Special Conditions: Airbus Model A321neo XLR Airplane; Side-Stick Controller-Controllability and Maneuverability, 46956-46958 [2023-15466]

Download as PDF 46956 Federal Register / Vol. 88, No. 139 / Friday, July 21, 2023 / Rules and Regulations for the Textron Model 560XL(XLS+) 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 applicant apply for an ATC to modify any other model included on the same type certificate 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 Textron Model 560XL(XLS+) airplane must comply with the exhaust-emission requirements of 14 CFR part 34, and the noisecertification 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. ddrumheller on DSK120RN23PROD with RULES1 Novel or Unusual Design Features The Textron Model 560XL(XLS+) airplane will incorporate a novel or unusual design feature, which is the installation of a digital system that contains a wireless and hardwired network with hosted application functionality that allows access, from sources internal to the airplane, to the airplane’s internal electronic components. Discussion The Textron Model 560XL(XLS+) airplane electronic system architecture and network configuration change is novel or unusual for commercial transport airplanes because it is composed of several connected wireless and hardwired networks. This proposed system and network architecture is used for a diverse set of airplane functions, including: • Flight-safety related control and navigation systems, • Airline business and administrative support, and • Passenger entertainment. The airplane’s control domain and airline information services domain of these networks perform functions required for the safe operation and maintenance of the airplane. Previously, these domains had very limited connectivity with other network sources. This network architecture creates a potential for unauthorized persons to access the aircraft control domain from sources internal to the airplane, and presents security vulnerabilities related to the VerDate Sep<11>2014 18:12 Jul 20, 2023 Jkt 259001 introduction of computer viruses and worms, user errors, and intentional sabotage of airplane electronic assets (networks, systems, and databases) critical to the safety and maintenance of the airplane. The existing FAA regulations did not anticipate these networked airplanesystem architectures. Furthermore, these regulations and the current guidance material do not address potential security vulnerabilities, which could be exploited by unauthorized access to airplane networks, data buses, and servers. Therefore, these special conditions ensure that the security (i.e., confidentiality, integrity, and availability) of airplane systems will not be compromised by unauthorized wireless or hardwired electronic connections from within the airplane. These special conditions also require the applicant to provide appropriate instruction to the operator to maintain all electronic-system safeguards that have been implemented as part of the original network design so that this feature does not allow or reintroduce security threats. These 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 Textron Model 560XL(XLS+) airplane. Should Textron apply at a later date for an amended type certificate to modify any other model included on Type Certificate No. A22CE to incorporate 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 Textron Model 560XL(XLS+) 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, and 44704. The Special Conditions Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type PO 00000 Frm 00004 Fmt 4700 Sfmt 4700 certification basis for the Textron 560XL(XLS+) airplane for airplane electronic-system internal access. 1. The applicant must ensure that the design provides isolation from, or airplane electronic-system security protection against, access by unauthorized sources internal to the airplane. The design must prevent inadvertent and malicious changes to, and all adverse impacts upon, airplane equipment, systems, networks, and other assets required for safe flight and operations. 2. The applicant must establish appropriate procedures to allow the operator to ensure that continued airworthiness of the airplane is maintained, including all post-typecertification modifications that may have an impact on the approved electronic-system security safeguards. Issued in Kansas City, Missouri, on July 17, 2023. Patrick R. Mullen, Manager, Technical Innovation Policy Branch, Policy and Innovation Division, Aircraft Certification Service. [FR Doc. 2023–15468 Filed 7–20–23; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. FAA–2021–1035; Special Conditions No. 25–819–SC] Special Conditions: Airbus Model A321neo XLR Airplane; Side-Stick Controller—Controllability and Maneuverability Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions; request for comments. AGENCY: These special conditions are issued for the Airbus Model A321neo XLR airplanes. The airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is sidestick controllers for pitch and roll control. