Story ID: 
Avcon STCs Learjet 60 AHRS Upgrade
By: Matt Thurber
Caption: Learjet upgrade replaces outdated AHRS with new and easier-to-calibrate Rockwell Collins AHC-3000A.
Word Count: 190
Butler National’s Avcon Industries subsidiary received supplemental type certificate approval to upgrade the attitude heading reference system (AHRS) in the Learjet 60 from the original Rockwell Collins AHC-85 to the Collins AHC-3000A. Bombardier Learjet partnered with Butler on the upgrade program, and operators can have the installation done through Butler National’s Butler Avionics subsidiary in New Century, Kan., which is a Rockwell Collins-authorized installation/repair facility. 

The upgrade replaces the AHC-85 with the AHC-3000A computer and adds the ECU-3000 External Compensation Unit. There are two key benefits to the STC: one is the ability to replace one of the two AHC-85s at a time, which helps keep costs low; and much simpler cockpit-based setup and calibration of the ACH-3000A. The modification at Butler Avionics takes two to three days. 

“The partnership with Learjet in facilitating the AHRS STC reinforces our commitment to the long-term support of Learjets,” said Butler National president and CEO Clark Stewart. “Maintaining and improving the Lear product line is integral to many of our Butler National businesses and to the longevity of the Lear heritage.”