Airworthiness Directives; General Electric Company Turbofan Engines, 75181-75185 [2022-26579]
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Federal Register / Vol. 87, No. 235 / Thursday, December 8, 2022 / Proposed Rules
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new airworthiness
directive:
■
The Boeing Company: Docket No. FAA–
2022–1312; Project Identifier AD–2022–
00551–T.
(a) Comments Due Date
The FAA must receive comments on this
airworthiness directive (AD) by January 23,
2023.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company
Model 777–200, –200LR, –300, –300ER, and
777F airplanes, certificated in any category,
as identified in Boeing Alert Requirements
Bulletin 777–53A0098 RB, dated April 5,
2022.
(d) Subject
Air Transport Association (ATA) of
America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by reports of cracks
found in the station (STA) 2370 pivot
bulkhead forward outer chord. Analysis
revealed higher bending stresses across the
chord than originally assessed. The FAA is
issuing this AD to address cracking in the
STA 2370 pivot bulkhead forward outer
chord. Such cracking, if not detected and
corrected, could result in a severed pivot
bulkhead outer chord, loss of horizontal
stabilizer control, and loss of controllability
of the airplane.
(f) Compliance
Comply with this AD within the
compliance times specified, unless already
done.
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(g) Required Actions
Except as specified by paragraph (h) of this
AD: At the applicable times specified in the
‘‘Compliance’’ paragraph of Boeing Alert
Requirements Bulletin 777–53A0098 RB,
dated April 5, 2022, do all applicable actions
identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert
Requirements Bulletin 777–53A0098 RB,
dated April 5, 2022.
Note 1 to paragraph (g): Guidance for
accomplishing the actions required by this
AD can be found in Boeing Alert Service
Bulletin 777–53A0098, dated April 5, 2022,
which is referred to in Boeing Alert
Requirements Bulletin 777–53A0098 RB,
dated April 5, 2022.
(h) Exceptions to Service Information
Specifications
(1) Where the Compliance Time columns
of the tables in the ‘‘Compliance’’ paragraph
of Boeing Alert Requirements Bulletin 777–
53A0098 RB, dated April 5, 2022, use the
phrase ‘‘the original issue date of
Requirements Bulletin 777–53A0098 RB,’’
this AD requires using ‘‘the effective date of
this AD.’’
(2) Where Boeing Alert Requirements
Bulletin 777–53A0098 RB, dated April 5,
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2022, specifies contacting Boeing for repair
instructions: This AD requires doing the
repair using a method approved in
accordance with the procedures specified in
paragraph (i) of this AD.
(i) Alternative Methods of Compliance
(AMOCs)
(1) The Manager, Seattle ACO 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 responsible Flight
Standards Office, as appropriate. If sending
information directly to the manager of the
certification office, send it to the attention of
the person identified in paragraph (j) of this
AD. Information may be emailed to: 9-ANMSeattle-ACO-AMOC-Requests@faa.gov.
(2) Before using any approved AMOC,
notify your appropriate principal inspector,
or lacking a principal inspector, the manager
of the responsible Flight Standards Office.
(3) An AMOC that provides an acceptable
level of safety may be used for any repair,
modification, or alteration required by this
AD if it is approved by The Boeing Company
Organization Designation Authorization
(ODA) that has been authorized by the
Manager, Seattle ACO Branch, FAA, to make
those findings. To be approved, the repair
method, modification deviation, or alteration
deviation must meet the certification basis of
the airplane, and the approval must
specifically refer to this AD.
(j) Related Information
For more information about this AD,
contact Luis Cortez-Muniz, Aerospace
Engineer, Airframe Sections, FAA, Seattle
ACO Branch, 2200 South 216th St., Des
Moines, WA 98198; phone and fax: 206–231–
3958; email: luis.a.cortez-muniz@faa.gov.
(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) Boeing Alert Requirements Bulletin
777–53A0098 RB, dated April 5, 2022.
(ii) [Reserved]
(3) For service information identified in
this AD, contact Boeing Commercial
Airplanes, Attention: Contractual & Data
Services (C&DS), 2600 Westminster Blvd.,
MC 110–SK57, Seal Beach, CA 90740–5600;
telephone 562–797–1717; website
myboeingfleet.com.
(4) You may view this service information
at the FAA, Airworthiness Products Section,
Operational Safety Branch, 2200 South 216th
St., Des Moines, WA. For information on the
availability of this material at the FAA, call
206–231–3195.
(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,
fr.inspection@nara.gov, or go to:
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75181
www.archives.gov/federal-register/cfr/ibrlocations.html.
Issued on October 21, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2022–26591 Filed 12–7–22; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2022–1416; Project
Identifier AD–2022–00725–E]
RIN 2120–AA64
Airworthiness Directives; General
Electric Company Turbofan Engines
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
The FAA proposes to
supersede Airworthiness Directive (AD)
2012–02–07, which applies to certain
General Electric Company (GE) CF6–45
and CF6–50 series model turbofan
engines with a specified low-pressure
turbine (LPT) rotor stage 3 disk
installed. AD 2012–02–07 requires
inspections of high-pressure turbine
(HPT) and LPT rotors, engine checks,
vibration surveys, an optional LPT rotor
stage 3 disk removal after a failed HPT
blade borescope inspection (BSI) or a
failed engine core vibration survey,
establishes a lower life limit for the
affected LPT rotor stage 3 disks, and
requires removing these disks from
service at times determined by a
drawdown plan. Since the FAA issued
AD 2012–02–07, four additional events
of separation of the LPT rotor assembly
have been reported resulting in the LPT
rotor assembly departing the rear of the
engine. The manufacturer has improved
the design of the LPT rotor stage 3 disk.
This proposed AD would continue to
require inspections of HPT and LPT
rotor stage 1 and stage 2 blades,
vibration surveys, and use of a lower life
limit for the affected LPT rotor stage 3
disks. As a terminating action to the
inspections, engine checks, and
vibration surveys, this proposed AD
would require removal and replacement
of the LPT rotor stage 3 disk with a
redesigned LPT rotor stage 3 disk. This
proposed AD would also revise the
compliance time of the drawdown plan
for the removal and replacement of the
LPT rotor stage 3 disk. This proposed
AD would also prohibit the installation
SUMMARY:
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Federal Register / Vol. 87, No. 235 / Thursday, December 8, 2022 / Proposed Rules
or reinstallation of certain LPT rotor
stage 3 disks. The FAA is proposing this
AD to address the unsafe condition on
these products.
