70770 Federal Register / Vol. 65, No. 229 / Tuesday, November 28, 2000 / Rules and Regulations

(measurement of height, weight, length,

girth, etc.) data. Therefore, we are

removing bobcats from the list of large

felines in § 3.127(d). Based on this

change, all outdoor housing facilities

(i.e., facilities not entirely indoors) for

bobcats would require a 6-foot perimeter

fence or an alternative method

identified in § 3.127(d)(1), (d)(2), (d)(3),

and (d)(4) rather than an 8-foot fence.

This document also revises the

authority citation for 9 CFR part 3 to

reflect a revision to 7 CFR part 371 that

took effect after our final rule was

published.

List of Subjects in 9 CFR Part 3

Animal welfare, Marine mammals,

Pets, Reporting and recordkeeping

requirements, Research, Transportation.

Accordingly, we are amending 9 CFR

part 3 as follows:

PART 3—STANDARDS

1. The authority citation for part 3 is

revised to read as follows:

Authority: 7 U.S.C. 2131–2159; 7 CFR 2.22,

2.80, and 371.7.

§ 3.127 [Amended]

2. In § 3.127, the second sentence of

the introductory text in paragraph (d) is

amended by removing the word

‘‘bobcats,’’.

Done in Washington, DC, this 17th day of

November 2000.

Bobby R. Acord,

Acting Administrator, Animal and Plant

Health Inspection Service.

[FR Doc. 00–30286 Filed 11–27–00; 8:45 am]

BILLING CODE 3410–34–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 29

[Docket No. SW008; Special Conditions No.

29–008–SC]

Special Conditions: Sikorsky Aircraft

Corporation Model S–92 Helicopters,

High-Intensity Radiated Fields

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final special condition; request

for comments.

SUMMARY: This special condition is

issued for Sikorsky Aircraft Corporation

(Sikorsky) Model S–92 helicopters.

These helicopters will have novel or

unusual design features associated with

the installation of electronic systems

that perform critical functions. The

applicable airworthiness regulations do

not contain adequate or appropriate

safety standards to protect systems that

perform critical control functions, or

provide critical displays, from the

effects of high-intensity radiated fields

(HIRF). This special condition contains

the additional safety standards that the

Administrator considers necessary to

ensure that critical functions of systems

will be maintained when exposed to

HIRF.

DATES: The effective date of this special

condition is November 13, 2000.

Comments must be received on or

before January 12, 2001.

ADDRESSES: Comments on this special

condition may be mailed in duplicate

to: Federal Aviation Administration,

Office of the Regional Counsel,

Attention: Rules Docket No. SW008,

Fort Worth, Texas 76193–0007, or

delivered in duplicate to the Office of

the Regional Counsel at 2601 Meacham

Blvd., Fort Worth, Texas 76137.

Comments must be marked: Rules

Docket No. SW008. Comments may be

inspected in the Rules Docket

weekdays, except Federal holidays,

between 8:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT:

Jorge Castillo, FAA, Rotorcraft

Directorate, Rotorcraft Standards, Fort

Worth, Texas 76193–0110; telephone

(817) 222–5127, fax (817) 222–5961.

SUPPLEMENTARY INFORMATION: The FAA

has determined that notice and

opportunity for prior public comment

hereon are impracticable because these

procedures would significantly delay

issuance of the approval design and

thus delivery of the affected aircraft. In

addition, notice and opportunity for

prior public comment are unnecessary

since the substance of this special

condition 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 this special

condition effective upon issuance.

Comments Invited

Interested persons are invited to

submit such written data, views, or

arguments as they may desire.

Communications should identify the

regulatory docket or special condition

number and be submitted in duplicate

to the address specified above. All

communications received on or before

the closing date for comments will be

considered. The special condition may

be changed in light of the comments

received. All comments received will be

available in the Rules Docket for

examination by interested persons. A

report summarizing each substantive

public contact with FAA personnel

concerning this rulemaking will be filed

in the docket. Commenters wishing the

FAA to acknowledge receipt of their

comments submitted in response to this

special condition must include a selfaddressed, stamped postcard on which

the following statement is made:

‘‘Comments to Rules Docket No.

SW008.’’ The postcard will be date

stamped and returned to the

commenter.

