[Federal Register Volume 63, Number 231 (Wednesday, December 2, 1998)]
[Proposed Rules]
[Pages 66500-66502]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-32048]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-ANE-02]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D-200 Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to Pratt & Whitney JT8D-200
series turbofan engines, that currently requires periodic inspection of
fan blades for locked rotors and foreign object damage (FOD), unlocking
of shrouds if necessary, lubrication of fan blade shrouds, and
dimensional restoration of the fan blade leading edge. In addition,
that AD requires installation of improved design fan blades as
terminating action for the inspections. This action would reduce the
lubrication interval, and require removal of rotors that experience
repeat lockups within 225 cycles in service. This proposal is prompted
by reports of 7 fan blade failures since publication of the current AD.
The actions specified by the proposed AD are intended to prevent fan
blade failure, which can result in damage to the aircraft.
DATES: Comments must be received by February 1, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 96-ANE-02, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``engineprop@faa.dot.gov''. Comments sent via the Internet must contain
the docket number in the subject line. Comments may be inspected at
this location between 8:00 a.m. and 4:30 p.m., Monday through Friday,
except Federal holidays.
The service information referenced in the proposed rule may be
obtained from fan blade failure, which can result in damage to the
aircraft. This information may be examined at the FAA, New England
Region, Office of the Regional Counsel, 12 New England Executive Park,
Burlington, MA.
FOR FURTHER INFORMATION CONTACT: Peter White, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7128, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 96-ANE-02.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 96-ANE-02, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
On November 7, 1996, the Federal Aviation Administration (FAA)
issued airworthiness directive AD 96-23-15, Amendment 39-9821 (61 FR
63706, December 2, 1996), applicable to Pratt & Whitney (PW) JT8D-200
series turbofan
[[Page 66501]]
engines, to require periodic inspection of fan blades for locked rotors
and foreign object damage (FOD), unlocking of shrouds if necessary,
lubrication of fan blade shrouds, and dimensional restoration of the
fan blade leading edge. In addition, that AD requires installation of
improved design fan blades as terminating action for the inspections.
That action was prompted by the introduction into service of improved
design fan blades. That condition, if not corrected, could result in
fan blade failure, which can result in damage to the aircraft.
Since the issuance of that AD, the FAA has received reports of 7
additional fan blade failures on engines that had been inspected in
accordance with the current AD. The fan blades are failing as a result
of high cycle fatigue. Contributing factors are foreign object damage
(FOD), leading edge erosion, manufacturing discrepancies, and locked
fan shrouds. These fan blade failures indicate that the currently
mandated fleet management plan is insufficient.
The FAA has reviewed and approved the technical contents of PW
Alert Service Bulletin (ASB) No. A6241, Revision 2, dated June 29,
1998, that reduces the lubrication interval, and requires removal of
rotors that experience repeat lockups within 225 cycles in service
(CIS).
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would supersede AD 96-23-15 to reduce the lubrication
interval, and require removal of rotors that experience repeat lockups
within 225 cycles in service.
There are approximately 2,650 engines of the affected design in the
worldwide fleet. The FAA estimates that 960 engines installed on
aircraft of U.S. registry would be affected by this proposed AD, that
it would take no additional work hours to perform these inspections
except at a shorter lubrication interval. Rework costs for the fan
blades are $275 per blade, of which approximately $140 per blade is
attributable to this AD action. With the manufacturer's rebate of $50
per blade, the total cost to industry of reworking these blades is
$2,750 per engine. The manufacturer estimates that it will take 19 work
hours per engine to remove and reinstall the blades. Using labor costs
of $60 per hour, the labor costs to remove and reinstall the blades are
$1,140 per engine. Hence, the increased costs generated by this
proposed AD on U.S. operators is estimated to be $3,890 per engine, or
$3,734,400 to retrofit the remaining 960 engines.
The regulations proposed herein would not have substantial direct
effects 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. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed
regulation: (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 copy of the draft
regulatory evaluation prepared for this action 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.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 39-9821 (61 FR
63706, December 2, 1998) and by adding a new airworthiness directive to
read as follows:
Pratt & Whitney: Docket No. 96-ANE-02. Supersedes AD 96-23-15,
Amendment 39-9821.
Applicability: Pratt & Whitney (PW) Models JT8D-209, -217, -
217A, -217C, and -219 turbofan engines that have not incorporated PW
Service Bulletin (SB) No. 6193, dated October 31, 1994, or with fan
blade, Part Numbers (P/N's) 798821, 798821-001, 808121, 808121-001,
809221, 811821, 851121, 851121-001, 5000021-02, 5000021-022, and
5000021-032 installed. These engines are installed on but not
limited to McDonnell Douglas MD-80 series aircraft.
Note 1: This airworthiness directive (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 (f) 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: Required as indicated, unless accomplished
previously.
To prevent fan blade failure, which can result in damage to the
aircraft, accomplish the following:
(a) Inspect fan blades and shrouds, unlock fan blade shrouds,
lubricate fan blade shrouds, restore leading edge dimensions, and
modify or install improved design fan blades in accordance with the
schedule and procedures described in Parts 1, 2, and 3 of the
Accomplishment Instructions of PW Alert Service Bulletin (ASB) No.
A6241, Revision 2, dated June 29, 1998.
(b) Modification of fan blades to the improved design
configuration or installation of improved design fan blades in
accordance with Part 3 of the Accomplishment Instructions of PW ASB
No. A6241, Revision 2, dated June 29, 1998, constitutes terminating
action to the inspections and maintenance actions described in
paragraph (a) of this AD.
(c) For the purpose of this AD, the accomplishment effective
date to be used for determination of compliance intervals, as
required by Section 2 of PW ASB No. A6241, Revision 2, dated June
29, 1998, is defined as the effective date of this AD.
(d) For the purpose of this AD, ``repair'' as specified in Part
3, Paragraph A.(1)(b) of the Accomplishment Instructions of PW ASB
No. A6241, Revision 2, dated June 29, 1998 is defined as the
refurbishment of fan blades in accordance with Part 3, Paragraph C
of the Accomplishment Instructions of PW ASB No. A6241, Revision 2,
dated June 29, 1998.
(e) Alternative methods of compliance that have been approved
for AD 95-12-19 are applicable for this AD and additional approval
is not required.
(f) 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. The
request should be forwarded through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved
alternative method of compliance with this AD, if any, may be
obtained from the Engine Certification Office.
(g) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the aircraft to
[[Page 66502]]
a location where the requirements of this AD can be accomplished.
Issued in Burlington, Massachusetts, on November 24, 1998.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 98-32048 Filed 12-1-98; 8:45 am]
BILLING CODE 4910-13-P