DATES: The FAA must receive comments
on this proposed AD by January 23,
2023.
You may send comments,
using the procedures found in 14 CFR
11.43 and 11.45, by any of the following
methods:
• Federal eRulemaking Portal: Go to
regulations.gov. Follow the instructions
for submitting comments.
• Fax: (202) 493–2251.
• Mail: U.S. Department of
Transportation, Docket Operations, M–
30, West Building Ground Floor, Room
W12–140, 1200 New Jersey Avenue SE,
Washington, DC 20590.
• Hand Delivery: Deliver to Mail
address above between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays.
AD Docket: You may examine the AD
docket at regulations.gov by searching
for and locating Docket No. FAA–2022–
1416; 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 NPRM, any
comments received, and other
information. The street address for
Docket Operations is listed above.
FOR FURTHER INFORMATION CONTACT:
Sungmo Cho, Aviation Safety Engineer,
ECO Branch, FAA, 1200 District
Avenue, Burlington, MA 01803; phone:
(781) 238–7241; email: Sungmo.D.Cho@
faa.gov.
SUPPLEMENTARY INFORMATION:
ADDRESSES:
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Comments Invited
The FAA invites you to send any
written relevant data, views, or
arguments about this proposal. Send
your comments to an address listed
under ADDRESSES. Include ‘‘Docket No.
FAA–2022–1416; Project Identifier AD–
2022–00725–E’’ at the beginning of your
comments. The most helpful comments
reference a specific portion of the
proposal, explain the reason for any
recommended change, and include
supporting data. The FAA will consider
all comments received by the closing
date and may amend the proposal
because of those comments.
Except for Confidential Business
Information (CBI) as described in the
following paragraph, and other
information as described in 14 CFR
11.35, the FAA will post all comments
received, without change, to
regulations.gov, including any personal
information you provide. The agency
will also post a report summarizing each
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substantive verbal contact received
about this NPRM.
Confidential Business Information
CBI is commercial or financial
information that is both customarily and
actually treated as private by its owner.
Under the Freedom of Information Act
(FOIA) (5 U.S.C. 552), CBI is exempt
from public disclosure. If your
comments responsive to this NPRM
contain commercial or financial
information that is customarily treated
as private, that you actually treat as
private, and that is relevant or
responsive to this NPRM, it is important
that you clearly designate the submitted
comments as CBI. Please mark each
page of your submission containing CBI
as ‘‘PROPIN.’’ The FAA will treat such
marked submissions as confidential
under the FOIA, and they will not be
placed in the public docket of this
NPRM. Submissions containing CBI
should be sent to Sungmo Cho, Aviation
Safety Engineer, ECO Branch, FAA,
1200 District Avenue, Burlington, MA
01803. Any commentary that the FAA
receives which is not specifically
designated as CBI will be placed in the
public docket for this rulemaking.
Background
The FAA issued AD 2012–02–07,
Amendment 39–16930 (77 FR 4650,
January 31, 2012) (AD 2012–02–07), for
GE CF6–45A, CF6–45A2, CF6–50A,
CF6–50C, CF6–50CA, CF6–50C1, CF6–
50C2, CF6–50C2B, CF6–50C2D, CF6–
50E, CF6–50E1, CF6–50E2, and CF6–
50E2B model turbofan engines,
including engines marked on the engine
data plate as CF6–50C2–F and CF6–
50C2–R, with a specified LPT rotor stage
3 disk, identified by part number (P/N),
installed. AD 2012–02–07 superseded
AD 2011–02–07, Amendment 39–16580
(76 FR 6323, February 4, 2011) and AD
2011–18–01, Amendment 39–16783 (76
FR 52213, August 22, 2011). AD 2012–
02–07 was prompted by the
determination that a new lower life
limit for the affected LPT rotor stage 3
disks was necessary. AD 2012–02–07
retained the requirements of the two
superseded ADs, which required
inspections of HPT and LPT rotors,
ultrasonic inspection (UI) of the LPT
rotor stage 3 disk forward spacer arm,
exhaust gas temperature (EGT)
resistance check, EGT thermocouple
inspection, cleaning, fluorescentpenetrant inspection (FPI) of the LPT
rotor stage 3 disk, engine checks, and
vibration surveys. AD 2012–02–07 also
added an optional LPT rotor stage 3 disk
removal after a failed HPT BSI or a
failed engine core vibration survey,
established a new lower life limit for the
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Sfmt 4702
affected LPT rotor stage 3 disks, and
required removing those disks from
service at times determined by a
drawdown plan. The agency issued AD
2012–02–07 to prevent critical lifelimited rotating engine part failure,
which could result in an uncontained
engine failure and damage to the
airplane.
Actions Since AD 2012–02–07 Was
Issued
Since the FAA issued AD 2012–02–
07, the FAA has received reports of four
additional events of separation of the
LPT rotor assembly, which resulted in
the LPT rotor assembly departing the
rear of the engine. Following the most
recent separation event, the FAA
determined that due to the complexity
of AD 2012–02–07, the limitations of
certain operators to access required
equipment and training needed to
accomplish the inspections, and the
manufacturer’s redesign of the LPT rotor
stage 3 disk, AD 2012–02–07 should be
superseded. The redesigned LPT rotor
stage 3 disk, P/N 2453M80P01, has a
thicker forward spacer arm, which
reduces stress on the forward arm area
and increases its high cycle fatigue
alternating stress capability.
Accordingly, the FAA is proposing to
require the replacement of the affected
LPT rotor stage 3 disk with a redesigned
LPT rotor stage 3 disk, P/N
2453M80P01, as a terminating action to
the HPT blade inspection, vibration
survey, UI, EGT resistance check, EGT
thermocouple inspection, cleaning, and
FPI. This proposed AD would also
revise the installation prohibition for
affected LPT rotor stage 3 disks. AD
2012–02–07 prohibited the installation
or reinstallation of an affected LPT rotor
stage 3 disk if it had exceeded 6,200
cycles since new. This proposed AD
would prohibit installing an affected
LPT rotor stage 3 disk onto any engine.
FAA’s Determination
The FAA is issuing this NPRM after
determining that the unsafe condition
described previously is likely to exist or
develop on other products of the same
type designs.
Proposed AD Requirements in This
NPRM
This proposed AD would retain
certain requirements of AD 2012–02–07.
