[Federal Register Volume 89, Number 100 (Wednesday, May 22, 2024)]
[Rules and Regulations]
[Pages 44911-44913]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-10498]



 ========================================================================
 Rules and Regulations
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains regulatory documents 
 having general applicability and legal effect, most of which are keyed 
 to and codified in the Code of Federal Regulations, which is published 
 under 50 titles pursuant to 44 U.S.C. 1510.
 
 The Code of Federal Regulations is sold by the Superintendent of Documents. 
 
 ========================================================================
 

  Federal Register / Vol. 89, No. 100 / Wednesday, May 22, 2024 / Rules 
and Regulations  

[[Page 44911]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2024-0722; Special Conditions No. 25-864-SC]


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

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

ACTION: Final special conditions; request for comments.

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

SUMMARY: These special conditions are issued for the Textron Aviation, 
Inc. (Textron) 550 (Bravo), 560 (Ultra Encore), and 560XL (Excel) 
series airplanes as modified by Aerospace Design & Compliance, LLC 
(ADC). This 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 the 
installation of an electronic networks system architecture that will 
allow increased connectivity to and access from external network 
sources to the airplane's previously isolated electronic assets 
(networks, systems, and databases). 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-2024-0722 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.
    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 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 2, 2022, ADC applied for a supplemental type 
certificate (STC) for the installation of an electronic networks system 
architecture that will allow increased connectivity to and access from 
external network sources (e.g., operator networks, wireless devices, 
internet connectivity, service provider satellite communications, 
electronic flight bags, etc.) to the airplane's previously isolated 
electronic assets (networks, systems, and databases). The Textron Model 
550 (Bravo), 560 (Ultra Encore), and 560XL (Excel) series airplane is a 
two-engine transport category airplane currently approved under Type 
Certificate No. A22CE. The maximum seating capacity for the Model 550 
(Bravo) is 11 passengers and 2 crew members. The maximum takeoff weight 
is 14,800

[[Page 44912]]

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.
    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 Feature

    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 an 
electronic networks system architecture that will allow increased 
connectivity to and access from external network sources, (e.g., 
operator networks, wireless devices, internet connectivity, service 
provider satellite communications, electronic flight bags, etc.) to the 
airplane's previously isolated electronic assets (networks, systems, 
and databases).

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 may allow increased connectivity to and access 
from external network sources, airline operations, and maintenance 
networks, to the airplane-control domain and the airline information-
services domain.
    The airplane's control domain and airline information-services 
domain perform functions required for the safe operation and 
maintenance of the airplane. Previously, these domains had very limited 
connectivity with external network sources. This data network and 
design integration creates a potential for unauthorized persons to 
access the airplane-control domain and airline information-services 
domain 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 the airplane's systems is not compromised by 
unauthorized wired or wireless electronic connections. This includes 
ensuring that the security of the airplane's systems is not compromised 
during maintenance of the airplane's electronic systems. 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 introduce 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.
    1. The applicant must ensure airplane electronic system security 
protection from access by unauthorized sources external to the 
airplane, including those possibly caused by maintenance activity.
    2. The applicant must ensure that electronic system security 
threats are identified and assessed, and that effective electronic 
network system security protection strategies are implemented to 
protect the airplane from all adverse impacts on safety, functionality, 
and continued airworthiness.
    3. 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.


[[Page 44913]]


    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. 2024-10498 Filed 5-21-24; 8:45 am]
BILLING CODE 4910-13-P