
[Federal Register Volume 79, Number 173 (Monday, September 8, 2014)]
[Rules and Regulations]
[Pages 53128-53129]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-21243]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0909; Special Conditions No. 25-533-SC]


Special Conditions: Airbus Model A350-900 Airplane; Electronic 
System-Security Protection From Unauthorized External Access

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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SUMMARY: These special conditions are issued for Airbus Model A350-900 
airplanes. These airplanes will have a novel or unusual design feature 
associated with electronic system-security protection from unauthorized 
external access. 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: Effective Date: October 8, 2014.

FOR FURTHER INFORMATION CONTACT: Varun Khanna, FAA, Airplane and 
Flightcrew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone (425) 227-1298; facsimile (425) 227-
1320.

SUPPLEMENTARY INFORMATION: 

Background

    On August 25, 2008, Airbus applied for a type certificate for their 
new Model A350-900 airplane. Later, Airbus requested, and the FAA 
approved, an extension to the application for FAA type certification to 
November 15, 2009. The Model A350-900 airplane has a conventional 
layout with twin wing-mounted Rolls-Royce Trent XWB engines. It 
features a twin-aisle, 9-abreast, economy-class layout, and 
accommodates side-by-side placement of LD-3 containers in the cargo 
compartment. The basic Model A350-900 airplane configuration 
accommodates 315 passengers in a standard two-class arrangement. The 
design cruise speed is Mach 0.85 with a maximum take-off weight of 
602,000 lbs.
    Contemporary transport-category airplanes have both safety-related 
and non-safety-related electronic system networks for many operational 
functions. However, electronic system-network-security considerations 
and functions have played a relatively minor role in the certification 
of such systems because of the isolation, protection mechanisms, and 
limited connectivity between the different networks.

Type Certification Basis

    Under Title 14, Code of Federal Regulations (14 CFR) 21.17, Airbus 
must show that the Model A350-900 airplane meets the applicable 
provisions of 14 CFR part 25, as amended by Amendments 25-1 through 25-
129.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Model A350-900 series because of a 
novel or unusual design feature, special conditions are prescribed 
under 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, the special conditions would also apply to the 
other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model A350-900 airplane 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 must issue a 
finding of regulatory adequacy under Sec.  611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    The FAA issues special conditions, as defined in 14 CFR 11.19, 
under Sec.  11.38, and they become part of the type-certification basis 
under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The Airbus Model A350-900 airplane will incorporate the following 
novel or unusual design feature:

[[Page 53129]]

    The digital systems architecture for the Airbus Model A350-900 
airplane is composed of several connected networks. This network 
architecture is used for a diverse set of functions, providing data 
connectivity between systems, including:
    1. Airplane control, communication, display, monitoring and 
navigation systems,
    2. Operator business and administrative support systems,
    3. Passenger entertainment systems, and
    4. Access by systems external to the airplane.

Discussion

    The Airbus Model A350-900 airplane network architecture and 
configuration may allow increased connectivity to, and access from, 
external network sources, and operator operations and maintenance 
networks to the airplane control domain and operator-information-
services domain. The airplane-control domain and operator-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. The network architecture 
and configuration may allow the exploitation of network-security 
vulnerabilities resulting in intentional or unintentional destruction, 
disruption, degradation, or exploitation of data, systems, and networks 
critical to the safety and maintenance of the airplane.
    The existing regulations and guidance material did not anticipate 
these types of airplane system architectures. Furthermore, 14 CFR 
regulations and current system-safety assessment policy and techniques 
do not address potential security vulnerabilities, which could be 
exploited by unauthorized access to airplane networks, data buses, and 
servers. Therefore, these special conditions are to ensure that 
unauthorized wired or wireless electronic connections do not compromise 
the security (i.e., confidentiality, integrity, and availability) of 
airplane systems.
    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.

Discussion of Comments

    Notice of proposed special conditions No. 25-13-17-SC for the 
Airbus Model A350-900 airplane was published in the Federal Register on 
December 17, 2013 (78 FR 76251)

Comment From Airbus

    Airbus had one comment about the following wording of the first 
paragraph of the Proposed Special Conditions:
    The applicant must ensure airplane electronic system security 
protection from access to or by unauthorized sources external to the 
airplane, including those possibly caused by maintenance activity.
    Airbus considers that the wording ``to or by'' is incorrect. The 
protection must prevent access from unauthorized sources external to 
the airplane only. The requirement of protection to unauthorized 
sources external to the airplane, is not relevant.
    Therefore, Airbus suggests that the wording be modified as follows:
    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.

FAA Response

    The FAA agrees with Airbus and has changed the special conditions 
accordingly.

Applicability

    As discussed above, these special conditions apply to Airbus Model 
A350-900 series 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 the Airbus Model A350-900 series airplanes. It is not a rule of 
general applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

0
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 A350-900 series 
airplanes.
    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 Renton, Washington, on August 15, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-21243 Filed 9-5-14; 8:45 am]
BILLING CODE 4910-13-P