As a terminating action to the HPT
blade inspection, vibration survey, UI,
EGT resistance check, EGT
thermocouple inspection, cleaning, and
FPI of the LPT rotor stage 3 disk, this
proposed AD would require removal
and replacement of the LPT rotor stage
3 disk with improved design LPT rotor
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Federal Register / Vol. 87, No. 235 / Thursday, December 8, 2022 / Proposed Rules
stage 3 disk P/N 2453M80P01 within 18
months of the effective date of the AD.
This proposed AD would also prohibit
the installation or reinstallation of
certain LPT rotor stage 3 disks on any
engine.
75183
engines installed on airplanes of U.S.
registry.
The FAA estimates the following
costs to comply with this proposed AD:
Costs of Compliance
The FAA estimates that this AD, if
adopted as proposed, would affect 26
ESTIMATED COSTS
Cost per
product
Labor cost
HPT blade inspection, vibration survey, UI,
EGT resistance check, EGT thermocouple
inspection, cleaning and FPI of the LPT
rotor stage 3 disk.
Remove and replace LPT rotor stage 3 disk
28 work-hours × $85 per hour = $2,380 ........
$0
$2,380
$61,880
620 work-hours × $85 per hour = $52,700 ....
276,300
329,000
8,554,000
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
The FAA determined that this
proposed AD would not have federalism
implications under Executive Order
13132. This proposed AD would not
have a substantial direct effect on the
States, on the relationship between the
Parts cost
Cost on U.S.
operators
Action
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 the proposed regulation:
(1) Is not a ‘‘significant regulatory
action’’ under Executive Order 12866,
(2) Would not affect intrastate
aviation in Alaska, and
(3) Would 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.
1. The authority citation for part 39
continues to read as follows:
■
Authority: 49 U.S.C. 106(g), 40113, 44701.
[Amended]
2. The FAA amends § 39.13 by:
a. Removing Airworthiness Directive
AD 2012–02–07, Amendment 39–16930
(77 FR 4650, January 31, 2012); and
■ b. Adding the following new
airworthiness directive:
■
■
General Electric Company: Docket No. FAA–
2022–1416; Project Identifier AD–2022–
00725–E.
(a) Comments Due Date
The FAA must receive comments on this
airworthiness directive (AD) action by
January 23, 2023.
(b) Affected ADs
The Proposed Amendment
Accordingly, under the authority
delegated to me by the Administrator,
the FAA proposes to amend 14 CFR part
39 as follows:
PART 39—AIRWORTHINESS
DIRECTIVES
§ 39.13
This AD replaces AD 2012–02–07,
Amendment 39–16930 (77 FR 4650, January
31, 2012) (AD 2012–02–07).
(c) Applicability
This AD applies to General Electric
Company (GE) CF6–45A, CF6–45A2, CF6–
50A, CF6–50C, CF6–50CA, CF6–50C1, CF6–
50C2, CF6–50C2B, CF6–50C2D, CF6–50E,
CF6–50E1, CF6–50E2, and CF6–50E2B model
turbofan engines, including engines marked
on the engine data plate as CF6–50C2–F and
CF6–50C2–R, with an installed low-pressure
turbine (LPT) rotor stage 3 disk having a part
number listed in Table 1 to paragraph (c) of
this AD.
TABLE 1 TO PARAGRAPH (c)—APPLICABLE LPT ROTOR STAGE 3 DISK PART NUMBERS
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9061M23P06
9061M23P10
9061M23P12
1479M75P02
1479M75P07
1479M75P14
9061M23P07
1473M90P01
9061M23P14
1479M75P03
1479M75P08
N/A
(d) Subject
Joint Aircraft System Component (JASC)
Code 7250, Turbine Section.
(e) Unsafe Condition
This AD was prompted by the occurrence
of four events of separation of the LPT rotor
assembly, occurring after the effective date of
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9061M23P08
1473M90P02
9061M23P15
1479M75P04
1479M75P09
N/A
9061M23P09
1473M90P03
9061M23P16
1479M75P05
1479M75P11
N/A
AD 2012–02–07, which resulted in the LPT
rotor assembly departing the rear of the
engine. The FAA is issuing this AD to
prevent critical life-limited rotating engine
part failure. The unsafe condition, if not
addressed, could result in an uncontained
engine failure and damage to the airplane.
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9224M75P01
1473M90P04
1479M75P01
1479M75P06
1479M75P13
N/A
(f) Compliance
Comply with this AD within the
compliance times specified, unless already
done.
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Federal Register / Vol. 87, No. 235 / Thursday, December 8, 2022 / Proposed Rules
(g) Required Actions
(1) Borescope Inspections (BSI) of HighPressure Turbine (HPT) Rotor Stage 1 and
Stage 2 Blades:
For the BSIs required by paragraphs
(g)(1)(i) through (iii) of this AD, inspect the
blades from the forward and aft directions.
Inspect all areas of the blade airfoil. The
inspection must include blade leading and
trailing edges and their convex and concave
airfoil surfaces. Inspect for signs of impact,
cracking, burning, damage, and distress.
(i) Within 75 cycles since last inspection
(CSLI) or before further flight, whichever
occurs later, perform an initial BSI of the
HPT rotor stage 1 and stage 2 blades.
(ii) Thereafter, within every 75 CSLI, repeat
the BSI of the HPT rotor stage 1 and stage 2
blades.
(iii) Within the cycle limits after the engine
has experienced any of the events specified
in Table 1 to paragraph (g)(1) of this AD,
borescope-inspect the HPT rotor stage 1 and
stage 2 blades.
(iv) If the engine fails any of the BSIs
required by this AD, before further flight,
remove the engine from service.
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TABLE 2 TO PARAGRAPH (g)(1)—CONDITIONAL BSI CRITERIA
If the engine has experienced:
Then borescope inspect:
(i) An exhaust gas temperature (EGT) above redline ...................................................................................................
(ii) A shift in the smoothed EGT trending data that exceeds 18 °F (10 °C), but is less than or equal to 36 °F (20
°C).
(iii) A shift in the smoothed EGT trending data that exceeds 36 °F (20 °C) ................................................................
(iv) Two consecutive raw EGT trend data points that exceed 18 °F (10 °C), but are less than or equal to 36 °F (20
°C), above the smoothed average.
(v) Two consecutive raw EGT trend data points that exceed 36 °F (20 °C) above the smoothed average ...............
Within 10 cycles.
Within 10 cycles.
