[Federal Register Volume 89, Number 131 (Tuesday, July 9, 2024)]
[Rules and Regulations]
[Pages 56198-56203]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-14936]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1640; Project Identifier AD-2022-00283-E;
Amendment 39-22768; AD 2024-12-04]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Pratt & Whitney (PW) Model PW2037, PW2037M, and PW2040 engines with a
certain high-pressure turbine (HPT) 2nd stage blade assembly installed.
This AD was prompted by an in-flight shutdown (IFSD) caused by the
fracture of HPT 2nd stage turbine hub assembly lugs, which resulted in
blade liberation and a titanium fire in the high-pressure compressor
(HPC). This AD requires a visual inspection of the HPT 2nd stage blade
assemblies for missing contact marks, a dimensional shadowgraph
inspection of the HPT 2nd stage blade assemblies for blade root profile
dimensional deviations, and an eddy current inspection (ECI) of the HPT
2nd stage turbine hub assembly for conforming slot flatness. This AD
also requires removal from service and replacement of any HPT 2nd stage
turbine hub assembly or HPT 2nd stage blade assembly that does not pass
any inspection. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective August 13, 2024.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 13,
2024.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-1640; 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.
Material Incorporated by Reference:
For service information, contact Pratt & Whitney, 400 Main
Street, East Hartford, CT 06118; phone: (860) 565-0140; email:
[email protected]; website: connect.prattwhitney.com.
You may view this service information at the FAA,
Airworthiness Products Section, 1200 District Avenue, Burlington, MA
01803. For information on the availability of this material at the FAA,
call (817) 222-5110. It is also available at regulations.gov under
Docket No. FAA-2023-1640.
FOR FURTHER INFORMATION CONTACT: Carol Nguyen, Aviation Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
(781) 238-7655; email: [email protected].
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all PW Model PW2037,
PW2037M, and PW2040 engines with a certain HPT 2nd stage blade assembly
installed. The NPRM published in the Federal Register on August 25,
2023 (88 FR 58114). The NPRM was prompted by an IFSD caused by the
fracture of HPT 2nd stage turbine hub assembly lugs, which resulted in
blade liberation and a titanium fire in the HPC.
In the NPRM, the FAA proposed to require a visual inspection of the
HPT 2nd stage blade assemblies for missing contact marks, a dimensional
shadowgraph inspection of the HPT 2nd stage blade assemblies for blade
root profile dimensional deviations, and an ECI of the HPT 2nd stage
turbine hub assembly for conforming slot flatness. The NPRM also
proposed to require removal from service and replacement of any HPT 2nd
stage turbine hub assembly or HPT 2nd stage blade assembly that does
not pass any inspection. The FAA is issuing this AD to address the
unsafe condition on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from six commenters. The commenters were
The Boeing Company (Boeing), Delta Air Lines (Delta), European Air
Transport (EAT), FedEx Express (FedEx), MTU Maintenance Hannover GmbH
(MTU), and United Parcel Service (UPS). Boeing supported the NPRM
without change. The following presents the comments received from
Delta, EAT, FedEx, MTU, and UPS on the NPRM and the FAA's response to
each comment.
Request To Exempt Certain Hubs From NPRM Cycle Limit
Delta requested that the FAA allow hubs with an ECI performed on
25% of the blade slots to be inspected in accordance with the updated
dimensional ECI procedure at the next piece part exposure of the HPT
2nd stage turbine hub assembly, rather than being inspected within the
cycle limit of the NPRM. Delta noted that Method 2, Step 4 in PW Alert
Service Bulletin PW2000 A72-777, Initial Issue, dated September 29,
2021 (PW2000 A72-777, Initial Issue) requires that HPT 2nd stage
turbine hub assemblies be installed that have passed the HPT 2nd stage
turbine hub assembly ECI inspection specified in PW2000 Engine Manual,
Task 72-52-16-200-006, but does not provide guidance on the required
amount of slots to be inspected. Delta also noted that in the beginning
of the HPT Field Management Program for this unsafe condition and
[[Page 56199]]
prior to the updated ECI procedure being released for the HPT 2nd stage
turbine hub assembly, T2 blades were inspected for conformance and
installed into HPT 2nd stage turbine hub assemblies that were made
serviceable with previous ECI instructions specified in the PW2000
Engine Manual, where only 16 out of 64 (25%) slots were required to be
eddy current inspected.
