Source: https://www.federalregister.gov/documents/2005/12/01/05-23523/special-conditions-cessna-aircraft-company-protection-of-systems-for-high-intensity-radiated-fields
Timestamp: 2018-03-19 21:23:22
Document Index: 257741125

Matched Legal Cases: ['§\u200921', 'art 23', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', '§\u200923', 'art 34', 'art 36', '§\u200921', '§\u200921']

Federal Register :: Special Conditions; Cessna Aircraft Company; Protection of Systems for High Intensity Radiated Fields (HIRF)
A Rule by the Federal Aviation Administration on 12/01/2005
The effective date of these special conditions is November 17, 2005. Comments must be received on or before January 3, 2006.
72068-72070 (3 pages)
Docket No. CE218, Special Condition 23-158-SC
05-23523
https://www.federalregister.gov/d/05-23523 https://www.federalregister.gov/d/05-23523
These special conditions are issued to Cessna Aircraft Co., for the Type Certificate of Model 510 Mustang airplane. This airplane will have novel and unusual design features when compared to the state of technology envisaged in the applicable airworthiness standards. The novel and unusual design features include the installation of an Electronic Flight Instrumentation System (EFIS), Digital Air Data Computer (ADC), and a Full Authority Digital Engine Control (FADEC). The applicable regulations do not adequately consider failure of Start Printed Page 72069electrical and electronic systems performing critical functions from the effects of external HIRF. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to the airworthiness standards applicable to this airplane.
Comments may be mailed in duplicate to: Federal Aviation Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk, Docket No. CE218, Room 506, 901 Locust, Kansas City, Missouri 64106. All comments must be marked: Docket No. CE218. Comments may be inspected in the Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.
Interested persons are invited to submit such written data, views, or arguments, as they may desire. Communications should identify the regulatory docket or notice number and be submitted in duplicate to the address specified above. All communications received on or before the closing date for comments will be considered by the Administrator. The special conditions may be changed in light of the comments received. All comments received will be available in the Rules Docket for examination by interested persons, both before and after the closing date for comments. A report summarizing each substantive public contact with FAA personnel concerning this rulemaking will be filed in the docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must include a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. CE218.” The postcard will be date stamped and returned to the commenter.
On January 28, 2004, Cessna Aircraft Company; One Cessna Boulevard; Post Office Box 7704; Wichita, KS 67277, made an application to the FAA for a new Type Certificate for the Cessna Model 510 Mustang. The Cessna 510 will be approved under a new Type Certificate Data Sheet (TCDS) Number when Type Certificate (TC) is issued. The proposed modification incorporates a novel or unusual design feature, a digital air data computer, which may be vulnerable to HIRF external to the airplane.
Under the terms of § 21.17, Cessna Aircraft must show that the Model 510 Mustang meets the following provisions, the provisions of other applicable special conditions, or the applicable regulations in effect on the date of application for their type certificate: Federal Aviation Regulations (FAR) part 23 effective February 1, 1965 as amended by Amendments 23-1 through 23-54; Special Conditions applied to § 23.45, § 23.51, § 23.53, § 23.55, § 23.57, § 23.59, § 23.61, § 23.63, § 23.66, § 23.67, § 23.73, § 23.75, § 23.77, § 23.177, § 23.201(e), § 23.203(c), § 23.251, § 23.253, § 23.735, § 23.1195, § 23.1197, § 23.1199, § 23.1201, § 23.1323, § 23.1505, § 23.1583, § 23.1585, § 23.1587; Equivalent Levels of Safety applied to § 23.1305(c)(2), § 23.1305(c)(5), § 23.1549(a) thru (d), § 23.841(b)(6), § 23.841(a), § 23.807(e), § 23.1435(a)(2), and § 23.1555(d); an exemption to § 23.181(b); FAR part 34 as amended by the Amendment in effect on the date of certification; and FAR part 36 as amended by the Amendment in effect on the day of application; the certification requirements applied to the EFIS, Air Data Computer, and FADEC, and these terms of these Special Conditions.
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 model already included on the same type certificate to incorporate the same novel or unusual design feature, the special conditions would also apply to the other model under the provisions of § 21.17.
Cessna plans to incorporate certain novel and unusual design features into an airplane for which the airworthiness standards do not contain adequate or appropriate safety standards for protection from the effects of HIRF. These features include the addition of an EFIS, ADC, and FADEC, which may be susceptible to the HIRF environment that were not envisaged by the existing regulations for this type of airplane.
Furthermore, the HIRF environment has undergone a transformation that was not foreseen when the current requirements were developed. Higher electromagnetic energy levels are radiated from transmitters that are used for radar, radio, and television. Also, the number of transmitters has increased significantly. There is also uncertainty concerning the effectiveness of airframe shielding for HIRF. Furthermore, coupling to cockpit-installed equipment through the cockpit window apertures is undefined.
The combined effect of the technological advances in airplane design and the changing environment has resulted in an increased level of vulnerability of electrical and electronic systems required for the continued safe flight and landing of the airplane. Effective measures against the effects of exposure to HIRF must be provided by Start Printed Page 72070the design and installation of these systems. The accepted maximum energy levels in which civilian airplane system installations must be capable of operating safely are based on surveys and analysis of existing radio frequency emitters. These special conditions require that the airplane be evaluated under these energy levels for the protection of the electronic system and its associated wiring harness. These external threat levels, which are lower than previous required values, are believed to represent the worst case to which an airplane would be exposed in the operating environment.
These special conditions require qualification of systems that perform critical functions, as installed in aircraft, to the defined HIRF environment in paragraph 1 or, as an option, to a fixed value using laboratory tests in paragraph 2, as follows:
As discussed above, these special conditions are applicable to the Cessna Model 510 Mustang airplane. Should Cessna apply at a later date for a supplemental type certificate to modify any other model on the same type certificate to incorporate the same novel or unusual design feature, the special conditions would apply to that model as well under the provisions of § 21.101.
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 510 Mustang airplane.
1. Protection of Electrical and Electronic Systems from High Intensity Radiated Fields (HIRF). Each system that performs critical functions must be designed and installed to ensure that the operations, and operational capabilities of these systems to perform critical functions, are not adversely affected when the airplane is exposed to HIRF external to the airplane.