Federal Register / Vol. 69, No. 197 / Wednesday, October 13, 2004 / Rules and Regulations 60797

Issued in Renton, Washington, on October 

1, 2004. 

Kalene C. Yanamura, 

Acting Manager, , Transport Airplane 

Directorate, Aircraft Certification Service.

[FR Doc. 04–22947 Filed 10–12–04; 8:45 am] 

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. NM291; Special Conditions No. 

25–273–SC] 

Special Conditions: Raytheon Aircraft 

MU–300–10 and 400 Airplanes; High 

Intensity Radiated Fields (HIRF)

AGENCY: Federal Aviation 

Administration (FAA), DOT.

ACTION: Final special conditions; request 

for comments. 

SUMMARY: These special conditions are 

issued for Raytheon Aircraft Company 

Model MU–300–10 and 400 airplanes 

modified by ARINC Inc. These airplanes 

will have novel and unusual design 

features when compared to the state of 

technology envisioned in the 

airworthiness standards for transport 

category airplanes. The proposed 

modification incorporates the 

installation of a Dual Thommen AD–32 

Air Data Display Units. 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.

DATES: The effective date of these 

special conditions is November 12, 

2004. Comments must be received on or 

before November 12, 2004.

ADDRESSES: Comments on these special 

conditions may be mailed in duplicate 

to: Federal Aviation Administration, 

Transport Airplane Directorate, Attn: 

Rules Docket (ANM–113), Docket No. 

NM291, 1601 Lind Avenue SW., 

Renton, Washington, 98055–4056; or 

delivered in duplicate to the Transport 

Airplane Directorate at the above 

address. Comments must be marked: 

Docket No. NM291. Comments may be 

inspected in the Rules Docket 

weekdays, except Federal holidays, 

between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: 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) 227–1149.

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA has determined that notice 

and opportunity for prior public 

comment hereon is unnecessary as 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. 

We will file in the docket all 

comments we receive, as well as a 

report summarizing each substantive 

public contact with FAA personnel 

concerning these special conditions. 

The docket is available for public 

inspection before and after the comment 

closing date. If you wish to review the 

docket in person, go to the address in 

the ADDRESSES section of this preamble 

between 7:30 a.m. and 4 p.m. Monday 

through Friday, except Federal holidays. 

We will consider all comments we 

receive on or before the closing date for 

comments. We will consider comments 

filed late if it is possible to do so 

without incurring expense or delay. We 

may change these special conditions in 

light of the comments received. 

If you want the FAA to acknowledge 

receipt of your comments on these 

special conditions, include with your 

comments a pre-addressed, stamped 

postcard on which the docket number 

appears. We will stamp the date on the 

postcard and mail it back to you.

Background 

On March 1, 2004, ARINC Inc., 1632 

South Murray Blvd. Colorado Springs, 

CO 80916, applied for a supplemental 

type certificate (STC) to modify 

Raytheon Aircraft Company Models 

MU–300–10 (Diamond II) and 400 

(Beechjet) airplanes. The Raytheon 

airplanes are small transport category 

airplanes powered by two turbojet 

engines, with maximum takeoff weights 

of up to 15,780 pounds. These airplanes 

operate with a 2-pilot crew and can seat 

up to 9 passengers. The proposed 

modification incorporates the 

installation of a Dual Thommen AD–32 

Air Data Display Units. The information 

this equipment presents is flight critical. 

The avionics/electronics and electrical 

systems to be installed on these 

airplanes have the potential to be 

vulnerable to high-intensity radiated 

fields (HIRF) external to the airplane. 

Type Certification Basis 

Under the provisions of 14 CFR 

21.101, ARINC Inc. must show that the 

Raytheon Aircraft Company Model MU–

300–10 and 400 airplanes, as changed, 

continue to meet the applicable 

provisions of the regulations 

incorporated by reference in Type 

Certificate No. A16SW, 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 regulations incorporated by 

reference in Type Certificate No. 

A16SW include 14 CFR part 25, as 

amended by Amendments 25–1 through 

25–40; § 25.1351(d), 25.1353(c)(5), and 

25.1450 as amended by Amendment 25–

41; §§ 25.29, 25.255, and 25.1353(c)(6) 

as amended by Amendment 25–42; 

§ 25.361(b) as amended by Amendment 

25–46; and 14 CFR part 36 as amended 

by Amendment 36–1 through 36–12. 

If the Administrator finds that the 

applicable airworthiness regulations 

(i.e., part 25, as amended) do not 

contain adequate or appropriate safety 

standards for modified Model MU–300–

10 and 400 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 Model MU–

300–10 and 400 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. 

Special conditions, as defined in 14 

CFR 11.19, are issued in accordance 

with § 11.38, and become part of the 

type certification basis in accordance 

with § 21.101. 