(2) Engines with Damaged HPT Rotor
Blades:
For those engines that fail any BSI
requirements of this AD, before returning the
engine to service, accomplish the actions
required by paragraph (g)(2)(i) or (ii) of this
AD:
(i) Remove the LPT rotor stage 3 disk from
service; or
(ii) Perform a fluorescent-penetrant
inspection (FPI) of the inner diameter surface
forward cone body (forward spacer arm) of
the LPT rotor stage 3 disk as specified in
paragraphs (g)(6)(i)(A) through (C) of this AD.
(3) EGT Thermocouple Probe Inspections.
(i) Within 750 CSLI, or before further flight,
whichever occurs later, inspect the EGT
thermocouple probe for damage.
Note 1 to paragraph (g)(3)(i): Damage to
the EGT thermocouple probe may be
indicated by wear through the thermocouple
guide sleeve or contact between the turbine
mid-frame liner and the EGT thermocouple
probe.
(ii) Thereafter, within every 750 CSLI, reinspect the EGT thermocouple probe for
damage.
(iii) If any EGT thermocouple probe shows
wear through the thermocouple guide sleeve
or contact between the turbine mid-frame
liner and the EGT thermocouple probe,
before further flight, remove and replace the
EGT thermocouple probe and ensure the
turbine mid-frame liner does not contact the
EGT thermocouple probe.
(4) EGT System Resistance Checks.
(i) Within 750 cycles since the last
resistance check on the EGT system or before
further flight, whichever occurs later,
perform an EGT system resistance check.
(ii) Thereafter, within every 750 cycles
since the last resistance check, repeat the
EGT system resistance check.
(iii) If an EGT system component fails the
resistance system check, before further flight,
remove and replace, or repair the EGT system
component.
(5) Engine Core Vibration Survey.
(i) Within 350 cycles since the last engine
core vibration survey or before further flight,
whichever occurs later, perform an initial
engine core vibration survey.
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(ii) Use about a one-minute acceleration
and a one-minute deceleration of the engine
between ground idle and 84% N2 (about
8,250 rpm) to perform the engine core
vibration survey.
(iii) Use a spectral/trim balance analyzer or
equivalent to measure the N2 rotor vibration.
(iv) If the vibration level is above 5 mils
Double Amplitude then, before further flight,
remove the engine from service.
(v) For those engines that fail any engine
core vibration survey requirements of this
AD, then before returning the engine to
service:
(A) Remove the LPT rotor stage 3 disk from
service; or
(B) Perform an FPI of the inner diameter
surface forward spacer arm of the LPT rotor
stage 3 disk as specified in paragraph
(g)(6)(i)(A) through (C) of this AD.
(vi) Thereafter, within every 350 cycles
since the last engine core vibration survey,
perform the engine core vibration survey as
required in paragraphs (g)(5)(i) through (v) of
this AD.
(vii) If the engine has experienced any
vibration reported by maintenance or flight
crew that is suspected to be caused by the
engine core (N2), within 10 cycles after the
report, perform the engine core vibration
survey as required in paragraphs (g)(5)(i)
through (v) of this AD.
(viii) Vibration surveys carried out in an
engine test cell as part of an engine manual
performance run fulfill the vibration survey
requirements of paragraphs (g)(5)(ii) and (iii)
of this AD.
(6) Initial and Repetitive FPI of LPT Rotor
Stage 3 Disk.
(i) At the next shop visit after accumulating
1,000 cycles since the last FPI of the LPT
rotor stage 3 disk forward spacer arm or
before further flight, whichever occurs later:
(A) Clean the LPT rotor stage 3 disk
forward spacer arm, including the use of a
wet-abrasive blast, to eliminate residual or
background fluorescence.
(B) Perform an FPI of the LPT rotor stage
3 disk forward spacer arm for cracks and for
a band of fluorescence. Include all areas of
the disk forward spacer arm and the inner
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Before further flight.
Within 10 cycles.
Before further flight.
diameter surface forward spacer arm of the
LPT rotor stage 3 disk.
(C) If a crack or a band of fluorescence is
present, before further flight, remove the disk
from service.
(ii) Thereafter, at each engine shop visit
that occurs after accumulating 1,000 cycles
since the last FPI of the LPT rotor stage 3 disk
forward spacer arm, clean and perform an
FPI of the LPT rotor stage 3 disk forward
spacer arm, as specified in paragraph
(g)(6)(i)(A) through (C) of this AD.
(7) Removal of LPT Rotor Stage 3 Disk.
(i) For any installed LPT rotor stage 3 disk
having a part number listed in Table 1 to
paragraph (c) of this AD, at the first
occurrence of any one of the conditions
identified in paragraphs (g)(7)(i)(A) through
(C) of this AD, remove the LPT rotor stage 3
disk from service and replace with LPT rotor
stage 3 disk part number 2453M80P01.
(A) For a disk that has accumulated fewer
than 3,200 cycles since new (CSN) as of
March 6, 2012 (the effective date of AD 2012–
02–07), remove the disk from service before
accumulating 6,200 CSN.
(B) For a disk that accumulated 3,200 or
more CSN as of March 6, 2012 (the effective
date of AD 2012–02–07), do the actions
required by paragraphs (g)(7)(i)(B)(1) or (2) of
this AD, as applicable to your engine.
(1) If the engine has a shop visit before the
disk accumulates 6,200 CSN, remove the disk
from service at that shop visit.
(2) If the engine does not have a shop visit
before the disk accumulates 6,200 CSN,
remove the disk from service at the next shop
visit after accumulating 6,200 CSN, not to
exceed 3,000 cycles from March 6, 2012 (the
effective date of AD 2012–02–07).
(C) Before exceeding 18 months from the
effective date of this AD.
(h) Terminating Action
Replacement of the LPT rotor stage 3 disk
in accordance with paragraph (g)(7) of this
AD constitutes terminating action for the
inspections, engine checks and vibration
surveys required by paragraphs (g)(1) through
(6) of this AD.
E:\FR\FM\08DEP1.SGM
08DEP1
Federal Register / Vol. 87, No. 235 / Thursday, December 8, 2022 / Proposed Rules
(i) Installation Prohibition
After the effective date of this AD, do not
install or reinstall onto any engine an LPT
rotor stage 3 disk listed in Table 1 to
paragraph (c) of this AD that has
accumulated 6,200 CSN or more.
(j) Definitions
(1) For the purposes of this AD, an EGT
above redline is a confirmed overtemperature indication that is not a result of
EGT system error.
