[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: ``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 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

[[Page 51483]]

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]
BILLING CODE 4910-13-P