EASA SIB 2021-01R1
Collins Aerospace Very High Frequency Data Radios - Data Link over Very High Frequency Data Link Mode 2 Operations
Summary
EASA Safety Information Bulletin 2021-01R1 is an informational bulletin addressing issues with Collins Aerospace Very High Frequency Data Radios (VDRs) used for Data Link over Very High Frequency Data Link Mode 2 operations. The affected VDRs, installed on various Airbus, Boeing, Bombardier, and Embraer aircraft, may experience a 'VDR deafness' issue where uplink messages are not decoded after receiving corrupted signals, impacting Controller Pilot Data Link Communications (CPDLC) performance. This bulletin provides guidance but does not mandate regulatory action.
What Changed
This revision of EASA SIB 2021-01 adds the VHF-920 radio with part number 822-1250-021 to the list of affected units and includes reference to the associated Service Bulletin SB-502. It updates the list of Collins Aerospace VDR types and part numbers subject to the 'VDR deafness' phenomenon and the recommended service bulletins for mitigation.
Why It Matters
The 'VDR deafness' issue can disrupt CPDLC communications, potentially affecting flight operations within the single European sky airspace. Operators and maintenance organizations need to be aware of this issue to maintain reliable data link communications and ensure operational efficiency. Although not currently considered an unsafe condition requiring mandatory corrective action, monitoring and mitigation are important to avoid communication interruptions.
What To Do
EASA recommends that owners, operators, and maintenance organizations apply the relevant Collins Aerospace Service Bulletins listed for their specific VHF Data Radio models at the earliest practical opportunity. These service bulletins provide instructions to address the 'VDR deafness' issue. There is no mandatory compliance deadline, as the recommendations are informational only.