I was tracking my Dad’s flight yesterday between ATL and LIRF and saw something very weird on the graft. Between 6:08 and 6:09 it says the went from 35,000’ to 16,100’ then back to 35,600’. I assume this is a glitch but could that be caused by a handoff between ground control?
My guess would be bad data in the data stream. A single anomalous reading. This happens occasionally.