1340 Federal Register / Vol. 87, No. 7 / Tuesday, January 11, 2022 / Rules and Regulations 

PART 39—AIRWORTHINESS 

DIRECTIVES 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by: 

■ a. Removing Airworthiness Directive 

(AD) 2019–03–26, Amendment 39– 

19578 (84 FR 7266, March 4, 2019); and 

■ b. Adding the following new AD: 

2021–26–17 The Boeing Company: 

Amendment 39–21876; Docket No. 

FAA–2021–0504; Project Identifier AD– 

2020–01380–T. 

(a) Effective Date 

This airworthiness directive (AD) is 

effective February 15, 2022. 

(b) Affected ADs 

This AD replaces AD 2019–03–26, 

Amendment 39–19578 (84 FR 7266, March 4, 

2019) (AD 2019–03–26). 

(c) Applicability 

This AD applies to The Boeing Company 

Model 737–600, –700, –700C, –800, –900, 

and –900ER series airplanes, certificated in 

any category, without a Boeing Sky Interior 

(BSI). 

(d) Subject 

Air Transport Association (ATA) of 

America Code 25, Equipment/furnishings. 

(e) Unsafe Condition 

This AD was prompted by reports of 

passenger service units (PSUs) becoming 

detached from the supporting airplane 

structure in several Model 737 series 

airplanes during survivable accidents. The 

FAA is issuing this AD to address PSUs and 

life vest panels detaching from the 

supporting airplane structure, which could 

lead to passenger injuries and impede 

passenger and crew egress during evacuation. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

Within 60 months after April 8, 2019 (the 

effective date of AD 2019–03–26), do all 

applicable actions identified as ‘‘RC’’ 

(required for compliance) in, and in 

accordance with, the Accomplishment 

Instructions of Boeing Special Attention 

Service Bulletin 737–25–1707, Revision 2, 

dated July 27, 2020. 

(h) Parts Installation Limitation 

As of the applicable time specified in 

paragraph (h)(1) or (2) of this AD, no person 

may install on any airplane a PSU or life vest 

panel, unless the lanyard assembly has been 

modified (secondary retention features 

added) or re-identified, as applicable, as 

required by paragraph (g) of this AD. 

(1) For airplanes that have PSUs or life vest 

panels without the secondary retention 

features installed: After modification or reidentification, as applicable, of the airplane 

as required by paragraph (g) of this AD. 

(2) For airplanes that have PSUs or life vest 

panels with the secondary retention features 

installed: As of the effective date 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. 

(4) AMOCs approved for AD 2019–03–26 

are approved as AMOCs for the 

corresponding provisions of Boeing Special 

Attention Service Bulletin 737–25–1707, 

Revision 2, dated July 27, 2020, that are 

required by paragraph (g) of this AD. 

(j) Related Information 

For more information about this AD, 

contact Tony Koung, Aerospace Engineer, 

Cabin Safety and Environmental Systems 

Section, FAA, Seattle ACO Branch, 2200 

South 216th St., Des Moines, WA 98198; 

phone and fax: 206–231–3985; email: 

tony.koung@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 Special Attention Service 

Bulletin 737–25–1707, Revision 2, dated July 

27, 2020. 

(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; internet https://

www.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, 

email fr.inspection@nara.gov, or go to: 

https://www.archives.gov/federal-register/cfr/ 

ibr-locations.html. 

Issued on December 13, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2022–00031 Filed 1–10–22; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0871; Project 

Identifier MCAI–2020–01581–A; Amendment 

39–21874; AD 2021–26–15] 

RIN 2120–AA64 

Airworthiness Directives; Vulcanair 

S.p.A. Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for certain 

km, Vulcanair S.p.A. Model P.68C, 

P.68C–TC, P.68 ‘‘OBSERVER,’’ P.68 

OBSERVER 2, P.68R, and P.68TC 

OBSERVER airplanes. This AD was 

prompted by mandatory continuing 

airworthiness information (MCAI) 

originated by an aviation authority of 

another country to identify and correct 

an unsafe condition on an aviation 

product. The MCAI identifies the unsafe 

condition as a damaged stabilator trim 

control cable. This AD requires 

inspecting the stabilator trim control 

cables and replacing if necessary. This 

AD also requires reporting the results of 

each inspection to Vulcanair S.p.A. The 

FAA is issuing this AD to address the 

unsafe condition on these products. 

DATES: This AD is effective February 15, 

2022. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of February 15, 2022. 

