Originally Posted by
AlphaVictorFoxtrot
At busier fields, have E down to 0 AGL.
In Canada you might have that, if a difference has been registered with ICAO.
ICAO airspace design says CTA (control areas) can't extend down to ground level.
I also make the point that in Australia transponders are not mandatory for VFR in Class E for all aircraft types. Many are exempt that are unable to power one.