2012-21633. 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).

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 [phone], fax [phone], email to: [e-mail].

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.