[Federal Register: March 13, 2003 (Volume 68, Number 49)]
[Rules and Regulations]
[Page 11971-11973]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13mr03-3]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NE-27-AD; Amendment 39-13083; AD 2003-05-07]
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: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD), that
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.
This amendment requires 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 amendment
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 this 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: Effective April 17, 2003. The incorporation by reference of
certain publications listed in the regulations is approved by the
Director of the Federal Register as of April 17, 2003.
ADDRESSES: The service information referenced in this AD may be
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108;
telephone (860) 565-8770; 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) to include an AD that is
applicable to PW 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 November 15, 2002, (67 FR 69152). That action
proposed to require removal from service of certain P/N 3rd-4th and
4th-5th stage compressor rotor spacer assemblies and incorporation of a
new tierod retention configuration in accordance with PW Service
Bulletin (SB) No. JT8D 6429, dated August 23, 2002.
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.
Agreement With Proposal as Written
The National Transportation Safety Board and one other commenter
agree with the proposal as written.
Compliance With Referenced Service Bulletins
One commenter states that compliance with PW SBs 5408, 5719, and
5734 should be considered direct compliance to the proposed rule in
place of PW SB 6429, dated August 23, 2002. The commenter believes that
these three service bulletins offer an equivalent level of safety to
that of PW SB 6429. Further, the commenter is concerned that the new PW
SB 6429 may introduce new failure modes.
The FAA does not agree. The proposed rule is worded such that the
intents of SBs 5409, 5719, and 5734 are contained in paragraph (a) of
the final rule. This wording was chosen at the request of the Air
Transport Association (ATA) to facilitate easier compliance by
operators. However, while the modifications identified by these
bulletins reduce the probability of encountering a tierod fracture and
some operators may not have experienced one since incorporating the
bulletins, they do not prevent the fractures completely. The FAA has
received reports from PW of tierod fractures occurring after
incorporating SBs 5409, 5719, and 5734. Accordingly, PW has issued SB
JT8D 6429, dated August 23, 2002, which adds a tierod retention feature
to prevent the escape of the fractured end of the tierod which can lead
to separation of the first and second stage fan sections from the rear
stages of the LPC and a subsequent uncontained engine failure. Further,
the new design features in question have been used on other engines
with similar tierod configurations. The new tierods meet all of the
airworthiness standards required for certification. Proven design
standards used for the new retention feature have demonstrated to the
FAA that no new failure modes will be introduced into the field.
Lack of Enforcement of Acceptable Maintenance Practices and Financial
Burden
One commenter states that the rule ignores enforcement of
acceptable, pertinent maintenance practices and adds monetary burden to
all operators, without regard to disciplined adherence to PW's or
operator's approved maintenance program.
The FAA does not agree. The FAA has identified an unsafe condition
that exists on a type certified product. The actions identified to
correct that condition are manufacturer's maintenance recommendations.
The FAA is required to mandate these recommendations in order to
correct the unsafe condition. Operators are still
[[Page 11972]]
afforded the opportunity to develop an alternative plan to correct the
unsafe condition under the provisions of paragraph (d) of this AD. Many
operators already incorporate the requirements in this AD under their
approved maintenance program, therefore their monetary burden should be
minimal.
Request for Alternate Compliance Time and Eliminate Time Restrictions
One commenter asks that the AD be written to allow AD compliance
during LPC module heavy maintenance, when at piece-part level, without
time restrictions.
The FAA does not agree. The proposal currently requires the
compliance at LPC accessibility which is defined as removal of the
affected parts at the piece-part level. No time restrictions are
included in the AD. If there are specific aspects of an operator's
maintenance plan that make this definition an unusual burden, the
operator should propose an alternative incorporation plan under the
provisions of paragraph (d) of 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.
Economic Analysis
There are approximately 4,180 PW JT8D-1, -1A, -1B, -7, -7A, -7B, -
9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines of
the affected design in the worldwide fleet. The FAA estimates that
1,800 engines installed on aircraft of U.S. registry will be affected
by this AD, that it will take approximately 41 work hours per engine to
perform the required actions, and that the average labor rate is $60
per work hour. Required parts will cost approximately $3,600 per
engine. Based on these figures, the total cost of the AD to U.S.
operators is estimated to be $10,908,000.
Regulatory Analysis
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) 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 by adding a new airworthiness directive
to read as follows:
2003-05-07 Pratt & Whitney: Amendment 39-13083. Docket No. 2002-NE-
27-AD.
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 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 (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 of the LPC, do the following:
(1) Remove from service 3rd-4th stage compressor rotor spacer
assemblies part numbers (P/Ns) 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/Ns 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 628778 that do not incorporate service bulletin (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 PW SBs No. 5409, SB No. 5716, and 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.
Documents That Have Been Incorporated By Reference
(f) The actions must be done in accordance with Pratt & Whitney
Service Bulletin JT8D 6429, dated August 23, 2002. 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
[[Page 11973]]
part 51. Copies may be obtained from Pratt & Whitney, 400 Main St.,
East Hartford, CT 06108; telephone (860) 565-8770; 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 April 17, 2003.
Issued in Burlington, Massachusetts, on March 4, 2003.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 03-5692 Filed 3-12-03; 8:45 am]
BILLING CODE 4910-13-P