The FAA disagrees with the request because there is a higher
probability of identifying damage to the hub when 100% of the slots are
inspected. Additionally, allowing hubs that have had an ECI performed
on 25% of blade slots to wait until the next piece-part exposure for
the updated ECI would increase the risk of failure. The FAA removed
previous credit for PW2000 A72-777, Initial Issue, to ensure only HPT
2nd stage turbine hub assemblies with ECI performed on 100% of the
blade slots comply with this AD. However, once this AD is published,
any person may request approval of an alternative method of compliance
(AMOC) under the provisions of paragraph (i) of this AD. The FAA did
not change this AD as a result of this comment.
Request To Clarify Applicability for Hubs Divorced From Mating Blades
Delta requested that the FAA provide guidance on whether hubs that
were divorced from their mating blades and do not have the required
inspection results are exempt from the requirements of the NPRM,
provided that the replacement set of blades to be installed are
conforming to the visual and shadowgraph inspection requirements of PW
Alert Service Bulletin PW2000 A72-777, Revision 2, dated April 11, 2023
(PW2000 A72-777, Rev. 2). Delta stated that there is no way to perform
the actions required in the NPRM and PW2000 A72-777, Rev. 2 to
determine serviceability related to this unsafe condition for piece
part hubs that were already divorced from their mating blades because
previously installed blades were not traced and may have already gone
through overhaul process or were scrapped. Delta noted that after
overhaul or scrapping of blades, visual contact patterns and blade
profile are no longer available for inspection.
The FAA agrees that clarification is necessary. Hubs that are
divorced from their mating blades are not exempt from the requirements
of this final rule and are considered unserviceable, and therefore no
exemption is necessary. The FAA did not change this AD as a result of
this comment.
Request To Define Methodology for Returning Hub to Service
Delta requested that the FAA define the methodology for returning a
hub to service using Section 1, Step 1.E. of PW2000 A72-777, Rev. 2,
and as it relates to previous methods of compliance in previous
revisions and previous PW Special Instructions (SIs). Delta noted that
Section 1, Step 1.E. of PW2000 A72-777, Rev. 2 states that if an HPT
2nd stage blade assembly fails the visual inspection as specified in
Step 1.B., all related HPT 2nd stage blade assemblies pass the
shadowgraph inspection as specified in Step 1.C., and the related HPT
2nd stage hub assembly passes the ECI as specified in Step 1.D, the HPT
2nd Stage Blade Assemblies could be returned to P&W Customer Technical
Service for additional inspection to identify the hub serviceability.
Delta also noted that PW provided Pratt and Whitney Cover E.A. No.
22FA014, dated 26 October 2022, to accept these hubs into service.
The FAA disagrees with the request. The FAA notes that while
Section 1, Step 1.E. of PW2000 A72-777, Rev. 2 is an optional method to
return the hubs to service, it is not an action required by this AD
and, therefore, defining the methodology for returning a hub to service
is unnecessary. The FAA did not change this AD as a result of this
comment.
Request To Clarify Requirements for Credit for Previous Actions
Delta requested that the FAA clarify if the required for compliance
(RC) steps listed in PW2000 A72-777, Rev. 2 carry over to the previous
versions of the ASB and previous versions of the PW SIs in order to
provide credit for previous actions. Alternatively, Delta requested
that the FAA provide the specific steps from each of the previous
service information documents that are required in order to receive
credit for previous actions. Delta noted that none of the previous
revisions of the service information contain RC steps, which could
cause confusion to operators regarding whether to request an AMOC for
deviations from those instructions.
The FAA agrees to revise paragraph (h) of the final rule by
removing PW2000 A72-777, Initial Issue, and instead including PW SI NO.
62F-21, dated June 7, 2021, PW SI NO. 62F-21A, dated October 4, 2021,
PW SI NO. 73F-21, Revision A, dated September 29, 2021 (SI NO. 73F-21,
Rev. A), and PW SI NO. 73F-21, Initial Issue, dated April 6, 2021 (SI
NO. 73F-21, Initial Issue).
