...but if you cannot accept any revised clearance your only
alternative is to cancel IFR.

No, my other alternative is to fly the clearance I already have.

But the point isn't that I can't accept =any= revised clearance (at
all), but rather, that I can't accept =any= (arbitrary) revised
clearance. You can't create capabilities in my aircraft by talking on
the radio, and you can't assume that any IFR aircraft is capable of
magic either.

If the original clearance was an option there never would have been a
reroute.

The original clearance was an option when it was given to me. It
remains an option throughout my flight. It is ATC's job to ensure that
it remains an option. ATC may, with the pilot's cooperation negotiate a
reroute. Usually this is done unilaterally with no problem. But ATC's
failure to ensure that my clearance remains viable does not impose upon
me an obligation to endanger myself (such as by climbing to an icing
altitude and/or flying sixty miles offshore).

ATC: Amend altitude, climb maintain niner thousand

Me: Unable due to ice.

ATC: Ok, I'll cancel IFR for you.

Me: Negative, we're IMC.

ATC: Well, you're no longer IFR, so you're in violation. I'll pull the
tapes and have an inspector waiting when you arrive.

Jose
--
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