Originally Posted by
ozziekiwi
On Flightradar24 is the ATD the off-blocks time or the airborne time which comes up in the left hand panel after you click on the
little yellow icon which represents an aircraft ??
AFAIK, it's usually the airborne time (and they should really refer to it as that) and not the ATD (which is generally understood by the industry to mean the "Out" element of the OOOI time).
If you think about it, there can't be many airports where FR24's enthusiast feeders are able to track aircraft down every cul-de-sac as far as each gate, in fact the airports themselves normally need a multi-antenna setup to do this.