Special conditions are initially 

applicable to the model for which they 

are issued. Should ARINC Inc. apply at 

a later date for supplemental type 

certificate to modify any other model 

included on the same type certificate to 

incorporate the same novel or unusual 

design feature, these special conditions 

would also apply to the other model 

under the provisions of § 21.101. 

60798 Federal Register / Vol. 69, No. 197 / Wednesday, October 13, 2004 / Rules and Regulations 

Novel or Unusual Design Features 

The modified Model MU–300–10 and 

400 airplanes will incorporate avionics/

electrical systems that will perform 

critical functions. These systems may be 

vulnerable to HIRF external to the 

airplane. 

Discussion 

There is no specific regulation that 

addresses protection requirements for 

electrical and electronic systems from 

HIRF. Increased power levels from 

ground-based radio transmitters and the 

growing use of sensitive avionics/

electrical and electronic systems to 

command and control airplanes have 

made it necessary to provide adequate 

protection. 

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 Model MU–300–10 and 400 

airplanes. 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. 

High-Intensity Radiated Fields (HIRF) 

With the trend toward increased 

power levels from ground-based 

transmitters, plus the advent of space 

and satellite communications, coupled 

with electronic command and control of 

the airplane, the immunity of critical 

digital avionics/electronics and 

electrical systems to HIRF must be 

established. 

It is not possible to precisely define 

the HIRF to which the airplane will be 

exposed in service. There is also 

uncertainty concerning the effectiveness 

of airframe shielding for HIRF. 

Furthermore, coupling of 

electromagnetic energy to cockpitinstalled 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 is shown with 

either HIRF protection special condition 

paragraph 1 or 2 below: 

1. A minimum threat of 100 volts rms 

(root-mean-square) per meter electric 

field strength from 10 KHz to 18 GHz. 

a. The threat must be applied to the 

system elements and their associated 

wiring harnesses without the benefit of 

airframe shielding. 

b. Demonstration of this level of 

protection is established through system 

tests and analysis. 

2. A threat external to the airframe of 

the field strengths indicated in the 

following table for the frequency ranges 

indicated. Both peak and average field 

strength components from the table are 

to be demonstrated.

Frequency 

Field strength 

(volts per meter) 

Peak Average 

10 kHz–100 kHz ........... 50 50 

100 kHz–500 kHz ......... 50 50 

500kHz–2 MHz ............. 50 50 

2MHz–30 MHz .............. 100 100 

30 MHz–70 MHz ........... 50 50 

70 MHz–100 MHz ......... 50 50 

100 MHz–200 MHz ....... 100 100 

200 MHz–400 MHz ....... 100 100 

400 MHz–700 MHz ....... 700 50 

700 MHz–1 GHz ........... 700 100 

1 GHz–2 GHz ............... 2000 200 

2 GHz–4 GHz ............... 3000 200 

4GHz–6 GHz ................ 3000 200 

6GHz–8 GHz ................ 1000 200 

8GHz–12 GHz .............. 3000 300 

12 GHz–18 GHz ........... 2000 200 

18 GHz–40 GHZ ........... 600 200 

The field strengths are expressed in terms 

of peak of the root-mean-square (rms) over 

the complete modulation period. 

The threat levels identified above are 

the result of an FAA review of existing 

studies on the subject of HIRF, in light 

of the ongoing work of the 

Electromagnetic Effects Harmonization 

Working Group of the Aviation 

Rulemaking Advisory Committee. 

Applicability 

As discussed above, these special 

conditions are applicable to the 

Raytheon Aircraft Company Model MU–

300–10 and 400 airplanes. Should 

ARINC Inc. apply at a later date for a 

change to the type certificate to include 

another model incorporating the same 

novel or unusual design feature, these 

special conditions would apply to that 

model as well under the provisions of 

14 CFR 21.101. 

Conclusion 

This action affects only certain novel 

or unusual design features on the 

Raytheon Aircraft Company Model MU–

300–10 and 400 airplanes. 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 airplanes. 

The substance of the special 

conditions for these airplanes has been 

subjected to the notice and comment 

procedure in several prior instances and 

has been derived without substantive 

change from those previously issued. 

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 

immediately. 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 

supplemental type certification basis for 

Raytheon Aircraft Company Model MU–

300–10 and 400 airplanes modified by 

ARINC Inc. 

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 

exposed to high intensity radiated 

fields. 

2. For the purpose of these special 

conditions, the following definition 

applies: Critical Functions: Functions 

whose failure would contribute to or 

cause a failure condition that would 

prevent the continued safe flight and 

landing of the airplane.

Issued in Renton, Washington, on October 

1, 2004. 

Kalene C. Yanamura, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service.

[FR Doc. 04–22946 Filed 10–12–04; 8:45 am] 

BILLING CODE 4910–13–P