Federal Register / Vol. 87, No. 66 / Wednesday, April 6, 2022 / Proposed Rules 19811 

allowed to make a general statement 

(within time limits determined by DOE), 

before the discussion of specific topics. 

DOE will permit, as time permits, other 

participants to comment briefly on any 

general statements. 

At the end of all prepared statements 

on a topic, DOE will permit participants 

to clarify their statements briefly. 

Participants should be prepared to 

answer questions by DOE and by other 

participants concerning these issues. 

DOE representatives may also ask 

questions of participants concerning 

other matters relevant to this 

rulemaking. The official conducting the 

webinar will accept additional 

comments or questions from those 

attending, as time permits. The 

presiding official will announce any 

further procedural rules or modification 

of the above procedures that may be 

needed for the proper conduct of the 

webinar. 

A transcript of the webinar will be 

included in the docket, which can be 

viewed as described in the Docket 

section at the beginning of this 

document. In addition, any person may 

buy a copy of the transcript from the 

transcribing reporter. 

Signing Authority 

This document of the Department of 

Energy was signed on April 1, 2022, by 

Kelly J. Speakes-Backman, Principal 

Deputy Assistant Secretary for Energy 

Efficiency and Renewable Energy, 

pursuant to delegated authority from the 

Secretary of Energy. That document 

with the original signature and date is 

maintained by DOE. For administrative 

purposes only, and in compliance with 

requirements of the Office of the Federal 

Register, the undersigned DOE Federal 

Register Liaison Officer has been 

authorized to sign and submit the 

document in electronic format for 

publication, as an official document of 

the Department of Energy. This 

administrative process in no way alters 

the legal effect of this document upon 

publication in the Federal Register. 

Signed in Washington, DC, on April 1, 

2022. 

Treena V. Garrett, 

Federal Register Liaison Officer, U.S. 

Department of Energy. 

[FR Doc. 2022–07278 Filed 4–5–22; 8:45 am] 

BILLING CODE 6450–01–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2021–0891; Notice No. 25– 

21–04–SC] 

Special Conditions: Airbus Model 

A321neoXLR Airplane; Passenger 

Protection From External Fire 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed special 

conditions. 

SUMMARY: This action proposes special 

conditions for the Airbus Model 

A321neoXLR airplane. This airplane 

will have a novel or unusual design 

feature when compared to the 

technology envisaged by the 

airworthiness standards for transport 

category airplanes. This design feature 

is an integral rear center tank (RCT). The 

applicable airworthiness regulations do 

not contain adequate or appropriate 

safety standards for this design feature. 

These proposed special conditions 

contain the additional safety standards 

that the Administrator considers 

necessary to establish a level of safety 

equivalent to that established by the 

existing airworthiness standards. 

DATES: Send comments on or before 

May 23, 2022. 

ADDRESSES: Send comments identified 

by Docket No. FAA–2021–0891 using 

any of the following methods: 

• Federal eRegulations Portal: Go to 

http://www.regulations.gov/ and follow 

the online instructions for sending your 

comments electronically. 

• Mail: Send comments to Docket 

Operations, M–30, U.S. Department of 

Transportation (DOT), 1200 New Jersey 

Avenue SE, Room W12–140, West 

Building Ground Floor, Washington, DC 

20590–0001. 

• Hand Delivery or Courier: Take 

comments to Docket Operations in 

Room W12–140 of the West Building 

Ground Floor at 1200 New Jersey 

Avenue SE, Washington, DC, between 9 

a.m. and 5 p.m., Monday through 

Friday, except Federal holidays. 

• Fax: Fax comments to Docket 

Operations at 202–493–2251. 

Privacy: 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 http://

www.regulations.gov/, including any 

personal information you provide. The 

FAA will also post a report 

summarizing each substantive verbal 

contact received about this proposal. 

Confidential Business Information: 

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 Notice 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 

Notice, 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 the indicated 

comments will not be placed in the 

public docket of this Notice. 