(2) For the purposes of this AD, a shift in
the smoothed EGT trending data is a shift in
a rolling average of EGT readings that can be
confirmed by a corresponding shift in the
trending of fuel flow or fan speed/core speed
(N1/N2) relationship. You can find further
guidance about evaluating EGT trend data in
GE Company Service Rep Tip 373
’’Guidelines For Parameter Trend
Monitoring.’’
(3) For the purposes of this AD, an engine
shop visit is the induction of an engine into
the shop, where the separation of a major
engine flange occurs; except the following
maintenance actions, or any combination, are
not considered engine shop visits:
(i) Induction of an engine into a shop
solely for removal of the compressor top or
bottom case for airfoil maintenance or
variable stator vane bushing replacement.
(ii) Induction of an engine into a shop
solely for removal or replacement of the stage
1 fan disk.
(iii) Induction of an engine into a shop
solely for replacement of the turbine rear
frame.
(iv) Induction of an engine into a shop
solely for replacement of the accessory
gearbox or transfer gearbox, or both.
(v) Induction of an engine into a shop
solely for replacement of the fan forward
case.
(4) For the purposes of this AD, a raw EGT
trend data point above the smoothed average
is a confirmed temperature reading over the
rolling average of EGT readings that is not a
result of EGT system error.
lotter on DSK11XQN23PROD with PROPOSALS1
(k) Credit for Previous Actions
You may take credit for the actions
required by paragraph (g) of this AD if they
were performed before the effective date of
this AD using GE Service Bulletin (SB) No.
CF6–50 SB 72–1315, Initial Issue, dated June
3, 2011, or GE SB No. CF6–50 SB 72–1315,
Revision 1, dated June 30, 2011.
(l) 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 certification office,
send it to the attention of the person
identified in paragraph (m) of this AD and
email it to: ANE-AD-AMOC@faa.gov.
(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.
VerDate Sep<11>2014
16:17 Dec 07, 2022
Jkt 259001
(3) AMOCs approved previously for AD
2010–12–10, Amendment 39–16331 (75 FR
32649, June 9, 2010), AD 2011–02–07,
Amendment 39–16580 (76 FR 6323, February
4, 2011), or AD 2011–18–01, Amendment 39–
16783 (76 FR 52213, August 22, 2011) are
approved as AMOCs for the corresponding
provisions of this AD.
(m) Related Information
For more information about this AD,
contact Sungmo Cho, Aviation Safety
Engineer, ECO Branch, FAA, 1200 District
Avenue, Burlington, MA 01803; phone: (781)
238–7241; email: Sungmo.D.Cho@faa.gov.
(n) Material Incorporated by Reference
None.
Issued on November 3, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2022–26579 Filed 12–7–22; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF THE TREASURY
Internal Revenue Service
26 CFR Part 1
[REG–106134–22]
RIN 1545–BQ39
Syndicated Conservation Easement
Transactions as Listed Transactions
Internal Revenue Service (IRS),
Treasury.
ACTION: Notice of proposed rulemaking
and notice of public hearing.
AGENCY:
This document contains
proposed regulations that identify
certain syndicated conservation
easement transactions and substantially
similar transactions as listed
transactions, a type of reportable
transaction. Material advisors and
certain participants in these listed
transactions are required to file
disclosures with the IRS and are subject
to penalties for failure to disclose. The
proposed regulations affect participants
in these transactions as well as material
advisors. In addition, while the
proposed regulations exclude qualified
organizations from being treated as
participants or parties to a prohibited
tax shelter transaction subject to excise
tax, this notice of proposed rulemaking
requests comments on whether the final
regulations should remove the exclusion
from the application of the excise tax for
qualified organizations that facilitate
syndicated conservation easement
transactions. Finally, this document
provides notice of a public hearing on
the proposed regulations.
DATES:
SUMMARY:
PO 00000
Frm 00007
Fmt 4702
Sfmt 4702
75185
Comment date: Electronic or written
comments must be received by February
6, 2023.
Public hearing: The public hearing is
scheduled to be held by teleconference
on March 1, 2023, at 10 a.m. ET.
Requests to speak and outlines of topics
to be discussed at the public hearing
must be received by February 6, 2022.
If no outlines are received by February
6, 2023, the public hearing will be
cancelled. Requests to attend the public
hearing must be received by 5 p.m. ET
on February 27, 2023. The telephonic
hearing will be made accessible to
people with disabilities. Requests for
special assistance during the telephonic
hearing must be received by February
24, 2023.
ADDRESSES: Commenters are strongly
encouraged to submit public comments
electronically. Submit electronic
submissions via the Federal
eRulemaking Portal at
www.regulations.gov (indicate IRS and
REG–106134–22). Once submitted to the
Federal eRulemaking Portal, comments
cannot be edited or withdrawn. The
Department of the Treasury (Treasury
Department) and the IRS will publish
any comments to the public docket.
Send paper submissions to:
CC:PA:LPD:PR (REG–106134–22), Room
5203, Internal Revenue Service, P.O.
Box 7604, Ben Franklin Station,
Washington, DC 20044.
For those requesting to speak during
the hearing, send an outline of topic
submissions electronically via the
Federal eRulemaking Portal at
www.regulations.gov (indicate IRS and
REG–106134–22).
