Maintenance and Modifications
Duncan Resumes TDR-94/94D Transponder Mods
A software upgrade is available for Rockwell Collins TDR-94/94D transponders at Duncan Aviation facilities.

After briefly suspending Rockwell Collins TDR-94/94D modifications on October 25, Duncan Aviation has resumed offering the upgrade to these transponders so they meet the FAA DO-260B standard for ADS-B Out. The work started again on November 13 at Duncan’s Lincoln, Nebraska headquarters.