Originally Posted by
Musician
To be logged by FR24, an ADS-B transmission has to be received by one of its receivers, and their coverage is not complete (and it also appears that messages drop out more in high-traffic areas). So if the last transmision FR24 receives from you is during your approach at 1500ft and 80 kts before your craft gets too low and loses radio contact, that is what it will display, because that is all it has. For the FR24 realtime tracking, there may also be programming that guesses where aircraft are when reception drops out intermittently;
Unfortunately I'm not allowed to post URLs to share recorded by FR24 data of our flight but believe me it's totally inaccurate for the whole flight from take off until landing. It's displayed ZERO altitude while we're flying 1500 for 12 minutes.