Request To Add Service Information for Shadowgraph Inspections
Delta requested that the FAA revise the NPRM to allow the
shadowgraph inspections of the hub to be performed in accordance with
all previous revisions to PW SI NO. 78F-21, Revision F, dated June 13,
2022 (SI NO. 78F-21, Rev. F). Delta noted that PW Alert Service
Bulletin PW2000 A72-777, Revision 1, dated December 21, 2022 (PW2000
A72-777, Rev. 1) and PW2000 A72-777, Rev. 2 refer to ``SI 78F-21, Rev F
released 6/13/2022 or later revision,'' and previous revisions of SI
NO. 78F-21 are permitted by PW2000 A72-777, Initial Issue. Delta also
noted that several of the PW SI revisions were issued prior to PW2000
A72-777, Initial Issue.
The FAA disagrees with the request to allow the shadowgraph
inspections of the hub to be performed in accordance with previous
revisions of SI NO. 78F-21. SI NO. 78F-21, Rev. F already provides
previous credit for previous revisions, which makes it unnecessary to
provide credit for actions done using the previous revisions. The FAA
did not change this AD as a result of this comment.
Request To Add Service Information for Visual Inspections
Delta requested that the FAA revise the NPRM to allow the visual
inspections of the hub for contact marks to be performed in accordance
with SI NO. 73F-21, Initial Issue. Delta noted that PW2000 A72-777,
Rev. 2 refers to ``SI 73F-21, Rev A released 9/29/2021 or later
revision,'' and SI NO. 73F-21, Initial Issue is permitted per PW2000
A72-777. Delta also noted that several of the PW SI revisions were
issued prior to PW2000 A72-777.
The FAA agrees with the request and has revised paragraph (h) of
this AD to include credit for actions done in accordance with SI NO.
73F-21, Initial Issue.
Request To Clarify Means To Accept New Blades
Delta requested that the FAA revise the NPRM to clarify that
communication from PW may be used as a means to accept new blades that
meet the intent of SI NO. 78F-21, Initial Issue and later revisions.
Delta noted that they have been using EagleNet Cases from PW for new
blades where the intent of SI NO. 78F-21, Initial Issue and later
revisions was accomplished. Delta also noted that PW does not include
SI NO. 78F-21, Initial Issue or later revisions on the form FAA 8130-3
for new blades, and the markings on the blades are not always listed.
[[Page 56200]]
The FAA disagrees with the request. The FAA notes that this AD
already refers to PW2000 A72-777, Rev. 2, as the appropriate service
information, which also references SI NO. 78F-21, Rev. F. Additionally,
SI NO. 78F-21, Rev. F allows credit for communications from PW as a
means to accept new blades that meet the intent of SI NO. 78F-21,
Initial Issue and later revisions. The FAA did not change this AD as a
result of this comment.
Request To Clarify Typographical Error in Service Information
Delta requested that the FAA comment or provide guidance related to
on a typographical error contained in the header of pages 3 through 8
of SI NO. 73F-21, Revision B, dated April 10, 2023 (SI NO. 73F-21, Rev.
B). The typographical error incorrectly lists the document as Special
Instruction No. 73F-21 A.
The FAA acknowledges that there is a typographical error contained
in the header of pages 3 through 8 of SI NO. 73F-21, Rev. B which
incorrectly lists the document as Special Instruction No. 73F-21 A.
However, the typographical error does not change the content of the
document, which is only allowed as credit for actions accomplished
prior to the effective date of this AD. Additionally, after the
effective date of this AD, the appropriate service information for the
required actions is PW2000 A72-777 R7, Rev. 2. The FAA did not change
this AD as a result of this comment.
Request To Add Credit Note to AD
Delta requested that the FAA add the following note from SI NO.
73F-21, Rev. B to the NPRM; ``Accomplishment of PW2000 Engine Manual
(Revision 131 or later) 72-52-17 Inspection/Check-14 is equivalent to
the accomplishment of this Special Instruction 73F-21.'' Delta noted
that since SI NO. 73F-21, Rev. B includes the PW2000 Engine Manual
allowance, the same allowance should carry over to previous revisions
of SI NO. 73F-21 that define the actions to correct the unsafe
condition.
The FAA disagrees with the request. Earlier revisions of SI NO.
73F-21 did not contain this note, and the note specifically applies to
SI NO. 73F-21, Rev. B. Additionally, after the effective date of this
AD, the appropriate service information for the required actions is
PW2000 A72-777 R7, Rev. 2. The FAA did not change this AD as a result
of this comment.
