Federal Register / Vol. 65, No. 94 / Monday, May 15, 2000 / Notices 31051

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

Proposed Advisory Circular;

Continued Airworthiness Assessments

of Powerplant and Auxiliary Power Unit

Installations on Transport Category

Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of availability of

proposed advisory circular and request

for comments.

SUMMARY: This notice announces the

availability of proposed Advisory

Circular (AC) No. 39XX, Continued

Airworthiness Assessments of

Powerplant and Auxiliary Power Unit

Installations on Transport Category

Airplanes.

DATES: Comments must be received on

or before July 14, 2000.

ADDRESSES: Send all comments on the

proposed AC to the Federal Aviation

Administration, Attn: Engine and

Propeller Standards Staff, ANE–110,

Engine and Propeller Directorate,

Aircraft Certification Service, 12 New

England Executive Park, Burlington,

MA, 01803–5299.

FOR FURTHER INFORMATION CONTACT: Ann

Azevedo, Engine and Propeller

Standards Staff, ANE–110, at the above

address, telephone (781) 238–7117, fax

(781) 238–7199. A copy of the subject

AC may also be obtained electronically

by writing to the following Internet

address: ‘‘ann.azevedo@faa.gov’’.

Additionally, you may obtain a copy of

the AC directly from the internet at the

following address: http://www.faa.gov/

avr/air/acs/draftach.htm.

SUPPLEMENTARY INFORMATION:

Comments Invited

A copy of the subject AC may be

obtained by contacting the person

named above under FOR FURTHER

INFORMATION CONTACT. Interested

persons are invited to comment on the

proposed AC, and to submit such

written data, views, or arguments as

they desire. Commenters must identify

the subject of the AC, and submit

comments in duplicate to the address

specified above. All communications

received on or before the closing date

for comments will be considered by the

Engine and Propeller Directorate,

Aircraft Certification Service, before

issuance of the final AC.

Background

This Advisory Circular (AC) describes

the Continued Airworthiness

Assessment Methodologies (CAAM).

The Federal Aviation Administration

(FAA) Engine & Propeller Directorate

(E&PD) and the Transport Airplane

Directorate (TAD) may use CAAM,

supplemented to meet each Directorate’s

needs, to identify those unsafe

conditions in products that deserve

priority attention. The FAA may issue

an Airworthiness Directive (AD) under

Part 39 of Title 14 of the Code of Federal

Regulations (14 CFR part 39) to

prescribe corrective actions that must be

taken to address an unsafe condition in

a product when ‘‘the unsafe condition is

likely to exist or develop in other

products of the same type design.’’

CAAM, as described in this proposed

AC, is intended to be used for products

associated with the Powerplant or

Auxiliary Power Unit (APU)

Installations on Transport Category

Airplanes.

Continued airworthiness requires that

safety concerns within the existing fleet

be addressed, and the knowledge gained

applied for the benefit of future fleets as

well. This AC provides CAAM guidance

for estimating the risks associated with

identified unsafe conditions; defining,

prioritizing, and selecting suitable

corrective actions for all identified

unsafe conditions; and verifying that the

corrective actions were effective. This

AC is intended to present a tangible

means of logically assessing and

responding to the safety risks posed by

unsafe conditions.

This AC does not establish any

requirement that the FAA must perform

a risk assessment before issuing an AD,

or that the FAA must wait to issue an

AD until the design approval holder

performs a risk assessment, or that the

FAA must accept the findings of a risk

assessment performed by the design

approval holder. CAAM, as described in

this proposed AC, assists the FAA in

making decisions concerning the

priority in which unsafe conditions

should be addressed. The FAA may

issue an AD for a particular unsafe

condition before a risk assessment is

performed, or without having an

assessment performed at all.

In this regard, CAAM does not define

‘‘unsafe condition’’ in a powerplant or

APU installation. Rather, CAAM is a

tool that the FAA usually will use to

make the kinds of decisions described

above.

It is recognized that the proposed AC

represents a significant change from the

specific CAAM process detailed in draft

AC39.XX that was published for public

comment several years ago. Therefore, it

is anticipated that comments will be

received on the newly-proposed AC.

The FAA does not intend to issue a final

document until those comments have

been appropriately reviewed and

resolved.

The FAA recognizes that many

manufacturers use risk assessment

practices to evaluate continued

airworthiness. The FAA considers these

current practices to be acceptable, and

no reassessment will take place until all

comments with the proposed are

properly dispositioned.

This proposed advisory circular,

published under the authority granted

to the Administrator by 49 U.S.C.

106(g), 40113, 44701–44702, 44704,

provides guidance for the use of CAAM.

Issued in Burlington, Massachusetts, on

May 4, 2000.

David A. Downey,

Assistant Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 00–12145 Filed 5–12–00; 8:45 am]

BILLING CODE 4910–13–M

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

Acceptance of Noise Exposure Maps

for Williams Gateway Airport, Mesa,

Arizona

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice.

SUMMARY: The Federal Aviation

Administration (FAA) announces its

determination that the Noise Exposure

Maps submitted by the Williams

Gateway Airport Authority for the

Williams Gateway Airport, Mesa,

Arizona under the provisions of Title I

of the Aviation Safety and Noise

Abatement Act of 1979 (Pub. L. 96–193)

and 14 CFR Part 150, are in compliance

with applicable requirements.

EFFECTIVE DATE: The effective date of the

FAA’s acceptance of the Noise Exposure

Maps for Williams Gateway Airport,

Mesa, Arizona is May 2, 2000.

FOR FURTHER INFORMATION CONTACT:

Brian Armstrong, Airport Planner,

Airports Division, AWP–611.1, Federal

Aviation Administration, WesternPacific Region. Mailing address: P.O.

Box 92007, Worldway Postal Center, Los

Angeles, California 90009–2007.

Telephone (310) 725–3614. Street

address: 15000 Aviation Boulevard,

Hawthorne, California 90261.

Documents reflecting this FAA action

may be reviewed at this same location.

SUPPLEMENTARY INFORMATION: This

notice announces that the FAA finds

that the Noise Exposure Maps submitted

for Williams Gateway Airport, Mesa,

Arizona are in compliance with

applicable requirements of Federal