10780 Federal Register / Vol. 86, No. 34 / Tuesday, February 23, 2021 / Rules and Regulations 

2020, uses the phrase ‘‘the original issue date 

of Requirements Bulletin 737–53A1383 RB’’ 

in a note or flag note. 

(2) Where Boeing Alert Requirements 

Bulletin 737–53A1383 RB, Revision 1, dated 

February 19, 2020, specifies contacting 

Boeing for repair instructions or for 

alternative inspections: This AD requires 

doing the repair, or doing the alternative 

inspections and applicable on-condition 

actions, using a method and compliance time 

approved in accordance with the procedures 

specified in paragraph (j) of this AD. 

(3) Where Boeing Alert Requirements 

Bulletin 737–53A13833 RB, Revision 1, dated 

February 19, 2020, in Tables 1 and 2, 

Condition 1 (Action 1), Condition 3, and 

Condition 4.1.1 (Action 1), specifies a 

compliance time of ‘‘before further flight’’: 

This AD requires compliance before 15,000 

total flight cycles or within 6,000 flight 

cycles after the effective date of this AD, 

whichever occurs later. 

(i) Credit for Previous Actions 

This paragraph provides credit for the 

actions specified in paragraph (g) of this AD, 

if those actions were performed before the 

effective date of this AD, using Boeing Alert 

Requirements Bulletin 737–53A1383 RB, 

dated May 9, 2019, except for airplanes on 

which Option 2, Condition 4, has been done. 

For airplanes on which Option 2, Condition 

4, has been done, credit is given for Boeing 

Alert Requirements Bulletin 737–53A1383 

RB, dated May 9, 2019, provided operators 

do the external low frequency eddy current 

(LFEC) inspection of the forward galley door 

bear strap and external high frequency eddy 

current (HFEC) inspection of the fuselage 

skin for any crack in accordance with Figure 

4 of the Accomplishment Instructions of 

Boeing Alert Requirements Bulletin 737– 

53A1383 RB, Revision 1, dated February 19, 

2020. The compliance time for 

accomplishing these actions is at the later of 

the times specified in paragraphs (i)(1) and 

(2) of this AD. Except as specified in 

paragraph (h)(3), do all applicable oncondition actions identified in, and in 

accordance with, the Accomplishment 

Instructions of Boeing Alert Requirements 

Bulletin 737–53A1383 RB, Revision 1, dated 

February 19, 2020, at the applicable times 

specified in the ‘‘Compliance’’ paragraph of 

Boeing Alert Requirements Bulletin 737– 

53A1383 RB, Revision 1, dated February 19, 

2020. 

(1) Before 15,000 total flight cycles. 

(2) Within 6,000 flight cycles after the 

effective date of this AD. 

(j) 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 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. Information may be emailed to: 9- 

ANM-Seattle-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 local flight standards district office/ 

certificate holding district 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, 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. 

(k) Related Information 

(1) For more information about this AD, 

contact Michael Bumbaugh, Aerospace 

Engineer, Airframe Section, FAA, Seattle 

ACO Branch, 2200 South 216th St., Des 

Moines, WA 98198; phone and fax: 206–231– 

3522; email: michael.bumbaugh@faa.gov. 

(2) Service information identified in this 

AD that is not incorporated by reference is 

available at the addresses specified in 

paragraphs (l)(3) and (4) of this AD. 

(l) Material Incorporated by Reference 

(1) The Director of the Federal Register 

approved the incorporation by reference 

(IBR) of the service information listed in this 

paragraph under 5 U.S.C. 552(a) and 1 CFR 

part 51. 

(2) You must use this service information 

as applicable to do the actions required by 

this AD, unless the AD specifies otherwise. 

(i) Boeing Alert Requirements Bulletin 

737–53A1383 RB, Revision 1, dated February 

19, 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; 

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

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

Issued on January 14, 2021. 

Gaetano A. Sciortino, 

Deputy Director for Strategic Initiatives, 

Compliance & Airworthiness Division, 

Aircraft Certification Service. 

