[Federal Register Volume 63, Number 170 (Wednesday, September 2, 1998)]
[Proposed Rules]
[Pages 46712-46714]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-23617]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-ANE-57]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT9D 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 an existing
airworthiness directive (AD), applicable to Pratt & Whitney JT9D series
turbofan engines, that currently requires installing an improved design
turbine exhaust case (TEC) with a thicker containment wall,
[[Page 46713]]
modifying the existing TEC to incorporate a containment shield, or
modifying the existing TEC to replace the ``P'' flange and case wall.
This proposal is prompted by the need to add additional affected TEC
assemblies eligible for modification, and to add an additional TEC
modification compliance option. The actions specified by the proposed
AD are intended to prevent release of uncontained debris from the TEC
following an internal engine failure, which can result in damage to the
aircraft.
DATES: Comments must be received by November 2, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 95-ANE-57, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``engineprop@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.
The service information referenced in the proposed rule may be
obtained from Pratt & Whitney, Publications Department, Supervisor
Technical Publications Distribution, M/S 132-30, 400 Main St., East
Hartford, CT 06108; telephone (860) 565-7700, fax (860) 565-4503. 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: Tara Goodman, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7130, 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 95-ANE-57.'' 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. 95-ANE-57, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
On December 4, 1996, the Federal Aviation Administration (FAA)
issued airworthiness directive (AD) 96-25-10, Amendment 39-9853 (61 FR
66892, December 19, 1996), applicable to Pratt & Whitney (PW) JT9D
series turbofan engines, to require installing an improved design
turbine exhaust case (TEC) with a thicker containment wall, modifying
the existing TEC to incorporate a containment shield, or modifying the
existing TEC to replace the ``P'' flange and case wall. That action was
prompted by reports of 64 uncontained engine failures since 1972. That
condition, if not corrected, could result in release of uncontained
debris from the TEC following an internal engine failure, which can
result in damage to the aircraft.
Since the issuance of that AD, PW has issued Service Bulletin (SB)
No. 6157, Revision 2, dated January 28, 1998, that lists by part number
additional affected TEC assemblies that are eligible for modification.
This superseding AD references this revised SB. In addition, this
proposed rule adds an additional TEC modification compliance option
described in PW SB No. 6320, dated February 5, 1998.
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 AD 96-25-10 to add additional affected TEC
assemblies that are eligible for modification, and to add an additional
TEC modification compliance option. The actions are required to be
accomplished in accordance with the SBs described previously.
There are approximately 566 engines of the affected design in the
worldwide fleet. The FAA estimates that 157 engines installed on
aircraft of U.S. registry would be affected by this proposed AD, that
it would take approximately zero additional work hours per engine to
accomplish the proposed actions when done at complete disassembly/
assembly, and that the average labor rate is $60 per work hour.
Required parts would cost approximately $6,705 per engine. Based on
these figures, the total cost impact of the proposed AD on U.S.
operators is estimated to be $1,052,685.
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:
[[Page 46714]]
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 39-9853 (61 FR
66892, December 19, 1996) and by adding a new airworthiness directive
to read as follows:
Pratt & Whitney: Docket No. 95-ANE-57. Supersedes AD 96-25-10,
Amendment 39-9853.
Applicability: Pratt & Whitney (PW) JT9D-3, -7, -20, -59A, -70A,
-7Q, and -7R4 series turbofan engines, installed on but not limited
to Airbus A300 and A310 series; Boeing 747 and 767 series; and
McDonnell Douglas DC-10 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 release of uncontained debris from the turbine
exhaust case (TEC) following an internal engine failure, which can
result in damage to the aircraft, accomplish the following:
(a) At the next removal of the TEC from the low pressure turbine
case ``P'' flange during a shop visit, but not later than 48 months
after the effective date of this AD, accomplish the following:
(1) For PW JT9D-3A, -7, -7A, -7AH, -7H, -7F, -7J, -20, and -20J
series turbofan engines, accomplish any one of the following
actions:
(i) Install a thicker-walled TEC, with part numbers (P/N's)
listed in PW service bulletin (SB) No. 6113, dated April 13, 1993,
as applicable; or
(ii) Install a modified TEC that incorporates a containment
shield, with P/N's listed in PW SB No. 5907, dated March 27, 1990,
as applicable; or
(iii) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with P/N's listed in PW SB No. 6118,
Revision 3, dated January 10, 1996, or
(iv) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with Chromalloy Supplemental Type
Certificate (STC) SE00047AT-D, dated October 15, 1996; or
(v) Install a modified TEC that incorporates replacement or
modified outer case detail in accordance with PW SB No. 6320, dated
February 5, 1998.
