Source: https://www.federalregister.gov/documents/2003/05/07/03-11227/special-conditions-mcdonnell-douglas-model-dc-9-81--82--83-and--87-airplanes-high-intensity-radiated
Timestamp: 2017-09-20 20:40:26
Document Index: 680598217

Matched Legal Cases: ['§\u200921', 'art 25', 'art 25', '§\u200921', '§\u200921', 'art 25', '§\u200921']

Federal Register :: Special Conditions: McDonnell Douglas Model DC-9-81, -82, -83, and -87 Airplanes; High Intensity Radiated Fields (HIRF)
Special Conditions: McDonnell Douglas Model DC-9-81, -82, -83, and -87 Airplanes; High Intensity Radiated Fields (HIRF)
The effective date of these special conditions is April 14, 2003. Comments must be received on or before June 6, 2003.
Docket No. NM252, Special Conditions No. 25-235-SC
https://www.federalregister.gov/d/03-11227 https://www.federalregister.gov/d/03-11227
These special conditions are issued for McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes modified by Electronic Cable Specialists. These airplanes will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. The modification involves installation of electronic flight displays that perform critical functions. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for the protection of these systems from the effects of high-intensity-radiated fields (HIRF). 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.
Comments on these special conditions may be mailed in duplicate to: Federal Aviation Administration, Transport Airplane Directorate, Attn: Rules Docket (ANM-113), Docket No. NM252, 1601 Lind Avenue SW., Renton, Washington, 98055-4056; or delivered in duplicate to the Transport Airplane Directorate at the above address. All comments must be marked: Docket No. NM252.
Meghan Gordon, FAA, Standardization Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification Start Printed Page 24339Service, 1601 Lind Avenue SW., Renton, Washington, 98055-4056; telephone (425) 227-2138; facsimile (425) 227-1149.
On September 12, 2002, Electronic Cable Specialists applied for a supplemental type certificate (STC) to modify McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes. These airplanes are currently approved under Type Certificate A6WE. The modification installs electronic flight displays in the cockpit. The existing Captain's and First Officer's electro-mechanical attitude indicators (ADIs) and horizontal situation indicators (HSIs) will be replaced by flat panel displays with associated cockpit display controllers. These avionics/electronics and electrical systems may be vulnerable to high intensity radiated fields (HIRF) external to the airplane.
Under the provisions of 14 CFR 21.101, Amendment 21-69, effective September 16, 1991, Electronic Cable Specialists must show that McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes, as modified, continue to meet the applicable provisions of the regulations incorporated by reference in Type Certificate A6WE or the applicable regulations in effect on the date of application for the change. Subsequent changes have been made to § 21.101 as part of Amendment 21-77, but those changes do not become effective until June 10, 2003.
The regulations incorporated by reference in the type certificate are commonly referred to as the “original type certification basis.” The certification basis for the McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes includes 14 CFR part 25, effective February 1, 1965, as amended by amendments 25-1 through 25-40, except for special conditions and exceptions noted in Type Certificate A6WE.
If the Administrator finds that the applicable airworthiness regulations (i.e., part 25, as amended) do not contain adequate or appropriate safety standards for the McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes modified by Electronic Cable Specialists because of novel or unusual design features, special conditions are prescribed under the provisions of § 21.16.
Special conditions are initially applicable to the model for which they are issued. Should Electronic Cable Specialists apply later for a supplemental type certificate to modify any other model included on Type Certificate A6WE to incorporate the same novel or unusual design features, these special conditions would also apply to the other model under the provisions of § 21.101(a)(1), Amendment 21-69, effective September 16, 1991.
The McDonnell Douglas Model DC-9-81, -81, -83, and -87 airplanes modified by Electronic Cable Specialists will incorporate new electronic flight displays that perform critical functions. This system may be vulnerable to high-intensity radiated fields (HIRF) external to the airplane. The current airworthiness standards of part 25 do not contain adequate or appropriate safety standards for the protection of this equipment from the adverse effects of HIRF. Accordingly, these systems are considered to be novel or unusual design features.
To ensure that a level of safety is achieved equivalent to that intended by the regulations incorporated by reference, special conditions are needed for the McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes modified by Electronic Cable Specialists. These special conditions require that new avionics/ electronic and electrical systems that perform critical functions be designed and installed to preclude component damage and interruption of function due to both the direct and indirect effects of HIRF.
With the trend toward increased power levels from ground-based transmitters and the advent of space and satellite communications, coupled with electronic command and control of airplanes, the immunity of critical avionic/ electronic and electrical systems to HIRF must be established.
It is not possible to precisely define the HIRF to which the airplanes will be exposed in service. There is also uncertainty concerning the effectiveness of airframe shielding for HIRF. Furthermore, coupling of electromagnetic energy to cockpit-installed equipment through the cockpit window apertures is undefined. Based on surveys and analysis of existing HIRF emitters, an adequate level of protection exists when compliance with the HIRF protection special condition is shown in accordance with either paragraph 1 OR 2 below:Start Printed Page 24340
1 GHz -2 GHz 2000 200
As discussed above, these special conditions are applicable to McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes modified by Electronic Cable Specialists. Should Electronic Cable Specialists apply later for design change approval to modify any other model included on Type Certificate A6WE to incorporate the same novel or unusual design feature, these special conditions would apply to that model as well under the provisions of § 21.101(a)(1), Amendment 21-69, effective September 16, 1991.
This action affects only certain novel or unusual design features on McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes modified by Electronic Cable Specialists. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of these features on these airplanes.
The FAA has determined that notice and opportunity for public comment are unnecessary, because the FAA has provided previous opportunities to comment on substantially identical special conditions and has fully considered and addressed all the substantive comments received. The FAA is satisfied that new comments are unlikely and finds, therefore, that good cause exists for making these special conditions effective upon issuance.
Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the supplemental type certification basis for McDonnell Douglas Model DC-9-81, -82, -83, and -87 airplanes modified by Electronic Cable Specialists.
[FR Doc. 03-11227 Filed 5-6-03; 8:45 am]