[FR Doc. 2021–03572 Filed 2–22–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2020–0331; Product 

Identifier 2020–NM–019–AD; Amendment 

39–21397; AD 2021–02–14] 

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 a report that the necessary sealant 

was not applied to the side of body 

(SOB) slot as a result of a production 

drawing that provided unclear SOB slot 

sealant application instructions. This 

AD requires a general visual inspection 

for insufficient sealant in the SOB slot, 

and related investigative and corrective 

actions. The FAA is issuing this AD to 

address the unsafe condition on these 

products. 

DATES: This AD is effective March 30, 

2021. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of March 30, 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–2020–0331. 

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– 

0331; 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 

Federal Register / Vol. 86, No. 34 / Tuesday, February 23, 2021 / Rules and Regulations 10781 

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: 

James Laubaugh, Aerospace Engineer, 

Propulsion Section, FAA, Seattle ACO 

Branch, 2200 South 216th St., Des 

Moines, WA 98198; phone and fax: 206– 

231–3622; email: james.laubaugh@

faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

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 26893). 

The NPRM was prompted by a report 

indicating that the necessary sealant 

was not applied to the SOB slot as a 

result of a production drawing 

providing unclear SOB slot sealant 

application instructions on certain The 

Boeing Company Model 737–600, –700, 

–700C, –800, –900, and –900ER series 

airplanes. The NPRM proposed to 

require a general visual inspection for 

insufficient sealant in the SOB slot, and 

related investigative and corrective 

actions. 

The FAA is issuing this AD to address 

fuel leaking into the air distribution mix 

bay (ADMB), which if not addressed, 

could possibly lead to an ignition of 

flammable fluid vapors, fire, or 

explosion, or fuel vapor inhalation by 

passengers and crew. 

Comments 

The FAA gave the public the 

opportunity to participate in developing 

this final rule. The following presents 

the comments received on the NPRM 

and the FAA’s response to each 

comment. 

Supportive Comment 

United Airlines stated it had no 

technical objection to the NPRM. 

Effects of Winglets on Accomplishment 

of the Proposed Actions 

Aviation Partners Boeing stated that 

the installation of blended or split 

scimitar winglets per Supplemental 

Type Certificate (STC) ST00830SE does 

not affect compliance with the proposed 

actions. 

The FAA agrees with the commenter 

that STC ST00830SE does not affect the 

accomplishment of the manufacturer’s 

service instructions. Therefore, the 

installation of STC ST00830SE does not 

affect the ability to accomplish the 

actions required by this AD. The FAA 

has not changed this AD in this regard. 

Request To Reference Later Revision of 

Multi Operator Message (MOM) 

Boeing requested that the FAA revise 

the proposed AD to reference a later 

revision of the MOM, specifically, 

Boeing Multi Operator Message MOM– 

MOM–20–0049–01B(R2), with an 

anticipated publication date of July 31, 

2020. Boeing stated that the revision has 

improved illustration and work 

instructions, clarifies how to distinguish 

between certain application flaws and 

more severe flaws and deterioration, 

and provides relief from certain 

corrective actions for certain secondary 

fuel barrier coating conditions. 

The FAA agrees to reference a later 

revision of the service information. 

However, Boeing has released 

additional later revisions that provide 

additional clarity. Boeing Multi 

Operator Message MOM–MOM–20– 

0049–01B(R4), dated September 28, 

2020, provides clarification on the 

definitions of sufficient sealant in the 

SOB slot, fillet seal in the SOB slot, and 

secondary fuel barrier. It also provides 

clarifications to the inspection area, and 

revisions were made to improve the 

identification of applicable figures. The 

changes in the revision provide relief on 

repairs of serviceable secondary fuel 

barrier coating. This later revision 4 

contains no substantive change from 

MOM–MOM–20–0049–01B(R1), dated 

January 29, 2020. The FAA has revised 

paragraphs (g) and (i) of this AD to 

reference Boeing Multi Operator 

Message MOM–MOM–20–0049– 

01B(R4), dated September 28, 2020. The 

FAA has also added paragraph (j) to this 

AD to provide credit for accomplishing 

certain earlier revisions of this service 

information before the effective date of 

this AD. 