Request To Clarify the Required Compliance Times
EAT requested that the FAA update the NPRM to clarify that actions
identified as ``RC'' in, and in accordance with, the Accomplishment
Instructions of PW2000 A72-777, Rev. 2, are one-time actions. EAT
inferred that without this clarification, engines would need to undergo
the required inspections every 1,800 flight cycles, which would limit
the on-wing time for all worldwide engines. FedEx requested that the
FAA revise the NPRM to include a terminating action paragraph. FedEx
pointed out that neither the NPRM nor the required service information
explicitly state that the actions are one-time only.
The FAA agrees to clarify. The actions required by this final rule
are identified as ``RC'' in PW2000 A72-777, Rev. 2, which is the
required service information. While not explicitly stated in either
this final rule or the required service information, those actions are
one-time only and have no stated repetitive compliance times. The FAA
also notes that terminating action paragraphs are used specifically to
terminate repetitive actions. However, the FAA is not mandating
repetitive actions in this AD and, therefore, a terminating action
paragraph is unnecessary. The FAA did not change this AD as a result of
this comment.
Request To Clarify Parts Eligible for Installation
EAT requested that the FAA clarify that parts that were overhauled
using the engine manual prior to the availability of PW2000 A72-777
should be eligible for installation. EAT noted that the NPRM and PW2000
A72-777, Rev. 2 do not mention HPT 2nd stage turbine hub assemblies
which were repaired/overhauled before the initial issue of PW2000 A72-
777 in September 2021. EAT also noted that the parts were overhauled in
accordance with the valid engine manual at that time and therefore
serviceable and eligible for installation.
The FAA agrees to clarify. Parts that were overhauled using the
engine manual prior to the availability of PW2000 A72-777 are not
eligible for installation. The FAA is publishing this AD to address a
quality escape on the HPT 2nd stage blade assemblies. Removing the non-
conforming blades and the corresponding HPT 2nd stage turbine hub from
service is necessary to correct the unsafe condition. If the actions
performed prior to the effective date of this AD do not meet the
definition of a part eligible for installation, the part cannot be
installed on an engine. Additionally, the FAA has included credit for
previous actions, using certain service information, in paragraph (h)
of this AD, provided that those actions were done before the effective
date of this AD. The FAA did not change this AD as a result of this
comment.
Request To Reduce Inspection Requirements for Certain Hub Assemblies
EAT requested that the FAA revise the NPRM to allow HPT 2nd stage
turbine hub assemblies removed prior to the initial issue of PW2000
A72-777 to pass only the 100% lug ECI inspection, instead of requiring
all blades previously installed on the hub to pass the visual and
shadowgraph inspection. EAT pointed out that the requirement for all
blades to pass the visual and shadowgraph inspections was not a
mandatory action at that time.
The FAA disagrees with the request. In order to correct the unsafe
condition, the HPT 2nd stage blade assemblies with part number (P/N)
1B7522 must pass the visual and shadowgraph inspections in order to be
considered a part eligible for installation. Additionally, the
serviceability of the HPT 2nd stage turbine hub assembly is dependent
on the blade assemblies passing the visual and shadowgraph inspections.
If the blade assemblies do not pass those inspections, then the HPT 2nd
stage turbine hub assembly also does not pass and becomes
unserviceable. The FAA did not change this AD as a result of this
comment.
Request To Clarify Guidance on Early Inspections Using Engine Manual
FedEx requested that the FAA revise paragraph (g) of the proposed
AD and PW2000 A72-777, Rev. 2, Section 2, Paragraph 1.B. to provide
guidance for operators that began conducting inspections early in
collaboration with the engine manufacturer. FedEx noted that the
general visual inspection requirement for blades installed on engines
with serial numbers listed in Table 1 on page 9 of PW2000 A72-777, Rev.
2 is waived by a Note in Section 2, Paragraph 1.B. of PW2000 A72-777,
Rev. 2. FedEx also noted that some engines were inspected before the
initial release of PW2000 A72-777, before the release of earlier
revisions of the SI, or per existing instructions for continued
airworthiness that were published at the time which makes it impossible
to directly claim compliance with the actions identified as ``RC''
within the Accomplishment Instructions of PW2000 A72-777, Rev. 2. FedEx
also provided the following example: some
[[Page 56201]]
engines were inspected per PW2000 Engine Manual 72-52-15, Insp/Chk -06
(Firtree ECI) and 72-52-17, Insp/Chk -14 (blade shadowgraph) in the
period between February, 2021 and September, 2021 (prior to their
October 1, 2021 revision date).
