There is good news for owners of GA aircraft on the EASA register that have a transponder, which is capable of ADS-B (extended squitter) but have not had a suitable GNSS position source.
Within the next month, EASA will be releasing an update to CS-STAN Standard Changes and Standard Repairs. If everything goes well, the update should include CS-SC005a, which will authorise aircraft maintenance engineers to connect GNSS position sources to an ADS-B capable transponder to enable ADS-B OUT.
Three configurations will be permissible under this standard change:
- Configuration 1
- certified transponder + certified GNSS
- conforms to AMC 20-24 but with (E)TSO-C166b unit for ADS-B OUT
- reports SIL = 3 and SDA = 2
- Configuration 2
- certified transponder + ADS-B OUT + TABS GNSS
- reports SIL = 1 and SDA = 1
- Configuration 3
- certified transponder + ADS-B OUT + uncertified GNSS
- reports SIL = 0 and SDA = 0 (for airborne traffic awareness only)
This SC is not suitable for the release to service of the aircraft by the Pilot-owner, it must be performed by a licensed aircraft maintenance engineer. However, the engineer does not have to apply for a Minor modification, which significantly reduces costs and saves time.
Please note that the CS-STAN address the airworthiness aspect (installation on the aircraft). The operation of this devices might be subject to limitations imposed by the Competent Authorities.
 See (E)TSO-C199 A1.2.6 for GNSS position source function requirements (for TABS class B devices)
Stay tuned, more details will come soon...