[Federal Register Volume 66, Number 226 (Friday, November 23, 2001)]
[Proposed Rules]
[Pages 58691-58693]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-29190]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NE-27-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT9D-59A, -70A, -7Q, 
and -7Q3 Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The Federal Aviation Administration (FAA) proposes to adopt a 
new airworthiness directive (AD) that is applicable to Pratt & Whitney 
(PW) JT9D-59A, -70A, -7Q, and -7Q3 turbofan engines. This proposal 
would require fluorescent penetrant inspection of the high pressure 
turbine (HPT) second stage airseal knife edges for cracks, each time 
the airseal is accessible. This proposal is prompted by reports of 
cracks found in the knife edges of HPT second stage airseals during HPT 
disassembly. The actions specified by the proposed AD are intended to 
prevent failure of HPT second stage airseals due to cracks in the knife 
edges, which if not detected could result in uncontained engine failure 
and damage to the airplane.

DATES: Comments must be received by January 22, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2001-NE-27-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location, by

[[Page 58692]]

appointment, between 8:00 a.m. and 4:30 p.m., Monday through Friday, 
except Federal Holidays. Comments may also be sent via the Internet 
using the following address: ``[email protected]''. Comments sent 
via the Internet must contain the docket number in the subject line. 
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, 
by appointment, 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 action 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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NE-27-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. 2001-NE-27-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    The FAA has received 25 reports of cracks found in the knife edges 
of HPT second stage airseals, part numbers (P/N's) 5002537-01 and 
807410, during HPT disassembly. To date, no failed airseal has caused 
an uncontained engine failure. Results from an evaluation conducted by 
PW reveal that engine operating temperatures and stresses in the stage 
1-to-stage 2 airseal cavity are higher than anticipated. As a result, 
heavy rubbing and thermal mechanical fatigue in a hot compression 
environment are causing cracks to initiate in the rear knife edge. 
These cracks will propagate axially until the airseal fails. Eleven of 
the 25 cracked HPT second stage airseals found at overhaul were 
fractured through from snap to snap. This condition, if not corrected, 
could result in an uncontained engine failure and damage to the 
airplane.

Manufacturer's Service Information

    The FAA has reviewed and approved the technical contents of PW 
service bulletin (SB) JT9D 6409, dated July 27, 2001, that describes 
procedures for fluorescent penetrant inspecting knife edges of HPT 
second stage airseals.

FAA's Determination of an Unsafe Condition and Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other PW JT9D-59A, -70A, -7Q, and -7Q3 turbofan 
engines of the same type design, the proposed AD would require 
fluorescent penetrant inspection of the knife edges of HPT second stage 
airseals for cracks each time the airseal is accessible. The actions 
would be required to be done in accordance with the SB described 
previously. The FAA has been informed by PW that a new design HPT 
second stage airseal is being developed. The FAA may revise this action 
to introduce the new design as terminating action.

Economic Analysis

    There are approximately 564 engines of the affected design PW JT9D-
59A, -70A, -7Q, and -7Q3 turbofan engines in the worldwide fleet. The 
FAA estimates that 176 engines installed on airplanes of U.S. registry 
would be affected by this proposed AD. The FAA also estimates that it 
would take approximately 1 work hour per engine to perform the 
fluorescent penetrant inspection, and that the average labor rate is 
$60 per work hour. Based on these figures, the total labor cost effect 
annually of the proposed AD on U.S. operators is estimated to be 
$10,560.

Regulatory Analysis

    This proposed rule does not have federalism implications, as 
defined in Executive Order 13132, because it would not have a 
substantial direct effect 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. 
Accordingly, the FAA has not consulted with state authorities prior to 
publication of this proposed rule.
    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. 2001-NE-27-AD.
    Applicability: This airworthiness directive (AD) is applicable 
to Pratt & Whitney (PW) JT9D-59A, -70A, -7Q, and -7Q3 turbofan 
engines. These engines are installed on, but not limited to, Airbus 
Indusrie A300 series, Boeing 747 series, and McDonnell Douglas DC-10 
series airplanes.


[[Page 58693]]


    Note 1: This 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 (b) 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: Compliance with this AD is required as indicated, 
unless already done.
    To prevent failure of high pressure turbine (HPT) second stage 
airseals due to cracks in the knife edges, which if not detected 
could result in uncontained engine failure and damage to the 
airplane, do the following:

Inspections

    (a) Perform a fluorescent penetrant inspection of the HPT second 
stage airseal knife edges for cracks in accordance with 
Accomplishment Instructions, Paragraphs 1 through 3 of PW Service 
Bulletin (SB) JT9D 6409, dated July 27, 2001, each time the HPT 
stage 1 and stage 2 rotors are separated. Remove from service those 
airseals that are found cracked.

Alternative Methods of Compliance

    (b) 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 (ECO). 
Operators must submit their request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

Special Flight Permits

    (c) Special flight permits may be issued in accordance 
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 done.

    Issued in Burlington, Massachusetts, on November 14, 2001.
Donald E. Plouffe,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-29190 Filed 11-21-01; 8:45 am]
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