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###### Department of Transportation

###### Federal Aviation Administration

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of availability and request for public comment. 

# SUMMARY:

This notice announces the availability of, and requests comment on proposed Technical Standard Order (TSO) C-178, Aircraft, Trip-Free Single Phase 115 VAC, 400 Hz Arc Fault Circuit Breakers. This proposed TSO tells persons seeking a TSO authorization or letter of design approval what minimum performance standards (MPS) their arc fault circuit breakers must meet to be identified with the appropriate TSO marking.

# DATES:

Comments must be received on or before January 4, 2006.

# ADDRESSES:

Send all comments on this proposed TSO to: Federal Aviation Administration (FAA), Aircraft Certification Service, Aircraft Engineering Division, Avionics Systems Branch (AIR-130), 800 Independence Avenue, SW., Washington, DC 20591. Attn: Ms. Charisse Green. Or, you may deliver comments to: Federal Aviation Administration, Room 815, 800 Independence Avenue, SW., Washington, DC 20591.

# FOR FURTHER INFORMATION CONTACT:

Ms. Charisse Green, AIR-130, Room 815, Federal Aviation Administration, 800 Independence Avenue, SW., Washington, DC 20591. Telephone (202) 385-4637, fax (202) 385-4651.

# SUPPLEMENTARY INFORMATION:

## Comments Invited

You are invited to comment on the proposed TSO by submitting written data, views, or arguments to the above address. Comments received may be examined, both before and after the closing date, in room 815 at the above address, weekdays except federal holidays, between 8:30 a.m. and 4:30 p.m. The Director, Aircraft Certification Service, will consider all comments received on or before the closing date before issuing the final TSO.

## Background

                    The proposed TSO-C178 provides a minimum operating standard for Trip-                          ( print page 72500)                        Free Single Phase 115 VAC, 400 Hz circuit breakers, which provides an equivalent level of thermal protection to existing thermal circuit breakers, with the added ability of detection and reaction to arc fault conditions, thus diminishing damage to the wiring system caused by prolonged arcing events. The Arc Fault Circuit Breaker thereby diminishes damage to the aircraft wiring from the circuit breaker to the first serial load element, which reduces the potential of igniting surrounding material.                

## How To Obtain Copies

                    You can view or download the proposed TSO from its online location at:                     *www.airweb.faa.gov/​rgl*. At this Web page, select “Technical Standard Orders.” At the TSO page, select “Proposed TSOs.” For a paper copy, contact the person listed in                     **FOR FURTHER INFORMATION CONTACT**                    . Note, SAE International documents are copyrighted and may not be reproduced without the written consent of SAE International. You may purchase copies of SAE International documents from: SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, or directly from their Web site:                     *http://www.sae.org/​*.                

Issued in Washington, DC, on November 28, 2005.

Susan J. M. Cabler,

Assistant Manager, Aircraft Engineering Division, Aircraft Certification Service.

[FR Doc. 05-23631 Filed 12-2-05; 8:45 am]

BILLING CODE 4910-13-M