EASA SIB 2016-19R1
Honeywell Mode S Transponders: Enhanced Surveillance Parameters not provided to Mode S Ground Stations
Summary
EASA Safety Information Bulletin 2016-19R1 is an airworthiness bulletin addressing an issue with certain Honeywell Mode S transponders installed on aircraft such as Textron Aviation, Embraer, Gulfstream, and Learjet models. The bulletin clarifies that these transponders do not provide Enhanced Surveillance (EHS) parameters to Mode S ground stations, affecting compliance with European surveillance requirements. The affected transponders include models XS-852E, XS-852F, XS-857A, and XS-858A incorporated in specific Primus II and Primus EPIC communication units.
What Changed
This revision replaces the original SIB 2016-19 and its correction to clarify the applicability of the issue. It highlights that the transponders send incorrect register content in response to Mode S ground station interrogations, preventing the ground stations from recognizing the aircraft's EHS capability. The bulletin also provides updated recommendations for software upgrades and modifications to correct the anomaly.
Why It Matters
The inability of Mode S ground stations to receive EHS parameters can impact air traffic controllers' situational awareness and the effectiveness of ground-based safety nets. Compliance with national AIP mandates and European Commission regulations requires accurate EHS data transmission. Operators flying in European airspace may face ramp checks and regulatory scrutiny if their transponders do not meet these requirements.
What To Do
Operators are recommended to apply the applicable Honeywell Service Bulletins to upgrade the Mode S transponder software and hardware as specified. These modifications ensure correct data transmission for Surveillance Identifier requests, altitude reporting to TCAS, and capability reporting. Stakeholders should contact Honeywell for technical support and obtain the relevant Service Bulletins to maintain compliance, although no mandatory compliance deadline is specified.