ADDRESSES: For service information 

identified in this final rule, contact 

Vulcanair S.p.A., Fulvio Oloferni, via 

Giovanni Pascoli, 7, Naples, 80026, 

Italy; phone: +39 081 5918 135; email: 

airworthiness@vulcanair.com; website: 

www.vulcanair.com. You may view this 

service information at the FAA, 


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Federal Register / Vol. 87, No. 7 / Tuesday, January 11, 2022 / Rules and Regulations 1341 

Airworthiness Products Section, 

Operational Safety Branch, 901 Locust, 

Kansas City, MO 64106. For information 

on the availability of this material at the 

FAA, call (817) 222–5110. It is also 

available at https://www.regulations.gov 

by searching for and locating Docket No. 

FAA–2021–0871. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0871; 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, the MCAI, 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: 

Gregory Johnson, Aviation Safety 

Engineer, International Validation 

Section, FAA, 901 Locust, Room 301, 

Kansas City, MO 64106; phone: (720) 

626–5462; email: gregory.johnson@

faa.gov. 

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 serial-numbered 

Vulcanair S.p.A. Model P.68C, P.68C– 

TC, P.68 ‘‘OBSERVER,’’ P.68 

OBSERVER 2, P.68R, and P.68TC 

OBSERVER airplanes. The NPRM 

published in the Federal Register on 

October 8, 2021 (86 FR 56229). The 

NPRM was prompted by MCAI 

originated by the European Union 

Aviation Safety Agency (EASA), which 

is the Technical Agent for the Member 

States of the European Union. EASA 

issued EASA AD 2020–0262, dated 

November 30, 2020 (referred to after this 

as ‘‘the MCAI’’), to correct an unsafe 

condition on certain serial-numbered 

Vulcanair S.p.A. Model P.68R, P.68C, 

P.68C–TC, P.68 ‘‘OBSERVER,’’ P.68 

‘‘OBSERVER 2,’’ and P.68TC 

‘‘OBSERVER’’ airplanes. The MCAI 

states: 

Two occurrences have been reported of 

finding a damaged stabilator trim control 

cable connected to the stabilator trim 

actuator assembly, mounted on fuselage 

frame No.16. The related technical 

investigation concluded that the cause of the 

damage is a design issue. 

This condition, if not detected and 

corrected, could lead to failure of an affect 

[sic] part, preventing trim surface control 

(remaining in the last position), possibly 

resulting in reduced control of the aeroplane. 

To address this potential unsafe condition, 

and pending a design improvement, 

Vulcanair published the [service bulletin] SB, 

to provide inspection instructions for 

detecting damage. 

For the reasons described above, this 

[EASA] AD requires repetitive inspections of 

the affected parts, and, depending on 

findings, replacement. 

This [EASA] AD is considered to be an 

interim action and further [EASA] AD action 

may follow. 

You may examine the MCAI in the 

AD docket at https://

www.regulations.gov by searching for 

and locating Docket No. FAA–2021– 

0871. 

Discussion of Final Airworthiness 

Directive 

Comments 

The FAA received no comments on 

the NPRM or on the determination of 

the costs. 

Conclusion 

This product has been approved by 

the aviation authority of another 

country and is approved for operation in 

the United States. Pursuant to the FAA’s 

bilateral agreement with this State of 

Design Authority, it has notified the 

FAA of the unsafe condition described 

in the MCAI referenced above. The FAA 

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. This AD is adopted as 

proposed in the NPRM. 

Related Service Information Under 1 

CFR Part 51 

The FAA reviewed Vulcanair S.p.A. 

P.68 Variants Service Bulletin No. 263, 

dated October 20, 2020. The service 

information contains procedures for 

repetitively inspecting each stabilator 

trim control cable part number 5.6067– 

1, 5.6161–1, 5.6171–1, 5.6231–2, or 

5.6231–4 for broken wires and replacing 

the cable if necessary. This service 

information is reasonably available 

because the interested parties have 

access to it through their normal course 

of business or by the means identified 

in the ADDRESSES section. 

Interim Action 

The FAA considers this AD an 

interim action. The inspection reports 

required by this AD will enable the 

manufacturer to obtain better insight 

into the nature, cause, and extent of the 

damage, and eventually to develop final 

action to address the unsafe condition. 

Once final action has been identified, 

the FAA might consider further 

rulemaking. 

Costs of Compliance 

The FAA estimates that this AD 

affects 127 airplanes of U.S. registry. 

The FAA estimates the following 

costs to comply with this AD: 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per airplane Cost on U.S. 

operators 

Inspection ......... 0.50 work-hour × $85 per hour = 

$42.50 per inspection cycle.

$0 $42.50 per inspection cycle .......... $5,397.50 per inspection cycle. 

Report ............... 1 work-hour × $85 per hour = $85 

per reporting cycle.

$0 $85 per inspection cycle ............... $10,795 per inspection cycle. 

