Federal Register / Vol. 65, No. 109 / Tuesday, June 6, 2000 / Rules and Regulations 35813

SIZE STANDARDS BY SIC INDUSTRY

SIC code and description

Size standards in number of employees or

millions of

dollars

*****

DIVISION I—SERVICES ........ $5.0

*****

EXCEPT:

*****

7363 Help Supply Services .................................. 10.0

*****

Dated: May 30, 2000.

Aida Alvarez,

Administrator.

[FR Doc. 00–14015 Filed 6–5–00; 8:45 am]

BILLING CODE 8025–01–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM170; Special Conditions No.

25–162–SC]

Special Conditions: Raytheon Aircraft

Company Model 4000; High Intensity

Radiated Fields (HIRF)

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final special conditions.

SUMMARY: These special conditions are

issued for the Raytheon Aircraft

Company Model 4000 airplane. This

airplane will utilize new avionics/

electronics and electrical systems that

will perform critical functions. The

applicable 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 provided by the

existing airworthiness standards.

EFFECTIVE DATE: July 6, 2000.

FOR FURTHER INFORMATION CONTACT:

Mark Quam, FAA, Standardization

Branch, ANM–113, Transport Airplane

Directorate, Aircraft Certification

Service, 1601 Lind Avenue SW.,

Renton, Washington, 98055–4056;

telephone (425) 227–2145; facsimile

(425) 227–1149.

SUPPLEMENTARY INFORMATION:

Background

On May 3, 1996, Raytheon Aircraft

Company, PO Box 85, Wichita, Kansas

67201–0085, submitted an application

for a new type certificate for the

Raytheon Model 4000. The significant

aircraft design features include an 84

inch diameter graphite composite

fuselage, new metal wing and a graphite

composite skin on aluminum substructure empennage. The Model 4000

is 69 feet, 2 inches in length and 61 feet,

9 inches in width. It has a Primus Epic

flightdeck, and two aft mounted

PW308A engines. There are 12 forwardfacing seats and a forward observer seat.

The significant systems features include

a new state of the art integrated

avionics/electronics and electrical

systems suite. 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.

Type Certification Basis

Under the provisions of 14 CFR

§ 21.17, Raytheon Aircraft Company

must show that the Model 4000 meets

the applicable provisions of part 25, as

amended by Amendment 25–1 through

Amendment 25–87 thereto.

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 4000 airplane because

of novel or unusual design features,

special conditions are prescribed under

the provisions of § 21.16.

In addition to the applicable

airworthiness regulations and special

conditions, the Model 4000 must

comply with the fuel vent and exhaust

emission requirements of part 34 and

the noise certification requirements of

part 36, and the FAA must issue a

finding of regulatory adequacy pursuant

to § 611 of Public Law 92–574, the

‘‘Noise Control Act of 1972.’’

Special conditions, as appropriate, are

issued in accordance with § 11.49, after

public notice, as required by §§ 11.28

and 11.29(b), and become part of the

type certification basis in accordance

with § 21.17(a)(2).

Special conditions are initially

applicable to the model for which they

are issued. Should the type certificate

for that model be amended later to

include any other model that

incorporates the same novel or unusual

design feature, the special conditions

would also apply to the other model

under the provisions of § 21.101(a)(1).

Novel or Unusual Design Features

The Raytheon Aircraft Company

Model 4000 airplanes will utilize new

avionics/electronics and electrical

systems that will perform critical

functions. These systems may be

vulnerable to HIRF external to the

airplane. The significant systems

features include a new state of the art

integrated avionics/electronics and

electrical systems suite. The avionics/

electronics and electrical systems

installed in this aircraft have the

potential to be vulnerable to highintensity radiated fields (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/

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 Raytheon Aircraft Company

Model 4000. 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, and the use of composite

material in the airplane structure, the

immunity of critical 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 with the HIRF

protection special condition is shown

with either paragraph 1, or 2 below:

35814 Federal Register / Vol. 65, No. 109 / Tuesday, June 6, 2000 / Rules and Regulations

1. A minimum threat of 100 volts rms

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 for

both of the following field strengths 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

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 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.

Discussion of Comments

Notice of proposed special conditions

No. 25–00–01–SC for the Raytheon

Aircraft Model 4000 airplanes was

published in the Federal Register on

March 14, 2000 (65 FR 13703). No

comments were received, and the

special conditions are adopted as

proposed.

Applicability

As discussed above, these special

conditions are applicable to the Model

4000 airplane. Should Raytheon Aircraft

Company apply at a later date for a

change to the type certificate to include

another model incorporating the same

novel or unusual design features, these

special conditions would apply to that

model as well under the provisions of

§ 21.101(a)(1).

Conclusion

This action affects only certain design

features on the Raytheon Aircraft

Company Model 4000 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 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

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the following special

conditions are issued as part of the type

certification basis for Raytheon Aircraft

Company Model 4000 airplanes.

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 this special

condition, 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 May 22,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–14156 Filed 6–5–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94–ANE–16–AD; Amendment

39–11758; AD 2000–11–10]

RIN 2120–AA64

Airworthiness Directives; Rolls-Royce

plc RB211 Series Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD)

applicable to certain Rolls-Royce plc (R–

R) RB211 series turbofan engines. That

AD currently requires the removal from

service of intermediate pressure (IP)

compressor stage 6–7 rotor shafts that

exceed reduced cyclic life limits. This

amendment requires further reduction

of cyclic life limits and introduction of

new reduced cyclic bands for rework.

This action is prompted by additional

stress analysis conducted following

failure of an IP compressor stage 6 disk.

The actions specified by this AD are

intended to prevent an uncontained

engine failure due to rupture of an IP

compressor stage 6–7 rotor shaft.

DATES: Effective August 7, 2000. The

incorporation by reference of certain

publications listed in the rule is

approved by the Director of the Federal

Register as of August 7, 2000.

ADDRESSES: The service information

referenced in this AD may be obtained

from Rolls-Royce plc, Technical

Publications Department, P.O. Box 31,

Derby, DE24 8BJ, UK, telephone 011–

44–1332–242424. This information may

be examined at the Federal Aviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

12 New England Executive Park,

Burlington, MA, or at the Office of the

Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Jason Yang, Aerospace Engineer, Engine

Certification Office, FAA, Engine and

Propeller Directorate, 12 New England

Executive Park, Burlington, MA 01803–

5299; telephone (781) 238–7747, fax

(781) 238–7199.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39)

by superseding AD 94–18–03,

Amendment 39–9016 (59 FR 46536),

applicable to R–R RB211–22B and –524

series turbofan engines, was published

in the Federal Register on August 31,

1999 (64 FR 47447). That action

proposed to require the removal from

service of IP compressor stage 6–7 rotor

shafts that exceed reduced cyclic life

limits.

Conclusion

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. No

comments were received on the

proposal or the FAA’s determination of

the cost to the public. The FAA has

determined that air safety and the

public interest require the adoption of

the rule as proposed.