Rule2021-25500
Airworthiness Directives; Pratt & Whitney Turbofan Engines
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
November 23, 2021
Effective
December 28, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is superseding Airworthiness Directive (AD) 2011-07-02 for all Pratt & Whitney (P&W) JT8D-209, JT8D-217, JT8D-217A, JT8D-217C, and JT8D-219 model turbofan engines. AD 2011-07-02 required initial and repetitive torque inspections of the 3rd-stage and 4th-stage low- pressure turbine (LPT) blades. AD 2011-07-02 also required replacement of the LPT blade if wear limits are exceeded, replacement of the LPT- to-exhaust case bolts and nuts, and installation of crushable sleeve spacers on the bolts. This AD was prompted by a report of an MD-82 airplane, equipped with a JT8D-217C model turbofan engine, experiencing an engine surge that resulted in the fracture of the LPT blade and uncontained release of the LPT blade. This AD retains certain requirements of AD 2011-07-02, while revising the inspection thresholds and replacement intervals for the 3rd-stage and 4th-stage LPT blades. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 86 Issue 223 (Tuesday, November 23, 2021)</title>
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[Federal Register Volume 86, Number 223 (Tuesday, November 23, 2021)]
[Rules and Regulations]
[Pages 66444-66447]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-25500]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0661; Project Identifier AD-2020-01349-E;
Amendment 39-21792; AD 2021-22-19]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2011-07-02
for all Pratt & Whitney (P&W) JT8D-209, JT8D-217, JT8D-217A, JT8D-217C,
and JT8D-219 model turbofan engines. AD 2011-07-02 required initial and
repetitive torque inspections of the 3rd-stage and 4th-stage low-
pressure turbine (LPT) blades. AD 2011-07-02 also required replacement
of the LPT blade if wear limits are exceeded, replacement of the LPT-
to-exhaust case bolts and nuts, and installation of crushable sleeve
spacers on the bolts. This AD was prompted by a report of an MD-82
airplane, equipped with a JT8D-217C model turbofan engine, experiencing
an engine surge that resulted in the fracture of the LPT blade and
uncontained release of the LPT blade. This AD retains certain
requirements of AD 2011-07-02, while revising the inspection thresholds
and replacement intervals for the 3rd-stage and 4th-stage LPT blades.
The FAA is issuing this AD to address the unsafe condition on these
products.
DATES: This AD is effective December 28, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 28,
2021.
ADDRESSES: For service information identified in this final rule,
contact Pratt & Whitney, 400 Main Street, East Hartford, CT 06118;
phone: (800) 565-0140; email: <a href="/cdn-cgi/l/email-protection#365e535a460402764644574242415e5f4258534f1855595b"><span class="__cf_email__" data-cfemail="a0c8c5ccd09294e0d0d2c1d4d4d7c8c9d4cec5d98ec3cfcd">[email protected]</span></a>; website: <a href="https://fleetcare.prattwhitney.com">https://fleetcare.prattwhitney.com</a>. You may view this service information at
the FAA, Airworthiness Products Section, Operational Safety Branch,
1200 District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call (781) 238-7759. It is
also available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and
locating Docket No. FAA-2021-0661.
[[Page 66445]]
Examining the AD Docket
You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by
searching for and locating Docket No. FAA-2021-0661; or in person at
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket contains this final rule, any
comments received, and other information. The address for Docket
Operations is U.S. Department of Transportation, Docket Operations, M-
30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue
SE, Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Nicholas Paine, Aviation Safety
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
phone: (781) 238-7116; fax: (781) 238-7199; email:
<a href="/cdn-cgi/l/email-protection#dfb1b6bcb7b0b3beacf1b5f1afbeb6b1ba9fb9bebef1b8b0a9"><span class="__cf_email__" data-cfemail="56383f353e393a3725783c7826373f38331630373778313920">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2011-07-02, Amendment 39-16639 (76 FR
16526, March 24, 2011), (AD 2011-07-02). AD 2011-07-02 applied to all
P&W JT8D-209, JT8D-217, JT8D-217A, JT8D-217C, and JT8D-219 model
turbofan engines. The NPRM published in the Federal Register on August
27, 2021 (86 FR 48080). The NPRM was prompted by a report of an MD-82
airplane, equipped with JT8D-217C model turbofan engines that, on
approach to Taipei Songshan Airport, experienced an engine surge on the
number one engine resulting in LPT blade fracture and uncontained LPT
blade failure. An inspection by the manufacturer determined that this
event was caused by shroud notch wear of the LPT blades, which led to
changes in the vibration mode and subsequent high-cycle fatigue of the
airfoil. In addition to this event, the FAA received reports of five
events that involved uncontained failure of the LPT blades on the
affected engines. Based on its investigation of these events, P&W
determined that revised or more restrictive inspection thresholds and
replacement intervals of the 3rd-stage and 4th-stage LPT blades are
necessary and revised its service information accordingly. In the NPRM,
the FAA proposed to require an initial torque inspection of certain
3rd-stage LPT blades and repetitive torque inspections of 4th-stage LPT
blades for shroud notch wear at revised inspection thresholds and
intervals. In the NPRM, the FAA also proposed to require replacement of
the 3rd-stage and 4th-stage LPT blades before accumulating 5,000 hours
time-in-service.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from one commenter. The Boeing Company
supported the NPRM without change.
