Airworthiness Directives; International Aero Engines AG V2500-A1 Series Turbofan Engines

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-76-AD]

RIN 2120-AA64

Airworthiness Directives; International Aero Engines AG V2500-A1

Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of two existing

airworthiness directives (ADs), applicable to International Aero

Engines AG (IAE) V2500-A1 series turofan engines, one of which, AD 98-

20-18, currently requires removal from service of affected high

pressure turbine (HPT) disks, identified by part number and serial

number in the applicability paragraph of that AD, and replacement with

a serviceable part. The other current AD, 99-05-05, requires initial

and repetitive inspections of certain HPT stage 1 and stage 2 disks

utilizing an improved ultrasonic method when the disks are exposed

during a normal shop visit, and is a subsurface anomaly is found,

removal from service and replacement with a serviceable part. This

action would require the initial inspection required by AD 99-05-05 to

be completed at the next shop visit regardless of the planned

maintenance or the reason for shop removal. The repetitive inspection

interval would also be redefined to eliminate the cyclic limit and thus

be less restrictive. This proposal is prompted by results from further

investigation subsequent to the publication of AD 98-20-18 that have

revealed that the HPT disks affected by that AD are part of the

population addressed by AD 99-05-05. These HPT disks can be safely

reintroduced into service after completing the initial inspection

requirements mandated by this proposed AD

limit and thus

be less restrictive. This proposal is prompted by results from further

investigation subsequent to the publication of AD 98-20-18 that have

revealed that the HPT disks affected by that AD are part of the

population addressed by AD 99-05-05. These HPT disks can be safely

reintroduced into service after completing the initial inspection

requirements mandated by this proposed AD. This proposal is also

prompted by further analysis which indicates a reduction in risk if the

initial inspection required by AD 99-05-05 is completed sooner and that

the subsequent required inspections can be redefined to eliminate the

cyclic limit creating less burden on operators.

The actions specified by the proposed AD are intended to prevent

HPT disk fracture, which could result in an uncontained engine failure

and damage to the airplane.

DATES: Comments must be received by October 15, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), New England Region, Office of the Regional

Counsel, Attention: Rules Docket No. 98-ANE-76-AD, 12 New England

Executive Park, Burlington, MA 01803-5299. Comments may also be sent

via the Internet using the following address: ``9-ane-

[email protected].'' 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 Rolls-Royce Commercial Aero Engine Limited, P.O. Box 31,

Derby, England, DE2488J, Attention: Publication Services ICL-TP;

telephone +44-1-33-22-4653, fax +44-1-33-22-46302. This information may

be examined at the FAA, New England Region, Office of the Regional

Counsel, 12 New England Executive Park, Burlington, MA.

The service information referenced in the proposed rule may be

obtained from Rolls-Royce Commercial Aero Engine Limited, P.O. Box 31,

Derby, England, DE2488J, Attention: Publication Services ICL-TP;

telephone +44-1-33-22-4653, fax +44-1-33-22-46302. 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: Diane Cook, Aerospace Engineer, Engine

Certification Office, FAA, Engine and Propeller Directorate, 12 New

England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-

7133, 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. Al

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-76-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

th

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-76-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-76-AD, 12 New England Executive

Park, Burlington, MA 01803-5299.

Discussion

On November 4, 1998, the Federal Aviation Administration (FAA)

issued airworthiness directive (AD) 98-20-18, Amendment 39-10871 (63 FR

63398, November 13, 1998), applicable to International Aero Engines AG

(IAE) V2500-A1 series turbofan engines, to require removal from service

of affected high pressure turbine (HPT) disks, identified by part

number (P/N) and serial number (S/N) in the applicability paragraph of

that AD, and replacement with a serviceable part. That action was

prompted by a report of an uncontained HPT disk failure. That

condition, if not corrected, could result in an HPT disk fracture, an

uncontained engine failure, and damage to the airplane.

On February 19, 1999, the FA issued AD 99-05-05, Amendment 39-11053

(64 FR 9910, March 1, 1999), applicable to IAE V2500-A1 series turbofan

engines, to require initial and repetitive inspections of certain HPT

stage 1 and stage 2 disks utilizing an improved ultrasonic method when

the disks are exposed during a normal shop visit, and if a subsurface

anomaly is found, removal from service and replacement with a

serviceable part. That action was prompted by the results of a stage 1

HPT disk fracture investigation which has identified a population of

HPT stage 1 and 2 disks that may have subsurface anomalies formed as a

result of the processes used to manufacture the part

the disks are exposed during a normal shop visit, and if a subsurface

anomaly is found, removal from service and replacement with a

serviceable part. That action was prompted by the results of a stage 1

HPT disk fracture investigation which has identified a population of

HPT stage 1 and 2 disks that may have subsurface anomalies formed as a

result of the processes used to manufacture the part. That condition,

if not corrected, could result in HPT disk fracture, which could result

in an uncontained engine failure and damage to the airplane.

