
[Federal Register Volume 77, Number 171 (Tuesday, September 4, 2012)]
[Notices]
[Page 53962]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-21632]



[[Page 53962]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Technical Standard Order (TSO)-C65a, Airborne Doppler Radar 
Ground Speed and/or Drift Angle Measuring Equipment (For Air Carrier 
Aircraft)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of cancellation of Technical Standard Order (TSO)-C65a, 
Airborne Doppler Radar Ground Speed and/or Drift Angle Measuring 
Equipment (For Air Carrier Aircraft).

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SUMMARY: This notice announces the FAA's cancellation of TSO-C65a. The 
effect of the cancelled TSO will result in no new TSO-C65a design or 
production approvals. However, cancellation will not affect current 
production of articles with an existing TSO authorization (TSOA). 
Articles produced under an existing TSOA can still be installed per the 
existing airworthiness approvals.

FOR FURTHER INFORMATION CONTACT: Mr. Albert Sayadian, AIR-130, Federal 
Aviation Administration, 470 L'Enfant Plaza, Suite 4102, Washington, DC 
20024. Telephone (202) 385-4652, fax (202) 385-4651, email to: 
albert.sayadian@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

    The Doppler radar ground speed and/or drift angle measuring 
equipment described by this TSO was used to provide inputs to 
semiautomatic self-contained dead reckoning navigation systems which 
were not continuously dependent on information derived from ground 
based or external navigation aids. The system employed radar signals to 
detect and measure ground speed and drift angle, using the aircraft 
compass system as its directional reference. This approach is less 
accurate than Inertial Navigation Systems (INS), and the use of an 
external reference is required for periodic updates if acceptable 
position accuracy is to be achieved on long range flights. Use of INS 
and Global Positioning System (GPS) has rendered TSO-C65a Doppler 
sensor equipment that provides inputs to dead reckoning navigation 
systems obsolete.
    On August 18, 1983, the FAA published TSO-C65a. The FAA has no 
record of any TSO-C65a applications dating back to 1990. Our research 
indicates there are no new TSO-C65a applications in progress, and there 
are no authorized manufacturers manufacturing, advertising, or selling 
TSO-C65a compliant equipment. Given the obsolescence of the equipment, 
and the lack of industry interest in new TSO-C65a product design, the 
FAA is cancelling TSO-C65a.

Comments

    Request for comments of our proposed cancellation of TSO-C65a as 
published in 77 FR 37470, June 21, 2012, produced no comments.
Conclusion
    TSO-C65a is cancelled effective February 1, 2013.

    Issued in Washington, DC, on August 28, 2012.
Susan J.M. Cabler,
Assistant Manager, Aircraft Engineering Division, Aircraft 
Certification Service.
[FR Doc. 2012-21632 Filed 8-31-12; 8:45 am]
BILLING CODE 4910-13-P


