[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: ``9-ad-
[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 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]
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