Submissions containing CBI should be 

sent to Shannon Lennon, Human 

Machine Interface, AIR–626, Technical 

Innovation Policy Branch, Policy and 

Innovation Division, Aircraft 

Certification Service, Federal Aviation 

Administration, 2200 South 216th 

Street, Des Moines, Washington 98198; 

telephone and fax 206–231–3209; email 

shannon.lennon@faa.gov. Comments 

the FAA receives, which are not 

specifically designated as CBI, will be 

placed in the public docket for this 

rulemaking. 

Docket: Background documents or 

comments received may be read at 

http://www.regulations.gov/ at any time. 

Follow the online instructions for 

accessing the docket or go to Docket 

Operations in Room W12–140 of the 

West Building Ground Floor at 1200 

New Jersey Avenue SE, Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

FOR FURTHER INFORMATION CONTACT: 

Shannon Lennon, Human Machine 

Interface, AIR–626, Technical 

Innovation Policy Branch, Policy and 

Innovation Division, Aircraft 

Certification Service, Federal Aviation 

Administration, 2200 South 216th 

Street, Des Moines, Washington 98198; 

telephone and fax 206–231–3209; email 

shannon.lennon@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites interested people to 

take part in this rulemaking by sending 

written comments, data, or views. The 

most helpful comments reference a 

specific portion of the special 

conditions, explain the reason for any 


lotter on DSK11XQN23PROD with PROPOSALS1
19812 Federal Register / Vol. 87, No. 66 / Wednesday, April 6, 2022 / Proposed Rules 

1See pg. 2 of FAA Advisory Circular 25.856–2A, 

Installation of Thermal/Acoustic Insulation for 

Burnthrough Protection (Jul. 29, 2008), available at 

drs.faa.gov. 

2 Improved Flammability Standards for Thermal/ 

Acoustic Insulation Materials Used In Transport 

Category Airplanes, 68 FR 45046, 45049 (Jul. 31, 

2003). 

recommended change, and include 

supporting data. 

The FAA will consider all comments 

received by the closing date for 

comments. The FAA may change these 

special conditions based on the 

comments received. 

Background 

On September 16, 2019, Airbus 

applied for an amendment to Type 

Certificate No. A28NM to include the 

new Model A321neoXLR airplane. The 

Model A321neoXLR airplane, which is 

a derivative of the Model A321neoACF 

airplane currently approved under Type 

Certificate No. A28NM, is a twin-engine 

transport category aircraft that seats 244 

passengers and has a maximum takeoff 

weight of 202,000 lbs. 

Type Certification Basis 

Under the provisions of title 14, Code 

of Federal Regulations (14 CFR) 21.101, 

Airbus must show that the Model 

A321neoXLR airplane meets the 

applicable provisions of the regulations 

listed in Type Certificate No. A28NM, or 

the applicable regulations in effect on 

the date of application for the change, 

except for earlier amendments as agreed 

upon by the FAA. 

If the Administrator finds that the 

applicable airworthiness regulations 

(e.g., 14 CFR part 25) do not contain 

adequate or appropriate safety standards 

for the Airbus Model A321NeoXLR 

airplane because of a novel or unusual 

design feature, special conditions are 

prescribed under the provisions of 

§ 21.16. 

Special conditions are initially 

applicable to the model for which they 

are issued. Should the type certificate 

for that model be amended later to 

include any other model that 

incorporates the same novel or unusual 

design feature, or should any other 

model already included on the same 

type certificate be modified to 

incorporate the same novel or unusual 

design feature, these special conditions 

would also apply to the other model 

under § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the Airbus Model 

A321NeoXLR airplane must comply 

with the fuel vent and exhaust emission 

requirements of 14 CFR part 34 and the 

noise certification requirements of 14 

CFR part 36. 

The FAA issues special conditions, as 

defined in 14 CFR 11.19, in accordance 

with § 11.38, and they become part of 

the type certification basis under 

§ 21.101. 

Novel or Unusual Design Feature 

The Airbus Model A321NeoXLR 

airplane will incorporate the following 

novel or unusual design feature: 

An integral RCT. 

