Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan Engines

[Federal Register Volume 67, Number 167 (Wednesday, August 28, 2002)]
[Rules and Regulations]
[Pages 55108-55111]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-21832]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-48-AD; Amendment 39-12867; AD 2002-17-02]
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 certain Pratt & Whitney JT8D series 
turbofan engines. That AD currently requires revisions to the Time 
Limits Section (TLS) of the manufacturer's Engine Manuals (EM's) to 
include required enhanced inspection of selected critical life-limited 
parts at each piece-part exposure. This amendment requires modification 
of the airworthiness limitations section of the manufacturer's manual 
and an air carrier's approved continuous airworthiness maintenance 
program to incorporate additional inspection

[[Page 55109]]

requirements. A Federal Aviation Administration (FAA) study of in-
service events involving uncontained failures of critical rotating 
engine parts indicated the need for mandatory inspections. The 
mandatory inspections are needed to identify those critical rotating 
parts with conditions, which if allowed to continue in service, could 
result in uncontained failures. The actions specified by this AD are 
intended to prevent critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to the 
airplane.

DATES: Effective February 24, 2003.

ADDRESSES: Information regarding this action 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.

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 2000-21-08, 
Amendment 39-11940 (65 FR 65731, November 2, 2000), which is applicable 
to Pratt & Whitney JT8D series turbofan engines, was published in the 
Federal Register on January 7, 2002, (67 FR 697). Subsequently, a 
supplemental proposal, which corrected the engine applicability in the 
proposal published on January 7, 2002, was published in the Federal 
Register on February 14, 2002 (67 FR 6888). That action proposed to 
require modifications to the airworthiness limitations section of the 
manufacturer's manual and an air carrier's approved continuous 
airworthiness maintenance program to include required enhanced 
inspections of selected critical life-limited parts at each piece part 
exposure.

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.

Correction of Errors

    Several commenters request correction of errors in the 
applicability of the notice of proposed rulemaking (NPRM).
    The FAA agrees. Most of the applicability errors were corrected 
with the issuance of the supplemental NPRM; however, in paragraph (b) 
the engine manual referenced to perform the inspections was incorrectly 
identified. The referenced Engine Manual is corrected corrected in this 
final rule.

Publication Date

    One commenter requests a 180-day period between the publication 
date and the effective date of the AD, similar to AD 2000-21-08.
    The FAA agrees. The effective date of this AD has been extended to 
180 days after publication to allow time for the specific procedures to 
be published. The extra time, until the AD becomes effective, should 
also allow the manufacturer to issue a manual revision.

Part Numbers in the AD

    One commenter believes that the FAA has reversed its position 
relative to not incorporating part numbers in the AD.
    The FAA partially agrees. As the commenter notes, the FAA had 
previously viewed the engine manual for this engine model to be 
structured so as to make reference to ``all'' part numbers impractical. 
The FAA has again reviewed the engine manual and the proposed new 
changes and has determined that individual part numbers may be removed. 
Therefore, this AD references ``all'' part numbers, as with other 
engine lines. The decision not to include part numbers was originally 
made to accommodate the industry. The removal of part numbers 
eliminates the requirement to modify the TLS and Continuous 
Airworthiness Maintenance programs every time a new part number is 
introduced by the manufacturer for those parts covered by the AD.

Proposed Cleaning and Inspection Procedures

    Two commenters express concern over the proposed cleaning and 
inspection procedures of the assembled high pressure turbine (HPT) and 
shaft assembly. Residual alkaline cleaning solution may introduce 
corrosion in the mating surfaces of the disk, shaft, or bolts, or 
damage the coated surfaces of the shaft during the subsequent rinse 
cycle. Entrapped fluorescent penetrant inspection (FPI) fluid may lead 
to chemical degradation of the disk shaft assembly.
    The FAA disagrees. The standard practice operating procedure for 
alkaline cleaning of the first stage HPT disk and shaft assembly 
requires a fresh water rinse after performing the alkaline cleaning. 
When properly rinsed, the residual alkaline cleaning solution is 
removed. Many overhaul shops have been using the alkaline and 
subsequent rinse on this part geometry and more complex part geometries 
for years without any reports of detrimental effects caused by the 
alkaline solution. In additon, all solutions used in the FPI process, 
penetrants, emulsifiers and developers, are not corrosive to engine 
parts and have passed corrosion compatibility testing. Based on the 
above supporting data, the FAA has determined that the proposed 
cleaning and inspection processes meet the applicable airworthiness 
requirements, and are therefore approved for the first stage HPT disk 
and shaft assembly as stated in the Engine Manual, 481672, Section 72-
52-04, inspection ``04.

Engine Manual 72-52-02, Inspections--04, Figure 801

    One commenter requests a change to the view of Figure 801 of 
inspection--04. The present view displays a disassembled view of the 
disk and shaft assembly, which could lead to confusion as the 
inspection applies to the assembly.
    The FAA agrees. The manufacturer has agreed to change Figure 801 to 
show the first stage HPT disk and shaft assembly in place of the 
disassembled view currently contained in the inspection procedure.
    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.

