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 has determined that prior public notice and comment are unnecessary, and finds that, for the same reason, good cause exists for adopting these special conditions upon publication in the Federal Register .

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 February 1, 2019, Avidyne Corporation applied for a supplemental type certificate for Avidyne Corporation avionics connected to the aircraft-control domain and airline information-services domain in Textron Model 550, 560, and 560XL airplanes.

The Model 550 is a twin-engine, transport-category airplane with a maximum takeoff weight of 14,800 pounds, and seating for up to 11 passengers, depending upon configuration.

The Model 560 is a twin-engine, transport-category airplane with a maximum takeoff weight of 16,630 pounds, and seating for up to 11 passengers, depending upon configuration.

The Model 560XL is a twin-engine, transport-category airplane with a maximum takeoff weight of 20,200 pounds, and seating for up to 12 passengers, depending upon configuration.

Type Certification Basis

Under the provisions of title 14, Code of Federal Regulations (14 CFR) 21.101, Avidyne Corporation must show that the Textron Model 550, 560, and 560XL airplanes, as changed, continue 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 ( i.e.,14 CFR part 25) do not contain adequate or appropriate safety standards for Textron Model 550, 560, and 560XL 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 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 § 21.101.

In addition to the applicable airworthiness regulations and special conditions, Textron Model 550, 560, and 560XL 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 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 Features

The Textron Model 550, 560, and 560XL airplanes, as modified by Avidyne Corporation, will incorporate the following novel or unusual design features:

Avidyne Corporation avionics that allow internal connection to previously isolated data networks, which are connected to systems that perform functions required for the safe operation of the airplane.

Discussion

The Textron Model 550, 560, and 560XL airplanes' architecture is novel or unusual for commercial transport airplanes because it allows connection to previously isolated data networks connected to systems that perform functions required for the safe operation of the airplane. This data network and design integration creates a potential for unauthorized persons to access the aircraft-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 existing regulations and guidance material did not anticipate this type of system architecture or electronic access to airplane systems. Furthermore, 14 CFR regulations and the current system-safety assessment policy and techniques ( printed page 43425) do not address potential security vulnerabilities, which could be exploited by unauthorized access to airplane networks and servers. Therefore, these special conditions ensure that the security of airplane systems and networks is not compromised by unauthorized wired or wireless internal access.

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 Textron Model 550, 560, and 560XL airplanes. Should Avidyne Corporation 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 certain novel or unusual design features on one model of airplane. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of the features on the airplane.

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 Textron Model 550, 560, and 560XL airplanes, as modified by Avidyne Corporation, for airplane electronic-system security protection from unauthorized 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, 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-system security safeguards.

85 FR 43423