Originally Posted by
snippercr
Those are very good and well thought out minimums. More or less, they are what our school limits our students on for solo IFR cross countries. Although we determine "known ice" as visible moisture near or below freezing. So it could be OVC at 3,000 but 2 degrees at the surface and -4 aloft and we call that "known ice."
After one very bad encounter with ice, I have pretty strict personal limitation with ice - has to be forecasted 2 degrees above freezing at or above my maximum cruise. For instance, winds aloft are forecasted 3,6,9,12000 feet. So if I want to fly at 4,000 then the 6,000 has to be 2 degrees or higher throughout the entire route of flight AND forecasted period. I use to also have another part - the temperature ALSO had to be 2 degrees following standard lapse rate. So a flight at 5,000 feet would require it to be 12 degrees at the surface (10 degrees plus 2). With all that, I am VERY strict about ice. I don't even want to mess around.
Clouds and visibility? Generally I will go with just about anything. I'd like to have a "take off alternate" - that is an airport within 30 minutes that I am pretty sure I can get into. But if not, I say no lower than the highest minimum for the favoring runway. That way I have at least 2 systems to get in on if the airport is so equipped.
Like I said, I am MUCH more conservative about ice than clouds/visibility. I am much more confident in my IFR flying skills than I am in my iced airplane skills. In fact, skills really won't help too much when your aircraft is iced up. Therefore, I just avoid ice all together.
/soapbox
I wish WMU let students fly solo IFR flights. At WMU actual IFR flight is prohibited w/ out a CFI. We must have 3000ft and 5 miles to do a solo flight and less than a 10 kt crosswind.
That is a very reasonable system you have for ice. My CFI told me about a time he got a SR20 so iced up that he couldn't maintain altitude anymore, I plan to never have that happen to me!
My only reason for having a higher ceiling/visibility is that I have never done a approach before without the GPS and autopilot helping me (my cfi would yell at me if I tried doing a approach brief w/out the autopilot!) I anticipate my minimum ceilings/visibility to lower after some experience doing approaches without gps/autopilot aid.