Bill Denton ) wrote:

You might want to rethink your reply

Easy there, Bill. There is no need for that.

A pilot in clouds or other IMC cannot provide separation to any traffic he
cannot see.

I am discussing IFR/VFR separation, not IFR/IFR separation. Hopefully,
no VFR aircraft will be in IMC, but that point is irrelevant since most
times ATC does not know if it is IMC or VMC; they only have blips on
their screen.

Consider this: It is quite possible that a) a VFR aircraft is climbing
or descending through an IFR aircraft's cruise altitude, or b) an IFR
cruise altitude is below 3,000 AGL, which means that a VFR aircraft
could be at any altitude 3,000 feet AGL or below s/he desires, including
that IFR aircraft's altitude.

Will ATC provide traffic callouts and or vectors around VFR traffic in
either scenario above? Most likely. Are US controllers required to?
Outside of class B airspace, the answer is no.

--
Peter