Comment by PeterisP
3 hours ago
AFAIK the transponder kind of turns itself on when powering on the plane, you'd have to explicitly disable it but then you'd have weird discussions with the airport tower guiding you to a free timeslot on the runway which would just delay your takeoff, since ignoring the airport tower is a good way to not get off the ground at all because you'll accidentally be hit by some other plane.
99.99% of airports do not have "timeslots on the runway." Most airports in the US have no tower whatsoever.
But I bet if you filter for airports that business jets park at, the percentage of airports without towers is much lower than the overall average.