The FAA agrees to provide guidance for operators that performed
early inspections in collaboration with the engine manufacturer. Credit
for compliance with the Firtree ECI can only be claimed if 100% of the
slots were inspected. Credit may not be claimed for the previous ECI of
the HPT T2 hub slots for the period between February 2021 and September
2021 because those instructions only required 25% of the slots to be
inspected, which does not fully mitigate the unsafe condition. The FAA
notes that the final field management plan to address this unsafe
condition is described in this AD. The FAA did not change this AD as a
result of this comment.
Request To Clarify Inspections for Mixed Blade Engines
MTU requested that the FAA clarify how to address inspections for
engines that have a mix of affected and unaffected HPT 2nd stage blade
assemblies installed. MTU notes that PW2000 SB 72-775 allows
interchangeability of old and new blade assemblies (differentiated by
P/N). MTU also inferred that the NPRM is not applicable to an engine
which has installed all 64 HPT 2nd stage blade assemblies having P/N
1B8722 in post PW2000 SB 72-775 configuration.
Engines with a mix of affected and unaffected HPT 2nd stage blade
assemblies installed must perform the required inspections on the
affected blades having P/N 1B7522 only, and 100% of the HPT T2 hub
slots. HPT T2 hubs that fail the ECI on any slot must be removed from
service. P/N 1B8722 blade assemblies are not required to perform the
inspections required by this AD. If an engine has 64 HPT 2nd stage
blade assemblies having P/N 1B8722 installed, then this AD is not
applicable to that engine. The FAA did not change this AD as a result
of this comment.
Request To Clarify Credit for Inspections Using Initial Release of SI
NO. 73F-21
MTU requested that the FAA provide credit for previous actions done
in accordance with SI NO. 73F-21, Initial Issue, dated April 6, 2021,
or earlier.
The FAA agrees with the request and has updated paragraph (h) of
this AD to provide credit for the required actions done before the
effective date of this AD using SI NO. 78F-21, dated April 12, 2021.
However, operators that prefer to address the unsafe condition by means
other than those specified in the referenced service information may
request an AMOC in accordance with paragraph (i) of this AD.
Request To Change Compliance Time
UPS requested that the FAA revise the NPRM to allow a longer
compliance time. UPS noted that PW part shortages and supply chain
constraints have resulted in long lead times. UPS also stated that the
required compliance times are not adequate to maintain PW2000 engine
spare levels, which would negatively impact UPS operations.
The FAA disagrees with the request to allow a longer compliance
time in this AD. In developing an appropriate compliance time, the FAA
considered the urgency associated with the subject unsafe condition,
the availability of required parts, and the practical aspect of
accomplishing the required modification within a period of time that
corresponds to the normal scheduled maintenance for most affected
operators. The FAA has determined that the compliance time provides an
acceptable level of safety. However, under the provisions of paragraph
(i) of this AD, the FAA will consider requests for an extension of the
compliance time if sufficient data are submitted to substantiate that
the change would provide an acceptable level of safety. The FAA did not
change this AD as a result of this comment.
Conclusion
The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes, and
any other changes described previously, this AD is adopted as proposed
in the NPRM. None of the changes will increase the economic burden on
any operator.
Related Service Information Under 1 CFR Part 51
The FAA reviewed PW2000 A72-777, Rev. 2, which specifies procedures
for performing a visual inspection of the HPT 2nd stage blade
assemblies for missing contact marks, dimensional shadowgraph
inspection of the HPT 2nd stage blade assemblies for dimensional
deviations, and an ECI of the HPT 2nd stage turbine hub assembly for
conforming slot flatness. This service information also specifies
removal from service of any HPT 2nd stage turbine hub assembly or HPT
2nd stage blade assembly that does not pass any inspection. 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.
Costs of Compliance
The FAA estimates that this AD affects 425 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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ECI of the HPT 2nd stage turbine hub 8 work-hours x $85 per $0 $680 $289,000
assembly. hour = $680.
