Federal Register / Vol. 86, No. 113 / Tuesday, June 15, 2021 / Rules and Regulations 31601 

by the Manager, New York ACO Branch, 

FAA; or TCCA; or De Havilland Aircraft of 

Canada Limited’s TCCA DAO. If approved by 

the DAO, the approval must include the 

DAO-authorized signature. 

(i) Related Information 

(1) Refer to Mandatory Continuing 

Airworthiness Information (MCAI) TCCA AD 

CF–2020–39, dated October 14, 2020, for 

related information. This MCAI may be 

found in the AD docket on the internet at 

https://www.regulations.gov by searching for 

and locating Docket No. FAA–2021–0183. 

(2) For more information about this AD, 

contact Antariksh Shetty, Aerospace 

Engineer, Airframe and Propulsion Section, 

FAA, New York ACO Branch, 1600 Stewart 

Avenue, Suite 410, Westbury, NY 11590; 

telephone 516–228–7300; fax 516–794–5531; 

email 9-avs-nyaco-cos@faa.gov. 

(j) 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 this AD specifies otherwise. 

(i) De Havilland Aircraft of Canada Limited 

Service Bulletin 84–54–32, dated October 10, 

2019. 

(ii) [Reserved] 

(3) For service information identified in 

this AD, contact De Havilland Aircraft of 

Canada Limited, Q-Series Technical Help 

Desk, 123 Garratt Boulevard, Toronto, 

Ontario M3K 1Y5, Canada; telephone 416– 

375–4000; fax 416–375–4539; email thd@

dehavilland.com; internet https://

dehavilland.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 fedreg.legal@nara.gov, or go to: https:// 

www.archives.gov/federal-register/cfr/ibrlocations.html. 

Issued on May 25, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–12435 Filed 6–14–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0499; Project 

Identifier MCAI–2021–00571–E; Amendment 

39–21612; AD 2021–13–07] 

RIN 2120–AA64 

Airworthiness Directives; GE Aviation 

Czech s.r.o. (Type Certificate 

Previously Held by WALTER Engines 

a.s., Walter a.s., and MOTORLET a.s.) 

Turboprop Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule; request for 

comments. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for all GE 

Aviation Czech s.r.o. (GEAC) M601D– 

11, M601E–11, M601E–11A, M601E– 

11AS, M601E–11S, and M601F model 

turboprop engines. This AD was 

prompted by the manufacturer finding 

errors in the Airworthiness Limitation 

Section (ALS) of the Engine 

Maintenance Manual (EMM), including 

errors in the formula to determine the 

equivalent flight cycles (FCs) of critical 

parts and errors with certain part 

numbers (P/Ns). The manufacturer also 

determined that the life limit of a 

certain compressor case is not listed in 

the ALS section of the applicable EMM. 

This AD requires recalculating the life 

of critical parts and, depending on the 

results of the recalculation, replacement 

of these critical parts. This AD also 

requires replacement of a certain 

compressor case. The FAA is issuing 

this AD to address the unsafe condition 

on these products. 

DATES: This AD is effective June 30, 

2021. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of June 30, 2021. 

The FAA must receive comments on 

this AD by July 30, 2021. 

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 

https://www.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. 

For service information identified in 

this final rule, contact GE Aviation 

Czech s.r.o., Beranovy ́ch 65, 199 00 

Praha 18, Letnany, Czech Republic; 

phone: +420 222 538 111; fax: +420 222 

538 222. 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–2021–0499. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0499; 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 street address for 

the Docket Operations is listed above. 

