[Federal Register Volume 64, Number 178 (Wednesday, September 15, 1999)]
[Proposed Rules]
[Pages 50020-50021]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-24092]


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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. 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.

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

    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. 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

[[Page 50021]]

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

    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.
    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.

    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:
    (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.

    (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 aircraft to a location where 
the inspection requirements of this AD can be accomplished. Issued 
in Burlington, Massachusetts, on September 8, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-24092 Filed 9-14-99; 8:45 am]
BILLING CODE 4910-13-U