Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations 65155 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–0919; Special 

Conditions No. 25–13–11–SC] 

Special Conditions: Learjet Model 45 

Series Airplanes; Isolation or Security 

Protection of the Aircraft Control 

Domain and the Airline Information 

Services Domain From the Passenger 

Services Domain 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special condition; request 

for comments. 

SUMMARY: These special conditions are 

issued for the Learjet Model 45 series 

airplanes. These airplanes will have 

novel or unusual design features 

associated with connectivity of the 

passenger service computer systems to 

the airplane critical systems and data 

networks. 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: The effective date of these 

special conditions is October 31, 2013. 

We must receive your comments by 

December 16, 2013. 

ADDRESSES: Send comments identified 

by docket number FAA–2013–0919 

using any of the following methods: 

• Federal eRegulations Portal: Go to 

http://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: The FAA will post all 

comments it receives, without change, 

to http://www.regulations.gov/, 

including any personal information the 

commenter provides. Using the search 

function of the docket Web site, anyone 

can find and read the electronic form of 

all comments received into any FAA 

docket, including the name of the 

individual sending the comment (or 

signing the comment for an association, 

business, labor union, etc.). DOT’s 

complete Privacy Act Statement can be 

found in the Federal Register published 

on April 11, 2000 (65 FR 19477–19478), 

as well as at http://DocketsInfo.dot 

.gov/. 

Docket: Background documents or 

comments received may be read at 

http://www.regulations.gov/ at any time. 

Follow the online instructions for 

accessing the docket or go to the 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, FAA, Airplane and 

Flight Crew Interface Branch, ANM– 

111, Transport Airplane Directorate, 

Aircraft Certification Service, 1601 Lind 

Avenue SW., Renton, Washington 

98057–3356; telephone 425–227–1298; 

facsimile 425–227–1149. 

SUPPLEMENTARY INFORMATION: The FAA 

has determined that notice of, and 

opportunity for prior public comment 

on, these special conditions are 

impracticable because these procedures 

would significantly delay issuance of 

the design approval and thus delivery of 

the affected aircraft. In addition, the 

substance of these special conditions 

has been subject to the public comment 

process in several prior instances with 

no substantive comments received. The 

FAA therefore finds that good cause 

exists for making these special 

conditions effective upon publication in 

the Federal Register. 

Comments Invited 

We invite 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. 

We will consider all comments we 

receive by the closing date for 

comments. We may change these special 

conditions based on the comments we 

receive. 

Background 

On April 21, 2010, Learjet applied for 

both a change to Type Certificate No. 

T00008WI and for a supplemental type 

certificate (STC) change in the digital 

systems architecture in the Learjet 

Model 45 series airplanes. The Learjet 

Model No. 45 series airplanes are a 

swept-wing aircraft equipped with two 

Honeywell TFE731–40BR turbojet 

engines, weighing 13,890 pounds empty 

and capable of carrying up to nine 

passengers plus two crew members. 

The proposed Learjet Model 45 

architecture is new and novel for 

commercial transport airplanes by 

allowing connection to previously 

isolated data networks connected to 

systems that perform functions required 

for the safe operation of the airplane. 

This proposed data network and design 

integration may result in security 

vulnerabilities from intentional or 

unintentional corruption of data and 

systems 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 aircraft systems. Furthermore, 

regulations and current system safety 

assessment policy and techniques do 

not address potential security 

vulnerabilities, which could be caused 

by unauthorized access to aircraft data 

buses and servers. The intent of these 

special conditions is to ensure that 

security, integrity, and availability of 

aircraft systems are not compromised by 

certain wired or wireless electronic 

connections between airplane data 

busses and networks. A separate Learjet 

Model 45 project special condition 

addresses aircraft electronic system 

security protection from unauthorized 

external access. 

Type Certification Basis 

Under Title 14, Code of Federal 

Regulations (14 CFR) 21.17, Learjet must 

show that the Model 45 series meets the 

applicable provisions of 14 CFR part 25, 

as amended by Amendments 25–1 

through 25–128. 

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 45 series because of a 

novel or unusual design feature, special 

conditions are prescribed under § 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 proposed special 

conditions would also apply to the other 

model under § 21.101. 

