Cessna 340/340A
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2.9
Human-Machine Interface; Time Pressure
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance
Procedure; Airspace Structure; Human Factors
Miami feeder final had numerous inbounds to Miami. Aircraft X; a VFR; climbs out of TMB under the Bravo to the northwest up to 029 (even indicated 030 for 2 miles); 10w Miami; with the bottom of the Bravo at 030. The callsign was only obtained when a controller tagged the VFR ''watch'' and due to ADSB got the numbers. The VFR proceeded to track north under the parallel finals; 1 ft under the glideslope at the 10 mi fixes where aircraft would descend. Feeder final had to turn Aircraft Y into Runway 12 tighter than necessary in the event the VFR decided to fly under Runway 12 in a dangerous spot. Had there been any traffic on the parallels as well; it would have been a very unsafe situation.Miami's Bravo airspace was designed back in the day from it's original terminal control area. It has been inadequate for years in terms of it's size; protecting the finals at this airport; and protecting the VFR flying public from the abundance of large; heavy; and super wake turbulence into and out of this major international airport. Presently; all arrivals drop out of the Bravo for about 1/8 mile to every runway at around 10mi around the field; and VFR's are allowed to fly there 1ft underneath all of these arrivals. That is extremely dangerous and unsafe and needs to change; before it's too late and lives are lost.
MIA TRACON Controller reported an airborne conflict and a request to change the Miami Class Bravo.