Originally Posted by
FlightDetent
The extended squitter seems to have a data filed for selected Baro ref, however the last value is retained for transmission instead of STD when the crew changes to that.
Which brings us to another unexpected conclusion. Mode S must have been transmitting Q1011 after this almost doomed crew accepted the wrong instruction.
AFAIK, baro pressure setting isn't part of the ADS-B extended squitter, but is only sent as part of Mode S EHS, if and when interrogated by SSR.
I don't know whether the CDG controllers typically see it on their screens (either fulltime or as an option) or not.