Individuals who want to testify by
telephone at the public hearing must
send an email to publichearings@irs.gov
to receive the telephone number and
access code for the hearing. The subject
line of the email must contain the
regulation number REG–106134–22 and
the word TESTIFY. For example, the
subject line may say: Request to
TESTIFY at Hearing for REG–106134–
22. The email should include a copy of
the speaker’s public comments and
outline of topics. Individuals who want
to attend by telephone the public
hearing must also send an email to
publichearings@irs.gov to receive the
telephone number and access code for
the hearing. The subject line of the
email must contain the regulation
number REG–106134–22 and the word
ATTEND. For example, the subject line
may say: Request to ATTEND Hearing
for REG–106134–22. To request special
assistance during the telephonic
hearing, contact the Publications and
Regulations Branch of the Office of
E:\FR\FM\08DEP1.SGM
08DEP1
]]>Agencies
[Federal Register Volume 87, Number 235 (Thursday, December 8, 2022)]
[Proposed Rules]
[Pages 75181-75185]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-26579]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-1416; Project Identifier AD-2022-00725-E]
RIN 2120-AA64
Airworthiness Directives; General Electric Company Turbofan
Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2012-02-07, which applies to certain General Electric Company (GE) CF6-
45 and CF6-50 series model turbofan engines with a specified low-
pressure turbine (LPT) rotor stage 3 disk installed. AD 2012-02-07
requires inspections of high-pressure turbine (HPT) and LPT rotors,
engine checks, vibration surveys, an optional LPT rotor stage 3 disk
removal after a failed HPT blade borescope inspection (BSI) or a failed
engine core vibration survey, establishes a lower life limit for the
affected LPT rotor stage 3 disks, and requires removing these disks
from service at times determined by a drawdown plan. Since the FAA
issued AD 2012-02-07, four additional events of separation of the LPT
rotor assembly have been reported resulting in the LPT rotor assembly
departing the rear of the engine. The manufacturer has improved the
design of the LPT rotor stage 3 disk. This proposed AD would continue
to require inspections of HPT and LPT rotor stage 1 and stage 2 blades,
vibration surveys, and use of a lower life limit for the affected LPT
rotor stage 3 disks. As a terminating action to the inspections, engine
checks, and vibration surveys, this proposed AD would require removal
and replacement of the LPT rotor stage 3 disk with a redesigned LPT
rotor stage 3 disk. This proposed AD would also revise the compliance
time of the drawdown plan for the removal and replacement of the LPT
rotor stage 3 disk. This proposed AD would also prohibit the
installation
[[Page 75182]]
or reinstallation of certain LPT rotor stage 3 disks. The FAA is
proposing this AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by January 23,
2023.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov by
searching for and locating Docket No. FAA-2022-1416; 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 NPRM, any comments
received, and other information. The street address for Docket
Operations is listed above.
FOR FURTHER INFORMATION CONTACT: Sungmo Cho, Aviation Safety Engineer,
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone:
(781) 238-7241; email: [email protected].
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2022-1416; Project Identifier
AD-2022-00725-E'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
the proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
Sungmo Cho, Aviation Safety Engineer, ECO Branch, FAA, 1200 District
Avenue, Burlington, MA 01803. Any commentary that the FAA receives
which is not specifically designated as CBI will be placed in the
public docket for this rulemaking.
Background
The FAA issued AD 2012-02-07, Amendment 39-16930 (77 FR 4650,
January 31, 2012) (AD 2012-02-07), for GE CF6-45A, CF6-45A2, CF6-50A,
CF6-50C, CF6-50CA, CF6-50C1, CF6-50C2, CF6-50C2B, CF6-50C2D, CF6-50E,
CF6-50E1, CF6-50E2, and CF6-50E2B model turbofan engines, including
engines marked on the engine data plate as CF6-50C2-F and CF6-50C2-R,
with a specified LPT rotor stage 3 disk, identified by part number (P/
N), installed. AD 2012-02-07 superseded AD 2011-02-07, Amendment 39-
16580 (76 FR 6323, February 4, 2011) and AD 2011-18-01, Amendment 39-
16783 (76 FR 52213, August 22, 2011). AD 2012-02-07 was prompted by the
determination that a new lower life limit for the affected LPT rotor
stage 3 disks was necessary. AD 2012-02-07 retained the requirements of
the two superseded ADs, which required inspections of HPT and LPT
rotors, ultrasonic inspection (UI) of the LPT rotor stage 3 disk
forward spacer arm, exhaust gas temperature (EGT) resistance check, EGT
thermocouple inspection, cleaning, fluorescent-penetrant inspection
(FPI) of the LPT rotor stage 3 disk, engine checks, and vibration
surveys. AD 2012-02-07 also added an optional LPT rotor stage 3 disk
removal after a failed HPT BSI or a failed engine core vibration
survey, established a new lower life limit for the affected LPT rotor
stage 3 disks, and required removing those disks from service at times
determined by a drawdown plan. The agency issued AD 2012-02-07 to
prevent critical life-limited rotating engine part failure, which could
result in an uncontained engine failure and damage to the airplane.
Actions Since AD 2012-02-07 Was Issued
Since the FAA issued AD 2012-02-07, the FAA has received reports of
four additional events of separation of the LPT rotor assembly, which
resulted in the LPT rotor assembly departing the rear of the engine.
Following the most recent separation event, the FAA determined that due
to the complexity of AD 2012-02-07, the limitations of certain
operators to access required equipment and training needed to
accomplish the inspections, and the manufacturer's redesign of the LPT
rotor stage 3 disk, AD 2012-02-07 should be superseded. The redesigned
LPT rotor stage 3 disk, P/N 2453M80P01, has a thicker forward spacer
arm, which reduces stress on the forward arm area and increases its
high cycle fatigue alternating stress capability.
Accordingly, the FAA is proposing to require the replacement of the
affected LPT rotor stage 3 disk with a redesigned LPT rotor stage 3
disk, P/N 2453M80P01, as a terminating action to the HPT blade
inspection, vibration survey, UI, EGT resistance check, EGT
thermocouple inspection, cleaning, and FPI. This proposed AD would also
revise the installation prohibition for affected LPT rotor stage 3
disks. AD 2012-02-07 prohibited the installation or reinstallation of
an affected LPT rotor stage 3 disk if it had exceeded 6,200 cycles
since new. This proposed AD would prohibit installing an affected LPT
rotor stage 3 disk onto any engine.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type designs.
Proposed AD Requirements in This NPRM
This proposed AD would retain certain requirements of AD 2012-02-
07. As a terminating action to the HPT blade inspection, vibration
survey, UI, EGT resistance check, EGT thermocouple inspection,
cleaning, and FPI of the LPT rotor stage 3 disk, this proposed AD would
require removal and replacement of the LPT rotor stage 3 disk with
improved design LPT rotor
[[Page 75183]]
stage 3 disk P/N 2453M80P01 within 18 months of the effective date of
the AD. This proposed AD would also prohibit the installation or
reinstallation of certain LPT rotor stage 3 disks on any engine.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 26 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
HPT blade inspection, vibration 28 work-hours x $85 per $0 $2,380 $61,880
survey, UI, EGT resistance check, EGT hour = $2,380.
thermocouple inspection, cleaning and
FPI of the LPT rotor stage 3 disk.
Remove and replace LPT rotor stage 3 620 work-hours x $85 per 276,300 329,000 8,554,000
disk. hour = $52,700.
----------------------------------------------------------------------------------------------------------------
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 determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD 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.
