Airworthiness Directives; General Electric Company Turbofan Engines

[Federal Register Volume 86, Number 35 (Wednesday, February 24, 2021)]
[Rules and Regulations]
[Pages 11113-11116]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-03606]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0371; Project Identifier AD-2019-00124-E; 
Amendment 39-21405; AD 2021-03-02]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
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 
certain General Electric Company (GE) CF6-80C2A1, CF6-80C2A2, CF6-
80C2A3, CF6-80C2A5, CF6-80C2A5F, CF6-80C2A8, CF6-80C2B1, CF6-80C2B1F, 
CF6-80C2B2, CF6-80C2B2F, CF6-80C2B4, CF6-80C2B4F, CF6-80C2B5F, CF6-
80C2B6, CF6-80C2B6F, CF6-80C2B6FA, CF6-80C2B7F, CF6-80C2B8F, and CF6-
80C2D1F model turbofan engines. This AD was prompted by reports of 
incidents that resulted in a significant fuel loss during flight and an 
in-flight shutdown (IFSD) of the engine. This AD requires initial and 
repetitive shim checks of the hydromechanical unit/main engine control 
(HMU/MEC) idler adapter on the accessory gearbox (AGB) assembly and, 
depending on the results of the shim check, possible replacement of the 
inserts on the HMU/MEC idler adapter. As a terminating action, this AD 
requires a protrusion check and a pull-out test, and the replacement of 
inserts on the HMU/MEC idler adapter that fail either test. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective March 31, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 31, 
2021.

ADDRESSES: For service information identified in this final rule, 
contact General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; 
phone: (513) 552-3272; email: [email protected]. You may 
view this service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 1200 District Avenue, Burlington, 
MA 01803. For information on the availability of this material at the 
FAA, call (781) 238-7759. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0371.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-0371; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this final rule, any 
comments received, and other information. The address for Docket 
Operations is U.S. Department of Transportation, Docket Operations, M-
30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue 
SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Kevin M. Clark, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7088; fax: (781) 238-7199; 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 certain GE CF6-80C2A1, 
CF6-80C2A2, CF6-80C2A3, CF6-80C2A5, CF6-80C2A5F, CF6-80C2A8, CF6-
80C2B1, CF6-80C2B1F, CF6-80C2B2, CF6-80C2B2F, CF6-80C2B4, CF6-80C2B4F, 
CF6-80C2B5F, CF6-80C2B6, CF6-80C2B6F, CF6-80C2B6FA, CF6-80C2B7F, CF6-
80C2B8F, and CF6-80C2D1F model turbofan engines. The NPRM published in 
the Federal Register on April 10, 2020 (85 FR 20211). The NPRM was 
prompted by reports of incidents that resulted in a significant fuel 
loss during flight and an IFSD of the engine. The incidents resulted 
from inserts on the HMU/MEC idler adapter on the AGB assembly pulling 
out of the housing. An investigation by the manufacturer discovered 
improperly cut threads on the inserts and erroneous instructions in the 
maintenance manual, which contributed to poor thread engagement. In the 
NPRM, the FAA proposed to require initial and repetitive shim checks of 
the HMU/MEC idler adapter on the AGB assembly and, depending on the 
results of the shim check, possible replacement of the inserts on the 
HMU/MEC idler adapter. As a terminating action to the repetitive shim

[[Page 11114]]

checks, the NPRM proposed to require a protrusion check and a pull-out 
test, and the replacement of inserts on the HMU/MEC idler adapter that 
fail either test. 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 four commenters. The commenters were 
All Nippon Airways (ANA), Delta Air Lines, Inc. (DAL), FedEx Express 
(FedEx), and Japan Airlines (JAL). All commenters requested changes, 
some of which resulted in changes to this AD. The following presents 
the comments received on the NPRM and the FAA's response to each 
comment.

Request To Update the Applicability

    DAL requested that paragraph (c), Applicability, of this AD be 
updated to align with the effectivity in GE CF6-80C2 Service Bulletin 
(SB) 72-1577 R01, dated August 16, 2019 (GE CF6-80C2 SB 72-1577 R01), 
which includes the part numbers (P/Ns) of the affected HMU/MEC idler 
adapters.
    The FAA agrees. The FAA confirmed with the manufacturer that only 
the P/Ns of the HMU/MEC idler adapter listed in GE CF6-80C2 SB 72-1577 
R01 are affected. The FAA updated the applicability of this AD to 
include the P/Ns of the affected HMU/MEC idler adapter. The number of 
engines affected by this AD is unchanged from the NPRM.

Request To Update Terminating Action

    DAL requested that paragraph (h), Terminating Action, of this AD 
also terminate the initial shim check of the HMU/MEC idler adapter 
inserts required by paragraph (g)(1) of this AD. DAL reasoned that 
since the NPRM proposed to allow for terminating the repetitive shim 
checks of the HMU/MEC idler adapter inserts, that this AD should add a 
terminating action for the initial shim check of the HMU/MEC idler 
adapter inserts if the action was performed within 1,200 flight hours 
(FHs) after the effective date of this AD.
    The FAA agrees. The FAA updated paragraph (h) of this AD to 
terminate the actions required by paragraph (g) of this AD.

