Marvin,

 

In answer to your questions about what is needed with the NAV425EX, the NAV425EX does not need a pitot line attached to the unit in order to operate properly.  We do not utilize any information from the pitot system and as a result do not need to have an air data computer built into the system.  Most if not all of the installations I have seen have another ADC already built in that the Chelton system utilizes.  If this is the case, you will not need to purchase an additional ADC.  The NAV425EX also does not require a remote magnetometer but will need to be installed in an area free from magnetic disturbances as we have noted in our installation manual. 

 

The NAV425EX relies upon patented Kalman filtering, magnetometer information and GPS information to improve the accuracy of the unit.  We do not rely upon any air data information to improve accuracy.

 

Sincerely,
 
Michael Smith
Application Engineer Inertial Systems
Crossbow Technology
Email: msmith@xbow.com
Phone: 408-965-3388