Originally Posted by
Shadoko
Could the published BTOs for T-Channel be computed in another way that R-Channel?
I think so. I believe the aircraft can transmit at any time on the R-channel, but is assigned specific timeslots on the T-channel (you can see T-channel assignment messages in the logs). So the logged offset is probably the offset from the assigned timeslot, and the logs presumably show the aircraft transmitting a few milliseconds before it was supposed to.