Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan Engines

[Federal Register Volume 66, Number 147 (Tuesday, July 31, 2001)]
[Rules and Regulations]
[Pages 39433-39435]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-18760]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-71-AD; Amendment 39-12353; AD 2001-15-18]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), that 
is applicable to Pratt & Whitney (PW) JT8D series turbofan engines. 
This amendment requires removing certain 2nd stage compressor disks, 
specified by part number (P/N) and serial number (SN), from service. 
This amendment is prompted by a report from PW of a number of JT8D 
engine 2nd stage compressor disks that were delivered to the field with 
potential machining damage to the tie rod, counterweight, and pin 
holes. The actions specified by this AD are intended to prevent rupture 
of the 2nd stage compressor disk caused by machining damage, which 
could result in an uncontained engine failure and damage to the 
airplane.

DATES: Effective date September 4, 2001. The incorporation by reference 
of certain publications listed in the regulations is approved by the 
Director of the Federal Register as of September 4, 2001.

ADDRESSES: The service information referenced in this AD may be 
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-6600, fax (860) 565-4503. This information may be 
examined at the Federal Aviation Administration (FAA), New England 
Region, Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA; or at the Office of the Federal Register, 800 North 
Capitol Street, NW, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Robert McCabe, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7138; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

[[Page 39434]]

Aviation Regulations (14 CFR part 39) to include an AD that is 
applicable to Pratt & Whitney JT8D series turbofan engines was 
published in the Federal Register on December 12, 2000 (65 FR 77530). 
That action proposed to require removing certain 2nd stage compressor 
disks, specified by P/N and SN, from service in accordance with PW JT8D 
Alert Service Bulletin (ASB) JT8D A6336, Revision 1, dated June 29, 
1999, that lists the SN's of certain 2nd stage compressor disks, P/N 
745902, P/N 790832, and P/N 807502, and describes procedures replacing 
the disk if it is listed by SN in the ASB.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Limit AD Applicability

    Two commenters request that the AD be limited to only those later 
or upper engine models specified by the JT8D Illustrated Parts Catalog, 
P/N 481675, referenced in the P&W Alert Service Bulletin (ASB) A6336, 
Revision 1, dated June 29, 1999. The affected 2nd stage compressor disk 
P/N's 745902, 790832 and 807502 are applicable only to engine models 
JT8D -9, -9A, -11, -15, -15A, -17A, -17R and -17AR. The FAA agrees and 
will limit applicability of the amendment to these specific engine 
models.

Cost Impact Statement

    The manufacturer requests that the Cost Impact Statement reflect 
that PW has provided a support program for the disk replacement, and 
that the program is identified in the PW ASB A6336, Revision 1, dated 
June 29, 1999. The FAA agrees. The cost statement reflects the costs of 
compliance with the AD without considering any original equipment 
manufacturer (OEM) industry support program. The cost statement also 
states that the OEM may offset some of those costs.
    Two commenters agree with the AD as written.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 110 engines of the affected design in the 
worldwide fleet. The FAA estimates that 60 engines, installed on 
airplanes of U.S. registry, would be affected by this proposed AD, that 
it would take approximately 48 work hours per engine to accomplish the 
proposed actions, and that the average labor rate is $60 per work hour. 
The prorated average cost of the unusable life of a 2nd stage disk is 
$30,000. Based on these figures, the FAA estimates the total cost 
impact of the proposed AD on U.S. operators to be $1,972,800. The 
manufacturer has informed the FAA that it may pay the cost of the disk, 
which may lower the cost to operators.

Regulatory Impact

    This final 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 final rule.
    For the reasons discussed above, I certify that this action (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 final evaluation has been prepared for 
this action and it 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding a new airworthiness directive to 
read as follows:

2001-15-18  Pratt & Whitney: Amendment 39-12353. Docket 98-ANE-71-
AD.

Applicability

    This airworthiness directive (AD) is applicable to Pratt & 
Whitney (PW) JT8D-9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR 
series turbofan engines with 2nd stage compressor disks, part number 
(P/N) 745902, P/N 790832, and P/N 807502, installed. These engines 
are installed on, but not limited to, Boeing 727 series airplanes, 
Boeing 737-100 and -200 series airplanes and McDonnell Douglas DC-9 
series airplanes.

    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 a rupture of the 2nd stage compressor disk caused 
by machining damage, which could result in an uncontained engine 
failure and damage to the airplane, accomplish the following:

Removal of Disk

    (a) Remove from service 2nd stage compressor disks, P/N 745902, 
P/N 790832, and P/N 807502, identified by serial number (SN) in the 
Accomplishment Instructions of PW JT8D Alert Service Bulletin (ASB) 
JT8D A6336, Revision 1, dated June 29, 1999, prior to accumulating 
2,000 cycles since new.

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 shall submit their requests 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 with 
Secs. 21.197 and 21.199 of the

[[Page 39435]]

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.

Documents That Have Been Incorporated By Reference

    (d) The disks identified by SN's must be removed in accordance 
with Pratt & Whitney ASB JT8D A6336, Revision 1, dated June 29, 
1999. This incorporation by reference was approved by the Director 
of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies of the ASB may be obtained from Pratt & Whitney, 400 
Main St., East Hartford, CT 06108; telephone (860) 565-6600, fax 
(860) 565-4503. Copies may be inspected at the FAA, New England 
Region, Office of the Regional Counsel, 12 New England Executive 
Park, Burlington, MA; or at the Office of the Federal Register, 800 
North Capitol Street, NW, suite 700, Washington, DC.
    (e) This amendment becomes effective on September 4, 2001.

    Issued in Burlington, Massachusetts on July 20, 2001.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-18760 Filed 7-30-01; 8:45 am]
BILLING CODE 4910-13-P

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