The FAA estimates the following 

costs to do any replacements that would 

be required based on the results of the 

inspection. The FAA has no way of 

determining the number of airplanes 

that might need this replacement: 


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1342 Federal Register / Vol. 87, No. 7 / Tuesday, January 11, 2022 / Rules and Regulations 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

airplane 

Replacement .... 2 work-hours × $85 per hour = $170 ....................................................................................... $340 $510 

Paperwork Reduction Act 

A federal agency may not conduct or 

sponsor, and a person is not required to 

respond to, nor shall a person be subject 

to a penalty for failure to comply with 

a collection of information subject to the 

requirements of the Paperwork 

Reduction Act unless that collection of 

information displays a currently valid 

OMB Control Number. The OMB 

Control Number for this information 

collection is 2120–0056. Public 

reporting for this collection of 

information is estimated to be 

approximately 1 hour per response, 

including the time for reviewing 

instructions, searching existing data 

sources, gathering and maintaining the 

data needed, completing and reviewing 

the collection of information. All 

responses to this collection of 

information are mandatory. Send 

comments regarding this burden 

estimate or any other aspect of this 

collection of information, including 

suggestions for reducing this burden to: 

Information Collection Clearance 

Officer, Federal Aviation 

Administration, 10101 Hillwood 

Parkway, Fort Worth, TX 76177–1524. 

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 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive: 

2021–26–15 Vulcanair S.p.A.: Amendment 

39–21874; Docket No. FAA–2021–0871; 

Project Identifier MCAI–2020–01581–A. 

(a) Effective Date 

This airworthiness directive (AD) is 

effective February 15, 2022. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to Vulcanair S.p.A. 

(Vulcanair) Model P.68C, P.68C–TC, P.68 

‘‘OBSERVER,’’ P.68 OBSERVER 2, P.68R, and 

P.68TC OBSERVER airplanes, serial numbers 

333, 337 to 339 inclusive, 378, 379, and 383 

and larger (except serial numbers 387 and 

398), certificated in any category, with a 

stabilator trim control cable part number 

5.6067–1, 5.6161–1, 5.6171–1, 5.6231–2, or 

5.6231–4 installed. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 2740, Stabilizer Control System. 

(e) Unsafe Condition 

This AD was prompted by a damaged 

stabilator trim control cable connected to the 

stabilator trim actuator assembly, mounted 

on fuselage frame No. 16. The FAA is issuing 

this AD to detect and address failure of a 

stabilator trim control cable, which could 

prevent trim surface control thereby leaving 

the cable remaining in the last position. The 

unsafe condition, if not addressed, could 

result in reduced control of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

Before a stabilator trim control cable part 

number 5.6067–1, 5.6161–1, 5.6171–1, 

5.6231–2, or 5.6231–4 accumulates more 

than 400 hours time-in-service (TIS) since 

first installation on an airplane or within 50 

hours TIS after the effective date of this AD, 

whichever occurs later, and thereafter at 

intervals not to exceed 50 hours TIS, visually 

inspect the stabilator trim control cable for 

broken wires and replace the stabilator trim 

control cable before further flight if there is 

broken wire in a strand in accordance with 

steps 1 through 22 of Part 2 Work Procedure 

in Vulcanair S.p.A. P.68 Variants Service 

Bulletin No. 263, dated October 20, 2020. 

(h) Reporting 

Within 14 days after the initial inspection 

required by paragraph (g) of this AD or 

within 14 days after the effective date of this 

AD, whichever occurs later, report the results 

of the initial inspection to Vulcanair at 

continued.airworthiness@vulcanaair.com or 

at the address in paragraph (l)(3) of this AD. 

Thereafter, report the inspection results 

within 14 days after each inspection. Each 

report must include the following 

information: 

(1) Owner/operator name, mailing address, 

phone number, and email address; 

(2) Airplane model, serial number, and 

registration number; 

(3) Airplane hours TIS at the time of the 

inspection; 

(4) Stabilator trim control cable hours TIS 

at the time of the inspection; 

(5) Date of the inspection; 

(6) Inspection result (positive or negative); 

and 

(7) A description of any non-conformity 

(damage). 

(i) Special Flight Permit 

Special flight permits are prohibited. 

(j) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, International Validation 

Branch, FAA, has the authority to approve 

AMOCs for this AD, if requested using the 


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Federal Register / Vol. 87, No. 7 / Tuesday, January 11, 2022 / Rules and Regulations 1343 

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 (k)(1) of this AD and 

email to: 9-AVS-AIR-730-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. 

(k) Related Information 

(1) For more information about this AD, 

contact Gregory Johnson, Aviation Safety 

Engineer, FAA, General Aviation & Rotorcraft 

Section, International Validation Section, 901 

Locust, Room 301, Kansas City, MO 64106; 

phone: (720) 626–5462; email: 

gregory.johnson@faa.gov. 

