[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.
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Description Section Inspection
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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.
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(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
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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]
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