[Federal Register Volume 87, Number 8 (Wednesday, January 12, 2022)]
[Rules and Regulations]
[Pages 1662-1663]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-00390]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2021-0484; Special Conditions No. 25-794-SC]


Special Conditions: Learjet, Inc.; Electronic System Security 
Protection From Unauthorized External 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 a supplemental type 
certificate on certain transport category airplanes. These airplanes, 
as modified by Learjet, Inc. (Learjet), 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 system that allows connection 
to airplane electronics and networks, and access from aircraft external 
sources (e.g., operator networks, wireless devices, internet 
connectivity, service provider satellite communications, electronic 
flight bags, etc.) to the previously isolated airplane 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 Learjet on January 12, 2022. Send 
comments on or before February 28, 2022.

ADDRESSES: Send comments identified by Docket No. FAA-2021-0484 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 
the person indicated in the Contact section below. 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 
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: Varun Khanna, Aircraft Information 
Systems Section, AIR-622, 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 206-231-3159; 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 May 15, 2020, Learjet applied for a supplemental type 
certificate to install an Aircraft Health Management System (AHMS) in 
the airplanes listed on the approved model list (AML) for STC No. 
ST01970WI. These airplanes are super-midsize-category business jets 
with maximum passenger capacity of 16. These airplanes have a maximum 
takeoff weight of 38,850 pounds.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Learjet must show that 
airplanes for which they make application to modify by STC no. 
ST01970WI, as changed, continue to meet the applicable provisions of 
the regulations

[[Page 1663]]

listed in each airplane's respective type certificate 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 listed 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 models for which 
they are issued. Should the applicant apply for a supplemental type 
certificate to modify any other models included on the same type 
certificate to incorporate the same novel or unusual design feature, 
these special conditions would also apply to the other models under 
Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the airplanes listed in the AML 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 airplanes listed on the AML in STC no. ST01970WI will 
incorporate the following novel or unusual design features:
    The installation of an AHMS that allows connection to airplane 
electronics and networks, and access from aircraft external sources 
(e.g., operator networks, wireless devices, internet connectivity, 
service provider satellite communications, electronic flight bags, 
etc.) to the previously isolated airplane electronic assets (networks, 
systems, and databases).

Discussion

    The architecture and network configuration of the airplanes listed 
on the AML of STC no. ST01970WI are novel or unusual for commercial 
transport airplanes because they may allow increased connectivity to 
and access from external network sources, airline operations, and 
maintenance networks to the airplanes' control domain and airline 
information-services domain. The airplanes' control domain and airline 
information-services domain perform functions required for the safe 
operation and maintenance of the airplanes. 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 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 airplanes.
    The existing 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 is not compromised by 
unauthorized wired or wireless electronic connections. This includes 
ensuring that the security of the airplanes' systems is not compromised 
during maintenance of airplane 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 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 
airplanes listed in the AML of STC no. ST01970WI. Should Learjet apply 
at a later date for another STC, to include another airplane model with 
the same novel or unusual design feature, these special conditions 
would also apply to that model as well. These special conditions are 
not applicable to those airplane models for which special conditions 
for protection from unauthorized external access have already been 
issued to the type certificate for those specific models.
    These special conditions are only applicable to design changes 
applied for after its effective date.

Conclusion

    This action affects only a certain novel or unusual design feature 
for airplane models listed on the AML of STC no. ST01970WI, as modified 
by Learjet. It is not a rule of general applicability and affects only 
the applicant.

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

    [squf] 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 airplane models listed on the 
approved model list of supplemental type certificate no. ST01970WI, as 
modified by Learjet.
    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-
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-system security 
safeguards.

    Issued in Kansas City, Missouri, on January 6, 2022.
Patrick R. Mullen,
Manager, Technical Innovation Policy Branch, Policy and Innovation 
Division, Aircraft Certification Service.
[FR Doc. 2022-00390 Filed 1-11-22; 8:45 am]
BILLING CODE 4910-13-P


