Document ID: FAA-2022-1416-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Company Turbofan Engines
Posted Date: 2022-12-08T05:00Z

[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]

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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