[Federal Register Volume 67, Number 221 (Friday, November 15, 2002)]
[Proposed Rules]
[Pages 69152-69154]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-29002]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NE-27-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D-1, -1A, -1B, -7, -
7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR 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 
JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -
17R, and -17AR turbofan engines. This proposal would require removal 
from service of certain part number (P/N) 3rd-4th and 4th-5th stage 
compressor rotor spacer assemblies and incorporation of a new tierod 
retention configuration. This proposal is prompted by two reports of 
uncontained failure of JT8D turbofan engines, caused by turbine rotor 
overspeed resulting from first and second stage fan section separation 
from the low pressure compressor (LPC). The actions specified by the 
proposed AD are intended to prevent first and second stage fan section 
separation from the LPC, resulting in turbine rotor overspeed, 
uncontained engine failure, and damage to the airplane.

DATES: Comments must be received by January 14, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2002-NE-27-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location, by appointment, between 8 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: Christopher Spinney, Aerospace

[[Page 69153]]

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 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 2002-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. 2002-NE-27-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    The FAA has received two reports of turbine rotor overspeed 
resulting in uncontained engine failure on JT8D turbofan engines. The 
overspeeds resulted from separation of the first and second stage fan 
section from the rear stages of the LPC. The separations resulted from 
LPC tierod fractures, which were caused by fretting due to spacer-to-
disk snap diameter looseness. The manufacturer has determined that 
incorporating a tighter snap diameter fit by installing new design or 
modified parts and incorporating increased sleeve-to-tierod clearances 
will reduce the number of tierod fractures due to fatigue initiated by 
fretting. Installation of the new tierod retention configuration will 
reduce the likelihood of a single tierod fracture damaging the 
remaining tierods. This condition, if not corrected, could result in a 
first and second stage fan section separation from the LPC, uncontained 
engine failure, and damage to the airplane.

Manufacturer's Service Information

    The FAA has reviewed and approved the technical contents of Pratt & 
Whitney Service Bulletin (SB) No. JT8D 6429, dated August 23, 2002, 
that describes procedures for incorporating a new tierod retention 
configuration. Pratt & Whitney SB's No. 5409, No. SB 5716, and No. SB 
No. 5734 are referenced in this proposal because they provide 
information on modification of the parts requiring removal to make them 
serviceable.

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 JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, 
-15, -15A, -17, -17A, -17R, and -17AR turbofan engines of the same type 
design that are used on airplanes registered in the United States, the 
proposed AD would require at the next accessibility:
    [sbull] Removing from service of 3rd-4th stage compressor rotor 
spacer assemblies part numbers (P/N's) 479927, 522194, 583385, 656814, 
656815, 660649, 660655, 716851, 716853, 716854, 762140, 762145, 762271, 
762468, 789554, and 789752 and replacement with a serviceable part.
    [sbull] Removing from service of 4th-5th stage compressor rotor 
spacer assemblies P/N's 479929, 522196, 656816, 656817, 660650, 660656, 
716855, 762138, and 762142 and replacement with a serviceable part.
    [sbull] Removing from service 4th-5th stage compressor rotor spacer 
assemblies P/N 628778 that do not incorporate SB 5409 and replacement 
with a serviceable part.
    [sbull] Incorporating a new tierod retention configuration in 
accordance with the service bulletin described previously.

Economic Analysis

    There are approximately 4,180 engines of the affected design in the 
worldwide fleet. The FAA estimates that 1,800 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD. The 
FAA also estimates that it would take approximately 41 work hours per 
engine to accomplish the proposed actions, and that the average labor 
rate is $60 per work hour. Required parts would cost approximately 
$3,600 per engine. Based on these figures, the total cost of the 
proposed AD to U.S. operators is estimated to be $10,908,000.

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. 2002-NE-27-AD.
    Applicability: This airworthiness directive (AD) is applicable 
to Pratt & Whitney JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -
15, -15A, -17, -17A, -17R, and -17AR turbofan engines. These engines 
are installed on, but

[[Page 69154]]

not limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9 
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 (d) 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 first and second stage fan section separation from 
the low pressure compressor (LPC), resulting in turbine rotor 
overspeed, uncontained engine failure, and damage to the airplane, 
do the following:
    (a) At the next accessibility, do the following:
    (1) Remove from service 3rd-4th stage compressor rotor spacer 
assemblies part numbers (P/N's) 479927, 522194, 583385, 656814, 
656815, 660649, 660655, 716851, 716853, 716854, 762140, 762145, 
762271, 762468, 789554, and 789752 and replace with a serviceable 
part.
    (2) Remove from service 4th-5th stage compressor rotor spacer 
assemblies P/N's 479929, 522196, 656816, 656817, 660650, 660656, 
716855, 762138, and 762142 and replace with a serviceable part.
    (3) Remove from service 4th-5th stage compressor rotor spacer 
assemblies P/N's 628778 that do not incorporate SB 5409, and replace 
with a serviceable part.

    Note 2: Information on modifying parts listed in paragraphs 
(a)(1), (a)(2), and (a)(3) of this AD into servicable parts is 
contained in Pratt & Whitney (PW) SB's No. 5409, No. SB 5716, and 
No. SB No. 5734.

    (4) Incorporate new tierods, retaining rings, 2nd stage 
compressor air seal or spacer assembly, flat washers and tierod nuts 
in the LPC in accordance with the Accomplishment Instructions of PW 
SB JT8D 6429, dated August 23, 2002.
    (b) After the effective date of this AD, do not install 3rd-4th 
or 4th-5th stage compressor rotor spacer assemblies listed in 
paragraphs (a)(1), (a)(2), and (a)(3) of this AD into any engine.

Definition

    (c) For the purpose of this AD, accessibility means removal of 
the LPC from the engine and disassembly that provides piece-part 
exposure to the parts listed in paragraph (a) of this AD.

Alternative Methods of Compliance

    (d) 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 3: 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

    (e) Special flight permits may be issued in accordance with 
Sec. Sec.  21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be done.

    Issued in Burlington, Massachusetts, on November 8, 2002.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 02-29002 Filed 11-14-02; 8:45 am]
BILLING CODE 4910-13-P