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These 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. SUMMARY: E:\FR\FM\21JYR1.SGM 21JYR1 Federal Register / Vol. 88, No. 139 / Friday, July 21, 2023 / Rules and Regulations This action is effective on Airbus on July 21, 2023. Send comments on or before September 5, 2023. ADDRESSES: Send comments identified by Docket No. FAA–2021–1035 using any of the following methods: • Federal eRegulations Portal: Go to https://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 title 14, Code of Federal Regulations (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 FAA will also post a report summarizing each substantive verbal contact received about these special conditions. 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 these special conditions contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to these special conditions, 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 these special conditions. Send submissions containing CBI to Troy Brown, Performance and Environment Unit, AIR–621A, Technical Policy Branch, Policy and Standards Division, Aircraft Certification Service, Federal Aviation Administration, 1801 S Airport Rd., Wichita, KS 67209–2190; telephone and ddrumheller on DSK120RN23PROD with RULES1 DATES: VerDate Sep<11>2014 18:12 Jul 20, 2023 Jkt 259001 fax 405–666–1050; email troy.a.brown@ faa.gov. Comments the FAA receives, which are not specifically designated as CBI, will be placed in the public docket for these special conditions. Docket: Background documents or comments received may be read at https://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: Troy Brown, Performance and Environment Unit, AIR–621A, Technical Policy Branch, Policy and Standards Division, Aircraft Certification Service, Federal Aviation Administration, 1801 S Airport Rd., Wichita, KS 67209–2190; telephone and fax 405–666–1050; email troy.a.brown@faa.gov. SUPPLEMENTARY INFORMATION: The substance of these special conditions has been published in the Federal Register for public comment in several prior instances with no substantive comments received. Therefore, the FAA finds, pursuant to § 11.38(b), that new comments are unlikely, and notice and comment prior to this publication are unnecessary. 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 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 A321neo XLR airplanes, which include the Model A321–271NY and –253NY airplanes. These airplanes are twin-engine, transport-category airplanes with seating for 244 passengers and a maximum takeoff weight of 222,000 pounds. Type Certification Basis Under the provisions of 14 CFR 21.101, Airbus must show that the Model A321neo XLR airplanes meet the applicable provisions of the regulations listed in Type Certificate No. A28NM, or the applicable regulations in effect on PO 00000 Frm 00005 Fmt 4700 Sfmt 4700 46957 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 A321neo XLR airplanes 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 A321neo XLR airplanes 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 § 11.19, in accordance with § 11.38, and they become part of the type certification basis under § 21.101. Novel or Unusual Design Features The Airbus Model A321neo XLR airplanes will incorporate the following novel or unusual design feature: Sidestick controllers for pitch and roll control. Discussion These proposed special conditions for the Airbus A321neo XLR airplane address the novel features of the sidestick controllers. The A321neo XLR will incorporate side-stick controllers controlling a fly-by-wire (FBW) electronic flight control system (EFCS). This system provides an electronic interface between the pilot’s flight controls and the flight control surfaces for both normal and failure states, and it generates the actual surface commands that provide for stability augmentation and control about all three airplane axes. In addition, pilot control authority may be uncertain, because the side-stick controllers are not mechanically interconnected as with conventional wheel and column controls. Current FAA regulations do not specifically address the use of side-stick controllers for pitch and roll control. E:\FR\FM\21JYR1.SGM 21JYR1 46958 Federal Register / Vol. 88, No. 139 / Friday, July 21, 2023 / Rules and Regulations The unique features of the side stick must therefore be demonstrated through flight and simulator tests to have suitable handling and control characteristics when considering the following: 1. The handling-qualities tasks and requirements of the Airbus Model A321neo XLR airplane special conditions, and other 14 CFR part 25 requirements for stability, control, and maneuverability, including the effects of turbulence. 2. General ergonomics: Armrest comfort and support, local freedom of movement, displacement angle suitability, and axis harmony. 3. Inadvertent input in turbulence. 