Background

On November 5, 1990, Sikorsky

applied for a new type certification of

Model S–92 helicopters. Since applying

for the new type certification, Sikorsky

has requested two extensions of the type

certification period. The first extension

to August 29, 1999 was approved by the

FAA on October 7, 1994, and the second

extension to May 31, 2000 was

approved on July 21, 1995. Sikorsky

Model S–92 helicopters are 19-

passenger Transport Category

helicopters, powered by two General

Electric Model CT7–8 engines. They

will incorporate one auxiliary power

unit for engine starting and back-up

electrical power. The helicopters will

have a conventional aluminum structure

with some composite parts and highly

integrated digital avionics.

Type Certification Basis

Under the provisions of 14 CFR 21.17,

Sikorsky must show that Sikorsky

Model S–92 helicopters meet the

applicable provisions of the regulations

as listed below:

• 14 CFR Part 29, Amendment 29–1

through Amendment 29–45, inclusive;

• 14 CFR Part 36, Appendix H,

Amendments 36–1 through the

amendment effective at the time of

certification; and

• Any special conditions,

exemptions, and equivalent safety

findings deemed necessary.

In addition, the certification basis

includes certain special conditions and

equivalent safety findings that are not

relevant to this special condition.

If the Administrator finds that the

applicable airworthiness regulations do

not contain adequate or appropriate

safety standards for these helicopters

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, Sikorsky Model S–92

helicopters must comply with the noise

certification requirements of 14 CFR

part 36; and the FAA must issue a

finding of regulatory adequacy pursuant

Federal Register / Vol. 65, No. 229 / Tuesday, November 28, 2000 / Rules and Regulations 70771

to § 611 of Public Law 92–574, the

‘‘Noise Control Act of 1972.’’

Special conditions, as appropriate, are

issued in accordance with § 11.49, 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

Sikorsky Model S–92 helicopters will

incorporate the following novel or

unusual design features: electrical,

electronic, or combination of electrical

electronic (electrical/electronic) systems

that perform critical control functions or

display critical information, such as

electronic flight instruments, required

for continued safe flight and landing of

the helicopter during operation in

Instrument Meteorological Conditions

(IMC); and Full Authority Digital Engine

Control (FADEC) that will be performing

engine control functions that are critical

to the continued safe flight and landing

of the helicopter during Visual Flight

Rules (VFR) and Instrument Flight Rules

(IFR) operations.

Discussion

Sikorsky Model S–92 helicopters, at

the time of application, were identified

as incorporating one and possibly more

electrical/electronic systems, such as

electronic flight instruments and

FADEC. After the design is finalized,

Sikorsky will provide the FAA with a

preliminary hazard analysis that will

identify any other critical functions

required for safe flight and landing that

are performed by the electrical/

electronic systems.

Recent advances in technology have

given rise to the application in aircraft

designs of advanced electrical/

electronic systems that perform critical

control functions or provide critical

displays. These advanced systems

respond to the transient effects of

induced electrical current and voltage

caused by a HIRF incident on the

external surface of the helicopter. These

induced transient currents and voltages

can degrade the performance of the

electrical/electronic systems by

damaging the components or by

upsetting the systems’ functions.

Furthermore, the electromagnetic

environment has undergone a

transformation not envisioned by the

current application of § 29.1309(a).

Higher energy levels radiate from

operational transmitters currently used

for radar, radio, and television. Also, the

number of transmitters has increased

significantly.

Existing aircraft certification

requirements are inappropriate in view

of these technological advances. In

addition, the FAA has received reports

of some significant safety incidents and

accidents involving military aircraft

equipped with advanced electrical/

electronic systems when they were

exposed to electromagnetic radiation.

The combined effects of the

technological advances in helicopter

design and the changing environment

have resulted in an increased level of

vulnerability of the electrical/electronic

systems required for the continued safe

flight and landing of the helicopters.

Effective measures to protect these

helicopters against the adverse effects of

exposure to HIRF will be provided by

the design and installation of these

systems. The following primary factors

contributed to the current conditions:

(1) Increased use of sensitive electronics

that perform critical functions; (2)

reduced electromagnetic shielding

afforded helicopter systems by

advanced technology airframe materials;

(3) adverse service experience of

military aircraft using these

technologies; and (4) an increase in the

number and power of radio frequency

emitters and the expected increase in

the future.

