# TSO-C163, VDL Mode 3 Communications Equipment Operating Within the Frequency Range 117.975 to 137.000 Megahertz (MHz)
**AGENCY:**
Federal Aviation Administration, DOT.
**ACTION:**
Availability of TSO-C163.
**SUMMARY:**
This notice announces the availability of the Technical Standard Order (TSO) for VDL Mode 3 Communications Equipment Operating within the Frequency Range 117.975 to 137.000 MHz. The VDL Mode 3 TSO recognizes the RTCA document No. (RTCA/DO)-271B, Minimum Operational Performance Standards (MOPS) for Aircraft VDL Mode 3 Transceiver Operating in the Frequency Range 117.975-137.000 MHz, as the minimum performance standards (MPS) for VDL Mode 3 equipment.
**DATES:**
The effective date for TSO-C163 is April 29, 2004.
**FOR FURTHER INFORMATION CONTACT:**
Mr. Gregory E. Frye, Federal Aviation Administration, Aircraft Engineering Division, Aircraft Certification Service, AIR-130, 470 L'Enfant Plaza, Suite 4107, SW., Washington, DC 20024; Telephone: (202) 385-4649, FAX: (202) 385-4651; E-mail address: *[email protected].*
**How To Obtain Copies**
You may get a copy of TSO-C163 from the Internet at *(http://av-info.faa.gov/tso/Tsocur/Current.htm).* See section entitled *for further information contact* for the complete address if requesting a copy by mail. You may inspect the RTCA document at: Federal Aviation Administration (FAA), Aircraft Certification Service, Aircraft Engineering Division, Room 815, 800 Independence Avenue, SW., Washington, DC 20591, weekdays except Federal holidays, between 8:30 a.m. and 4:30 p.m. However, RTCA documents are copyrighted and may not be reproduced without the written consent of RTCA, Inc. You may purchase copies of Document No. RTCA/DO-271B from: RTCA Inc., 1828 L Street, NW., Suite 807, Washington, DC 20036 (Web site: *http://www.rtca.org.* )
Issued in Washington, DC, on April 29, 2004.
Susan J. M. Cabler,
Assistant Manager, Aircraft Engineering Division, Aircraft Certification Service.