4. Inadvertent pitch-roll crosstalk. The FAA Handling Qualities Rating Method (HQRM) of Appendix E of the Flight Test Guide for Certification of Transport Category Airplanes, AC 25– 7D, may be, but is not required to be, used to show compliance. These 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 apply to Airbus Model A321neo XLR airplanes. Should Airbus apply later for a change to the type certificate to include another model incorporating the same novel or unusual design feature, the special conditions would apply to that model as well. Conclusion This action affects only certain novel or unusual design features on one model series of airplanes. It is not a rule of general applicability. List of Subjects in 14 CFR Part 25 The authority citation for these special conditions is as follows: The Special Conditions ddrumheller on DSK120RN23PROD with RULES1 BILLING CODE 4910–13–P CONSUMER PRODUCT SAFETY COMMISSION 16 CFR Part 1270 [CPSC Docket No. CPSC–2013–0022] Safety Standard for Adult Portable Bed Rails The U.S. Consumer Product Safety Commission (Commission or CPSC) has determined that there is an unreasonable risk of injury and death associated with entrapment and other hazards from adult portable bed rails (APBRs). CPSC has identified 284 fatal incidents related to entrapment by APBRs between January 2003 and December 2021. To address the risk, the Commission is promulgating a rule under the Consumer Product Safety Act (CPSA) to require that APBRs meet the requirements of the existing voluntary standard for APBRs, with modifications. CPSC estimates that the final rule will SUMMARY: Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, 44704. Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type certification basis for Airbus Model A321neo XLR airplanes. (a) Pilot Strength. In lieu of the ‘‘strength of pilots’’ limits of § 25.143(d) for pitch and roll, and in lieu of the specific pitch force requirements of Jkt 259001 [FR Doc. 2023–15466 Filed 7–20–23; 8:45 am] Consumer Product Safety Commission. ACTION: Final rule. Authority Citation 18:12 Jul 20, 2023 Issued in Kansas City, Missouri, on July 17, 2023. Patrick R. Mullen, Manager, Technical Policy Branch, Policy and Standards Division, Aircraft Certification Service. AGENCY: Aircraft, Aviation safety, Reporting and recordkeeping requirements. VerDate Sep<11>2014 §§ 25.145(b) and 25.175(d), the following applies: The applicant must show that the temporary and maximum prolonged force levels for the side-stick controllers are suitable for all expected operating conditions and configurations, whether normal or non-normal. (b) Controller Coupling. The electronic side-stick controller coupling design must provide for corrective and/ or overriding control inputs by either pilot with no unsafe characteristics. Annunciation of controller status must be provided and must not be confusing to the flightcrew. (c) Pilot Control. The applicant must show by flight tests that the use of sidestick controllers does not produce unsuitable pilot-in-the-loop control characteristics when considering precision path control tasks and turbulence. In addition, pitch and roll control-force sensitivity and displacement sensitivity must be compatible, so that normal inputs on one control axis will not cause significant unintentional inputs on the other. PO 00000 Frm 00006 Fmt 4700 Sfmt 4700 provide up to $298 million per year in societal benefits, while the costs associated with the rule’s requirements are expected to be approximately $2 million per year. The rule is effective on August 21, 2023. The incorporation by reference of the publication listed in this rule is approved by the Director of the Federal Register as of August 21, 2023. DATES: Will Cusey, Small Business Ombudsman, U.S. Consumer Product Safety Commission, 4330 East West Highway, Bethesda, MD 20814; telephone (301) 504–7945 or (888) 531–9070; email: sbo@cpsc.gov. FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: I. Background and Statutory Authority In 2013, the CPSC received two requests to initiate rulemaking proceedings under the Consumer Product Safety Act (CPSA) to address an unreasonable risk of injury associated with APBRs. Gloria Black, the National Consumer Voice for Quality Long-Term Care, Consumer Federation of America, and 60 other organizations submitted one request; Public Citizen Health Research Group submitted the other request. Collectively, the petitioners stated that many of the deaths and injuries involving APBRs result from asphyxiation caused by entrapment within openings of the APBR rail or between the rail and the mattress or bed frame. The petitioners requested that the CPSC initiate rulemaking proceedings under section 8 of the CPSA to ban all APBRs. Alternatively, petitioners requested that the Commission initiate a rulemaking under section 9 of the CPSA to promulgate mandatory standards, including warning labels, to reduce the unreasonable risk of asphyxiation and entrapment posed by APBRs. Petitioners also requested action under section 27(e) of the CPSA to require manufacturers of APBRs to provide performance and technical data regarding the safety of their products. The CPSC docketed the petition requests as a single petition: Petition CP 13–1, Petition Requesting a Ban or Standard on APBRs under the CPSA. On June 4, 2013, the Commission published a notice in the Federal Register seeking public comment on the petition. 78 FR 33393. Also in 2013, ASTM International (ASTM) formed the ASTM F15.70 subcommittee to begin developing a voluntary standard for APBRs. On April 23, 2014, staff sent a briefing package on APBRs to the Commission E:\FR\FM\21JYR1.SGM 21JYR1

