11072 Federal Register / Vol. 62, No. 47 / Tuesday, March 11, 1997 / Rules and Regulations

Dated: March 5, 1997.

Floyd Fithian,

Secretary, Farm Credit Administration Board.

[FR Doc. 97–5967 Filed 3–10–97; 8:45 am]

BILLING CODE 6705–01–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM–137; Special Condition No.

25–ANM–123]

Special Condition: Boeing Model 747–

200B, High-Intensity Radiated Fields

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final special condition; request

for comments.

SUMMARY: This special condition is

issued for the Boeing Model 747–200B

airplanes. This airplane, as modified by

ARINC Incorporated, utilizes new

avionics/electronic systems, such as the

electronic flight information systems

(EFIS), which perform critical functions.

The applicable regulations do not

contain adequate or appropriate safety

standards for the protection of these

systems from the effects of highintensity radiated fields (HIRF). This

special condition contains 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 this special

condition is February 12, 1997.

Comments must be received on or

before April 25, 1997.

ADDRESSES: Comments on this special

condition may be mailed in duplicate

to: Federal Aviation Administration,

Office of the Assistant Chief Counsel,

Attn: Rules Docket (ANM–7), Docket

No. NM–137, 1601 Lind Avenue SW.,

Renton, Washington 98055–4056; or

delivered in duplicate to the Office of

the Assistant Chief Counsel at the above

address. Comments must be marked:

Docket No. NM–137. Comments may be

inspected in the Rules Docket

weekdays, except Federal holidays,

between 7:30 a.m. and 4:00 p.m.

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 (206) 227–2145; facsimile

(206) 227–1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA has determined that good

cause exists for making this special

condition effective upon issuance;

however, interested persons are invited

to submit such written data, views, or

arguments as they may desire.

Communications should identify the

regulatory docket and 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 by the Administrator. This

special condition may be changed in

light of the comments received. All

comments submitted will be available in

the Rules Docket for examination by

interested persons, both before and after

the closing date for comments. A report

summarizing each substantive public

contact with FAA personnel concerning

this rulemaking will be filed in the

docket. Persons wishing the FAA to

acknowledge receipt of their comments

submitted in response to this request

must submit with those comments a

self-addressed, stamped postcard on

which the following statement is made:

‘‘Comments to Docket No. NM–137.’’

The postcard will be date stamped and

returned to the commenter.

Background

On January 26, 1995, ARINC

Incorporated of Annapolis, Maryland,

applied for a Supplemental Type

Certificate (STC) to incorporate the

installation of an Allied-Signal (Bendix

King) EFIS–10 Electronic Flight

Instrument System (EFIS) on a Boeing

Model 747–200B airplane. The

installation may be vulnerable to highintensity radiated fields (HIRF) external

to the airplane.

Boeing Model 747–200B series

airplanes are listed on Type Certificate

(TC) A20WE. The airplanes are

pressurized, large transport type

airplanes powered by four wingmounted turbofan engines.

Type Certification Basis

Under the provisions of § 21.101 of 14

CFR part 21, ARINC Incorporated must

show that the modified Boeing Model

747–200B continues to meet the

applicable provisions of the regulations

incorporated by reference in TC A20WE,

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 TC A20WE

include the following for the Boeing

Model 747–200B series airplanes: 14

CFR part 25, dated February 1, 1965, as

amended by Amendments 25–1 through

25–8, plus Amendments 25–15, 25–17,

25–18, 25–20, and 25–39. In addition,

under § 21.101(b)(1), the following

regulations apply to the EFIS

installation: §§ 25.1303(b) and 25.1322,

as amended by Amendment 25–38;

§§ 25.1309, 25.1321(a)(b) (d) and (e),

25.1331, 25.1333, and 25.1355 as

amended by Amendment 25–41; and

§ 25.1316 as amended by Amendment

25–80. This special condition will form

an additional part of the type

certification basis.

If the Administrator finds that the

applicable airworthiness regulations

(i.e., CAR 4b or Part 25, as amended) do

not contain adequate or appropriate

safety standards for the Boeing Model

747–200B series airplanes because of a

novel or unusual design feature, special

conditions are prescribed under the

provisions of § 21.16 to establish a level

of safety equivalent to that established

in the regulations.