Economic Analysis

    There are approximately 5,821 Pratt & Whitney JT8D series turbofan 
engines of the affected design in the worldwide fleet. The FAA 
estimates that 5,821 engines installed on aircraft of U.S. registry 
will be affected by this AD, that it will take approximately 8 work 
hours per engine to perform the required enhanced inspections. The 
average labor rate is $60 per work hour. The cost of the enhanced 
inspections per engine is approximately $480 per year while the 
approximate total cost to the U.S. fleet will be $2,794,080 per year.

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

[[Page 55110]]

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, 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 by removing Amendment 39-11940 (65 FR 
65731, November 2, 2000) and by adding a new airworthiness directive to 
read as follows:

2002-17-02  Pratt & Whitney: Docket No. 98-ANE-48-AD. Supersedes AD 
2000-21-08, Amendment 39-11940.

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 series turbofan engines, installed 
on but not limited to Boeing 727 and 737 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 (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

    Compliance with this AD is required as indicated, unless already 
done.
    To prevent critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to 
the airplane, do the following:

Inspections

    (a) Within 30 days after the effective date of this AD, revise 
the Time Limits Section (TLS) of the JT8D-1, -1A, -1B, -7, -7A, -7B, 
-9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR Turbofan Engine 
Manual, part number 481672, and for air carrier operations revise 
the approved continuous airworthiness maintenance program, by adding 
the following:

``Critical Life Limited Part Inspection

A. Inspection Requirements

    (1) This section has the definitions for individual engine piece 
parts and the inspection procedures which are necessary when these 
parts are removed from the engine.
    (2) It is necessary to do the inspection procedures of the piece 
parts in paragraph B when:
    (a) The part is removed from the engine and disassembled to the 
level specified in paragraph B and
    (b) The part has accumulated more than 100 cycles since the last 
piece part inspection, provided that the part was not damaged or 
related to the cause for its removal from the engine.
    (3) The inspections specified in this paragraph do not replace 
or make not necessary other recommended inspections for these parts 
or other parts.

B. Parts Requiring Inspection

    Note: Piece part is defined as any of the listed parts with all 
the blades removed.


------------------------------------------------------------------------
           Description                 Section           Inspection
------------------------------------------------------------------------
Hub (Disk), 1st Stage
 Compressor:
    Hub Detail--All P/N's.......  72-33-31          -02, -03, -04
    Hub Assembly--All P/N's.....  72-33-31          -02, -03, -04
2nd Stage Compressor:
    Disk--All P/N's.............  72-33-33          -02
    Disk Assembly--All P/N's....  72-33-33          -02
Disk, 13th Stage Compressor--All  72-36-47          -02
 P/N's.
HP Turbine Disk, First Stage w/   72-52-04          -03
 integral Shaft All P/N's.
HP Turbine, First Stage, w/
 Separable shaft:
    Rotor Assembly--All P/N's...  72-52-02          -04
    Disk--All P/N's.............  72-52-02          -03
Disk, 2nd Stage Turbine--All P/   72-53-16          -02
 N's.
Disk, 3rd Stage Turbine--All P/   72-53-17          -02
 N's.
Disk (Separable), 4th Stage       72-53-15          -02
 Turbine--All P/N's.
Disk (Integral Disk/Hub), 4th     72-53-18          -02''
 Stage Turbine--All P/N's.
------------------------------------------------------------------------

    (b) Except as provided in paragraph (c) of this AD, and 
notwithstanding contrary provisions in section 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these mandatory inspections 
must be performed using the TLS of the PW JT8D-1, -1A, -1B, -7, -7A, 
-7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR Turbofan 
Engine Manual.

Alternative Methods of Compliance

    (c) 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 (PMI), 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

    (d) Special flight permits may be issued in accordance with 
21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 
and 21.199) to operate the airplane to a

[[Page 55111]]

location where the requirements of this AD can be done.

Continuous Airworthiness Maintenance Program

    (e) FAA-certificated air carriers that have an approved 
continuous airworthiness maintenance program in accordance with the 
record keeping requirement of Sec. 121.369 (c) of the Federal 
Aviation Regulations (14 CFR 121.369 (c)) of this chapter must 
maintain records of the mandatory inspections that result from 
revising the Time Limits section of the Instructions for Continuous 
Airworthiness (ICA) and the air carrier's continuous airworthiness 
program. Alternately, certificated air carriers may establish an 
approved system of record retention that provides a method for 
preservation and retrieval of the maintenance records that include 
the inspections resulting from this AD, and include the policy and 
procedures for implementing this alternate method in the air 
carrier's maintenance manual required by Sec. 121.369 (c) of the 
Federal Aviation Regulations (14 CFR 121.369 (c)); however, the 
alternate system must be accepted by the appropriate PMI and require 
the maintenance records be maintained either indefinitely or until 
the work is repeated. Records of the piece-part inspections are not 
required under Sec. 121.380 (a) (2) (vi) of the Federal Aviation 
Regulations (14 CFR 121.380 (a) (2) (vi)). All other operators must 
maintain the records of mandatory inspections required by the 
applicable regulations governing their operations.

    Note 3: The requirements of this AD have been met when the 
engine manual changes are made and air carriers have modified their 
continuous airworthiness maintenance plans to reflect the 
requirements in the engine manuals.

Effective Date

    (f) This amendment becomes effective on February 24, 2003.

    Issued in Burlington, Massachusetts, on August 21, 2002.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 02-21832 Filed 8-27-02; 8:45 am]
BILLING CODE 4910-13-P

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