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contains regulatory documents having general

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are keyed to and codified in the Code of

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Rules and Regulations Federal Register

20029 

Vol. 72, No. 77 

Monday, April 23, 2007 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. NM376; Special Conditions No. 

25–352–SC] 

Special Conditions: McDonnell 

Douglas Models DC–10–10, 10–15, 10– 

30, 10–30F, 10–40, and 10–40F 

Airplanes; High-Intensity Radiated 

Fields (HIRF) 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions; request 

for comments. 

SUMMARY: The FAA issues these special 

conditions for McDonnell Douglas 

Models DC–10–10, 10–15, 10–30, 10– 

30F, 10–40, and 10–40F airplanes 

modified by Canard Aerospace 

Corporation. These modified airplanes 

will have novel or unusual design 

features when compared with the state 

of technology envisioned in the 

airworthiness standards for transport 

category airplanes. The modification 

consists of installing electronic flight 

and engine instrument systems. The 

applicable airworthiness regulations do 

not contain adequate or appropriate 

safety standards for protecting these 

systems from 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 April 16, 2007. We 

must receive your comments on or 

before May 23, 2007. 

ADDRESSES: You may mail or deliver 

comments on these special conditions 

in duplicate to: Federal Aviation 

Administration, Transport Airplane 

Directorate, Attention: Rules Docket 

(ANM–113), Docket No. NM376, 1601 

Lind Avenue SW., Renton, Washington 

98057–3356. You must mark your 

comments Docket No. NM376. 

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 98057–3356; 

telephone (425) 227–2799; facsimile 

(425) 227–1320. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA has determined that notice 

and opportunity for prior public 

comment for these special conditions is 

impracticable because these procedures 

would significantly delay certification 

and 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. We therefore find that good 

cause exists for making these special 

conditions effective upon issuance. 

However, we invite interested persons 

to take part in this rulemaking by 

submitting written comments. 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 

about these special conditions. You may 

inspect the docket 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 

based on the comments we receive. 

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 October 24, 2006, Canard 

Aerospace Corporation, 250 South 

Fuller Street, Shakopee, Minnesota, 

55379, applied for a supplemental type 

certificate (STC) to modify McDonnell 

Douglas Models DC–10–10, 10–15, 10– 

30, 10–30F, 10–40, and 10–40F 

airplanes. The McDonnell Douglas 

Model DC–10 airplanes are powered by 

three turbofan engines, with maximum 

takeoff weights of up to 590,000 pounds. 

These airplanes operate with a 2-pilot 

crew and can seat up to 380 passengers. 

The modification consists of installing 

electronic flight and engine instrument 

systems. These systems have a potential 

to be vulnerable to high-intensity 

radiated fields (HIRF) external to the 

airplane. 

Type Certification Basis 

Under provisions of 14 CFR 21.101, 

Canard Aerospace Corporation must 

show that the McDonnell Douglas 

Models DC–10–10, 10–15, 10–30, 10– 

30F, 10–40, and 10–40F airplanes, as 

changed, continue to meet the 

applicable provisions of the regulations 

incorporated by reference in Type 

Certificate No. A22WE 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 specific 

regulations are 14 CFR part 25, as 

amended by Amendments 25–1 through 

25–22. In addition, the certification 

basis includes certain special conditions 

and exemptions that are not relevant to 

these special conditions. 

If the Administrator finds that the 

applicable airworthiness regulations 

(part 25, as amended) do not contain 

adequate or appropriate safety standards 

for the McDonnell Douglas Model DC– 

10 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 McDonnell Douglas 

Model DC–10 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. 


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20030 Federal Register / Vol. 72, No. 77 / Monday, April 23, 2007 / Rules and Regulations 

The FAA issues special conditions, as 

defined in § 11.19, under § 11.38, and 

they become part of the type 

certification basis under the provisions 

of § 21.101. 