FOR FURTHER INFORMATION CONTACT: 

Barbara Caufield, Aviation Safety 

Engineer, ECO Branch, FAA, 1200 

District Avenue, Burlington, MA 01803; 

phone: (781) 238–7146; fax: (781) 238– 

7199; email: barbara.caufield@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The European Union Aviation Safety 

Agency (EASA), which is the Technical 

Agent for the Member States of the 

European Community, has issued EASA 

Emergency AD 2021–0125–E, dated May 

7, 2021 (referred to after this as ‘‘the 

MCAI’’), to address an unsafe condition 

for the specified products. The MCAI 

states: 

Errors have been identified in the ALS 

section of the EMM [Engine Maintenance 

Manual], including errors in the formula to 

determine the equivalent flight cycles of 

critical parts, and certain part numbers. It 

was also determined that, inadvertently, 

certain M601E engines have a compressor 

case P/N M601–154.61 installed, the life 

limit of which is not listed in the ALS section 

of the applicable EMM. 

These conditions, if not corrected, may 

lead to operation of an engine beyond the life 

limit of one or more critical parts, possibly 

resulting in failure of the engine and 

consequent reduced control of the aeroplane. 

To address this potential unsafe 

conditions, GEAC issued [GEAC Alert 

Service Bulletin (ASB) ASB–M601D–72–00– 

00–0075, ASB–M601E–72–00–00–0106, 

ASB–M601F–72–00–00–0057 and ASB– 

M601Z–72–00–00–0057 (issued as a single 

document)], providing instructions to 

recalculate the consumed life of certain 


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critical parts, and [GEAC ASB–M601E–72– 

30–00–0105], providing instructions for 

certain M601E engines to replace the 

compressor case with an eligible part. 

For the reason described above, this 

[EASA] AD requires replacement of critical 

parts, the recalculated life of which exceeds 

the applicable life limit, and replacement of 

the compressor case on certain M601E 

engines. 

You may obtain further information 

by examining the MCAI in the AD 

docket at https://www.regulations.gov 

by searching for and locating Docket No. 

FAA–2021–0499. 

FAA’s Determination 

The FAA is issuing this AD because 

the agency has determined the unsafe 

condition described previously is likely 

to exist or develop in other products of 

the same type design. 

Related Service Information Under 1 

CFR Part 51 

The FAA reviewed GE Aviation Czech 

ASB–M601F–72–00–00–0057 [00], 

ASB–M601E–72–00–00–0106 [00], 

ASB–M601D–72–00–00–0075 [00], and 

ASB–M601Z–72–00–00–0057 [00] 

(single document; formatted as service 

bulletin identifier [revision number]), 

dated May 7, 2021. This ASB specifies 

procedures for calculating consumed 

life of the critical parts. This service 

information is reasonably available 

because the interested parties have 

access to it through their normal course 

of business or by the means identified 

in ADDRESSES. 

Other Related Service Information 

The FAA reviewed GE Aviation Czech 

ASB–M601E–72–30–00–0105 [00] 

(formatted as service bulletin identifier 

[revision number]), dated May 7, 2021. 

This ASB introduces life limits to 

compressor case P/N M601–154.61. 

AD Requirements 

This AD requires recalculating the life 

of critical parts and, depending on the 

results of the recalculation, replacement 

of critical parts. This AD also requires 

replacement of compressor case, part 

number M601–154.61, installed on 

GEAC M601E model turboprop engines. 

Differences Between the AD and the 

Service Information 

EASA Emergency AD 2021–0125–E, 

dated May 7, 2021, applies to GEAC 

M601D, M601D–1, M601D–2, M601D– 

11, M601D–11NZ, M601E, M601E–11, 

M601E–11A, M601E–11AS, M601E– 

11S, M601E–21, M601F, M601FS, 

M601F–11, M601F–22, M601F–32, 

M601T, and M601Z model turboprop 

engines. This AD does not include 

GEAC M601D, M601D–1, M601D–2, 

M601D–11NZ, M601E, M601E–21, 

M601FS, M601F–11, M601F–22, 

M601F–32, M601T, and M601Z model 

turboprop engines as these engine 

models are not type certificated in the 

United States. 

Interim Action 

The FAA considers this AD to be an 

interim action. This unsafe condition is 

still under investigation by the 

manufacturer and, depending on the 

results of that investigation, the FAA 

may consider further rulemaking action. 