Request To Remove the Shim Check

    DAL requested that the FAA remove the shim check of the HMU/MEC 
idler adapter inserts in paragraph (g)(3)(ii) of the NPRM. DAL reasoned 
that performing this shim check is not necessary because the (g)(3)(ii) 
shim check is already required by paragraph (g)(3)(i) of this AD. 
Additionally, DAL stated that referencing paragraph (g)(1) of this AD 
to perform the shim check may confuse operators as paragraph (g)(1) of 
this AD includes the requirement to perform the shim check within 1,200 
FHs after the effective date of this AD. Therefore, DAL suggested that 
paragraph (g)(3)(ii) of this AD should only address the requirement to 
perform the terminating action if the shim check fails.
    The FAA partially agrees. The FAA disagrees that paragraph 
(g)(3)(ii) of this AD should only address the requirement to perform 
the terminating action if the shim check of the HMU/MEC idler adapter 
inserts fails. After retorque of the bolts at each bolt location that 
failed the shim check, operators must perform the shim check again. If 
that shim check fails, then the terminating action is required. The FAA 
agrees that referencing paragraph (g)(1) of this AD may confuse 
operators whether to perform the shim check after the aircraft operated 
for some time or within 1,200 FHs after the effective date of this AD. 
The FAA updated paragraph (g)(3)(ii) of this AD to reference the 
service information when performing the shim check rather than 
paragraph (g)(1) of this AD.

Request To Update Credit for Previous Actions

    ANA, DAL, FedEx, and JAL requested updates to paragraph (i), Credit 
for Previous Actions, of this AD. ANA requested adding credit for the 
repetitive shim checks of the HMU/MEC idler adapter inserts and 
terminating action. DAL and FedEx requested credit for the terminating 
action. JAL requested credit for the repetitive shim checks of the HMU/
MEC idler adapter inserts, retorque of the bolts that failed the shim 
check, and the terminating action. The commenters reasoned that GE CF6-
80C2 SB 72-1577 R00, dated October 31, 2018 (GE CF6-80C2 SB 72-1577 
R00), instructs the operator to perform the same tasks required by GE 
CF6-80C2 SB 72-1577 R01. Therefore, credit should be allowed for 
initial and repetitive shim checks of the HMU/MEC idler adapter inserts 
and the terminating action.
    The FAA agrees. The FAA reviewed GE CF6-80C2 SB 72-1577 R00, and 
determined that the instructions are consistent with GE CF6-80C2 SB 72-
1577 R01. The FAA updated this AD to allow credit for the initial and 
repetitive shim checks of the HMU/MEC idler adapter inserts, retorque 
of the bolts that failed the shim check, and the terminating action, if 
performed before the effective date of this AD using GE CF6-80C2 SB 72-
1577 R00.

Request for an Alternate Marking Area

    ANA requested that the FAA approve an alternate marking area to 
show compliance with performing the terminating action of this AD. ANA 
stated that the marking areas indicated in GE CF6-80C2 SB 72-1577 R01, 
are difficult to access because many components are installed to AGB 
assembly.
    The FAA disagrees with approving an alternate marking area. The 
manufacturer provided two possible marking areas in GE CF6-80C2 SB 72-
1577 R01, and confirmed the suitability of the areas.

Request To Not Mandate the Marking Requirement

    DAL requested that the FAA not mandate the provision in GE CF6-80C2 
SB 72-1577 R01 to mark the HMU/MEC idler adapter to show compliance 
with the terminating actions of this AD. DAL reasoned that the NPRM did 
not propose to apply to all engines and therefore should not be 
required.
    The FAA disagrees. Marking the HMU/MEC idler adapter identifies if 
the terminating action of this AD has been completed. As noted in a 
previous comment response, the FAA revised the applicability of this AD 
to limit applicability to affected engines with certain HMU/MEC idler 
adapter P/Ns installed. Operators who determine that their engines are 
not applicable to this AD do not need to perform the terminating action 
or mark the HMU/MEC idler adapter.

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 GE CF6-80C2 SB 72-1577 R01, dated August 16, 2019. 
The SB describes procedures for performing shim checks of the HMU/MEC 
idler adapter and for replacing the HMU/MEC idler adapter inserts. This 
service information is reasonably available because the interested 
parties have access to it through their normal

[[Page 11115]]

course of business or by the means identified in ADDRESSES.