Conclusion
The FAA reviewed the relevant data, considered the comment
received, and determined that air safety requires adopting the AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. This AD is adopted as proposed in the
NPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Pratt & Whitney Alert Service Bulletin (ASB) No.
JT8D A6224, Revision No. 7, dated August 26, 2019. This service
information specifies procedures for the initial and repetitive torque
inspections of the 3rd-stage and 4th-stage LPT blades for shroud notch
wear at revised inspection thresholds and intervals. This service
information is reasonably available because the interested parties have
access to it through their normal course of business or by the means
identified in ADDRESSES.
Other Related Service Information
The FAA reviewed Pratt & Whitney ASB No. JT8D A6494, Revision No.
1, dated January 26, 2010, Pratt & Whitney ASB JT8D A6507, dated
November 2, 2020, and Sections 72-53-12 through 72-53-13 of Pratt &
Whitney Engine Maintenance Manual (EMM), Part No. 773128, Revision 107,
dated October 15, 2020. Pratt & Whitney ASB No. JT8D A6494, Revision
No. 1, dated January 26, 2010, describes procedures for replacing the
LPT-to-exhaust case bolts and nuts and installing the crushable sleeve
spacers. Pratt & Whitney ASB JT8D A6507, dated November 2, 2020,
describes procedures for replacing the 3rd-stage and 4th-stage LPT
blades. Sections 72-53-12 through 72-53-13 of Pratt & Whitney EMM, Part
No. 773128, Revision 107, dated October 15, 2020, describe procedures
for inspecting and repairing the 3rd-stage and 4th-stage LPT blades.
Costs of Compliance
The FAA estimates that this AD affects 42 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspect 3rd-stage and 4th-stage LPT 1 work-hour x $85 per $0 $85 $3,570
blades. hour = $85.
Replace 3rd-stage and 4th-stage LPT 150 work-hours x $85 per 350,000 362,750 15,235,500
blades. hour = $12,750.
Replace the LPT-to-exhaust case bolts 1.5 work-hours x $85 per 4,576 4,703.50 197,547
and nuts and install the crushable hour = 127.50.
sleeve spacers.
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Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, Section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, General
requirements'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
The FAA has determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on the States, on the relationship between
the national government and the States, or on the distribution of
[[Page 66446]]
power and responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Will not affect intrastate aviation in Alaska, 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
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]
0
2. The FAA amends Sec. 39.13 by:
0
a. Removing Airworthiness Directive AD 2011-07-02, Amendment 39-16639
(76 FR 16526, March 24, 2011); and
0
b. Adding the following new airworthiness directive:
2021-22-19 Pratt & Whitney: Amendment 39-21792; Docket No. FAA-2021-
0661; Project Identifier AD-2020-01349-E.
(a) Effective Date
This airworthiness directive (AD) is effective December 28,
2021.
(b) Affected ADs
This AD replaces AD 2011-07-02, Amendment 39-16639 (76 FR 16526,
March 24, 2011).
(c) Applicability
This AD applies to Pratt & Whitney (P&W) JT8D-209, JT8D-217,
JT8D-217A, JT8D-217C, and JT8D-219 model turbofan engines.
(d) Subject
Joint Aircraft System Component (JASC) Code 7230, Turbine Engine
Compressor Section.
(e) Unsafe Condition
This AD was prompted by a report of an MD-82 airplane, equipped
with a JT8D-217C model turbofan engine, experiencing an engine surge
that resulted in the fracture of the low-pressure turbine (LPT)
blade and uncontained release of the LPT blade. Five prior
uncontained LPT blade failures were also reported on affected model
turbofan engines. The FAA is issuing this AD to prevent LPT blade
fracture and uncontained release of the LPT blade. The unsafe
condition, if not addressed, could result in uncontained engine
debris, damage to the engine, and damage to the aircraft.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) For JT8D-209, JT8D-217, and JT8D-217A model turbofan
engines, within the compliance times specified in the Accomplishment
Instructions, Part 1: JT8D-209, -217, -217A Engines (Part 1),
paragraph 1.A., of P&W Alert Service Bulletin No. JT8D A6224,
Revision No. 7, dated August 26, 2019 (the ASB), perform an initial
torque inspection for shroud notch wear of the 3rd-stage LPT blades
using the procedures in Part 1, paragraph 1, of the ASB.