In addition to the applicable 

airworthiness regulations and proposed 

special conditions, the Learjet Model 45 

series airplane must comply with the 

fuel vent and exhaust emission 

requirements of 14 CFR part 34 and the 

noise certification requirements of 14 


wreier-aviles on DSK5TPTVN1PROD with RULES
65156 Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations 

CFR part 36 and the FAA must issue a 

finding of regulatory adequacy under 

§ 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 § 11.38, 

and they become part of the typecertification basis under § 21.17(a)(2). 

Novel or Unusual Design Features 

The Learjet Model 45 series airplanes 

will incorporate the following novel or 

unusual design features: The proposed 

architecture and network configuration 

may be used for, or interfaced with, a 

diverse set of functions, including: 

1. Flight-safety related control, 

communication, and navigation systems 

(aircraft control domain); 

2. Operator business and 

administrative support (operator 

information domain); and 

3. Passenger information and 

entertainment systems (passenger 

entertainment domain). 

In addition, the operating systems 

(OS) for current aircraft systems are 

usually and historically proprietary. 

Therefore, they are not as susceptible to 

corruption from worms, viruses, and 

other malicious actions as more widely 

used commercial operating systems, 

such as Microsoft Windows NT, because 

access to the design details of these 

proprietary OS is limited to the system 

developer and aircraft integrator. Some 

systems installed on the Learjet Model 

45 series airplanes will use operating 

systems that are widely used and 

commercially available from third party 

software suppliers. The security 

vulnerabilities of these operating 

systems may be more widely known 

than proprietary operating systems 

currently used by avionics 

manufacturers. 

Discussion 

The integrated network configurations 

in the Learjet Model 45 series airplanes 

may allow increased connectivity with 

external network sources and will have 

more interconnected networks and 

systems, such as passenger 

entertainment and information services 

than previous airplane models. This 

may allow the exploitation of network 

security vulnerabilities and increased 

risks potentially resulting in unsafe 

conditions for the airplanes and 

occupants. This potential exploitation of 

security vulnerabilities may result in 

intentional or unintentional destruction, 

disruption, degradation, or exploitation 

of data and systems critical to the safety 

and maintenance of the airplane. The 

existing regulations and guidance 

material did not anticipate these types 

of 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 and servers. Therefore, these 

special conditions are being issued to 

ensure that the security (i.e., 

confidentiality, integrity, and 

availability) of airplane systems is not 

compromised by unauthorized wired or 

wireless electronic connections between 

airplane systems and the passenger 

entertainment services. 

For the reasons discussed above, 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 Learjet 

Model 45 series airplanes. Should 

Learjet apply at a later date 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 one model 

series of airplanes. It is not a rule of 

general applicability. 

The substance of these special 

conditions has been subjected to the 

notice and comment period in several 

prior instances and has been derived 

without substantive change from those 

previously issued. It is unlikely that 

prior public comment would result in a 

significant change from the substance 

contained herein. Therefore, because a 

delay would significantly affect the 

certification of the airplane, which is 

imminent, the FAA has determined that 

prior public notice and comment are 

unnecessary and impracticable, and 

good cause exists for adopting these 

special conditions upon publication in 

the Federal Register. The FAA is 

requesting comments to allow interested 

persons to submit views that may not 

have been submitted in response to the 

prior opportunities for comment 

described above. 

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 

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 Learjet Model 45 

series airplanes. 

Isolation or Security Protection of the 

Aircraft Control Domain and the Airline 

Information Services Domain From the 

Passenger Services Domain 

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 aircraft is 

maintained, including all post-typecertification modifications that may 

have an impact on the approved 

electronic system security safeguards. 

Issued in Renton, Washington, on October 

22, 2013. 

Stephen P. Boyd, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2013–25851 Filed 10–30–13; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–0820; Notice No. 

25–499–SC] 

Special Conditions: Bombardier Inc., 

Models BD–500–1A10 and BD–500– 

1A11 Series Airplanes; Interactions of 

Systems and Structures 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions; request 

for comments. 

SUMMARY: These special conditions are 

issued for the Bombardier Inc. Models 

BD–500–1A10 and BD–500–1A11 series 

airplanes. These airplanes will have 

novel or unusual features when 

compared to the state of technology 

envisioned in the airworthiness 

standards for transport category 

airplanes. These design features include 

systems that, directly or as a result of 


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