Request To Define Type of Inspection 

Required 

Delta Air Lines (Delta) requested 

clarification on what type of inspection 

is needed to accomplish the inspection 

requirements. Delta noted that in the 

General Notes section of the attachment 

to Boeing Multi Operator Message 

MOM–MOM–20–0049–01B(R2), dated 

August 4, 2020, the MOM provides a 

definition of a detailed inspection. 

However, Delta noted that because 

‘‘detailed inspection’’ is not used in 

other parts of the service information, it 

seems the definition of a detailed visual 

inspection should have been provided 

instead. Delta stated that this 

inconsistency could lead to an inability 

to comply with the instructions in the 

MOM. 

The FAA agrees to clarify. As stated 

previously, the FAA has revised this AD 

to reference Boeing Multi Operator 

Message MOM–MOM–20–0049– 

01B(R4), dated September 28, 2020, and 

in this later revision, both the steps and 

General Notes refer to ‘‘detailed 

inspection’’ as well as ‘‘general visual 

inspection.’’ The FAA has removed 

paragraph (g) of the proposed AD as this 

definition is no longer needed. The FAA 

has redesignated subsequent paragraphs 

accordingly. 

Request To Clarify Figures 

Alaska Airlines (Alaska) and Delta 

requested that the figures within Boeing 

Multi Operator Message MOM–MOM– 

20–0049–01B(R1), dated January 29, 

2020, be revised to add clarity. Alaska 

and Delta stated that the figures lack 

clear reference links from the text to the 

figures. Delta also stated that not 

addressing the unclear figures could 

lead to incorrect accomplishment of the 

SOB slot inspection. 

The FAA agrees that the figures are 

unclear and the internal reference links 

need to be revised. As stated previously, 

this AD has been revised to reference 

Boeing Multi Operator Message MOM– 

MOM–20–0049–01B(R4), dated 

September 28, 2020, which contains 

improved figure references. No further 

changes to this AD have been made. 

Request To Clarify Inspection Area and 

Acceptance Criteria for Sealant 

Alaska, Delta, and Southwest Airlines 

requested clarification on what is 

considered to be acceptable or 

insufficient sealant in the SOB slot. 

Alaska and Delta requested that the 

inspection area and acceptance criteria 

for sealant in the SOB slot and 

secondary fuel barrier be clarified. 

Southwest Airlines proposed a 

compliance table be added to the 

proposed AD to define acceptable 

sealant conditions, and Alaska 

supported Southwest Airlines’ idea. 

Delta also suggested that the unclear 

criteria for sealant could lead to 

incorrect accomplishment of the SOB 

slot inspection. 

The FAA agrees that the criteria for 

acceptable sealant are unclear. As 

described above, the FAA has revised 

this AD to refer to Boeing Multi 

Operator Message MOM–MOM–20– 

0049–01B(R4), dated September 28, 

2020, which clarifies the area of 

inspection and the acceptable 

conditions of the sealant. 

10782 Federal Register / Vol. 86, No. 34 / Tuesday, February 23, 2021 / Rules and Regulations 

Request To Clarify an Inspection Area 

Delta requested clarification on the 

inspection area addressed in certain 

portions (Part 2, Step 3 and View 2D21’s 

flagnote 63) of Boeing Multi Operator 

Message MOM–MOM–20–0049– 

01B(R1), dated January 29, 2020. Delta 

stated that those parts could be 

interpreted to specify that the entire 

front spar of the center tank must be 

inspected for the fillet seal and SOB 

slot, or only the SOB slot area. 

The FAA agrees that the 

specifications of the area to be inspected 

should be clearer. As discussed above, 

the FAA has revised this AD to 

reference Boeing Multi Operator 

Message MOM–MOM–20–0049– 

01B(R4), dated September 28, 2020, 

which clarifies that only the SOB slot 

area must be inspected as shown in 

Figure 1 of Boeing Multi Operator 

Message MOM–MOM–20–0049– 

01B(R4), dated September 28, 2020. No 

additional changes to this AD have been 

made. 