(i) Thereafter, within the applicable reinspection interval
specified in Table 1--Reinspection Interval for all 3rd Stage
Blades, of the ASB, repeat the torque inspection for shroud notch
wear required by paragraph (g)(1) of this AD.
(ii) If the results of the torque inspection required by
paragraphs (g)(1) or (g)(1)(i) of this AD meet the criteria for
engine removal specified in Table 1--Reinspection Interval for all
3rd Stage Blades, of the ASB, perform piece-part inspections in
accordance with the Instructions for Continued Airworthiness (ICA)
on all 3rd-stage LPT blades before exceeding 20 hours time-in-
service (TIS) since the last torque inspection.
(2) For JT8D-209, JT8D-217, and JT8D-217A model turbofan
engines, within the compliance times specified in Table A or Table
B, of the ASB, as applicable, perform an initial torque inspection
for shroud notch wear of the 4th-stage LPT blades using the
procedures in Part 1, paragraph 1, of the ASB. Wherever the ASB
refers to ``Revision 7 Release Date'' and ``At SB Release Date,''
use the effective date of this AD.
(i) For engines in which the last inspection prior to the
effective date of this AD had a torque inspection result of less
than 15 LB-IN on any 4th-stage LPT blade, perform piece-part
inspections in accordance with the ICA on all 3rd-stage and 4th-
stage LPT blades within 20 hours TIS after the effective date of
this AD.
(ii) Thereafter, within the applicable reinspection interval
specified in Table 2--Reinspection Interval for all 4th Stage
Blades, of the ASB, repeat the torque inspection for shroud notch
wear required by paragraph (g)(2) of this AD.
(iii) If the results of the torque inspection required by
paragraphs (g)(2) or (g)(2)(ii) of this AD meet the criteria for
engine removal specified in Table 2--Reinspection Interval for all
4th Stage Blades, of the ASB, perform piece-part inspections in
accordance with the ICA on all 3rd-stage and 4th-stage LPT blades
before exceeding 20 hours TIS since the last torque inspection.
(3) For JT8D-217C and JT8D-219 model turbofan engines, within
the compliance times specified in Table A or Table B, of the ASB, as
applicable, perform an initial torque inspection for shroud notch
wear of the 4th-stage LPT blades using the procedures in the
Accomplishment Instructions, Part 2: JT8D-217C, -219 Engines (Part
2), paragraph 1, of the ASB. Wherever the ASB refers to ``Revision 7
Release Date'' and ``At SB Release Date,'' use the effective date of
this AD.
(i) For engines in which the last inspection prior to the
effective date of this AD had a torque inspection result of less
than 15 LB-IN on any 4th-stage LPT blade, perform piece-part
inspections in accordance with the ICA on all 3rd-stage and 4th-
stage LPT blades within 20 hours TIS after the effective date of
this AD.
(ii) Thereafter, within the reinspection interval specified in
Table 3--Reinspection Interval for all 4th Stage Blades, of the ASB,
repeat the torque inspection for shroud notch wear required by
paragraph (g)(3) of this AD.
(iii) If the results of the torque inspection required by
paragraph (g)(3) and (g)(3)(ii) of this AD meet the criteria for
engine removal specified in Table 3--Reinspection Interval for all
4th Stage Blades, of the ASB, perform piece-part inspections in
accordance with the ICA on all 3rd-stage and 4th-stage LPT blades
before exceeding 20 hours TIS since the last torque inspection.
(4) At the first engine shop visit after January 1, 2023, or
prior to accumulating 5,000 TIS on the 3rd-stage and 4th-stage LPT
blades, whichever occurs later, but not to exceed 6 years after the
effective date of the AD, replace the 3rd-stage and 4th-stage LPT
blades with parts eligible for installation.
(5) Thereafter, prior to accumulating 5,000 hours TIS on the
3rd-stage and 4th-stage LPT blades since their last replacement,
replace the 3rd-stage and 4th-stage LPT blades with parts eligible
for installation.
(6) After every replacement of the 3rd-stage or 4th-stage LPT
blades, perform initial and repetitive torque inspections of the
3rd-stage or 4th-stage LPT blades using, as applicable, the
accomplishment instructions and compliance times in Part 1,
paragraph 1, or Part 2, paragraph 1, of the ASB.
(i) If the results of the torque inspection required by
paragraph (g)(6) of this AD meet the criteria for engine removal
specified in Table 1, 2 or 3, of the ASB, as applicable, perform
piece-part inspections in accordance with the ICA on all 3rd-stage
and 4th-stage LPT blades before exceeding 20 hours TIS since the
last torque inspection.