Special conditions, as appropriate, are

issued in accordance with 14 CFR part

11, § 11.49, of the FAR after public

notice, as required by §§ 11.28 and

11.29, and become part of the type

certification basis in accordance with

§ 21.101(b)(2).

Special conditions are initially

applicable to the model for which they

are issued. Should the applicant apply

for a supplemental type certificate to

modify any other model included on the

same type certificate to incorporate 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 Boeing Model 747–200B

incorporates new avionics/electronic

systems, such as the electronic flight

instrument system (EFIS), that 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 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, a special condition is needed

for the Boeing Model 747–200B, as
Federal Register / Vol. 62, No. 47 / Tuesday, March 11, 1997 / Rules and Regulations 11073

modified by ARINC Incorporated, which

requires that new electrical and

electronic 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 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 paragraphs 1, OR 2 below:

1. A minimum threat of 100 volts per

meter peak 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 following field strengths for the

frequency ranges indicated.

Frequency Peak

(V/M)

Average

(V/M)

10 KHz–100 KHz .......... 50 50

100 KHz–500 KHz ........ 60 60

500 KHz–2 MHz ............ 70 70

2 MHz–30 MHz ............. 200 200

30 MHz–100 MHz ......... 30 30

100 MHz–200 MHz ....... 150 33

200 MHz–400 MHz ....... 70 70

400 MHz–700 MHz ....... 4,020 935

700 MHz–1 GHz ........... 1,700 170

1 GHz–2 GHz ............... 5,000 990

2 GHz–4 GHz ............... 6,680 840

4 GHz–6 GHz ............... 6,850 310

6 GHz–8 GHz ............... 3,600 670

8 GHz–12 GHz ............. 3,500 1,270

12 GHz–18 GHz ........... 3,500 360

18 GHz–40 GHz ........... 2,100 750

As discussed above, this special

condition is applicable to the Boeing

Model 747–200B airplanes, as modified

by ARINC Incorporated. Should ARINC

Incorporated apply at a later date for a

supplemental type certificate to modify

any other model included on Type

Certificate No. A20WE to incorporate

the same novel or unusual design

feature, this special condition 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 Boeing Model 747–200B

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.

The substance of the special condition

for this airplane has been subjected to

the notice and comment procedure 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 airplane,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 immediately.

Therefore, this special condition is

being made effective 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 25

Aircraft, aviation safety, Reporting

and recordkeeping requirements.

The authority citation for this special

condition is as follows:

Authority: 49 U.S.C. 106(f), 40113, 44701,

44702, 44704.

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 the Boeing Model

747–200B airplane, as modified by

ARINC Incorporated.

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 February

12, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service,

ANM–100.

[FR Doc. 97–5900 Filed 3–10–97; 8:45 am]

BILLING CODE 4910–13–M

14 CFR Part 71

[Airspace Docket No. 96–ASO–39]

Amendment to Class D, E2 and E4

Airspace; Gainesville, FL

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: This amendment modifies

Class D, E2 and E4 surface area airspace

at Gainesville, FL. GPS RWY 6 and GPS

RWY 24 Standard Instrument Approach

Procedures (SIAPs) have been

developed for the Gainesville Regional

Airport. Additional controlled airspace

extending upward from the surface is

needed to accommodate these SIAPs.

EFFECTIVE DATE: 0901 UTC, May 22,

1997.

FOR FURTHER INFORMATION CONTACT:

Benny L. McGlamery, System

Management Branch, Air Traffic

Division, Federal Aviation

Administration, P.O. Box 20636,

Atlanta, Georgia 30320; telephone (404)

305–5570.

SUPPLEMENTARY INFORMATION:

History

On January 13, 1997, the FAA

proposed to amend Part 71 of the

Federal Aviation Regulations (14 CFR

Part 71) by modifying Class D, E2 and

E4 airspace at Gainesville, FL. (62 FR

1699). This action would provide

adequate Class D, E2 and E4 airspace for

IFR operations at the Gainesville

Regional Airport. Interested parties were

invited to participate in this rulemaking

proceeding by submitting written

comments on the proposal to the FAA.

No comments objecting to the proposal

were received. Class D, E2 and E4

airspace designations are published in

Paragraphs 5000, 6002 and 6004,

respectively, of FAA Order 7400.9D,

dated September 4, 1996, and effective

September 16, 1996, which is

incorporated by reference in 14 CFR

71.1. The Class D, E2 and E4 airspace