[Federal Register Volume 64, Number 184 (Thursday, September 23, 1999)]
[Proposed Rules]
[Pages 51481-51483]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-24789]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-80-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A,
-217C, and -219 Series Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to Pratt & Whitney (PW) JT8D-209, -
217, -217A, -217C, and -219 series turbofan engines. The proposed AD
would require inspection of the 3rd stage and 4th stage low pressure
turbine (LPT) blades for shroud notch wear and replacement of the blade
if wear limits are exceeded. This proposal is prompted by a report of
an uncontained blade failure. The actions specified by the proposed AD
are intended to prevent an uncontained blade failure that could result
in damage to the airplane.
DATES: Comments must be received by November 22, 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-80-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``adcomment@faa.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, 400 Main St., East Hartford, CT 06108;
telephone (860) 565-8770, 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: Christopher Spinney, Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299;
telephone (781) 238-7175, 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
[[Page 51482]]
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-80-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRM's
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-80-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Background Information
The Federal Aviation Administration (FAA) has received numerous
reports of JT8D 3rd and 4th stage low pressure turbine (LPT) blade
failures. In one instance, the debris from the failure was not
contained within the engine case. The primary cause of the 3rd and 4th
stage LPT blade failures is metal fatigue, which occurs when the blade
shroud notches wear. The FAA is aware of several approaches to managing
LPT shroud notch wear that are currently incorporated into operators'
approved maintenance plans and offer an equivalent level of safety to
the inspections of service bulletin (SB) 6224. It is not the intent of
this AD to change successful blade management programs but to institute
blade management programs where they do not exist. Operators, who have
determined that their current blade management program offers a level
of safety that is equivalent to SB 6224, are encouraged to submit their
current blade management program to the FAA for approval under the
provisions of paragraph (c) of this AD. The actions proposed for this
AD are to inspect the LPT blades for shroud wear and to remove
excessively worn blades prior the onset of fatigue. This condition, if
not corrected, could result in an uncontained blade failure that could
result in damage to the airplane.
Service Information
The FAA has reviewed and approved the technical contents of Pratt &
Whitney (PW) SB 6224, Revision 2, dated August 27, 1998, that describes
procedures for visual inspection of the 3rd stage and 4th stage LPT
blades for shroud notch wear.
Proposed Requirements
Since an unsafe condition has been identified that is likely to
exist or develop on other JT8D-209, -217, -217A, -217C and -219 model
engines of the same type design, the proposed AD would require
inspection of the 3rd stage and 4th stage LPT blades on JT8D-209, -217,
and -217A model engines and 4th stage LPT blades on JT8D-217C and -219
model engines for premature notch wear. The actions must be
accomplished in accordance with the SB described previously.
Cost Impact
There are approximately 2631 PW JT8D-209, -217, -217A, -217C, and -
219 series turbofan engines of the affected design in the worldwide
fleet. The FAA estimates that 1,279 engines installed on aircraft of
U.S. registry would be affected by this proposed AD, that it would take
approximately 1 work hour per engine to accomplish the proposed
actions, and that the average labor rate is $60 per work hour. There
are no required parts. Based on these figures, the total cost impact of
the proposed AD on U.S. operators is estimated to be $76,740.
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 adding the following new
airworthiness directive:
Pratt & Whitney: Docket No. 98-ANE-80-AD.
Applicability: Pratt & Whitney JT8D-209, -217, -217A, -217C, and
-219 series turbofan engines installed on, but not limited to
McDonnell Douglas MD-80 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 an uncontained blade failure that could result in
damage to the airplane, accomplish the following:
Inspection
(a) For JT8D-209, -217, and -217A engines, perform the 3rd and
4th stage low pressure turbine (LPT) blade torque inspections in
accordance with the intervals and procedures described in PW service
bulletin (SB) 6224, Revision 2, dated August 27, 1998,
Accomplishment Instructions, Part 1, A(1) through B(3).
(b) For JT8D-217C and -219 engines, perform the 4th stage LPT
blade torque inspection in accordance with the intervals and
procedures described in PW SB 6224, Revision 2, dated August 27,
1998, Accomplishment Instructions, Part 2, C(1) through C(3).
Alternate Method of Compliance
(c) An alternative method of compliance or adjustment of the
compliance time that
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provides an acceptable level of safety may be used if approved by
the Manager, Engine Certification Office. Operators shall submit
their request 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.
Special Flight Permits
(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 September 16, 1999.
Donald E. Plouffe,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 99-24789 Filed 9-22-99; 8:45 am]
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