Minutes, not seconds.
If the system sends signals EXACTLY every 30 minutes, then a very careful reconstruction of signal running times (combined of course with the positions of the recieving antennae and the EXACT times the signals were recieved) can reveal information about the heading and position.
This would be nothing for an airplane - $0.40 per hour? Why don't they do this already?
They would likely receive pushback from private jets that don't want all of their flight path transmitted back to RR.
Make a law that the owner has to preserve the data for one week, but doesn't have to provide it to anyone.
And doesn't the US military track every overland flight anyway?
But it's even easier than that: Just make all US owned airlines require it, and any flight landing in the US. Phase it in, etc, to give time to upgrade, but it's certainly possible.
(Of course, it is a business, rather than branch of a government, and not the only manufacturer of jet engines).
My numbers were $0.40 per hour, plus a few hundred for the equipment (it's available off the shelf, don't need anything custom). Don't know how much installation would be, but certainly not millions.