Novel or Unusual Design Features 

As noted earlier, the McDonnell 

Douglas Model DC–10 airplanes 

modified by Canard Aerospace will 

incorporate the Astronautics Electronic 

Flight Information System (EFIS) that 

will perform critical functions. This 

system may be vulnerable to highintensity radiated fields external to the 

airplane. Current airworthiness 

standards of part 25 do not contain 

adequate or appropriate safety standards 

for protecting this equipment from 

adverse effects of HIRF. So this system 

is considered to be a novel or unusual 

design feature. 

Discussion 

As previously stated, there is no 

specific regulation that addresses 

protection for electrical and electronic 

systems from HIRF. Increased power 

levels from radio frequency transmitters 

and the growing use of sensitive 

avionics/electronics and electrical 

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 McDonnell Douglas Model DC–

10 airplanes modified by Canard 

Aerospace Corporation. 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 

because of HIRF. 

High-Intensity Radiated Fields (HIRF) 

High-power radio frequency 

transmitters for radio, radar, television, 

and satellite communications can 

adversely affect operation of airplane 

electric and electronic systems. 

Therefore, the immunity of critical 

avionics/electronics and electrical 

systems to HIRF must be established. 

Based on surveys and an analysis of 

existing HIRF emitters, an adequate 

level of protection exists when airplane 

system immunity is demonstrated when 

exposed to the HIRF environments in 

either paragraph 1 OR 2 below: 

1. A minimum environment of 100 

volts rms (root-mean-square) per meter 

electric field strength from 10 KHz to 18 

GHz. 

a. System elements and their 

associated wiring harnesses must be 

exposed to the environment without 

benefit of airframe shielding. 

b. Demonstration of this level of 

protection is established through system 

tests and analysis. 

2. An environment external to the 

airframe of the field strengths shown in 

the table below for the frequency ranges 

indicated. Immunity to both peak and 

average field strength components from 

the table must be demonstrated. 

Frequency 

Field strength 

(volts per meter) 

Peak Average 

10 kHz–100 kHz ........... 50 50 

100 kHz–500 kHz ......... 50 50 

500 kHz–2 MHz ............ 50 50 

2 MHz–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 

4 GHz–6 GHz ............... 3000 200 

6 GHz–8 GHz ............... 1000 200 

8 GHz–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 environment levels identified 

above are the result of an FAA review 

of existing studies on the subject of 

HIRF and of the work of the 

Electromagnetic Effects Harmonization 

Working Group of the Aviation 

Rulemaking Advisory Committee. 

Applicability 

These special conditions are 

applicable to McDonnell Douglas Model 

DC–10 airplanes modified by Canard 

Aerospace Corporation. Should Canard 

Aerospace apply at a later date for a 

supplemental type certificate to modify 

any other model included on Type 

Certificate No. A22WE to incorporate 

the same or similar novel or unusual 

design feature, these special conditions 

would apply to that model as well 

under provisions of § 21.101. 

Conclusion 

This action affects only certain novel 

or unusual design features on 

McDonnell Douglas Model DC–10 

airplanes modified by Canard Aerospace 

Corporation. 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. 

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 

■ Therefore, under the authority 

delegated to me by the Administrator, 

the following special conditions are 

issued as part of the supplemental type 

certification basis for the McDonnell 

Douglas Models DC–10–10, 10–15, 10–

30, 10–30F, 10–40, and 10–40F 

airplanes modified by Canard Aerospace 

Corporation. 

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 

continued safe flight and landing of the 

airplane. 

Issued in Renton, Washington, on April 16, 

2007. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E7–7699 Filed 4–20–07; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2007–27866; Directorate 

Identifier 2007–NM–055–AD; Amendment 

39–15027; AD 2007–08–09] 

RIN 2120–AA64 

Airworthiness Directives; Short 

Brothers Model SD3–60 SHERPA, 

SD3–SHERPA, SD3–30, and SD3–60 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule; request for 

comments. 


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