rainbow462 wrote:Thanks for the replies
I'm observing the FL from the transponder screen. Also when I check back FR24 it matches what I saw in flight. Finally using getyourwings software and a polotaware base station I can it is receiving the ADBS signal and the altitude is significantly out e.g. -600'
I'm assuming the TRT800H has a built in encoder.
The static port at the back is not connected to the altimeter/external port and is just is open in the back of the dashboard
It will not work properly unless plumbed to the same static pressure as the altimeter.
I would suggest you get the system checked over and sorted properly before it gets you into trouble.
On a similar note, there are likely a bunch of the new crop of carry-on EC devices with similar cockpit static/ altimeter static pressure discrepancies.