[Federal Register Volume 61, Number 232 (Monday, December 2, 1996)]
[Rules and Regulations]
[Pages 63706-63707]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-30096]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-ANE-02; Amendment 39-9821; AD 96-23-15]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D-200 Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes 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. This amendment adds a
requirement to install improved design fan blades as terminating action
for the inspections. This amendment is prompted by the introduction
into service of improved design fan blades. The actions specified by
this AD are intended to prevent fan blade failure, which can result in
damage to the aircraft.
DATES: Effective January 2, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 2, 1997.
ADDRESSES: The service information referenced in this AD may be
obtained from Pratt & Whitney, Publication Department, Supervisor
Technical Publications Distribution, M/S 132-30, 400 Main St., East
Hartford, CT 06108; telephone (860) 565-7700, fax (860) 565-4503. This
information may be examined at the Federal Aviation Administration
(FAA), New England Region, Office of the Assistant Chief Counsel, 12
New England Executive Park, Burlington, MA 01803-5299; or at the Office
of the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Diane Cook, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-
7134, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding airworthiness
directive (AD) 95-12-19, Amendment 39-9270 (60 FR 31388, June 15,
1995), applicable to certain Pratt & Whitney (PW) JT8D-200 series
turbofan engines, was published in the Federal Register on May 6, 1996
(61 FR 20194). That action proposed to add a requirement to install
improved design fan blades as terminating action for the 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. The
action would be required to be accomplished in accordance with PW Alert
Service Bulletin (ASB) No. A6241, dated January 25, 1996.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
One commenter supports the rule as proposed.
One commenter concurs with the inspection and maintenance
provisions of the proposed AD. However, the commenter questions the
proposed compliance schedule for the terminating action to incorporate
the new fan blades. The compliance schedule is based on fan blade
cycles in service (CIS). The commenter states that since (1) the fan
blade fractures are due to a high cycle fatigue (HCF) failure mode that
is not linked to total part CIS on the fan blade, and (2) that
individual fan blade CIS are currently not tracked, an alternative
compliance requirement based on completing a specific yearly percentage
rate of the operator's engine sets would be less burdensome to the
operators. The FAA concurs in part. When the FAA assessed the risk, the
FAA based the compliance schedule on total part CIS. It has been the
FAA's practice to define intervals for corrective action in an AD by
means of part CIS. Monitoring this program on a fleet-wide basis using
the suggested percentage rate would not provide the FAA with an
adequate means to ensure that blades were removed before becoming a
safety problem. Individual operators, however, may request such a
percentage-based program that includes those assurances as an
alternative method of compliance to the AD. The FAA, therefore, does
not concur that the proposed AD should be revised.
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.
The FAA estimates that 1,100 engines installed on aircraft of U.S.
registry will be affected by this AD, that it will take approximately
19 work hours per engine to accomplish the required actions, and
[[Page 63707]]
that the average labor rate is $60 per work hour. The FAA also
estimates that the parts modification will cost $1,020 per engine,
which includes a manufacturer's discount of $1,700 per engine. Based on
these figures, the total cost impact of the AD on U.S. operators is
estimated to be $2,376,000.
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
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 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
from 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. Sec. 39.13 is amended by removing Amendment 39-9270 (60 FR
31388, June 15, 1995) and by adding a new airworthiness directive,
Amendment 39-9821, to read as follows:
96-23-15 Pratt & Whitney: Amendment 39-9821. Docket 96-ANE-02.
Supersedes AD 95-12-19, Amendment 39-9270.
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, dated January 25, 1996.
(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, dated January 25, 1996, constitutes terminating action to
the inspections and maintenance actions described in Parts 1 and 2
of that ASB.
(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, dated January 25, 1996,
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, dated January 25, 1996, is defined as the refurbishment
of fan blades in accordance with Part 3, Paragraph C of the
Accomplishment Instructions of PW ASB No. A6241, dated January 25,
1996.
(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 a location where
the requirements of this AD can be accomplished.
(h) The actions required by this AD shall be done in accordance
with the following Pratt & Whitney ASB:
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Document No. Pages Revision Date
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A6241................................... 1-14 Original................... January 25, 1996.
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Total pages: 14.
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, Publication
Department, Supervisor Technical Publications Distribution, M/S 132-
30, 400 Main St., East Hartford, CT 06108; telephone (860) 565-7700,
fax (860) 565- 4503. Copies may be inspected at the FAA, New England
Region, Office of the Assistant Chief 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.
(i) This amendment becomes effective on January 2, 1997.
Issued in Burlington, Massachusetts, on November 7, 1996.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 96-30096 Filed 11-29-96; 8:45 am]
BILLING CODE 4910-13-U
