This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

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REGISTER issue of each week.

Rules and Regulations Federal Register

17531

Vol. 62, No. 69

Thursday, April 10, 1997

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM–140; Special Conditions

No. 25–ANM–125]

Special Conditions: Lockheed Martin

Aerospace Corp. Model L382J

Airplane, High-Intensity Radiated

Fields

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final special conditions; request

for comments.

SUMMARY: These special conditions are

issued for the Lockheed Martin

Aerospace Corp. Model L382J airplane.

This model airplane will utilize new

avionics/electronic systems, Mil Std

1553 data buses and dual head-up

displays that provide critical data to the

flightcrew. The applicable regulations

do not contain adequate or appropriate

safety standards for the protection of

these systems from the effects of highintensity radiated fields. 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 2, 1997.

Comments must be received on or

before May 27, 1997.

ADDRESSES: Comments on these special

conditions may be mailed in duplicate

to: Federal Aviation Administration,

Office of the Assistant Chief Counsel,

Attn: Rules Docket (ANM–7), Docket

No. NM–140, 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–140. 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:

Mike Zielinski, Standardization Branch,

ANM–113, Transport Airplane

Directorate, Aircraft Certification

Service, 1601 Lind Avenue SW.,

Renton, Washington 98055–4056;

telephone (206) 227–2279.

SUPPLEMENTARY INFORMATION:

Comment Invited

The FAA has determined that good

cause exists for making these special

conditions 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. These

special conditions 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–140.’’

The postcard will be date stamped and

returned to the commenter.

Background

On August 2, 1992, Lockheed Martin

Aerospace Corp. applied for an

amendment to their Type Certificate No.

A1SO to include their new Model

L382J. The Model L382J is a derivative

of the L382B/E/G currently approved

under Type Certificate No. A1SO, and

features a new engine (with

approximately the same rated

horsepower, but heavily flat-rated) and

propeller, both of which are controlled

by a full authority digital engine control.

Additionally, the flight deck is

substantially modified by the

installation of four liquid crystal flight

displays, dual head-up displays, and

Mil Std 1553 data buses. The flight

engineer position is deleted, requiring

automation of some functions as well as

redesign of the front and overhead

panels. Some structure has been

modified but the aerodynamics of the

airplane are essentially unchanged. The

latest Part 25 requirement will be used

for all significantly modified portions of

the Model 382J (as compared to the

present L382), and, for the unmodified

portions of the airplane, the applicable

certification standard will be the Part 25

rules that were effective on February 1,

1965.

Type Certification Basis

Under the provisions of § 21.101,

Lockheed Martin Aerospace Corp. must

show that the Model L382J airplanes

meet the applicable provisions of the

regulations incorporated by reference in

Type Certificate No. A1SO or the

applicable regulations in effect on the

date of application for the changes to

the Model L382. In addition, the

certification basis includes certain

special conditions and later amended

sections of Part 25 that are not relevant

to these proposed special conditions.

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 L382J 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 § 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 type certificate

for that model be amended later to

include any other model that

incorporates the same novel or unusual

design feature, or should any other

model already included on the same

type certificate be modified 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 Model L382J incorporates new

avionic/electronic installations,

including a digital Electronic Flight
17532 Federal Register / Vol. 62, No. 69 / Thursday, April 10, 1997 / Rules and Regulations

Instrument System (EFIS), Mil Std 1553

data buses and dual head-up displays

that provide critical data to the

flightcrew and a Full Authority Digital

Engine Control (FADEC) system that

controls critical engine parameters.

These systems may be vulnerable to

high-intensity 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 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 issued

for the L382J which require that new

technology electrical and electronic

systems, such as the EFIS, FADEC,

HUD, etc., 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

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–2000 KHz ...... 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–1000 MHz ..... 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, these special

conditions would be applicable initially

to the Model L382J. Should Lockheed

Martin Aerospace Corp. 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 § 21.101(a)(1).

Conclusion

This action affects only certain design

features on the Lockheed Martin

Aerospace Corporation Model L382J

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 these special

conditions for this airplane has been

submitted 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 these

special conditions immediately.

Therefore, these special conditions are

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 these

proposed 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 the Lockheed

Martin Aerospace Corp. Model L382J

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

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 April 2,

1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service,

ANM–100.

[FR Doc. 97–9244 Filed 4–9–97; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96–NM–93–AD; Amendment

39–9992; AD 97–08–04]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A320–111, –211, –212, and –231 Series

Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain Airbus Model

A320–111, –211, –212, and –231 series

airplanes, that requires reinforcement of

the tail section of the fuselage at frames

68 and 69. This amendment is prompted

by reports indicating that the tail section

has struck the runway during takeoffs

and landings. The actions specified by

this AD are intended to prevent

structural damage to the tail section

when it strikes the runway; that