Visual Inspection of the HPT 2nd stage 8 work-hours x $85 per 0 680 289,000
blade assembly. hour = $680.
Dimensional shadowgraph inspection of 8 work-hours x $85 per 0 680 289,000
HPT 2nd stage blade assemblies. hour = $680.
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The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
inspections. The agency has no way of determining the number of
aircraft that might need these replacements:
[[Page 56202]]
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Replace HPT 2nd stage turbine hub assembly.... 0 work-hours x $85 per hour = $0 $456,000 $456,000
Replace HPT 2nd stage blade assembly.......... 0 work-hours x $85 per hour = $0 17,000 17,000
----------------------------------------------------------------------------------------------------------------
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
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 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 adding the following new airworthiness
directive:
2024-12-04 Pratt & Whitney: Amendment 39-22768; Docket No. FAA-2023-
1640; Project Identifier AD-2022-00283-E.
(a) Effective Date
This airworthiness directive (AD) is effective August 13, 2024.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Pratt & Whitney (PW) Model PW2037, PW2037M,
and PW2040 engines with a high-pressure turbine (HPT) 2nd stage
blade assembly, part number (P/N) 1B7522 installed.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by an in-flight shutdown caused by the
fracture of HPT 2nd stage turbine hub assembly lugs. The FAA is
issuing this AD to prevent failure of the HPT 2nd stage turbine hub
assembly lug and HPT 2nd stage blade assemblies. The unsafe
condition, if not addressed, could result in the uncontained release
of the HPT 2nd stage blade assemblies, damage to the engine, and
damage to the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
Before exceeding the applicable compliance times specified in
Planning Information, Compliance, page 2, of PW Alert Service
Bulletin PW2000 A72-777, Revision 2, dated April 11, 2023 (PW2000
A72-777, Rev. 2), or before accumulating 500 cycles after the
effective date of this AD, whichever occurs later, perform all
applicable actions identified as ``RC'' (required for compliance)
in, and in accordance with, the Accomplishment Instructions of
PW2000 A72-777, Rev. 2.
(h) Credit for Previous Actions
You may take credit for the inspections required by paragraph
(g) of this AD if you performed those inspections before the
effective date of this AD using PW Alert Service Bulletin PW2000
A72-777, Revision 1, dated December 21, 2022, PW Special Instruction
(SI) NO. 62F-21, Initial Issue, dated June 7, 2021, or PW SI NO.
62F-21A, dated October 4, 2021.
You may take credit for the inspection specified in Section 1,
paragraph 1.B. of the Accomplishment Instructions of PW2000 A72-777,
Rev. 2, which is required by paragraph (g) of this AD, if you
performed the inspection before the effective date of this AD using
PW SI NO. 73F-21, Initial Issue, dated April 6, 2021, or PW SI NO.
73F-21, Revision A, dated September 29, 2021.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, AIR-520 Continued Operational Safety 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, AIR-520 Continued Operational
Safety Branch, send it to the attention of the person identified in
paragraph (j) of this AD and email to: [email protected].
(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.
(3) For service information that contains steps that are labeled
as Required for Compliance (RC), the following provisions apply.
(i) The steps labeled as RC, including substeps under an RC step
and any figures identified in an RC step, must be done to comply
with the AD. An AMOC is required for any deviations to RC steps,
including substeps and identified figures.
(ii) Steps not labeled as RC may be deviated from using accepted
methods in accordance with the operator's maintenance or inspection
program without obtaining approval of an AMOC, provided the RC
steps, including substeps and identified figures, can still be done
as specified, and the airplane can be put back in an airworthy
condition.
(j) Additional Information
For more information about this AD, contact Carol Nguyen,
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
WA 98198; phone: (781) 238-7655; email: [email protected].
[[Page 56203]]
(k) 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 PW2000 A72-777,
Revision 2, dated April 11, 2023.
(ii) [Reserved]
(3) For Pratt & Whitney service information, contact Pratt &
Whitney, 400 Main Street, East Hartford, CT 06118; phone: (800) 565-
0140; email: [email protected]; website: connect.prattwhitney.com.
(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 (817) 222-5110.
(5) You may view this material at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
Issued on June 11, 2024.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2024-14936 Filed 7-8-24; 8:45 am]
BILLING CODE 4910-13-P