werbil
I agree with your points made except to say in scenarios 1 and 2:-
- VFR often do not self announce
- VFR often do not understand IFR tracking and position reports [particularly if an IFR non-runway aligned procedure is being flown]
- VFR sometimes omit activating transponders
Class D clearances and separation [where necessary] addresses all of the above! Which as I read your other points, supports a higher level boundary split which solves these deficiencies.
Scenario 3:
D/E boundary @ A025
IFR jet ready at Broome for departure
IFR piston inbound on descent through A040.
Tower cordinates clearance with centre. Departing jet is held on ground until piston twin has landed. Some delay.
Negative, the tower will separate the two, even if still in conflict whilst still in the overlying adjoining CTA. It happens everyday in every D tower. It is part and parcel of their separation co-operation at and around the adjoining Centre airspace boundary!
The tower will achieve the separation any number of ways depending on cloudbase, approach being flown, and its orientation to the runway in use etc etc. In your example above, there is virtually NO chance the IFR jet will not be airborne before the twin lands. This of course applies irrespective of the height of the split between TWR and
Enroute CTA! Conversely, if the separation confict is a long way out, sector will separate these!
Where delays occur, is when tower applicable separation is not available, but
a separation standard is still
technically required i.e. close in to the aerodrome whilst in class E [below A100, and most certainly below A050], with G CTAF below.