Justification for Immediate Adoption 

and Determination of the Effective Date 

Section 553(b)(3)(B) of the 

Administrative Procedure Act (APA) (5 

U.S.C. 551 et seq.) authorizes agencies 

to dispense with notice and comment 

procedures for rules when the agency, 

for ‘‘good cause,’’ finds that those 

procedures are ‘‘impracticable, 

unnecessary, or contrary to the public 

interest.’’ Under this section, an agency, 

upon finding good cause, may issue a 

final rule without providing notice and 

seeking comment prior to issuance. 

Further, section 553(d) of the APA 

authorizes agencies to make rules 

effective in less than thirty days, upon 

a finding of good cause. 

An unsafe condition exists that 

requires the immediate adoption of this 

AD without providing an opportunity 

for public comments prior to adoption. 

The FAA has found that the risk to the 

flying public justifies foregoing notice 

and comment prior to adoption of this 

rule. In May 2021, the FAA received a 

notification from the manufacturer 

about their discovery of errors with the 

formula for calculating the life limit of 

critical parts located in the ALS of the 

EMM. The manufacturer also discovered 

that compressor case, P/N M601–154.61, 

which was modified and installed in 

GEAC M601E model turboprop engines, 

had no corresponding life limit listed in 

the ALS of the corresponding EMM. As 

a result of discovering these errors, the 

manufacturer published service 

information providing instructions to 

update the formula used to recalculate 

life limits on critical parts and introduce 

a life limit for compressor case P/N 

M601–154.61. 

Critical parts exceeding their life 

limits can result in failure of the engine, 

further resulting in uncontained release 

of a critical part, damage to the engine, 

and damage to the airplane. The FAA 

considers the failure of a critical part to 

be an urgent safety issue that requires 

immediate action to avoid damage to the 

engine and airplane. 

Accordingly, notice and opportunity 

for prior public comment are 

impracticable and contrary to the public 

interest pursuant to 5 U.S.C. 

553(b)(3)(B). In addition, the FAA finds 

that good cause exists pursuant to 5 

U.S.C. 553(d) for making this 

amendment effective in less than 30 

days, for the same reasons the FAA 

found good cause to forego notice and 

comment. 

Comments Invited 

The FAA invites you to send any 

written data, views, or arguments about 

this final rule. Send your comments to 

an address listed under ADDRESSES. 

Include ‘‘Docket No. FAA–2021–0499 

and Project Identifier MCAI–2021– 

00571–E’’ at the beginning of your 

comments. The most helpful comments 

reference a specific portion of the final 

rule, 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 this final rule 

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 https://

www.regulations.gov, including any 

personal information you provide. The 

agency will also post a report 

summarizing each substantive verbal 

contact received about this final rule. 

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 AD 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 AD, 

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 AD. Submissions containing CBI 

should be sent to Barbara Caufield, 

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. 

Regulatory Flexibility Act 

The requirements of the Regulatory 

Flexibility Act (RFA) do not apply when 


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Federal Register / Vol. 86, No. 113 / Tuesday, June 15, 2021 / Rules and Regulations 31603 

an agency finds good cause pursuant to 

5 U.S.C. 553 to adopt a rule without 

prior notice and comment. Because FAA 

has determined that it has good cause to 

adopt this rule without prior notice and 

comment, RFA analysis is not required. 

Costs of Compliance 

The FAA estimates that this AD 

affects 9 engines installed on 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 

product 

Cost on U.S. 

operators 

Recalculate life of critical parts ....................... 1 work-hour × $85 per hour = $85 ................. $0 $85 $765 

Replace compressor case .............................. 10 work-hours × $85 per hour = $850 ........... 64,655 65,505 589,545 

The FAA has included all known 

costs in its cost estimate. According to 

the manufacturer, however, some of the 

costs of this AD may be covered under 

warranty, thereby reducing the cost 

impact on affected operators. 

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, 

and 

(2) Will not affect intrastate aviation 

in Alaska. 

