Source: https://www.federalregister.gov/documents/2005/12/19/05-24158/special-conditions-raytheon-aircraft-company-model-hs125-airplanes-high-intensity-radiated-fields
Timestamp: 2018-04-26 12:16:18
Document Index: 600177940

Matched Legal Cases: ['art 25', '§\u200921', 'art 34', 'art 36', '§\u200911', '§\u200921', '§\u200921', 'art 25', '§\u200921']

Federal Register :: Special Conditions: Raytheon Aircraft Company Model HS.125 Airplanes; High-Intensity Radiated Fields (HIRF)
Special Conditions: Raytheon Aircraft Company Model HS.125 Airplanes; High-Intensity Radiated Fields (HIRF)
A Rule by the Federal Aviation Administration on 12/19/2005
The effective date of these special conditions is December 9, 2005. Comments must be received on or before January 18, 2006.
70 FR 75002
75002-75004 (3 pages)
Docket No. NM337
Special Conditions No. 25-310-SC
05-24158
https://www.federalregister.gov/d/05-24158 https://www.federalregister.gov/d/05-24158
These special conditions are issued for a Raytheon Aircraft Company Model HS.125 airplane modified by AeroMech Incorporated. This modified airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. The modification incorporates the installation of Innovative Solutions and Support air data display units (ADDU). These systems 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 Start Printed Page 75003that established by the existing airworthiness standards.
You must mail two copies of your comments to: Federal Aviation Administration, Transport Airplane Directorate, Attention: Rules Docket (ANM-113), Docket No. NM337, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. You may deliver two copies to the Transport Airplane Directorate at the above address. You must mark your comments: Docket No. NM337. You can inspect comments in the Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.
Greg Dunn, FAA, Airplane and Flight Crew Interface Branch, ANM-111, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2799; facsimile (425) 227-1320.
The FAA has determined that notice and opportunity for prior public comment is impracticable because these procedures would significantly delay certification of the airplane 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 issuance; however, 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 ask that you send us two copies of written comments.
On June 6, 2005, AeroMech Incorporated, 1616 Hewitt Avenue, Suite 312, Everett, Washington 98201, applied for a supplemental type certificate (STC) to modify a Raytheon Aircraft Company Model HS.125 Series 400A airplane. This model is currently approved under Type Certificate No. A3EU. The Raytheon Model HS.125 airplane is a small transport category airplane powered by two turbine engines. It operates with a 2-pilot crew and can seat up to 15 passengers. The modification incorporates the installation of Innovative Solutions and Support air data display units. The avionics/electronics and electrical systems installed in this airplane have the potential to be vulnerable to high-intensity radiated fields (HIRF) external to the airplane.
Under the provisions of 14 CFR 21.101, AeroMech Incorporated must show that Raytheon Aircraft Company Model HS.125 Series 400A airplane, as changed, continues to meet the applicable provisions of the regulations incorporated by reference in Type Certificate No. A3EU, or the applicable regulations in effect on the date of application for the change. The regulations incorporated by reference in the type certificate are commonly referred to as the “original type certification basis.” The certification basis for the Raytheon Aircraft Company Model HS.125 Series 400A airplane includes Civil Air Regulations (CAR) 10, British Civil Airworthiness Requirements, and Special Conditions. This certification is equivalent to CAR 4b dated December 1953, Amendment 4b-1 through Amendment 4b-11, exclusive of CAR 4b.350(e), and includes Special Regulations SR.422B. Type Certificate No. A3EU was amended to include HS.125 Series 400A on November 15, 1968. Compliance over and above certification basis requirements has been met with CAR Amendment 4B-12 and Amendment 4B-14. Compliance has been established with the special retroactive requirements of 14 CFR 25.2 as amended by Amendment 25-1 through Amendment 25-20, 14 CFR 21 at Amendment 21-27, and 14 CFR 36(1)(c)(2).
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 Raytheon Model HS.125 Series 400A airplane because of a novel or unusual design feature, special conditions are prescribed under § 21.16.
In addition to the applicable airworthiness regulations and special conditions, Raytheon Aircraft Company Model HS.125 Series 400A 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.
Special conditions, as defined in 14 CFR 11.19, are issued under § 11.38 and become part of the type certification basis under § 21.101.
Special conditions are initially applicable to the model for which they are issued. Should AeroMech Incorporated apply at a later date for a supplemental type certificate to modify any other model included on Type Certificate No. A3EU to incorporate the same or similar novel or unusual design feature, these special conditions would also apply to the other model under § 21.101.
As noted earlier, Raytheon Model HS.125 airplane modified by AeroMech Incorporated will incorporate Innovative Solutions and Support air data display units that will perform critical functions. These systems may be vulnerable to high-intensity radiated fields 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, this system is considered to be a novel or unusual design feature.
To ensure that a level of safety is achieved equivalent to that intended by the regulations incorporated by Start Printed Page 75004reference, special conditions are needed for Raytheon Aircraft Company Model HS.125 Series 400A airplane modified by AeroMech Incorporated. These special conditions require that new avionics/electronics 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.
The field strengths are expressed in terms of peak root-mean-square (rms) over the complete modulation period.
As discussed above, these special conditions are applicable to a Raytheon Aircraft Company Model HS.125 Series 400A airplane modified by AeroMech Incorporated. Should AeroMech Incorporated apply at a later date for a supplemental type certificate to modify any other model included on Type Certificate No. A3EU to incorporate the same or similar novel or unusual design feature, these special conditions would apply to that model as well under § 21.101.
This action affects only certain novel or unusual design features on a Raytheon Aircraft Company Model HS.125 Series 400A airplane modified by AeroMech Incorporated. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of these features on the airplane.
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 the Raytheon Aircraft Company Model HS.125 Series 400A airplane modified by AeroMech Incorporated.
1. Protection from Unwanted Effects of HIRF. Each electrical and electronic system that performs critical functions must be designed and installed to ensure that the operation and operational capability of these systems to perform critical functions are not adversely affected when the airplane is exposed to high-intensity radiated fields.
Issued in Renton, Washington, on December 9, 2005.
[FR Doc. 05-24158 Filed 12-16-05; 8:45 am]