Discussion 

The proposed Airbus Model 

A321neoXLR incorporates an integral 

RCT. This tank is a ‘‘center’’ fuel tank, 

in that would, if approved, be located in 

the airplane fuselage rather than in its 

wings. The tank is a ‘‘rear’’ tank, that 

would be located aft of the wheel bay; 

it would be in an area of the lower 

fuselage that partially replaces the aft 

cargo compartment of the airplane from 

which this proposed model is derived. 

The top of the tank would be directly 

below the floor of the passenger cabin. 

The fuel tank would be ‘‘integral’’ to the 

airplane, in that its walls would be part 

of the airplane structure. The exterior 

skin of the airplane fuselage would 

constitute part of the walls of the fuel 

tank, and these areas would lack the 

thermal/acoustic insulation that usually 

lines the exterior skin of an airplane 

fuselage. 

This proposed design was not 

envisaged by the FAA’s regulatory 

requirements for insulation installations 

on transport category airplanes. 14 CFR 

25.856(b) requires all thermal/acoustic 

insulation in the lower half of the 

airplane fuselage and their installation 

to comply with the flame penetration 

resistance test of Appendix F Part VII. 

The FAA adopted § 25.856(b) to raise 

the level of post-crash fire safety on 

transport category airplanes. Part VII of 

Appendix F requires a stringent test 

method for all thermal/acoustic 

insulation proposed for installation in 

the lower half of the fuselage. The 

FAA’s intent in imposing this 

requirement was to ensure that this 

insulation provides an additional barrier 

between the occupants and an external 

post-crash fire, especially a fire resulting 

from a pool of spilled aviation fuel.1

This barrier extends the time available 

for evacuation. 

While the rule applies to the thermal/ 

acoustic insulation that an applicant 

proposes as part of their design, it does 

not require applicants to install such 

insulation. Since the fuselage skins of 

the lower half of transport category 

airplanes are generally insulated, and 

were at the time these standards were 

developed, the FAA considered this 

approach to be sufficient to ensure 

safety. The rulemaking also noted, 

however, that if applicants began to 

propose designs that omitted this 

thermal/acoustic insulation, the FAA 

would revisit the need for a specific 

fuselage burnthrough standard.2

Thus, since this proposed design will 

lack thermal/acoustic insulation under 

the fuselage skin in the area of the fuel 

tank, current FAA regulations do not 

ensure that it will provide a continuous 

flame penetration (burnthrough) 

resistant barrier between the passengers 

and an external fire, nor that it will 

provide enough protection, against an 

external post-crash fire, to allow time 

for passengers to evacuate. 

According to Airbus, its proposed 

design does not allow for compliant 

thermal/acoustic insulation to be placed 

beneath the cabin floor. This large 

volume of unheated liquid (fuel), 

directly below the floor of the passenger 

cabin, would, without mitigation, create 

a ‘cold feet’ effect for the passengers 

above it. Therefore, Airbus plans to 

install insulation panels between the 

fuel tank and the cabin floor, for comfort 

reasons. These insulation panels would 

normally be required to meet 

§ 25.856(b). However, Airbus states that 

it is technically not feasible to install 

thermal/acoustic insulation that 

complies with § 25.856(b), due to the 

lack of space in this area, and the need 

to keep nearby decompression panels 

free of blockages and ensure adequate 

ventilation. 

To address the assumption in the 

FAA’s current flammability standards 

that proposed airplane designs would 

include thermal/acoustic insulation in 

the lower fuselage, and to ensure that 

this proposed design does not reduce 

the time available for passenger 

evacuation in the case of a post-crash 

external fire, special conditions are 

needed. Specifically, the FAA proposes 

to require that the lower half of the 

airplane fuselage, spanning the 

longitudinal area of the tank, be 

resistant to fire penetration. ‘‘Resistant 

to fire penetration’’ would, for this 

special condition, mean that this area 

provides fire penetration resistance 

equivalent to the resistance which 

would be provided if the fuselage were 

lined with thermal/acoustic insulation 

that meets the flame penetration 

resistance test requirements of part VII 

of Appendix F. The applicant’s method 

of compliance may, but is not required 

to, be based upon any inherent flame 

penetration resistance capability 


lotter on DSK11XQN23PROD with PROPOSALS1
Federal Register / Vol. 87, No. 66 / Wednesday, April 6, 2022 / Proposed Rules 19813 

provided by the construction of the fuel 

tank and/or other surrounding features. 

