[Federal Register Volume 64, Number 189 (Thursday, September 30, 1999)]
[Notices]
[Page 52820]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25454]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Proposed Advisory Circular 25.XX, Airworthiness Criteria for the 
Installation Approval of a Terrain Awareness and Warning System (TAWS) 
Approved Under Technical Standard Order (TSO) C151

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of availability of proposed Advisory Circular 25.XX and 
request for comments.

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SUMMARY: This notice announces the availability of and requests comment 
on a proposed advisory circular (AC) that provides guidance on one 
method for obtaining airworthiness approval for the installation of a 
Terrain Awareness and Warning System (TAWS) approved under Technical 
Standard Order (TSO) C151. The guidance provided in the proposed AC is 
specific to installations of these systems on transport category 
airplanes. This notice is necessary to give all interested persons an 
opportunity to present their views on the proposed AC.

DATES: Comments must be received on or before December 29, 1999.

ADDRESSES: Send all comments on the proposed AC to: Federal Aviation 
Administration, Attn: J. Kirk Baker, ANM-130L, FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Blvd., Lakewood, California 90712. Comments may be inspected at the 
above address between 7:30 a.m. and 4:00 p.m. weekdays, except Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Jill DeMarco, Program Management 
Branch, ANM-114, Transport Airplane Directorate, FAA, 1601 Lind Avenue 
SW., Renton, Washington 98055-4056; telephone (425) 227-1313.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to comment on the proposed AC by 
submitting such written data, views, or arguments as they may desire. 
Commenters must identify the AC by title 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 
Transport Airplane Directorate before issuing the final AC.

Availability of Proposed AC

    The proposed AC can also be found and downloaded from the Internet 
at http://www.faa.gov/avr/air/airhome.htm, at the link titled ``Draft 
Advisory Circulars.'' A paper copy of the proposed AC may be obtained 
by contacting the person named above under the caption FOR FURTHER 
INFORMATION CONTACT.

Discussion

    The FAA is proposing to issue an AC that describes an acceptable 
means, but not the only means, of obtaining airworthiness installation 
approval of a Terrain Awareness and Warning System (TAWS) that has been 
approved under Technical Standard Order (TSO) C151, ``Terrain Awareness 
and Warning System.'' A TAWS is a system that provides the flightcrew 
with sufficient information and alerting to detect a potentially 
hazardous terrain situation and take effective action. The guidance 
provided in the proposed AC is specific to installations of these 
systems on transport category airplanes.
    The FAA's TSO process is a means of obtaining FAA design and 
performance approval for an appliance, system, or product. However, the 
TSO does not provide installation approval or procedures for design or 
implementation of an installation. With heightened interest by 
manufacturers and operators to equip transport category airplanes with 
TAWS systems that are compliant with TSO-C151, the FAA has recognized 
the need to establish guidance material for the design and test 
requirements for the installation of such systems.
    This proposed AC has been developed as the means for providing such 
guidance for designing an acceptable installation for a TAWS that is 
compliant with TSO-C151. It describes the airworthiness considerations 
for such installations as they apply to the unique features of the TAWS 
and the interface of the TAWS with other systems on the airplane.

    Issued in Renton, Washington, on September 23, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-25454 Filed 9-29-99; 8:45 am]
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