Source: https://www.federalregister.gov/documents/2005/07/12/05-13662/special-conditions-raytheon-model-bh125-series-400a-dh125-series-400a-and-hs125-series-400b
Timestamp: 2018-04-21 17:39:01
Document Index: 151084667

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

Federal Register :: Special Conditions: Raytheon Model BH.125 Series 400A, DH.125 Series 400A, and HS.125 Series 400B Airplanes; High-Intensity Radiated Fields (HIRF)
Special Conditions: Raytheon Model BH.125 Series 400A, DH.125 Series 400A, and HS.125 Series 400B Airplanes; High-Intensity Radiated Fields (HIRF)
70 FR 39908
39908-39910 (3 pages)
Docket No. NM311
Special Conditions No. 25-291-SC
05-13662
https://www.federalregister.gov/d/05-13662 https://www.federalregister.gov/d/05-13662
These special conditions are issued for Raytheon Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes modified by Envoy Aerospace. These modified airplanes 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 digital air data computers and 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, Attention: Rules Docket (ANM-113), Docket No. NM311, 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. NM311.
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 airplanes. 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 persons to participate in this rulemaking by submitting 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 March 28, 2005, Envoy Aerospace, 5027 Switch Grass Lane, Naperville, Illinois 60564-5368, applied for a supplemental type certificate (STC) to modify Raytheon Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes. Raytheon Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes are currently approved under Type Certificate No. A3EU. The Raytheon Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes are transport category airplanes powered by two turbofan engines, with maximum takeoff weights of up to 23,600 pounds. These airplanes operate with a 2-pilot crew and can seat up to 8 passengers. The proposed modification includes the incorporation of dual Innovative Solutions and Support Air Data Systems. The avionics installed in these airplanes have the potential to be vulnerable to high-intensity radiated fields (HIRF) external to the airplane.
Under the provisions of 14 CFR 21.101, Envoy Aerospace must show that the Raytheon Aircraft Company Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes, as changed, continue 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 BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes includes CAR.4b dated December 1953, Amendment 4b-1 through 4b-11, exclusive of CAR 4b.350(e), and includes Special Regulation SR.422B. In addition, the certification basis includes later amended sections of 14 CFR part 25 that are not relevant to these special conditions.
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 Aircraft Company Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes, because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.
In addition to the applicable airworthiness regulations and special conditions, the Raytheon Aircraft Company Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes 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. Start Printed Page 39909
Special conditions are initially applicable to the model for which they are issued. Should Envoy Aerospace 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 the provisions of § 21.101.
As noted earlier, the Raytheon Aircraft Company Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes modified by Envoy Aerospace will incorporate dual Innovative Solutions and Support Air Data Systems 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 reference, special conditions are needed for the Raytheon Aircraft Company Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes modified by Envoy Aerospace. 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.
As discussed above, these special conditions are applicable to Raytheon Aircraft Company Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes modified by Envoy Aerospace. Should Envoy Aerospace 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 the provisions of § 21.101.
This action affects only certain novel or unusual design features on Raytheon Aircraft Company Model BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes modified by Envoy Aerospace. 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 BH.125 series 400A, DH.125 series 400A, and HS.125 series 400B airplanes modified by Envoy Aerospace.
1. Protection from Unwanted Effects of High-Intensity Radiated Fields (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 Start Printed Page 39910exposed to high-intensity radiated fields.
[FR Doc. 05-13662 Filed 7-11-05; 8:45 am]