For the reasons discussed above, I certify that the proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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 2012-02-07, Amendment 39-16930
(77 FR 4650, January 31, 2012); and
0
b. Adding the following new airworthiness directive:
General Electric Company: Docket No. FAA-2022-1416; Project
Identifier AD-2022-00725-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) action by January 23, 2023.
(b) Affected ADs
This AD replaces AD 2012-02-07, Amendment 39-16930 (77 FR 4650,
January 31, 2012) (AD 2012-02-07).
(c) Applicability
This AD applies to General Electric Company (GE) CF6-45A, CF6-
45A2, CF6-50A, CF6-50C, CF6-50CA, CF6-50C1, CF6-50C2, CF6-50C2B,
CF6-50C2D, CF6-50E, CF6-50E1, CF6-50E2, and CF6-50E2B model turbofan
engines, including engines marked on the engine data plate as CF6-
50C2-F and CF6-50C2-R, with an installed low-pressure turbine (LPT)
rotor stage 3 disk having a part number listed in Table 1 to
paragraph (c) of this AD.
Table 1 to Paragraph (c)--Applicable LPT Rotor Stage 3 Disk Part Numbers
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
9061M23P06 9061M23P07 9061M23P08 9061M23P09 9224M75P01
9061M23P10 1473M90P01 1473M90P02 1473M90P03 1473M90P04
9061M23P12 9061M23P14 9061M23P15 9061M23P16 1479M75P01
1479M75P02 1479M75P03 1479M75P04 1479M75P05 1479M75P06
1479M75P07 1479M75P08 1479M75P09 1479M75P11 1479M75P13
1479M75P14 N/A N/A N/A N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by the occurrence of four events of
separation of the LPT rotor assembly, occurring after the effective
date of AD 2012-02-07, which resulted in the LPT rotor assembly
departing the rear of the engine. The FAA is issuing this AD to
prevent critical life-limited rotating engine part failure. The
unsafe condition, if not addressed, could result in an uncontained
engine failure and damage to the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
[[Page 75184]]
(g) Required Actions
(1) Borescope Inspections (BSI) of High-Pressure Turbine (HPT)
Rotor Stage 1 and Stage 2 Blades:
For the BSIs required by paragraphs (g)(1)(i) through (iii) of
this AD, inspect the blades from the forward and aft directions.
Inspect all areas of the blade airfoil. The inspection must include
blade leading and trailing edges and their convex and concave
airfoil surfaces. Inspect for signs of impact, cracking, burning,
damage, and distress.
(i) Within 75 cycles since last inspection (CSLI) or before
further flight, whichever occurs later, perform an initial BSI of
the HPT rotor stage 1 and stage 2 blades.
(ii) Thereafter, within every 75 CSLI, repeat the BSI of the HPT
rotor stage 1 and stage 2 blades.
(iii) Within the cycle limits after the engine has experienced
any of the events specified in Table 1 to paragraph (g)(1) of this
AD, borescope-inspect the HPT rotor stage 1 and stage 2 blades.
(iv) If the engine fails any of the BSIs required by this AD,
before further flight, remove the engine from
service.[FEDREG][VOL]*[/VOL][NO]*[/NO][DATE]*[/
DATE][PRORULES][PRORULE][PREAMB][AGENCY]*[/AGENCY][SUBJECT]*[/
SUBJECT][/PREAMB][SUPLINF][HED]*[/HED][EXTRACT][P]*[/P]?>
Table 2 to Paragraph (g)(1)--Conditional BSI Criteria
------------------------------------------------------------------------
Then borescope
If the engine has experienced: inspect:
------------------------------------------------------------------------
(i) An exhaust gas temperature (EGT) above Within 10 cycles.
redline.
(ii) A shift in the smoothed EGT trending data Within 10 cycles.
that exceeds 18 [deg]F (10 [deg]C), but is less
than or equal to 36 [deg]F (20 [deg]C).
(iii) A shift in the smoothed EGT trending data Before further flight.
that exceeds 36 [deg]F (20 [deg]C).
(iv) Two consecutive raw EGT trend data points Within 10 cycles.
that exceed 18 [deg]F (10 [deg]C), but are less
than or equal to 36 [deg]F (20 [deg]C), above
the smoothed average.
(v) Two consecutive raw EGT trend data points Before further flight.
that exceed 36 [deg]F (20 [deg]C) above the
smoothed average.
------------------------------------------------------------------------
(2) Engines with Damaged HPT Rotor Blades:
For those engines that fail any BSI requirements of this AD,
before returning the engine to service, accomplish the actions
required by paragraph (g)(2)(i) or (ii) of this AD:
(i) Remove the LPT rotor stage 3 disk from service; or
(ii) Perform a fluorescent-penetrant inspection (FPI) of the
inner diameter surface forward cone body (forward spacer arm) of the
LPT rotor stage 3 disk as specified in paragraphs (g)(6)(i)(A)
through (C) of this AD.
(3) EGT Thermocouple Probe Inspections.
(i) Within 750 CSLI, or before further flight, whichever occurs
later, inspect the EGT thermocouple probe for damage.
Note 1 to paragraph (g)(3)(i): Damage to the EGT thermocouple
probe may be indicated by wear through the thermocouple guide sleeve
or contact between the turbine mid-frame liner and the EGT
thermocouple probe.
(ii) Thereafter, within every 750 CSLI, re-inspect the EGT
thermocouple probe for damage.
(iii) If any EGT thermocouple probe shows wear through the
thermocouple guide sleeve or contact between the turbine mid-frame
liner and the EGT thermocouple probe, before further flight, remove
and replace the EGT thermocouple probe and ensure the turbine mid-
frame liner does not contact the EGT thermocouple probe.
(4) EGT System Resistance Checks.
(i) Within 750 cycles since the last resistance check on the EGT
system or before further flight, whichever occurs later, perform an
EGT system resistance check.
(ii) Thereafter, within every 750 cycles since the last
resistance check, repeat the EGT system resistance check.
(iii) If an EGT system component fails the resistance system
check, before further flight, remove and replace, or repair the EGT
system component.
(5) Engine Core Vibration Survey.
(i) Within 350 cycles since the last engine core vibration
survey or before further flight, whichever occurs later, perform an
initial engine core vibration survey.
(ii) Use about a one-minute acceleration and a one-minute
deceleration of the engine between ground idle and 84% N2 (about
8,250 rpm) to perform the engine core vibration survey.
(iii) Use a spectral/trim balance analyzer or equivalent to
measure the N2 rotor vibration.