Request To Add Service-Based 

Compliance Time 

Southwest Airlines requested that a 

service-based compliance time be added 

to the calendar-based compliance time 

proposed in the NPRM. Southwest 

Airlines proposed that the compliance 

time be re-written to require compliance 

within ‘‘9 months or 2,000 flight cycles 

from AD effective date, whichever 

occurs later.’’ Southwest Airlines 

pointed out that due to the reduced 

flight schedules in response to the 

COVID–19 pandemic, many airplanes 

are in long-term storage. Southwest 

Airlines added that some of these longterm storage facilities might not be 

capable of providing heavy 

maintenance, and airplanes would need 

to be ferried to a facility where these 

actions may be accomplished. 

The FAA disagrees with adding the 

2,000 flight cycles to the compliance 

time. In developing an appropriate 

compliance time, the FAA considered 

the safety implications, parts 

availability, and normal maintenance 

schedules. In consideration of all of 

these factors, the FAA determined that 

the compliance time, as proposed, 

represents an appropriate interval for 

the general visual inspection for 

insufficient sealant in the SOB slot 

within the fleet, while still maintaining 

an adequate level of safety. However, 

under the provisions of paragraph (k) of 

this AD, the FAA will consider requests 

for approval of an extension of the 

compliance time if sufficient data are 

submitted to substantiate that the new 

compliance time would provide an 

acceptable level of safety. The FAA has 

not changed this AD in this regard. 

Request To Extend Compliance Time 

Alaska requested that an additional 

compliance time deferral of 24 months 

be allowed under the following 

conditions: No fuel contamination in 

the ADMB; no external leak or signs of 

a previous external leak around the SOB 

slot; insufficient sealing conditions 

temporarily corrected with PR–1826 B– 

1/4 sealant or SF5387 secondary fuel 

barrier materials, in accordance with 

certain service information instructions; 

and repetitive inspections for fuel 

contamination of the ADMB done at 

intervals not to exceed 12 months until 

the repair specified in paragraph (g) of 

this AD is completed. Alaska stated that 

the extended compliance time would 

relieve some of the operational impact 

and would aid in planning for the timeintensive repair during a heavy 

maintenance visit. 

The FAA does not agree to provide a 

24-month compliance time for the 

repair. The technical specifications 

provided for the proposed alternative 

sealant for temporary repair do not 

provide the FAA with enough 

information to determine that the 

temporary repair would comply with 

the certification basis of the airplane 

and provide an acceptable level of safety 

when incorporated into the existing fuel 

system design. There is also insufficient 

information on how the procedures for 

use in the temporary repair would differ 

from the permanent repair. However, 

under the provisions of paragraph (k) of 

this AD, the FAA will consider requests 

for approval of an extension of the 

repair compliance time if sufficient data 

are submitted to substantiate that the 

conditions and temporary repair would 

provide an acceptable level of safety. 

The FAA has not changed this AD in 

this regard. 

Request To Allow Removing Certain 

Other Parts To Gain Inspection Access 

American Airlines and Delta 

requested a revision to the proposed AD 

to allow removing the air return grilles 

or sidewall panels to expose a hole in 

a beam above the SOB slot area so the 

inspection of the sealant can be done 

through the opening. Both commenters 

stated that the access procedure 

specified in Boeing Multi Operator 

Message MOM–MOM–20–0049– 

01B(R1), dated January 29, 2020, 

removes seats and cabin floor panels to 

gain access to the inspection area. 

American Airlines also stated that 

allowing the alternative access 

procedure for the inspection would 

reduce the amount of time necessary to 

accomplish an inspection of the SOB 

slot, and that accomplishing any 

required corrective action would then 

require the removal of seats and cabin 

floor panels to gain access to the SOB 

slot area. 

The FAA agrees that the inspection 

could be accomplished by removing the 

air return grilles or sidewall panels. As 

discussed previously, the FAA has 

revised this AD to reference Boeing 

Multi Operator Message MOM–MOM– 

20–0049–01B(R4), dated September 28, 

2020, which does contain this 

additional method of compliance for 

accessing the inspection area. The FAA 

has not made any additional revisions to 

this AD in this regard. 

