Document ID: FAA-2012-0950-0001
Agency: faa
Document Type: Notice
Title: Technical Standing Orders; Cancellations: Airborne Automatic Dead Reckoning Computer Equipment Utilizing Aircraft Heading and Doppler Ground Speed and Drift Angle Data (for Air Carrier Aircraft)
Posted Date: 2012-09-04T04:00Z

[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: 2012-21633]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

Technical Standard Order (TSO)-C68a, Airborne Automatic Dead 
Reckoning Computer Equipment Utilizing Aircraft Heading and Doppler 
Ground Speed and Drift Angle Data (for Air Carrier Aircraft)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of cancellation of Technical Standard Order (TSO)-C68a, 
Airborne Automatic Dead Reckoning Computer Equipment Utilizing Aircraft 
Heading and Doppler Ground Speed and Drift Angle Data (for Air Carrier 
Aircraft).

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SUMMARY: This notice announces the FAA's cancellation of TSO-C68a. The 
effect of the cancelled TSO-C68a will result in no new TSO-C68a design 
or production 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

    Doppler radar is a semiautomatic self-contained dead reckoning 
navigation system (radar sensor plus computer) which is not 
continuously dependent on information derived from ground based or 
external aids. The system employs radar signals to detect and measure 
ground speed and drift angle, using the aircraft compass system as its 
directional reference. Doppler is less accurate than Inertial 
Navigation System (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-C68a systems obsolete. The FAA has no 
record of any applications for TSO-C68a since it was published in 1983. 
Given the obsolescence of the equipment, and the lack of industry 
interest in TSO-C68a product designs, the FAA is cancelling TSO-C68a.

Comments

    Request for comments of our proposed cancellation of TSO-C68a as 
published in 77 FR 37733, June 22, 2012, produced no comments.

Conclusion

    TSO-C68a 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. 2012-21633 Filed 8-31-12; 8:45 am]
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