The FAA recognizes the need for

aircraft certification standards to keep

pace with the developments in

technology and environment and, in

1986, initiated a high priority program

to (1) determine and define

electromagnetic energy levels; (2)

develop and describe guidance material

for design, test, and analysis; and (3)

prescribe and promulgate regulatory

standards.

The FAA participated with industry

and airworthiness authorities of other

countries to develop internationally

recognized standards for certification.

The FAA and airworthiness

authorities of other countries have

identified two levels of the HIRF

environment that a helicopter could be

exposed to, one environment for VFR

operations and a different environment

for IFR operations. While the HIRF

rulemaking requirements are being

finalized, the FAA is adopting a special

condition for the certification of aircraft

that employ electrical/electronic

systems that perform critical control

functions or provide critical displays.

The accepted maximum energy levels

that civilian helicopter system

installations must withstand for safe

operation are based on surveys and

analysis of existing radio frequency

emitters. This special condition will

require the helicopters’ electrical/

electronic systems and associated

wiring to be protected from these energy

levels. These external threat levels are

believed to represent the exposure for a

helicopter operating under VFR or IFR.

Compliance with HIRF requirements

will be demonstrated by tests, analysis,

models’ similarity with existing

systems, or a combination of these

methods. Service experience alone will

not be acceptable since such experience

in normal flight operations may not

include an exposure to HIRF. Reliance

on a system with similar design features

for redundancy as a means of protection

against the effects of external HIRF is

generally insufficient because all

elements of a redundant system are

likely to be concurrently exposed to the

radiated fields.

This special condition will require the

aircraft-installed systems that perform

critical control functions or provide

critical displays to meet certain

standards based on either a defined

HIRF environment or a fixed value

using laboratory tests. Control system

failures and malfunctions can more

directly and abruptly contribute to a

catastrophic event than display system

failures and malfunctions. Therefore, it

is considered appropriate to require

more rigorous HIRF verification

methods for critical control systems

than for critical display systems.

The applicant may demonstrate that

the operation and operational

capabilities of the installed electrical/

electronic systems that perform critical

functions are not adversely affected

when the aircraft is exposed to the

defined HIRF test environment. The

FAA has determined that the test

environment defined in Table 1 is

acceptable for critical control functions

in helicopters. The test environment

defined in Table 2 is acceptable for

critical display systems in helicopters.

The applicant may also demonstrate,

using a laboratory test, that the

electrical/electronic systems that

perform critical control functions or

provide critical displays can withstand

peak electromagnetic field strength in a

frequency range of 10 kHz to 18 GHz. If

a laboratory test is used to show

compliance with the defined HIRF

environment, no credit will be given for

signal attenuation due to installation. A

level of 100 volts per meter (v/m) is

appropriate for critical display systems.

A level of 200 v/m is appropriate for

critical control functions. Laboratory

test levels are defined according to

RTCA/DO–160D Section 20 Category W

70772 Federal Register / Vol. 65, No. 229 / Tuesday, November 28, 2000 / Rules and Regulations

(100 v/m and 150 mA) and Category Y

(200 v/m and 300 mA). As stated in DO–

160D Section 20, the test levels are

defined as the peak of the root means

squared (rms) envelope. As a minimum,

the modulations required for RTCA/

DO–160D Section 20 Categories W and

Y will be used. Other modulations

should be selected as the signal most

likely to disrupt the operation of the

system under test, based on its design

characteristics. For example, flight

control systems may be susceptible to 3

Hz square wave modulation while the

video signals for electronic display

systems may be susceptible to 400 Hz

sinusoidal modulation. If the worst-case

modulation is unknown or cannot be

determined, default modulations may be

used. Suggested default values are a 1

kHz sine wave with 80 percent depth of

modulation in the frequency range from

10 kHz to 400 MHz and 1 kHz square

wave with greater than 90 percent depth

of modulation from 400 MHz to 18 GHz.

For frequencies where the unmodulated

signal would cause deviations from

normal operation, several different

modulating signals with various

waveforms and frequencies should be

applied.

Applicants must perform a

preliminary hazard analysis to identify

electrical/electronic systems that

perform critical functions. The term

‘‘critical’’ means those functions whose

failure would contribute to or cause an

unsafe condition that would prevent the

continued safe flight and landing of the

helicopters. The systems identified by

the hazard analysis as performing

critical functions are required to have

HIRF protection. A system may perform

both critical and non-critical functions.