Request To Allow Use of Alternative 

Sealant 

Alaska stated that the sealant AC–360 

B1/2, which is specified as the sealant 

to use to fill a void, is discontinued. The 

FAA infers that Alaska wants the AD to 

be revised to remove reference to the 

discontinued sealant. 

The FAA agrees that the sealant AC– 

360 B1/2 has been discontinued. As 

discussed above, this AD has been 

revised to reference Boeing Multi 

Operator Message MOM–MOM–20– 

0049–01B(R4), dated September 28, 

2020, which removes the reference to 

the sealant AC–360 B1/2, but retains the 

reference to sealant BMS 5–142, which 

is the appropriate sealant to use. The 

FAA has not made any further changes 

to this AD in this regard. 

Request To Use Faster-Curing Sealants 

Alaska requested that the FAA allow 

alternative sealants that cure faster than 

the ones specified in the service 

information. Alaska suggested allowing 

the use of sealant PR–1826 B1/4 in place 

of BMS 5–142, and SF5387 in place of 

BMS 5–81. Alaska also provided 

technical data sheets for the proposed 

sealants. Alaska noted that use of the 

slower-curing sealants could result in an 

airplane being out of service for up to 

34 hours, and that time could be 

reduced by use of faster-curing sealants 

that provide an equivalent level of 

safety. 

The FAA agrees that the alternative 

sealants would provide a faster cure 

time. However, the FAA does not have 

enough data to determine if the 

alternative sealants comply with the 

certification basis of the airplane and if 

they will provide an acceptable level of 

safety when incorporated into the 

existing fuel system design. The FAA 

will consider requests for alternative 

sealants as an alternative method of 

compliance if requested using the 

procedure specified in paragraph (k) of 

Federal Register / Vol. 86, No. 34 / Tuesday, February 23, 2021 / Rules and Regulations 10783 

this AD. The FAA has not changed the 

AD in this regard. 

Conclusion 

The FAA reviewed the relevant data, 

considered the comments received, and 

determined that air safety and the 

public interest require adopting this 

final rule with the changes described 

previously and minor editorial changes. 

The FAA has determined that these 

minor changes: 

• Are consistent with the intent that 

was proposed in the NPRM for 

addressing the unsafe condition; and 

• Do not add any additional burden 

upon the public than was already 

proposed in the NPRM. 

The FAA also determined that these 

changes will not increase the economic 

burden on any operator or increase the 

scope of this final rule. 

Related Service Information Under 1 

CFR Part 51 

The FAA reviewed Boeing Multi 

Operator Message MOM–MOM–20– 

0049–01B(R4), dated September 28, 

2020. This service information describes 

procedures for a general visual 

inspection for insufficient sealant in the 

SOB slot. The service information also 

describes procedures for related 

investigative actions including a general 

visual inspection of the ADMB for fuel 

contamination, a check for external 

leaks of the center fuel tank external 

surfaces inside the pressure boundary, 

and an internal leak check of the center 

fuel tank to identify the leakage path(s). 

The service information also describes 

procedures for corrective actions 

including removal of all insulation 

blankets below the crease beam (left 

side to right side), clean-up of all fuel 

contamination, repair of any leak, 

preparation of the SOB slot for sealing, 

application of sealant, and repair of the 

secondary fuel barrier. 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. 

Costs of Compliance 

The FAA estimates that this AD 

affects 731 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 

Inspection for sealant ...................................... 30 work-hours × $85 per hour = $2,550 ........ $0 $2,550 $1,864,050 

The FAA estimates the following 

costs to do any necessary repairs that 

would be required based on the results 

of the inspection. The FAA has no way 

of determining the number of aircraft 

that might need these repairs: 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

product 

Repair of sealant .......................................................... 2 work-hours × $85 per hour = $170 ........................... $129 $299 

Insulation blanket replacement ..................................... 24 work-hours × $85 per hour = $2,040 ...................... 6,312 8,352 

Leak checks .................................................................. 6 work-hours × $85 per hour = $510 ........................... 0 510 

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. 

Adoption of 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: 

2021–02–14 The Boeing Company: 

Amendment 39–21397 ; Docket No. 

