[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]
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