(iv) If the vibration level is above 5 mils Double Amplitude
then, before further flight, remove the engine from service.
(v) For those engines that fail any engine core vibration survey
requirements of this AD, then before returning the engine to
service:
(A) Remove the LPT rotor stage 3 disk from service; or
(B) Perform an FPI of the inner diameter surface forward spacer
arm of the LPT rotor stage 3 disk as specified in paragraph
(g)(6)(i)(A) through (C) of this AD.
(vi) Thereafter, within every 350 cycles since the last engine
core vibration survey, perform the engine core vibration survey as
required in paragraphs (g)(5)(i) through (v) of this AD.
(vii) If the engine has experienced any vibration reported by
maintenance or flight crew that is suspected to be caused by the
engine core (N2), within 10 cycles after the report, perform the
engine core vibration survey as required in paragraphs (g)(5)(i)
through (v) of this AD.
(viii) Vibration surveys carried out in an engine test cell as
part of an engine manual performance run fulfill the vibration
survey requirements of paragraphs (g)(5)(ii) and (iii) of this AD.
(6) Initial and Repetitive FPI of LPT Rotor Stage 3 Disk.
(i) At the next shop visit after accumulating 1,000 cycles since
the last FPI of the LPT rotor stage 3 disk forward spacer arm or
before further flight, whichever occurs later:
(A) Clean the LPT rotor stage 3 disk forward spacer arm,
including the use of a wet-abrasive blast, to eliminate residual or
background fluorescence.
(B) Perform an FPI of the LPT rotor stage 3 disk forward spacer
arm for cracks and for a band of fluorescence. Include all areas of
the disk forward spacer arm and the inner diameter surface forward
spacer arm of the LPT rotor stage 3 disk.
(C) If a crack or a band of fluorescence is present, before
further flight, remove the disk from service.
(ii) Thereafter, at each engine shop visit that occurs after
accumulating 1,000 cycles since the last FPI of the LPT rotor stage
3 disk forward spacer arm, clean and perform an FPI of the LPT rotor
stage 3 disk forward spacer arm, as specified in paragraph
(g)(6)(i)(A) through (C) of this AD.
(7) Removal of LPT Rotor Stage 3 Disk.
(i) For any installed LPT rotor stage 3 disk having a part
number listed in Table 1 to paragraph (c) of this AD, at the first
occurrence of any one of the conditions identified in paragraphs
(g)(7)(i)(A) through (C) of this AD, remove the LPT rotor stage 3
disk from service and replace with LPT rotor stage 3 disk part
number 2453M80P01.
(A) For a disk that has accumulated fewer than 3,200 cycles
since new (CSN) as of March 6, 2012 (the effective date of AD 2012-
02-07), remove the disk from service before accumulating 6,200 CSN.
(B) For a disk that accumulated 3,200 or more CSN as of March 6,
2012 (the effective date of AD 2012-02-07), do the actions required
by paragraphs (g)(7)(i)(B)(1) or (2) of this AD, as applicable to
your engine.
(1) If the engine has a shop visit before the disk accumulates
6,200 CSN, remove the disk from service at that shop visit.
(2) If the engine does not have a shop visit before the disk
accumulates 6,200 CSN, remove the disk from service at the next shop
visit after accumulating 6,200 CSN, not to exceed 3,000 cycles from
March 6, 2012 (the effective date of AD 2012-02-07).
(C) Before exceeding 18 months from the effective date of this
AD.
(h) Terminating Action
Replacement of the LPT rotor stage 3 disk in accordance with
paragraph (g)(7) of this AD constitutes terminating action for the
inspections, engine checks and vibration surveys required by
paragraphs (g)(1) through (6) of this AD.
[[Page 75185]]
(i) Installation Prohibition
After the effective date of this AD, do not install or reinstall
onto any engine an LPT rotor stage 3 disk listed in Table 1 to
paragraph (c) of this AD that has accumulated 6,200 CSN or more.
(j) Definitions
(1) For the purposes of this AD, an EGT above redline is a
confirmed over-temperature indication that is not a result of EGT
system error.
(2) For the purposes of this AD, a shift in the smoothed EGT
trending data is a shift in a rolling average of EGT readings that
can be confirmed by a corresponding shift in the trending of fuel
flow or fan speed/core speed (N1/N2) relationship. You can find
further guidance about evaluating EGT trend data in GE Company
Service Rep Tip 373 ''Guidelines For Parameter Trend Monitoring.''
(3) For the purposes of this AD, an engine shop visit is the
induction of an engine into the shop, where the separation of a
major engine flange occurs; except the following maintenance
actions, or any combination, are not considered engine shop visits:
(i) Induction of an engine into a shop solely for removal of the
compressor top or bottom case for airfoil maintenance or variable
stator vane bushing replacement.
(ii) Induction of an engine into a shop solely for removal or
replacement of the stage 1 fan disk.
(iii) Induction of an engine into a shop solely for replacement
of the turbine rear frame.
(iv) Induction of an engine into a shop solely for replacement
of the accessory gearbox or transfer gearbox, or both.
(v) Induction of an engine into a shop solely for replacement of
the fan forward case.
(4) For the purposes of this AD, a raw EGT trend data point
above the smoothed average is a confirmed temperature reading over
the rolling average of EGT readings that is not a result of EGT
system error.
(k) Credit for Previous Actions
You may take credit for the actions required by paragraph (g) of
this AD if they were performed before the effective date of this AD
using GE Service Bulletin (SB) No. CF6-50 SB 72-1315, Initial Issue,
dated June 3, 2011, or GE SB No. CF6-50 SB 72-1315, Revision 1,
dated June 30, 2011.
(l) 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
certification office, send it to the attention of the person
identified in paragraph (m) of this AD and email it 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) AMOCs approved previously for AD 2010-12-10, Amendment 39-
16331 (75 FR 32649, June 9, 2010), AD 2011-02-07, Amendment 39-16580
(76 FR 6323, February 4, 2011), or AD 2011-18-01, Amendment 39-16783
(76 FR 52213, August 22, 2011) are approved as AMOCs for the
corresponding provisions of this AD.
(m) Related Information
For more information about this AD, contact Sungmo Cho, Aviation
Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington,
MA 01803; phone: (781) 238-7241; email: [email protected].
(n) Material Incorporated by Reference
None.
Issued on November 3, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2022-26579 Filed 12-7-22; 8:45 am]
BILLING CODE 4910-13-P
