Originally Posted by
CaptainMongo
Class B excursions (descending below Class B airspace on approach) have been getting quite a lot of attention in the US. KLAX (and KSFO, NYC airports, KORD among others) has been identified as a threat because of close proximity of general aviation aircraft.
GA aircraft, I have been told, have avionics that can tell them in great detail where exactly they are in relation to Class B airspace, so they are more confident in using the airspace allotted to them which puts them in closer proximity to the boundaries of, but not in, Class B airspace.
Some GA aircraft certainly do have that capability, but many still do not.
Although it is a regulatory violation for an air carrier airplane to descend below Class B, that doesn't get the attention that compromising IFR separation does, because the latter becomes a matter of a controller staying out of trouble when the "Snitch" goes off. That did happen quite often on hot summer days in the Ontario, California area where the SoCal unti that controls KLAX has airspace in the KONT area controlled by a different SoCal unit that is below the KLAX airspace.
One way to ensure we remain in Class B airspace is to follow published approach altitudes.
There have been cases where FAA designers have screwed that pooch by the left hand (airspace designers) not knowing what the right hand (approach designers) were doing.