Agencies

[Federal Register Volume 88, Number 139 (Friday, July 21, 2023)]
[Rules and Regulations]
[Pages 46956-46958]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-15466]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2021-1035; Special Conditions No. 25-819-SC]


Special Conditions: Airbus Model A321neo XLR Airplane; Side-Stick 
Controller--Controllability and Maneuverability

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

-----------------------------------------------------------------------

SUMMARY: These special conditions are issued for the Airbus Model 
A321neo XLR airplanes. The airplane will have a novel or unusual design 
feature when compared to the state of technology envisioned in the 
airworthiness standards for transport-category airplanes. This design 
feature is side-stick controllers for pitch and roll control. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for this design feature. These 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.

[[Page 46957]]


DATES: This action is effective on Airbus on July 21, 2023. Send 
comments on or before September 5, 2023.

ADDRESSES: Send comments identified by Docket No. FAA-2021-1035 using 
any of the following methods:
     Federal eRegulations Portal: Go to https://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 title 14, Code of Federal Regulations (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 FAA will also post a report summarizing each substantive verbal 
contact received about these special conditions.
    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 these special 
conditions contain commercial or financial information that is 
customarily treated as private, that you actually treat as private, and 
that is relevant or responsive to these special conditions, 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 these special conditions. Send submissions containing CBI to 
Troy Brown, Performance and Environment Unit, AIR-621A, Technical 
Policy Branch, Policy and Standards Division, Aircraft Certification 
Service, Federal Aviation Administration, 1801 S Airport Rd., Wichita, 
KS 67209-2190; telephone and fax 405-666-1050; email 
[email protected]. Comments the FAA receives, which are not 
specifically designated as CBI, will be placed in the public docket for 
these special conditions.
    Docket: Background documents or comments received may be read at 
https://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: Troy Brown, Performance and 
Environment Unit, AIR-621A, Technical Policy Branch, Policy and 
Standards Division, Aircraft Certification Service, Federal Aviation 
Administration, 1801 S Airport Rd., Wichita, KS 67209-2190; telephone 
and fax 405-666-1050; email [email protected].

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been published in the Federal Register for public comment in 
several prior instances with no substantive comments received. 
Therefore, the FAA finds, pursuant to Sec.  11.38(b), that new comments 
are unlikely, and notice and comment prior to this publication are 
unnecessary.

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 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 A321neo XLR airplanes, 
which include the Model A321-271NY and -253NY airplanes. These 
airplanes are twin-engine, transport-category airplanes with seating 
for 244 passengers and a maximum takeoff weight of 222,000 pounds.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Airbus must show that the 
Model A321neo XLR airplanes meet 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 A321neo XLR airplanes 
because of a novel or unusual design feature, special conditions are 
prescribed under the provisions of Sec.  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 Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Airbus Model A321neo XLR airplanes 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 Sec.  11.19, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.101.

Novel or Unusual Design Features

    The Airbus Model A321neo XLR airplanes will incorporate the 
following novel or unusual design feature: Side-stick controllers for 
pitch and roll control.

Discussion

    These proposed special conditions for the Airbus A321neo XLR 
airplane address the novel features of the side-stick controllers. The 
A321neo XLR will incorporate side-stick controllers controlling a fly-
by-wire (FBW) electronic flight control system (EFCS). This system 
provides an electronic interface between the pilot's flight controls 
and the flight control surfaces for both normal and failure states, and 
it generates the actual surface commands that provide for stability 
augmentation and control about all three airplane axes. In addition, 
pilot control authority may be uncertain, because the side-stick 
controllers are not mechanically interconnected as with conventional 
wheel and column controls.
    Current FAA regulations do not specifically address the use of 
side-stick controllers for pitch and roll control.

[[Page 46958]]

The unique features of the side stick must therefore be demonstrated 
through flight and simulator tests to have suitable handling and 
control characteristics when considering the following:
    1. The handling-qualities tasks and requirements of the Airbus 
Model A321neo XLR airplane special conditions, and other 14 CFR part 25 
requirements for stability, control, and maneuverability, including the 
effects of turbulence.
    2. General ergonomics: Armrest comfort and support, local freedom 
of movement, displacement angle suitability, and axis harmony.
    3. Inadvertent input in turbulence.
    4. Inadvertent pitch-roll crosstalk.
    The FAA Handling Qualities Rating Method (HQRM) of Appendix E of 
the Flight Test Guide for Certification of Transport Category 
Airplanes, AC 25-7D, may be, but is not required to be, used to show 
compliance.
    These 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 apply to Airbus Model 
A321neo XLR airplanes. Should Airbus apply later for a change to the 
type certificate to include another model incorporating the same novel 
or unusual design feature, the special conditions would apply to that 
model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on one model series of airplanes. 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 Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Airbus Model A321neo XLR airplanes.
    (a) Pilot Strength. In lieu of the ``strength of pilots'' limits of 
Sec.  25.143(d) for pitch and roll, and in lieu of the specific pitch 
force requirements of Sec. Sec.  25.145(b) and 25.175(d), the following 
applies:
    The applicant must show that the temporary and maximum prolonged 
force levels for the side-stick controllers are suitable for all 
expected operating conditions and configurations, whether normal or 
non-normal.
    (b) Controller Coupling. The electronic side-stick controller 
coupling design must provide for corrective and/or overriding control 
inputs by either pilot with no unsafe characteristics. Annunciation of 
controller status must be provided and must not be confusing to the 
flightcrew.
    (c) Pilot Control. The applicant must show by flight tests that the 
use of side-stick controllers does not produce unsuitable pilot-in-the-
loop control characteristics when considering precision path control 
tasks and turbulence. In addition, pitch and roll control-force 
sensitivity and displacement sensitivity must be compatible, so that 
normal inputs on one control axis will not cause significant 
unintentional inputs on the other.

    Issued in Kansas City, Missouri, on July 17, 2023.
Patrick R. Mullen,
Manager, Technical Policy Branch, Policy and Standards Division, 
Aircraft Certification Service.
[FR Doc. 2023-15466 Filed 7-20-23; 8:45 am]
BILLING CODE 4910-13-P

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