Federal Register / Vol. 78, No. 239 / Thursday, December 12, 2013 / Rules and Regulations 75453 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–1037; Special 

Conditions No. 25–509–SC] 

Special Conditions: Cessna Model 750 

Series Airplanes; Aircraft Electronic 

System Security Isolation or Protection 

From Internal Access 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special condition; request 

for comments. 

SUMMARY: These special conditions are 

issued for the Cessna Model 750 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. 

DATES: The effective date of these 

special conditions is December 12, 

2013. We must receive your comments 

by January 27, 2014. 

ADDRESSES: Send comments identified 

by docket number FAA–XXXX–XXXX 

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 

network architecture is composed of 

several connected networks including 

the following: 

1. Flight-safety related control and 

navigation systems, 

2. Operator business and 

administrative support, and 

3. Passenger entertainment. 

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. 

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 September 10, 2010, Cessna 

applied for a change to Type Certificate 

No. T00007WI in the digital systems 

architecture in the Cessna Model 750 

series airplanes. 

The Model 750 is a twin-engine 

pressurized executive jet airplane with 

standard seating provisions for 14 

passenger/crew. This airplane will have 

a maximum takeoff weight of 36,600 

pounds with a wingspan of 69.2 feet, a 

maximum operating altitude of 51,000 

feet, and will have two aft-mounted 

Rolls-Royce AE3007C2 engines. 

The proposed Cessna Model 750 

architecture is novel or unsual for 

executive jet 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 Cessna 

Model 750 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, Cessna 

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 


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75454 Federal Register / Vol. 78, No. 239 / Thursday, December 12, 2013 / Rules and Regulations 

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 Cessna Model 

750 series 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 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 Cessna Model 750 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 

because access to the design details of 

these proprietary OS is limited to the 

system developer and aircraft integrator. 

Some systems installed on the Cessna 

Model 750 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 Cessna Model 750 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. 

Cessna Aircraft Company should 

develop instructions for the operators to 

maintain the built-in security safeguards 

after the airplane enters commercial 

service. The instructions should address 

physical security, operational security, 

audit and monitoring of the 

effectiveness of security safeguards and 

key management procedures. A test plan 

should also be developed and 

implemented to insure that security 

requirements are met and there is no 

inadvertent or malicious change to any 

system, software or data. 

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 Cessna 

Model 750 series airplanes. Should 

Cessna 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 Cessna Model 750 

series airplanes. 

Isolation or Security Protection of the 

Aircraft Control Domain and the 

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 

December 4, 2013. 

John P. Piccola, Jr., 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2013–29683 Filed 12–11–13; 8:45 am] 

BILLING CODE 4910–13–P 


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