EASA SIB AIR-21-15R1
Aeroplanes with Honeywell Primus II Radio System with Radio Management Unit (RMU) 855 - Navigation System
The FAA Special Airworthiness Information Bulletin SAIB: AIR-21-15 R1 provides information regarding the Honeywell Primus II Radio System with Radio Management Unit (RMU) 855 installed on various aircraft models including 328 Support Services GmbH Model 328-100 and -300, Learjet Model 45, Embraer EMB-135 and EMB-145 series, Textron Aviation models 500, 550, 560, 650, Hawker 800 series, Bombardier CL-600 and BD-700 series, Viking Air CL-215-6B11, and Textron Aviation Model 750. The bulletin addresses the potential for inadvertent disabling of the Automatic Dependent Surveillance–Broadcast (ADS-B) Out function due to certain avionics power-up sequences involving the RMU-855. This is an informational bulletin and does not mandate regulatory action.