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: 

2021–13–07 GE Aviation Czech s.r.o (Type 

Certificate previously held by WALTER 

Engines a.s., Walter a.s., and MOTORLET 

a.s.): Amendment 39–21612; Docket No. 

FAA–2021–0499; Project Identifier MCAI– 

2021–00571–E. 

(a) Effective Date 

This airworthiness directive (AD) is 

effective June 30, 2021. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to GE Aviation Czech 

s.r.o. (GEAC) M601D–11, M601E–11, M601E– 

11A, M601E–11AS, M601E–11S, and M601F 

model turboprop engines. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 7200, Engine (Turbine/Turboprop). 

(e) Unsafe Condition 

This AD was prompted by the 

manufacturer finding errors in the 

Airworthiness Limitation Section (ALS) of 

the Engine Maintenance Manual (EMM), 

including errors in the formula to determine 

the consumed equivalent flight cycles (FCs) 

of critical parts and errors with certain part 

numbers (P/Ns). The manufacturer also 

determined that the life limit of compressor 

case, P/N M601–154.61, installed on certain 

GEAC M601E model engines is not listed in 

the ALS of the applicable EMM. The FAA is 

issuing this AD to prevent the failure of the 

engine. The unsafe condition, if not 

addressed, could result in uncontained 

release of a critical part, damage to the 

engine, and damage to the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

(1) For all affected GEAC model turboprop 

engines, within one FC after the effective 

date of this AD, perform all actions in the 

Accomplishment Instructions, paragraphs 2.1 

through 2.3, of GE Aviation Czech Alert 

Service Bulletin (ASB) ASB–M601F–72–00– 

00–0057 [00], ASB–M601E–72–00–00–0106 

[00], ASB–M601D–72–00–00–0075 [00], and 

ASB–M601Z–72–00–00–0057 [00] (single 

document; formatted as service bulletin 

identifier [revision number]) (the ASB), dated 

May 7, 2021. 

(2) For GEAC M601E–11, M601E–11A, and 

M601F model turboprop engines listed in 

Attachment 1, Group 1 Engines Serial 

Numbers, in the ASB, before the recalculated 

life exceeds the critical part’s life limit or 

within one FC after the effective date of this 

AD, whichever occurs later, replace each 

critical part. 

(3) For GEAC M601D–11, M601E–11AS, 

and M601E–11S model turboprop engines, 

before the recalculated life exceeds the 

critical part’s life limit or within 30 days after 

the effective date of this AD, whichever 

occurs later, replace each critical part. 

(4) For GEAC M601E–11, M601E–11A, 

M601E–11AS, and M601E–11S model 

turboprop engines, before the compressor 

case, P/N M601–154.61, accumulates 11,000 

equivalent FCs or within 350 flight hours 

from the effective date of this AD, whichever 

occurs first, remove the compressor case from 

service and replace it with compressor case, 

P/N M601–154.6 or P/N M601–154.65. 

(h) Installation Prohibition 

After the effective date of this AD, do not 

install onto any airplane an engine with a 

critical part having a recalculated life that 

exceeds the critical part’s life limit as 

specified in the Airworthiness Limitation 

Section (ALS) of the applicable EMM. 

(i) No Reporting Requirement 

The reporting requirement in the 

Accomplishment Instructions, paragraph 

2.2.1.4., of the ASB, is not required by this 

AD. 


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(j) Definitions 

(1) For the purpose of this AD, a ‘‘critical 

part’’ is an engine part listed in paragraph 

2.3.1, Table B—List of Critical Parts and the 

Accelerating Factor, of the ASB. 

(2) For the purpose of this AD, 

‘‘recalculated life’’ is the consumed life of the 

critical part using the recalculation required 

by (g)(1) of this AD. 

(3) For the purpose of this AD, where the 

ASB says the ‘‘applicable Airworthiness 

Limitation Section’’ use the following: 

(i) For affected model engines M601D–1, 

M601D–11, M601D–11NZ, M601D–2, 

M601Z: ‘‘the ALS section of GE Aviation 

Engine Maintenance Manual 0982309.’’ 