FAA–2020–0331; Product Identifier 

2020–NM–019–AD. 

(a) Effective Date 

This airworthiness directive (AD) is 

effective March 30, 2021. 

(b) Affected ADs 

None. 

10784 Federal Register / Vol. 86, No. 34 / Tuesday, February 23, 2021 / Rules and Regulations 

(c) Applicability 

This AD applies to The Boeing Company 

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

and –900ER series airplanes, certificated in 

any category, line numbers 1 through 1934 

inclusive. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 28, Fuel. 

(e) Unsafe Condition 

This AD was prompted by a report that 

sealant was not applied to the side of body 

(SOB) slot inside of a pressurized boundary, 

which could lead to inconsistent application 

of the required secondary fuel barrier sealant 

(vapor barrier). The FAA is issuing this AD 

to address possible ignition of flammable 

fluid vapors, fire, or explosion, or fuel vapor 

inhalation by passengers and crew. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) SOB Slot Inspection and Related 

Investigative and Corrective Actions 

Within 9 months after the effective date of 

this AD: Do a general visual inspection for 

insufficient sealant in the SOB slot, and do 

all applicable related investigative and 

corrective actions, in accordance with Boeing 

Multi Operator Message MOM–MOM–20– 

0049–01B(R4), dated September 28, 2020. Do 

all related investigative and corrective 

actions before further flight, except as 

provided in paragraph (h) of this AD. 

(h) Deferred Repair 

Repair of insufficient sealant as required by 

paragraph (g) of this AD may be deferred for 

10 days provided there is no fuel present in 

the center tank as specified in the procedures 

in item 28–02A of the operator’s existing 

FAA-approved minimum equipment list, and 

there is no fuel contamination in the air 

distribution mix bay (ADMB). 

(i) Reporting Provisions 

Although the service information 

referenced in Boeing Multi Operator Message 

MOM–MOM–20–0049–01B(R4), dated 

September 28, 2020, specifies to report 

inspection findings, this AD does not require 

any report. 

(j) Credit for Previous Actions 

This paragraph provides credit for the 

actions specified in paragraphs (g), (h), and 

(i) of this AD, if those actions were performed 

before the effective date of this AD using the 

service information identified in paragraph 

(j)(1), (2), or (3) of this AD. 

(1) Boeing Multi Operator Message MOM– 

MOM–20–0049–01B(R1), dated January 29, 

2020. 

(2) Boeing Multi Operator Message MOM– 

MOM–20–0049–01B(R2), dated August 4, 

2020. 

(3) Boeing Multi Operator Message MOM– 

MOM–20–0049–01B(R3), dated September 

23, 2020. 

(k) 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 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 (l)(1) of 

this AD. Information may be emailed to: 9- 

ANM-Seattle-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 local flight standards district office/ 

certificate holding district 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. 

(l) Related Information 

(1) For more information about this AD, 

contact James Laubaugh, Aerospace Engineer, 

Propulsion Section, FAA, Seattle ACO 

Branch, 2200 South 216th St., Des Moines, 

WA 98198; phone and fax: 206–231–3622; 

email: james.laubaugh@faa.gov. 

(2) Service information identified in this 

AD that is not incorporated by reference is 

available at the addresses specified in 

paragraphs (m)(3) and (4) of this AD. 

(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) Boeing Multi Operator Message MOM– 

MOM–20–0049–01B(R4), dated September 

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

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

Issued on January 14, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–03592 Filed 2–22–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2020–0467; Product 

Identifier 2020–NM–056–AD; Amendment 

39–21399; AD 2021–02–16] 

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 all The 

Boeing Company Model 717–200 

airplanes. This AD was prompted by a 

report that during takeoff, both the 

captain’s and first officer’s airspeed 

indications froze at 80 knots. This AD 

requires modifying the air data heat 

(ADH) system to display the proper 

airspeed indications, testing, and any 

applicable corrective actions. The FAA 

is issuing this AD to address the unsafe 

condition on these products. 

DATES: This AD is effective March 30, 

2021. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of March 30, 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–2020–0467. 

Examining the AD Docket 

You may examine the AD docket on 

the internet at https://