Primary electronic flight display

systems and their associated

components perform critical functions

such as attitude, altitude, and airspeed

indications. HIRF requirements would

apply only to the systems that perform

critical functions, including control and

display.

Acceptable system performance

would be attained by demonstrating that

the critical function components of the

system under consideration continue to

perform their intended function during

and after exposure to required

electromagnetic fields. Deviations from

system specifications may be acceptable

but must be independently assessed by

the FAA on a case-by-case basis.

TABLE 1.—VFR ROTORCRAFT

(CRITICAL CONTROL FUNCTIONS)

Field strength volts/meter

Frequency Peak Average

10 kHz–100 kHz 130 130

100 kHz–500

kHz ................ 180 140

500 kHz–2 MHz 60 60

2 MHz–30 MHz 320 320

30 MHz–70 MHz 80 80

70 MHz–100

MHz ............... 70 70

100 MHz–200

MHz ............... 140 140

200 MHz–400

MHz ............... 140 140

400 MHz–700

MHz ............... 400 400

700 MHz–1 GHz 690 400

1 GHz–2 GHz ... 2400 80

2 GHz–4 GHz ... 5120 350

4 GHz–6 GHz ... 13700 570

6 GHz–8 GHz ... 130 80

8 GHz–12 GHz 4900 200

12 GHz–18 GHz 1300 560

18 GHz–40 GHz 1300 30

TABLE 2.—ROTORCRAFT (CRITICAL

DISPLAY FUNCTIONS)

Field strength volts/meter

Frequency Peak Average

10 kHz–100 kHz 30 30

100 kHz–500

kHz ................ 40 30

500 kHz–2 MHz 30 30

2 MHz–30 MHz 190 190

30 MHz–70 MHz 20 20

70 MHz–100

MHz ............... 20 20

100 MHz–200

MHz ............... 30 30

200 MHz–400

MHz ............... 30 30

400 MHz–700

MHz ............... 80 80

700 MHz–1 GHz 690 240

1 GHz–2 GHz ... 970 70

2 GHz–4 GHz ... 1570 350

4 GHz–6 GHz ... 7200 300

6 GHz–8 GHz ... 130 80

8 GHz–12 GHz 2100 80

12 GHz–18 GHz 500 330

18 GHz–40 GHz 780 20

Applicability

As previously discussed, this special

condition is applicable to Sikorsky

Model S–92 helicopters. Should

Sikorsky apply at a later date for a

change to the type certificate to include

another model incorporating the same

novel or unusual design feature, the

special condition would apply to that

model as well under the provisions of

§ 21.101(a)(1).

Conclusion

This action affects only certain novel

or unusual design features on one model

series of helicopters. 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

helicopters.

The substance of this special

condition has been subjected to the

notice and comment period in several

prior instances and has been derived

without substantive change from those

previously issued. It is unlikely that

prior public comment would result in a

significant change from the substance

contained herein. For this reason and

because a delay would significantly

affect the certification of the helicopters,

which is imminent, the FAA has

determined that prior public notice and

comment are unnecessary and

impracticable, and good cause exists for

adopting this special condition upon

issuance. 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 29

Aircraft, Air transportation, Aviation

safety, Rotorcraft, Safety.

Authority: The authority citation for these

special conditions is as follows: 42 U.S.C.

7572; 49 U.S.C. 106(g), 40105, 40113, 44701–

44702, 44704, 44709, 44711, 44713, 44715,

45303.

The Special Condition

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the following special

condition is issued as part of the type

certification basis for Sikorsky Model S–

92 helicopters.

Protection for Electrical and Electronic

Systems From High-Intensity Radiated

Fields

Each system that performs critical

functions must be designed and

installed to ensure that the operation

and operational capabilities of these

critical functions are not adversely

affected when the helicopter is exposed

to high-intensity radiated fields external

to the helicopter.

Issued in Fort Worth, Texas, on November

13, 2000.

Michelle M. Owsley,

Acting Manager, Rotorcraft Directorate,

Aircraft Certification Service.

[FR Doc. 00–30304 Filed 11–27–00; 8:45 am]

BILLING CODE 4910–13–P