, 51A751, or

51A345, as applicable, for PW Model

PW4050, PW4052, PW4056, PW4060,

PW4060A, PW4060C, PW4062, PW4152,

PW4156, PW4156A, PW4158, PW4160,

PW4460, PW4462, PW4168, PW4168A,

PW4164, PW4074, PW4074D, PW4077,

PW4077D, PW4084, PW4084D, PW4090,

PW4090D, PW4090–3 and PW4098 turbofan

engines, and for air carrier operations revise

the approved mandatory inspections section

of the continuous airworthiness maintenance

program, to read as follows:

‘‘MANDATORY INSPECTIONS

(1) Perform inspections of the following

parts at each piece-part opportunity in

accordance with the instructions provided in

the applicable PW4000 series Engine

Cleaning, Inspection, and Repair (CIR)

Manuals:

For Engine Manual 50A605 only, insert the

following table:

Nomenclature Part Number CIR Manual

Section CIR Manual Inspection CIR Manual

Hub, Front Compressor .................................................. ALL ..................................... 72–31–07 Insp/Check–02 ................... 51A357

Hub, Turbine Front (Stage 1) ......................................... ALL ..................................... 72–52–05 Insp/Check–02 ................... 51A357

Hub, Turbine Intermediate Rear (Stage 2) ..................... ALL ..................................... 72–52–06 Insp/Check–02 ................... 51A357

For Engine Manual 50A443 only, insert the following table:

Nomenclature Part Number CIR Manual

Section CIR Manual Inspection CIR Manual

Hub, Front Compressor .................................................. ALL ..................................... 72–31–07 Insp/Check–02 ................... 51A357

Hub, Turbine Front (Stage 1) ......................................... ALL ..................................... 72–52–05 Insp/Check–02 ................... 51A357

Hub, Turbine Intermediate Rear (Stage 2) ..................... ALL ..................................... 72–52–06 Insp/Check–02 ................... 51A357

For Engine Manual 50A822 only, insert the following table:

Nomenclature Part Number CIR Manual

Section CIR Manual Inspection CIR Manual

Hub, Front Compressor .................................................. ALL ..................................... 72–31–07 Insp/Check–02 ................... 51A357

Hub, Turbine Front (Stage 1) ......................................... ALL ..................................... 72–52–05 Insp/Check–02 ................... 51A357

37476 Federal Register / Vol. 65, No. 116 / Thursday, June 15, 2000 / Rules and Regulations

Nomenclature Part Number CIR Manual

Section CIR Manual Inspection CIR Manual

Hub, Turbine Intermediate Rear (Stage 2) ..................... ALL ..................................... 72–52–06 Insp/Check–02 ................... 51A357

For Engine Manual 51A342 only, insert the following table:

Nomenclature Part Number CIR Manual

Section CIR Manual Inspection CIR Manual

Hub, LPC Assembly ....................................................... ALL ..................................... 72–31–07 Insp/Check–02 ................... 51A357

Hub, Turbine Front Assembly (1st Stage) ...................... ALL ..................................... 72–52–05 Insp/Check–02 ................... 51A357

Hub, Turbine Rear (Stage 2) .......................................... ALL ..................................... 72–52–06 Insp/Check–02 ................... 51A357

For Engine Manual 51A345 only, insert the following table:

Nomenclature Part Number CIR Manual

Section CIR Manual Inspection CIR Manual

Hub, LPC Assembly ....................................................... ALL ..................................... 72–31–07 Insp/Check–02 ................... 51A370

Seal—Air, HPT, 1st Stage .............................................. ALL ..................................... 72–52–19 Insp/Check–02 ................... 51A750

Hub, Turbine Front Assembly (1st Stage) ...................... ALL ..................................... 72–52–05 Insp/Check–02 ................... 51A750

Seal—Air, HPT, 2nd Stage Assembly ............................ ALL ..................................... 72–52–22 Insp/Check–02 ................... 51A750

Hub, Turbine Rear Assembly (2nd Stage) ..................... ALL ..................................... 72–52–06 Insp/Check–02 ................... 51A750

For Engine Manual 51A751 only, insert the following table:

Nomenclature Part Number CIR Manual

Section CIR Manual Inspection CIR Manual

Hub, LPC Assembly ....................................................... ALL ..................................... 72–31–07 Insp/Check–02 ................... 51A750

Seal—Air, HPT, 1st Stage .............................................. ALL ..................................... 72–52–19 Insp/Check–02 ................... 51A750

Hub, Turbine Front Assembly (1st Stage) ...................... ALL ..................................... 72–52–05 Insp/Check–02 ................... 51A750

Seal—Air, HPT, 2nd Stage Assembly ............................ ALL ..................................... 72–52–22 Insp/Check–02 ................... 51A750

Hub, Turbine Rear Assembly (2nd Stage) ..................... ALL ..................................... 72–52–06 Insp/Check–02 ................... 51A750

(2) For the purpose of these mandatory

inspections, piece-part opportunity means:

(i) The part is considered completely

disassembled when accomplished in

accordance with the disassembly instructions

in the manufacturer’s engine manuals to

either the part detail or part assembly level

part numbers for the parts listed in the Tables

above; and

(ii) The part has accumulated more than

100 cycles in service since the last piece-part

opportunity inspection, provided that the

part was not damaged or related to the cause

for its removal from the engine.’’

(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 of the manufacturer’s EM’s.

Alternative Method 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 Engine Certification

Office (ECO). Operators shall submit their

requests through an appropriate FAA

Principal Maintenance Inspector (PMI), who

may add comments and then send it to the

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.

Ferry Flights

(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.

Continuous Airworthiness Maintenance

Program

(e) FAA-certificated air carriers that have

an approved continuous airworthiness

maintenance program in accordance with the

record keeping requirement of § 121.369(c) of

the Federal Aviation Regulations [14 CFR

121.369(c)] must maintain records of the

mandatory inspections that result from

revising the Time Limits Section of the EM’s

and the air carrier’s continuous airworthiness

program. Alternately, certificated air carriers

may establish an approved 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 § 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. Records of the piece-part

inspections are not required under

§ 121.380(a)(2)(vi) of the Federal Aviation

Regulations [14 CFR 121.380(a)(2)(vi)]. All

other operators must maintain the records of

mandatory inspections required by the

applicable regulations governing their

operations.

Note 3: The requirements of this AD have

been met when the engine manual changes

are made and air carriers have modified their

continuous airworthiness maintenance plans

to reflect the requirements in the EM’s.

(f) This amendment becomes effective on

September 13, 2000.

Issued in Burlington, Massachusetts, on

June 5, 2000.

Diane S. Romanosky,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 00–14789 Filed 6–14–00; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–64–AD; Amendment

39–11784; AD 2000–12–06]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A330 and A340 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.