Since the issuance of AD 98-20-18, further investigation have

revealed that the HPT disks affected by that AD are part of the

population addressed by AD

99-05-05. These HPT disks can be safely reintroduced into service after

completing the initial inspection requirements mandated by this

proposed AD.

In addition, the manufacturer has performed analysis which

indicates a reduction in risk if the initial inspection required by AD

99-05-05 is completed sooner and that the subsequent inspections can be

redefined to eliminate the cyclic limit creating less burden on

operators.

Service Information

Subsequent to the publication of AD 99-05-05, IAE has issued

Revision 1 to Service Bulletin (SB) No. V2500-ENG-72-0344, dated

February 12, 1999, that describes procedures for ultrasonic inspections

for subsurface anomalies. For the purpose of this AD, the original

issue of that SB, dated December 18, 1998, is also acceptable for

performing the required inspections.

Proposed Actions

rmation

Subsequent to the publication of AD 99-05-05, IAE has issued

Revision 1 to Service Bulletin (SB) No. V2500-ENG-72-0344, dated

February 12, 1999, that describes procedures for ultrasonic inspections

for subsurface anomalies. For the purpose of this AD, the original

issue of that SB, dated December 18, 1998, is also acceptable for

performing the required inspections.

Proposed Actions

Since an unsafe condition has been identified that is likely to

exist or develop on other products of this same type design, the

proposed AD would supersede ADs 98-20-18 and 99-05-05 to require the

initial ultrasonic inspection to be completed at the next shop visit

regardless of the planned maintenance or the reason for shop removal.

However, the repetitive inspection interval would become less

restrictive by eliminating the cyclic limit and requiring inspections

whenever the HPT stage 1 or stage 2 disks are dissembled from the HPT

module.

In addition, this AD allows the disks identified by S/N that were

retired by AD 98-20-18 to be reintroduced into service following an

initial ultrasonic inspection required by this AD.

Cost Impact

Since this AD only adjusts the timing of inspections already

required, there is no additional adverse economic impact.

Regulatory Impact

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

ubstantial 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-10871 (63 FR

63398, November 13, 1998) and amendment 39-11053 (6 FR 9910, March 1,

1999) and by adding a new airworthiness directive to read as follows:

International Aero Engines AG: Docket No. 98-ANE-76-AD. Supersedes

AD 98-20-18, Amendment 39-10871, and AD 99-05-05, Amendment 39-

11053.

U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-10871 (63 FR

63398, November 13, 1998) and amendment 39-11053 (6 FR 9910, March 1,

1999) and by adding a new airworthiness directive to read as follows:

International Aero Engines AG: Docket No. 98-ANE-76-AD. Supersedes

AD 98-20-18, Amendment 39-10871, and AD 99-05-05, Amendment 39-

11053.

Applicability: International Aero Engines AG (IAE) V2500-A1

series turbofan engines, installed on but not limited to Airbus

Industrie A320 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 high pressure turbine (HPT) disk fracture, which

could result in an uncontained engine failure and damage to the

airplane, accomplish the following:

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 high pressure turbine (HPT) disk fracture, which

could result in an uncontained engine failure and damage to the

airplane, accomplish the following:

(a) Perform initial and repetitive ultrasonic inspections of HPT

stage 1 and 2 disks for subsurface anomalies, identified by serial

numbers (S/Ns) in Table 1 of IAE Service Bulletin (SB) V2500-ENG-72-

0344, Revision 1, dated February 12, 1999, in accordance with the

Accomplishment Instructions of SB V2500-ENG-72-0344, dated December

18, 1998, or Revision 1, dated February 12, 1999, as follows:

(1) Initially inspect at the first opportunity when the engine

is at a maintenance base after the effective date of this AD

regardless of the planned maintenance or the reason for engine

removal.

(2) Thereafter, inspect whenever the HPT stage 1 or stage 2

disks are dissembled from the HPT module.

(3) Remove disks from service if a subsurface anomaly is found,

and replace with serviceable parts.

(b) HPT stage 1 disks, part number (P/N) 2A1801, S/Ns P100421,

P100430, P100618, and P100621, may return to service following a

successful inspection in accordance with paragraph (a) of this AD.

(c) An alternative method of compliance or adjustment of the

compliance time that provides an acceptable level of safety may be

used if approved by the Manager, Engine Certification Office (ECO).

Operators shall submit their requests through an appropriate FAA

Principal Maintenance Inspector, who may add comments and then send

it to the Manager, ECO.

Note 2: Information concerning the existence of approved

alternative methods of compliance with this airworthiness directive,

if any, may be obtained from the ECO.