To IanW
Guess what - mandates are already in place for use of ADS-C, ADS-B and SSR.
Indeed expect these mandates to require retrofit to all the older airframes within the next 5 years.
Tracking exists, it works, aircraft can be tracked with an accuracy of a runway width if necessary anywhere in the world.
So please stop trying to propose more expensive** hardware be fitted aircraft to replicate what is already completely adequate tracking capability.
Thanks for the update. I stand corrected.