Originally Posted by
slip and turn
The stray 267kts ADS-B plot for FR9431 also carried an altitude of 19800.
As an aside, beware of data from FR24 and other online sources that appears to show speed and altitude at the same point in time. That's not how ADS-B works - those two parameters are never sent in the same transmission and may therefore be misleadingly populated with stale values in the published data.