Peuce said
“In E Airspace, IFR aircraft are vectored/instructed to manouver. This manouvering takes no account of unknown aircraft in the same airspace. In G Airspace, IFR aircraft, once advised of IFR traffic, make their own determination about when/how/if to manouver”
It is my understanding that there should be no unknown aircraft in E airspace in a radar environment because all aircraft in E must be transponder equipped. In a non radar E airspace environment there also would be no unknown aircraft to an IFR aircraft if the IFR was equipped with TCAS. I realise that TCAS is a last line of defence, but it does increase safety and this is all that I imagine Dick is argueing for with the regionals. The other line of defence that you have as an IFR aircraft in non radar E is that whilst in cloud there should be no unknown aircraft at all. So, to an IFR aircraft the only unknown aircraft in E would be in procedural airspace, in visual conditions, and then only if the IFR didn’t have TCAS. Of course there is also the mark 1 eyeball in visual conditions too!