Costs of Compliance

    The FAA estimates that this AD affects 555 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
----------------------------------------------------------------------------------------------------------------
Shim check............................  1 work-hour x $85 per                 $0             $85         $47,175
                                         hour = $85.
Protrusion check/pull-out test........  4 work-hours x $85 per                 0             340         188,700
                                         hour = $340.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that are required based on the results of the shim check. 
The agency has no way of determining the number of aircraft that might 
need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace HMU/MEC idler adapter insert..........  4 work-hours x $85 per hour =                $50            $390
                                                 $340.
----------------------------------------------------------------------------------------------------------------

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:

2021-03-02 General Electric Company: Amendment 39-21405; Docket No. 
FAA-2020-0371; Project Identifier AD-2019-00124-E.

(a) Effective Date

    This airworthiness directive (AD) is effective March 31, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) CF6-80C2A1, 
CF6-80C2A2, CF6-80C2A3, CF6-80C2A5, CF6-80C2A5F, CF6-80C2A8, CF6-
80C2B1, CF6-80C2B1F, CF6-80C2B2, CF6-80C2B2F, CF6-80C2B4, CF6-
80C2B4F, CF6-80C2B5F, CF6-80C2B6, CF6-80C2B6F, CF6-80C2B6FA, CF6-
80C2B7F, CF6-80C2B8F, and CF6-80C2D1F model turbofan engines that 
underwent an engine shop visit before November 1, 2018, and with 
accessory gearbox (AGB) adapter hydromechanical unit (HMU)/main 
engine control (MEC) idler adapter with part number (P/N) 
9395M78G01, P/N 9395M78G02, P/N 9395M78G04, P/N 9395M78G05, P/N 
9395M78G08, or P/N 9395M78G10, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7321, Fuel Control/
Turbine Engines.

(e) Unsafe Condition

    This AD was prompted by failure of the HMU/MEC on the AGB 
assembly. The FAA is issuing this AD to prevent failure of the HMU/
MEC. The unsafe condition, if not addressed, could result in engine 
fire and damage to the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Perform a shim check of the HMU/MEC idler adapter inserts 
using paragraph 3.B.(1) of GE CF6-80C2 Service Bulletin (SB) 72-1577 
R01, dated August 16, 2019 (the SB), within 1,200 flight hours (FHs) 
after the effective date of this AD.
    (2) Thereafter, perform a repetitive shim check of the HMU/MEC 
idler adapter inserts using paragraph 3.B.(1) of the SB within every 
1,200 FHs since the last shim check.
    (3) If any HMU/MEC idler adapter insert fails the shim check 
required by paragraph (g)(1) or (2) of this AD, perform the 
following before further flight:
    (i) Retorque the bolts at each bolt location that failed the 
shim check using paragraph 3.B.(1)(c) of the SB.
    (ii) Perform the shim check again using paragraph 3.B.(1)(b) of 
the SB. If the shim check fails, perform the terminating action 
required by paragraph (h) of this AD.

[[Page 11116]]

(h) Terminating Action

    As a terminating action to the requirements of paragraph (g) of 
this AD, perform the following:
    (1) Do a protrusion check at all eight bolt locations using 
paragraph 3.C.(3) of the SB.
    (2) Do a pull-out test at all eight bolt locations using 
paragraph 3.C.(4) of the SB.
    (3) If the inserts on the HMU/MEC idler adapter fail the 
protrusion check or pull-out test required by paragraph (h)(1) or 
(2) of this AD, replace the inserts using paragraph 3.C.(5) of the 
SB. After replacement of the inserts is accomplished, the 
requirements of this AD have been met and no further action is 
required.
    (4) If the inserts on the HMU/MEC idler adapter pass both the 
protrusion check and the pull-out test required by paragraphs (h)(1) 
and (2) of this AD, the requirements of this AD have been met and no 
further action is required.

(i) Credit for Previous Actions

    (1) You may take credit for any shim check of the HMU/MEC idler 
adapter required by paragraph (g) of this AD if you performed this 
shim check before the effective date of this AD using GE CF6-80C2 SB 
72-1577 R00, dated October 31, 2018.
    (2) You may take credit for the terminating action required by 
paragraph (h) of this AD if you performed this action before the 
effective date of this AD using GE CF6-80C2 SB 72-1577 R00, dated 
October 31, 2018.

(j) Definition

    For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine case flanges, except 
separation of engine flanges solely for the purposes of 
transportation of the engine without subsequent maintenance, which 
does not constitute an engine shop visit.

(k) 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 Related Information. You may email your request 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.

(l) Related Information

    For more information about this AD, contact Kevin M. Clark, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7088; fax: (781) 238-7199; 
email: [email protected].

(m) 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) General Electric Company (GE) CF6-80C2 Service Bulletin 72-
1577 R01, dated August 16, 2019.
    (ii) [Reserved]
    (3) For GE service information identified in this AD, contact 
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; 
phone: (513) 552-3272; email: [email protected].
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 1200 District Avenue, 
Burlington, MA 01803. For information on the availability of this 
material at the FAA, call (781) 238-7759.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on January 21, 2021.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-03606 Filed 2-23-21; 8:45 am]
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