(ii) For affected model engines M601E–11, 

M601E–11S, M601E–11A, M601E–11AS, 

M601F, M601FS: ‘‘the ALS section of GE 

Aviation Engine Maintenance Manual 

0982302.’’ 

(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: 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. 

(l) Related Information 

(1) For more information about this AD, 

contact Barbara Caufield, Aviation Safety 

Engineer, ECO Branch, FAA, 1200 District 

Avenue, Burlington, MA 01803; phone: (781) 

238–7146; fax: (781) 238–7199; email: 

barbara.caufield@faa.gov. 

(2) Refer to European Union Aviation 

Safety Agency (EASA) Emergency AD 2021– 

0125–E, dated May 7, 2021, for more 

information. You may examine the EASA AD 

in the AD docket at https://

www.regulations.gov by searching for and 

locating it in Docket No. FAA–2021–0499. 

(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) GE Aviation Czech Alert Service 

Bulletin (ASB) ASB–M601F–72–00–00–0057 

[00], ASB–M601E–72–00–00–0106 [00], 

ASB–M601D–72–00–00–0075 [00], and ASB– 

M601Z–72–00–00–0057 [00] (single 

document; formatted as service bulletin 

identifier [revision number]), dated May 7, 

2021. 

(ii) [Reserved] 

(3) For GE Aviation Czech service 

information identified in this AD, contact GE 

Aviation Czech s.r.o., Beranovy ́ch 65, 199 00 

Praha 18, Letnany, Czech Republic; phone: 

+420 222 538 111; fax: +420 222 538 222. 

(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: fedreg.legal@nara.gov, or go to: 

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

ibr-locations.html. 

Issued on June 10, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–12659 Filed 6–11–21; 11:15 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2020–0341; Project 

Identifier 2020–NM–017–AD; Amendment 

39–21586; AD 2021–11–24] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for certain 

The Boeing Company Model 737–600, 

–700, –700C, –800, –900, and –900ER 

series airplanes. This AD was prompted 

by significant changes made to the 

airworthiness limitations (AWLs) 

related to fuel tank ignition prevention 

and the nitrogen generation system 

(NGS). This AD requires revising the 

existing maintenance or inspection 

program, as applicable, to incorporate 

the April 2019 or November 2020 

revision of the airworthiness limitations 

document. The FAA is issuing this AD 

to address the unsafe condition on these 

products. 

DATES: This AD is effective July 20, 

2021. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of July 20, 2021. 

ADDRESSES: For service information 

identified in this final rule, 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. 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. 

It is also available on the internet at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2020–0341. 

Examining the AD Docket 

You may examine the AD docket on 

the internet at https://

www.regulations.gov by searching for 

and locating Docket No. FAA–2020– 

0341; 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: 

Christopher Baker, Aerospace Engineer, 

Propulsion Section, FAA, Seattle ACO 

Branch, 2200 South 216th St., Des 

Moines, WA 98198; phone and fax: 206– 

231–3552; email: Christopher.R.Baker@

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 The Boeing Company 

Model 737–600, –700, –700C, –800, 

–900, and –900ER series airplanes. The 

NPRM published in the Federal 

Register on May 6, 2020 (85 FR 26888). 

The NPRM was prompted by significant 

changes made to the AWLs related to 

fuel tank ignition prevention and the 

NGS. The NPRM proposed to require 

revising the existing maintenance or 

inspection program, as applicable, to 

incorporate the April 2019 revision of 

the airworthiness limitations document. 

The FAA is issuing this AD to prevent 

the potential for ignition sources inside 

the fuel tanks and also to prevent 

increasing the flammability exposure of 

the center fuel tank caused by latent 

failures, alterations, repairs, or 

maintenance actions, which could result 

in a fuel tank explosion and consequent 

loss of an airplane. In addition, the FAA 

is issuing this AD to address the 

potential loss of engine fuel suction feed 


khammond on DSKJM1Z7X2PROD with RULES