I believe that the altimeter instrument does not show altitude. Altitude is shown in the AGL and MSL instruments, I believe. I understand the concept of GPS altitudes, but that isn't my question.
Thanks, Walter. Your reply came through while I was typing.
That does explain the reading and I can see how that would be very helpful.
Thanks for the question, it's made me realize we need to label that instrument differently to make it more clear.
I saw the new instrument yesterday but wasn't sure what it represented, since nothing I had was feeding barometric pressure to the iFly. I didn't consider the source could be ADS-B. What a fantastic idea!