[Federal Register Volume 64, Number 49 (Monday, March 15, 1999)]
[Proposed Rules]
[Pages 12770-12772]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-6214]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 92-ANE-15]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D-200 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 certain Pratt & Whitney 
JT8D-200 series turbofan engines, that currently requires installation 
of high pressure turbine (HPT) containment hardware. This action 
proposes the removal of low pressure turbine (LPT)-to-exhaust case 
bolts and nuts and replacement with improved LPT-to-exhaust case bolts 
and nuts, and installation of improved HPT containment hardware. This 
proposal is prompted by uncontained HPT events resulting from HPT shaft 
fractures and LPT flange separations resulting from LPT blade failures. 
The actions specified by the proposed AD are intended to prevent damage 
to the aircraft resulting from uncontained engine debris following an 
HPT shaft fracture or an LPT blade failure.

DATE: Comments must be received by May 14, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 92-ANE-15, 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: James Rosa, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7152, 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 92-ANE-15.'' 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. 92-ANE-15, 12 New England Executive Park, 
Burlington, MA 01803-5299.

[[Page 12771]]

Discussion

    On November 19, 1993, the Federal Aviation Administration (FAA) 
issued airworthiness directive AD 93-23-10, Amendment 39-8746 (57 FR 
57705, December 17, 1993), applicable to certain Pratt & Whitney JT8D-
200 series turbofan engines, to require installation of high pressure 
turbine (HPT) containment hardware. That action was prompted by reports 
of HPT shaft fractures, which caused uncontained HPT failures. That 
condition, if not corrected, could result in damage to the aircraft 
resulting from uncontained engine debris following an HPT shaft 
fracture.
    Since the issuance of that AD, the FAA has received reports of two 
uncontained HPT events in PW JT8D-219 engines. Liberated blade debris 
deflected off, and escaped forward of, the leading edge of the 
containment hardware. These events were caused by HPT shaft fractures, 
which resulted from oil fires in the No. 4/5 bearing compartment. Any 
PW JT8D-209, -217, -217A, -217C and -219 engine produced prior to 
issuance of Alert Service Bulletin (ASB) No. 6053 could have the 
previous version of the containment shield installed in accordance with 
AD 93-23-10; those engines produced after ASB 6053 was issued have 
containment shields as shipped from Pratt & Whitney.
    The FAA has also received reports of uncontained low pressure 
turbine (LPT) failures caused by worn 3rd and 4th stage turbine shrouds 
which resulted in fatigue cracking and subsequent LPT blade failures. 
The impact of failed blades caused separation of the LPT and turbine 
exhaust case flange allowing uncontained failures to occur. The FAA has 
determined that only -217C and -219 models are in danger of uncontained 
failures from HPT shaft fractures but all -209, -217, -217A, -217C and 
-219 model engines are in danger of uncontained failures due to LPT 
blade failures.
    The FAA has reviewed and approved the technical contents of PW JT8D 
Alert Service Bulletin (ASB) No. A6346, dated September 10, 1998, that 
describes procedures for installing improved HPT containment hardware, 
and PW Service Bulletin (SB) No. 6149, dated January 19, 1994, that 
describes procedures for installation of improved LPT to turbine 
exhaust case bolts and nuts.
    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 93-23-10 to require, for PW Model JT8D-
217C and -219 engines, installation of improved HPT containment 
hardware. This proposed AD would also require, for PW Model JT8D-209, -
217, -217A, -217C and -219 engines, installation of improved LPT to 
turbine exhaust case bolts and nuts.
    There are approximately 2,727 engines of the affected design in the 
worldwide fleet. The FAA estimates that 1,473 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD, and 
that it would take no additional work hours per engine to accomplish 
the proposed actions since they should take place when an engine is 
already sufficiently disassembled for normal maintenance on those 
parts. Required parts would cost approximately $19,911 per engine 
(hardware supplied by Pratt & Whitney free of charge for engines with 
current HPT containment hardware) for the 560 engines requiring 
improved (over AD 93-23-10) containment hardware, and $3,275 for 1,473 
engines requiring improved bolts and nuts. Based on these figures, the 
total cost impact of the proposed AD on U.S. operators is estimated to 
be $15,974,235. However, since Pratt and Whitney may provide HPT 
containment hardware free of charge, the actual cost to operators may 
be substantially reduced.
    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 39-8746 (57 FR 
57705, December 17, 1993) and by adding a new airworthiness directive 
to read as follows:

Pratt & Whitney: Docket No. 92-ANE-15. Supersedes AD 93-23-10, 
Amendment 39-8746.

    Applicability: Pratt & Whitney (PW) Model JT8D-209, -217, -217A, 
-217C, and -219 turbofan engines, installed on but not limited to 
McDonnell Douglas MD-80 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 damage to the aircraft resulting from uncontained 
engine debris following a high pressure turbine (HPT) shaft fracture 
or a low pressure turbine (LPT) blade failure, accomplish the 
following:
    (a) For PW Model JT8D-217C and -219 engines, install improved 
HPT containment hardware at the next shop visit after the effective 
date of this AD but no later than December 31, 2004, in accordance 
with PW JT8D Alert Service Bulletin (ASB) No. A6346, dated September 
10, 1998.
    (b) For PW Model JT8D-209, -217, -217A, -217C and -219 engines, 
install improved LPT to turbine exhaust case bolts and nuts at the 
next shop visit after the effective date of this AD but no later 
than December 31, 2004, in accordance with paragraph 2.A.(1) and 
2.B.(1) of PW Service Bulletin (SB) No. 6149, dated January 19, 
1994.
    (c) For the purpose of this AD, an engine shop visit is defined 
as engine maintenance that entails the separation of the J and K 
flanges.

[[Page 12772]]

    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 
Secs. 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 March 8, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-6214 Filed 3-12-99; 8:45 am]
BILLING CODE 4910-13-U