(2) For PW JT9D-7Q and -7Q3 series turbofan engines, accomplish
any one of the following actions:
(i) Install a thicker-walled TEC, with P/N's listed in PW SB No.
5977, dated December 14, 1990; or
(ii) Install a modified TEC that incorporates a containment
shield, with P/N's listed in PW SB No. 5907, dated March 27, 1990,
as applicable; or
(iii) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with P/N's listed in PW SB No. 6157,
Revision 2, dated January 28, 1998; or
(iv) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with Chromalloy STC SE00047AT-D, dated
October 15, 1996; or
(v) Install a modified TEC that incorporates replacement or
modified outer case detail in accordance with PW SB No. 6320, dated
February 5, 1998.
(3) For PW JT9D-59A and -70A series turbofan engines, accomplish
one of the following actions:
(i) Install a thicker-walled TEC, with P/N's listed in PW SB No.
6243, dated February 1, 1996; or
(ii) Install a modified TEC that incorporates a containment
shield, with P/N's listed in PW SB No. 5907, dated March 27, 1990,
as applicable;
(iii) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with P/N's listed in PW SB No. 6157,
Revision 2, dated January 28, 1998; or
(iv) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with Chromalloy STC SE00047AT-D, dated
October 15, 1996; or
(v) Install a modified TEC that incorporates replacement or
modified outer case detail in accordance with PW SB No. 6320, dated
February 5, 1998.
(4) For PW JT9D-7R4D (BG-700 series) turbofan engines,
accomplish one of the following actions:
(i) Install a thicker-walled TEC, with P/N's listed in PW SB No.
JT9D-7R4-72-479, Revision 1, dated November 12, 1993; or
(ii) Install a modified TEC that incorporates a containment
shield, with P/N's listed in PW SB No. JT9D-7R4-72-407, Revision 1,
dated August 16, 1990, as applicable; or
(iii) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with Chromalloy STC SE00047AT-D, dated
October 15, 1996.
(5) For PW JT9D-7R4D (BG-800 series), -7R4D (BG-900 series), -
7R4D1 (AI-500 series), -7R4E (BG-800 series), -7R4E (BG-900 series),
-7R4E1 (AI-500 series), -7R4E1 (AI-600 series), -7R4E4 (BG-900
series), -7R4G2 (BG-300 series), and -7R4H1 (AI-600 series) turbofan
engines, accomplish any one of the following actions:
(i) Install a thicker-walled TEC, with P/N's listed in PW SB No.
JT9D-7R4-72-534, dated October 18, 1996; or
(ii) Install a modified TEC that incorporates a containment
shield, with P/N's listed in PW SB No. JT9D-7R4-72-466, Revision 2,
dated May 10, 1996; or
(iii) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with P/N's listed in PW SB No. JT9D-7R4-
72-534, dated October 18, 1996; or
(iv) Install a modified TEC that incorporates a replacement
``P'' flange and case wall, with Chromalloy STC SE00054AT-D, dated
October 19, 1994.
(6) For PW JT9D-7R4D (BG-800 series), -7R4D (BG-900 series), -
7R4D1 (AI-500 series), -7R4E (BG-800 series), -7R4E (BG-900 series),
-7R4E1 (AI-500 series), -7R4E1 (AI-600 series), -7R4E4 (BG-900
series), -7R4G2 (BG-300 series), and -7R4H1 (AI-600 series) turbofan
engines, with TECs that have been modified to incorporate a
replacement ``P'' flange and case wall, in accordance with PW SB No.
JT9D-7R4-72-513, Revision 3, dated November 13, 1996, or previous
revisions, perform heat treatment of the TECs in accordance with the
Accomplishment Instructions of PW SB No. JT9D-7R4-72-534, dated
October 18, 1996.
(b) For the purpose of this AD, a shop visit is defined as
induction of an engine into the shop for scheduled maintenance.
(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.
Operators shall forward their requests through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, 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 aircraft to a location where
the requirements of this AD can be accomplished.
Issued in Burlington, Massachusetts, on August 26, 1998.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 98-23617 Filed 9-1-98; 8:45 am]
BILLING CODE 4910-13-U