(ii) [Reserved]
(7) The initial inspection or the reinspection interval should
not be reset unless the blades are refurbished. Whenever a used
blade is reinstalled in a rotor, the previous used time should be
subtracted from the initial inspection threshold.
(8) Whenever a refurbished or used blade is intermixed with zero
hours time-since-new (TSN) blades in a rotor, use the lowest initial
inspection threshold that is applicable.
(9) At the next accessibility to the LPT-to-exhaust case bolts
and nuts after the effective date of this AD, do the following:
(i) Replace the bolts with part number (P/N) MS9557-26 bolts;
(ii) Replace the nuts with P/N 375095 nuts or P/N 490270 nuts;
and
(iii) Install crushable sleeve spacers, P/N 822903, under the
head of the bolts.
[[Page 66447]]
Note 1 to paragraph (g): Guidance on replacing the 3rd-stage and
4th-stage LPT blades can be found in P&W ASB JT8D A6507, dated
November 2, 2020.
Note 2 to paragraph (g): Guidance on replacing the LPT-to-
exhaust case bolts and nuts and installing the crushable sleeve
spacers can be found in P&W ASB No. JT8D A6494, Revision No. 1,
dated January 26, 2010.
(h) Definitions
For the purpose of this AD:
(1) An ``engine shop visit'' is the induction of an engine into
the shop for maintenance involving the separation of pairs of major
mating engine flanges, except that the separation of engine flanges
solely for the purposes of transportation without subsequent engine
maintenance does not constitute an engine shop visit.
(2) Accessibility to the LPT-to-exhaust case bolts refers to
maintenance involving the inner turbine fan ducts being removed from
the engine.
(3) Parts eligible for installation are 3rd-stage or 4th-stage
LPT blades with less than 5,000 hours TIS.
(4) A ``piece-part inspection'' is when the blades are removed
from the rotor.
(5) A ``used blade'' refers to a 3rd-stage or 4th-stage LPT
blade that has more than zero hours TSN.
(i) Credit for Previous Actions
You may take credit for any initial torque inspection for shroud
notch wear required by paragraphs (g)(1) through (3) of this AD if
you performed the initial inspection before the effective date of
this AD using P&W ASB No. JT8D A6224, Revision No. 5, dated June 11,
2004, or Revision No. 6, dated May 3, 2007.
(j) Alternative Methods of Compliance (AMOCs)
(1) The Manager, ECO Branch, FAA, has the authority to approve
AMOCs for this AD, if requested using the procedures found in 14 CFR
39.19. In accordance with 14 CFR 39.19, send your request to your
principal inspector or local Flight Standards District Office, as
appropriate. If sending information directly to the manager of the
ECO Branch, send it to the attention of the person identified in
paragraph (k) of this AD. You may email your request to: <a href="/cdn-cgi/l/email-protection#c5848b80e88481e884888a8685a3a4a4eba2aab3"><span class="__cf_email__" data-cfemail="63222d264e22274e222e2c20230502024d040c15">[email protected]</span></a>.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(k) Related Information
For more information about this AD, contact Nicholas Paine,
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue,
Burlington, MA 01803; phone: (781) 238-7116; fax: (781) 238-7199;
email: <a href="/cdn-cgi/l/email-protection#99f7f0faf1f6f5f8eab7f3b7e9f8f0f7fcd9fff8f8b7fef6ef"><span class="__cf_email__" data-cfemail="7816111b101714190b561256081911161d381e1919561f170e">[email protected]</span></a>.
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
(i) Pratt & Whitney Alert Service Bulletin No. JT8D A6224,
Revision No. 7, dated August 26, 2019.
(ii) [Reserved]
(3) For service information identified in this AD, contact Pratt
& Whitney, 400 Main Street, East Hartford, CT 06118; phone: (800)
565-0140; email: <a href="/cdn-cgi/l/email-protection#ef878a839fdddbaf9f9d8e9b9b9887869b818a96c18c8082"><span class="__cf_email__" data-cfemail="147c7178642620546466756060637c7d607a716d3a777b79">[email protected]</span></a>; website: <a href="https://fleetcare.prattwhitney.com">https://fleetcare.prattwhitney.com</a>.
(4) You may view this service information at FAA, Airworthiness
Products Section, Operational Safety Branch, 1200 District Avenue,
Burlington, MA 01803. For information on the availability of this
material at the FAA, call (781) 238-7759.
(5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, email: <a href="/cdn-cgi/l/email-protection#5c3a2e7235322f2c393f283533321c323d2e3d723b332a"><span class="__cf_email__" data-cfemail="563024783f3825263335223f3938163837243778313920">[email protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued on October 21, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-25500 Filed 11-22-21; 8:45 am]
BILLING CODE 4910-13-P
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