The proposed special conditions 

contain the additional safety standards 

that the Administrator considers 

necessary to establish a level of safety 

equivalent to that established by the 

existing airworthiness standards. 

Applicability 

As discussed above, these special 

conditions are applicable to the Airbus 

Model A321NeoXLR airplane. Should 

Airbus apply at a later date for a change 

to the type certificate to include another 

model incorporating the same novel or 

unusual design feature, these special 

conditions would apply to that model as 

well. 

Conclusion 

This action affects only a certain 

novel or unusual design feature on one 

model of airplane. It is not a rule of 

general applicability. 

List of Subjects in 14 CFR Part 25 

Aircraft, Aviation safety, Reporting 

and recordkeeping requirements. 

Authority Citation 

The authority citation for these 

special conditions is as follows: 

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

44701, 44702, 44704. 

The Proposed Special Conditions 

The Federal Aviation Administration 

(FAA) proposes the following special 

conditions as part of the type 

certification basis for Airbus Model 

A321NeoXLR airplanes. 

Passenger Protection From External 

Fire 

The lower half of the fuselage, 

spanning the longitudinal location of 

the rear center fuel tank, must be 

resistant to fire penetration. 

Issued in Kansas City, Missouri, on April 

1, 2022. 

Patrick R. Mullen, 

Manager, Technical Innovation Policy 

Branch, Policy and Innovation Division, 

Aircraft Certification Service. 

[FR Doc. 2022–07228 Filed 4–5–22; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2022–0394; Project 

Identifier MCAI–2021–00904–T] 

RIN 2120–AA64 

Airworthiness Directives; De Havilland 

Aircraft of Canada Limited (Type 

Certificate Previously Held by 

Bombardier, Inc.) Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain De Havilland Aircraft of Canada 

Limited Model DHC–8–401 and –402 

airplanes. This proposed AD was 

prompted by reports of nose wheel 

steering (NWS) hydraulic motors 

jamming during pushback or towing. 

This proposed AD would require doing 

an inspection to determine the part 

number and serial number of the NWS 

hydraulic motor, and re-identifying or 

replacing the NWS hydraulic motor if 

necessary. This proposed AD would 

also prohibit the installation of certain 

NWS hydraulic motors. The FAA is 

proposing this AD to address the unsafe 

condition on these products. 

DATES: The FAA must receive comments 

on this proposed AD by May 23, 2022. 

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 NPRM, 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. 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. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2022–0394; or in person at Docket 

Operations between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal 

holidays. The AD docket contains this 

NPRM, any comments received, and 

other information. The street address for 

Docket Operations is listed above. 

FOR FURTHER INFORMATION CONTACT: 

Elizabeth Dowling, Aerospace Engineer, 

Mechanical Systems and Administrative 

Services 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. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 

arguments about this proposal. Send 

your comments to an address listed 

under ADDRESSES. Include ‘‘Docket No. 

FAA–2022–0394; Project Identifier 

MCAI–2021–00904–T’’ at the beginning 

of your comments. The most helpful 

comments reference a specific portion of 

the proposal, explain the reason for any 

recommended change, and include 

supporting data. The FAA will consider 

all comments received by the closing 

date and may amend the proposal 

because of those comments. 

Except for Confidential Business 

Information (CBI) as described in the 

following paragraph, and other 

information as described in 14 CFR 

11.35, the FAA will post all comments 

received, without change, to 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 NPRM. 

Confidential Business Information 

CBI is commercial or financial 

information that is both customarily and 

actually treated as private by its owner. 

Under the Freedom of Information Act 

(FOIA) (5 U.S.C. 552), CBI is exempt 

from public disclosure. If your 

comments responsive to this NPRM 

contain commercial or financial 

information that is customarily treated 

as private, that you actually treat as 

private, and that is relevant or 

responsive to this NPRM, it is important 

that you clearly designate the submitted 

comments as CBI. Please mark each 

page of your submission containing CBI 


lotter on DSK11XQN23PROD with PROPOSALS1