[Federal Register Volume 89, Number 100 (Wednesday, May 22, 2024)]
[Rules and Regulations]
[Pages 44913-44914]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-10500]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2024-0721; Special Conditions No. 25-863-SC]


Special Conditions: Aerospace Design & Compliance, LLC (ADC), 
Textron Aviation Inc. Model 550, 560, and 560XL Airplane; Electronic 
System Security Protection From Unauthorized Internal Access

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Textron Aviation, 
Inc. (Textron) 550 (Bravo), 560 (Ultra Encore), and 560XL (Excel) 
series airplane as modified by Aerospace Design & Compliance, LLC 
(ADC). These airplanes 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 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. 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.

DATES: This action is effective on ADC on May 22, 2024. Send comments 
on or before July 8, 2024.

ADDRESSES: Send comments identified by Docket No. FAA-2024-0721 using 
any of the following methods:
     Federal eRegulations Portal: Go to 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.
    Docket: Background documents or comments received may be read at 
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: Thuan T. Nguyen, Avionics Software & 
Components Unit, AIR-626D, Technical Policy Branch, Policy and 
Standards Division, Aircraft Certification Service, Federal Aviation 
Administration, 2200 South 216th Street, Des Moines, Washington 98198; 
telephone and fax 206-231-3365; email [email protected].

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 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.

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 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 the individual listed in the FOR FURTHER 
INFORMATION CONTACT section above. Comments the FAA receives, which are 
not specifically designated as CBI, will be placed in the public docket 
for these special conditions.

Background

    On September 02, 2022, ADC applied for a supplemental type 
certificate (STC) for the installation of an electronic networks system 
architecture 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 in the 
Model 550 (Bravo), 560 (Ultra Encore), and 560XL (Excel) series 
airplane. The Textron Model 550 (Bravo), 560 (Ultra Encore), and 560XL 
(Excel) series airplane, currently approved under Type Certificate No. 
A22CE, is a two-engine transport category airplane. The maximum seating 
capacity for the Model 550 (Bravo) is 11 passengers and 2 crew members. 
The maximum takeoff weight is 14,800 pounds. The seating capacity for 
the Model 560 (Ultra Encore) is 11 passengers and 2 crew members. The 
maximum takeoff weight is 16,630 pounds. The seating capacity for the 
Model 560XL (Excel) is 12 passengers and 2 crew members. The maximum 
takeoff weight is 20,200 pounds.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, ADC must show that the Textron Model 550 (Bravo), 560 
(Ultra Encore), and 560XL (Excel), as changed, continues to meet the 
applicable provisions of the regulations listed in Type Certificate No. 
A22CE or the applicable regulations in effect on the date of 
application for the change, except for earlier amendments as agreed 
upon by the FAA.

[[Page 44914]]

    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 Textron Model 550 (Bravo), 560 
(Ultra Encore), and 560XL (Excel) airplane 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 applicant apply for a supplemental type 
certificate 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 
Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Textron Aviation Inc. Model 550 (Bravo), 560 (Ultra 
Encore), and 560XL (Excel) airplane must comply with the 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 Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.101.

Novel or Unusual Design Features

    The STC requested by ADC for the Textron Model 550 (Bravo), 560 
(Ultra Encore), and 560XL (Excel) series airplane will incorporate the 
following novel or unusual design feature: 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 550 (Bravo), 560 (Ultra Encore), and 560XL 
(Excel) series airplane system architecture and network configuration 
change proposed by ADC is novel or unusual for transport category 
airplanes because it is composed of several connected wireless and 
hardwired networks. This 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 
airplane-control domain and airline information-services domain from 
sources internal to the airplane and presents security vulnerabilities 
related to the 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 applicable FAA regulations did not anticipate these networked 
airplane system 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 hardwired or wireless electronic connections from within 
the airplane. These special conditions also require the applicant to 
provide appropriate instructions 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 550 (Bravo), 560 (Ultra Encore), and 560XL (Excel) series 
airplane, as proposed to be modified by ADC. Should ADC apply at a 
later date for a supplemental 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 
of ADC's proposed STC for the Textron Model 550 (Bravo), 560 (Ultra 
Encore), and 560XL (Excel) series of airplane. It is not a rule of 
general applicability and affects only the applicant who applied to the 
FAA for approval of that feature on the airplane.

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 certification basis for Textron Model 550 (Bravo), 560 (Ultra 
Encore), and 560XL (Excel) series airplanes, as modified by ADC, for 
airplane electronic-system internal access:
    1. The applicant must ensure that the design provides isolation 
from, or airplane electronic network 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, or 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 type certification modifications that 
may have an impact on the approved electronic network system security 
safeguards.

    Issued in Kansas City, Missouri, on May 9, 2024.
Patrick R. Mullen,
Manager, Technical Policy Branch, Policy and Standards Division, 
Aircraft Certification Service.
[FR Doc. 2024-10500 Filed 5-21-24; 8:45 am]
BILLING CODE 4910-13-P