(2) Refer to European Union Aviation 

Safety Agency (EASA) AD 2020–0262, dated 

November 30, 2020, for more information. 

You may examine the EASA AD in the AD 

docket at https://www.regulations.gov by 

searching for and locating Docket No. FAA– 

2021–0871. 

(l) Material Incorporated by Reference 

(1) The Director of the Federal Register 

approved the incorporation by reference 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) Vulcanair S.p.A. P.68 Variants Service 

Bulletin No. 263, dated October 20, 2020. 

(ii) [Reserved] 

(3) For service information identified in 

this AD, contact Vulcanair S.p.A., Fulvio 

Oloferni, via Giovanni Pascoli, 7, Naples, 

80026, Italy; phone: +39 081 5918 135; email: 

airworthiness@vulcanair.com; website: 

www.vulcanair.com. 

(4) You may view this service information 

at FAA, Airworthiness Products Section, 

Operational Safety Branch, 901 Locust, 

Kansas City, MO 64106. For information on 

the availability of this material at the FAA, 

call (817) 222–5110. 

(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: fr.inspection@nara.gov, or go to: 

https://www.archives.gov/federal-register/cfr/ 

ibr-locations.html. 

Issued on December 10, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2022–00056 Filed 1–10–22; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0567; Project 

Identifier AD–2021–00663–E; Amendment 

39–21865; AD 2021–26–06] 

RIN 2120–AA64 

Airworthiness Directives; General 

Electric Company Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for certain 

General Electric Company (GE) GE90 

model turbofan engines. This AD was 

prompted by two separate in-flight 

shutdowns (IFSDs) resulting from 

failure of the transfer gearbox (TGB) 

radial bevel gear (TGB radial gearshaft). 

This AD requires visual inspection of 

the TGB radial gearshaft and, depending 

on the results of the inspection, 

replacement of the TGB radial gearshaft. 

The FAA is issuing this AD to address 

the unsafe condition on these products. 

DATES: This AD is effective February 15, 

2022. 

The Director of the Federal Register 

approved the incorporation by reference 

of certain publications listed in this AD 

as of February 15, 2022. 

ADDRESSES: For service information 

identified in this final rule, contact 

General Electric Company, GE Aviation, 

Room 285, 1 Neumann Way, Cincinnati, 

OH 45215; phone: (513) 552–3272; 

email: aviation.fleetsupport@ge.com; 

website: https://www.ge.com. 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 (817) 222– 

5110. It is also available at https://

www.regulations.gov by searching for 

and locating Docket No. FAA–2021– 

0567. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0567; 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: 

Stephen Elwin, Aviation Safety 

Engineer, ECO Branch, FAA, 1200 

District Avenue, Burlington, MA 01803; 

phone: (781) 238–7236; fax: (781) 238– 

7199; email: Stephen.L.Elwin@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The FAA issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 by adding an AD that would 

apply to all GE GE90–76B, GE90–85B, 

GE90–90B, GE90–94B, GE90–110B1, 

and GE90–115B model turbofan engines 

with a certain TGB radial gearshaft 

installed. The NPRM published in the 

Federal Register on August 12, 2021 (86 

FR 44321). The NPRM was prompted by 

notification of two separate IFSDs 

resulting from the failure of the TGB 

radial gearshaft. After further 

investigation, the manufacturer 

determined that rework on the TGB 

radial gearshaft teeth chamfers during 

manufacturing may have caused local 

burrs and micro-cracks which led to 

high-cycle fatigue failure. GE 

subsequently issued service information 

to provide instructions for a one-time 

visual inspection of the affected radial 

gearshafts for the presence of burrs or 

rework on TGB radial gearshaft teeth 

chamfers. In the NPRM, the FAA 

proposed to require visual inspection of 

the TGB radial gearshaft and, depending 

on the results of the inspection, 

replacement of the TGB radial gearshaft. 

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 5 

commenters. The commenters were Air 

Line Pilots Association, International, 

The Boeing Company, FedEx Express, 

Japan Airlines (JAL), and United 

Airlines. The following presents the 

comments received on the NPRM and 

the FAA’s response to each comment. 

Question on the Difference Between 

This AD and the Service Information 

JAL asked why there is a difference 

between the affected serial numbers (S/ 

Ns) in this AD and the related service 

bulletins (SBs). 

The FAA notes that the applicable 

SBs include several populations of TGB 

radial gearshafts. The FAA determined 

that TGB radial gearshafts with S/Ns 

starting with prefix FIAAXXXX, 

FIA05XXX to FIA09XXX, or FIA0AXXX 

to FIA0NXXX are not subject to the 


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