Chelton flight systems - Service Difficulty Advisory

AV 2003-08
11 December 2003

The FAA has informed with Special Airworthiness Information Bulletin (SAIB) CE-04-21, related to a certain Chelton Avionics System model that a safety concern exists regarding missed approach procedures at certain airports.

This system is approved for installation on a very large number of aircraft on the Canadian registrar.

SAIB excerpt.


The Chelton equipment displays real-time graphic terrain and situational awareness information to alert pilots of possible conflicts during departure and approach to landing. We have determined that under certain circumstances, misleading guidance into non-protected areas can occur.

The manufacturer has released two Service Bulletins, 150-045972, Rev. A, and 150-045973, Rev. A, both dated 11/18/2003, addressing how to recognize when misleading guidance is being displayed, procedures to follow for continued operation, and how to obtain and install an updated navigation database software application.

The manufacturer is developing an additional design change to the software that will eliminate the potential for this concern. We expect it to be available sometime after January 2004. The Service Bulletins can be obtained from:


We strongly recommend that you obtain and follow the instructions and information presented in the two Service Bulletins listed above.

Transport Canada concurs and strongly recommends owners follow this recommendation.

Any defects or further occurrences of this nature are to be reported to Transport Canada, Continuing Airworthiness, Ottawa, via the Service Difficulty Reporting program.

For further information contact a Transport Canada Center, or call Mr. Paul Jones, Continuing Airworthiness, Ottawa, telephone (613) 952-4431, facsimile (613) 996-9178 or e-mail

For Director, Aircraft Certification

B. Goyaniuk
Chief, Continuing Airworthiness

Note: For the electronic version of this document, please consult the following Web address: