Daily Rules, Proposed Rules, and Notices of the Federal Government
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.
Request for comments of our proposed cancellation of TSO-C68a as published in 77 FR 37733, June 22, 2012, produced no comments.
TSO-C68a is cancelled effective February 1, 2013.