Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan Engines

[Federal Register Volume 68, Number 114 (Friday, June 13, 2003)]
[Rules and Regulations]
[Pages 35286-35287]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-14844]



[[Page 35286]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-05-AD; Amendment 39-13192; AD 2003-12-07]
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 supersedes an existing 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. That AD currently requires a determination of the utilization 
rate and protective coating type of the 7th, 8th, 9th, 10th, 11th, and 
12th stage high pressure compressor (HPC) disks, and removal, 
inspection for corrosion, and recoating of those HPC disks based on 
utilization rate. This amendment requires removal and replacement of 
protective coating of 7th, 8th, 9th, 10th, 11th, and 12th stage HPC 
disks, initial and repetitive inspections for corrosion pits and 
cracks, and removal from service as required. This amendment is 
prompted by operator reports of cracks found on several JT8D steel HPC 
disks since the existing AD was published. The actions specified by 
this AD are intended to prevent fracture of the HPC disks, which can 
result in uncontained release of engine fragments, inflight engine 
shutdown, and airframe damage.

DATES: Effective July 18, 2003. The incorporation by reference of 
certain publications listed in the regulations is approved by the 
Director of the Federal Register as of July 18, 2003.

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, by appointment, 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: 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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 98-12-07, 
Amendment 39-10563 (63 FR 31340, June 9, 1998), which is applicable to 
Pratt & Whitney JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -
15A, -17, -17A, -17R, and -17AR turbofan engines was published in the 
Federal Register on January 24, 2003 (68 FR 3475). That action proposed 
to require removal and replacement of protective coating of 7th, 8th, 
9th, 10th, 11th, and 12th stage HPC disks, initial and repetitive 
inspections for corrosion pits and cracks, and removal from service as 
required in accordance with Pratt & Whitney (PW) Alert Service Bulletin 
(ASB) No. JT8D A6431, dated November 27, 2002. Since the publication of 
the proposed rule, PW ASB No. JT8D A6431 was reissued as Revision 1 on 
March 7, 2003.

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.

Effective Dates Should Coincide

    One commenter states that the effective date of the AD should 
coincide with the revision of the Standard Practices Manual to 
incorporate the disk preservation and storage instructions.
    The FAA does not agree. The Standard Practice Manual will be 
updated to incorporate the disk preservation steps specified in PW ASB 
No. JT8D A6431, Revision 1, dated March 7, 2003; however until that 
time, the steps specified in the accomplishment instructions, 
Paragraphs 8.A. through 8.H. of the ASB, are sufficient to properly 
perform the preservation technique. Therefore, no changes will be made 
to the AD.

Underestimated Operational Impact

    One commenter states that the operational impact on the operators 
of the proposed requirements is underestimated. The commenter believes 
that the more stringent inspection requirements on certain 9th stage 
HPC disks will increase the demand on other 9th stage HPC disks 
creating industry shortages.
    The FAA agrees. The FAA and the original equipment manufacturer 
(OEM) are aware that the demand for new 9th stage HPC disks will 
increase because of the more stringent re-inspection requirements 
imposed on older 9th stage disks. As a result, steps have been 
initiated at the OEM to meet the increased demand. The FAA expects that 
the steps the OEM has taken will prevent industry shortages significant 
enough not to change the economic impact of this AD. Therefore, no 
changes will be made to the AD.

Underestimated Costs of Replacement Disks

    One commenter states that the costs associated with a new HPC disk 
are underestimated. The commenter notes that the $7,000 cost of a 
replacement disk specified in the proposed rule is too low, and that 
new disk prices range from $11,920 to $23,190.
    The FAA does not agree. The FAA believes that it is not necessary 
to include the full cost of the disk in the economic analysis because 
the disks must be replaced before reaching their certified life, which 
would be part of the normal costs of operation. The $7,000 figure is 
the prorated replacement cost of the disk. This figure is the estimated 
average residual value of disks lost due to removal before reaching the 
full certified life of the disk. Therefore, no changes will be made to 
the AD.

Allowance for Preservation Status

    One commenter requests that the AD include a provision to allow 
spare engines and disks not to accumulate time if placed in a 
preservation status in accordance with the JT8D Maintenance Manual. The 
commenter believes that once the engine is installed, then time will 
accumulate from the installation date, and this will allow the 
operators to maintain spare equipment and comply with the AD.
    The FAA agrees. As the proposed rule is currently worded, an engine 
or disk does not accumulate time while in storage if preserved in 
accordance with procedures described in the compliance section of PW 
ASB No. JT8D A6431, Revision 1, dated March 7, 2003. Paragraphs 1.C. 
and 1.D of the compliance section of the ASB explain the storage 
requirements for the full engine and disk piece-parts respectively, and 
the associated time credits allowed for each storage method. Therefore, 
no changes will be made to the AD.
    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 as proposed.

Regulatory Analysis

    This final rule does not have federalism implications, as defined 
in Executive Order 13132, because it

[[Page 35287]]

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) 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

0
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

0
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]

0
2. Section 39.13 is amended by removing Amendment 39-10563 (63 FR 
31340, June 9, 1998) and by adding a new airworthiness directive, 
Amendment 39-13192, to read as follows:

2003-12-07 Pratt & Whitney: Amendment 39-13192. Docket No. 97-ANE-
05-AD. Supersedes AD 98-12-07, Amendment 39-10563.

    Applicability: This airworthiness directive (AD) is applicable 
to Pratt & Whitney (PW) 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 not limited to Boeing 737 and 727 
series, 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 (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 fracture of the 7th, 8th, 9th, 10th, 
11th, and 12th stage high pressure compressor (HPC) disks, which can 
result in uncontained release of engine fragments, inflight engine 
shutdown, and airframe damage, do the following:
    (a) Perform initial and repetitive inspections of HPC disks for 
corrosion pits and cracks after stripping the protective coating in 
accordance with the intervals specified in the compliance section 
and procedures specified in the accomplishment instructions of PW 
Alert Service Bulletin (ASB) No. JT8D A6431, Revision 1, dated March 
7, 2003.
    (b) Before further flight, replace HPC disks found with 
corrosion pits or cracks beyond serviceable limits as defined by PW 
ASB No. JT8D A6431, Revision 1, dated March 7, 2003.
    (c) For the purposes of this AD, use the effective date of this 
AD for computing compliance intervals whenever PW ASB No. JT8D 
A6431, Revision 1, dated March 7, 2003, refers to the release date 
of the ASB.

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 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

    (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 airplanes to a location where 
the requirements of this AD can be done.

Documents That Have Been Incorporated by Reference

    (f) The actions must be done in accordance with Pratt & Whitney 
Alert Service Bulletin No. JT8D A6431, Revision 1, dated March 7, 
2003. 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 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.

Effective Date

    (g) This amendment becomes effective on July 18, 2003.

    Issued in Burlington, Massachusetts, on June 5, 2003.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 03-14844 Filed 6-12-03; 8:45 am]
BILLING CODE 4910-13-P

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