Using the magenta circles

Thanks, Richard. That's somewhat along the lines I was wondering
about. However, both of the cases you listed are for IFR flights.
Makes me wonder why, if this information is more useful to the IFR
pilot than the VFR pilot, is it on sectional charts when it sounds
like it would be more useful on low level enroute charts (although,
I'll be the first to admit that I have a sectional or WAC available
when flying IFR).

"Richard Kaplan" wrote in message ws.com...
"Ace Pilot" wrote in message
om...

common use is doing T&Gs in the pattern below 700 feet AGL when the
weather is marginal. Other uses?

1. The altitude where controlled airspace begins can be a factor for an IFR
pilot selecting an airport at which to fly an instrument approach if he is
concerned about airplanes legally flying a traffic pattern 1 foot below him
when he breaks out of a cloud.

2. In areas with unusual and predictable weather patterns, i.e. a very thin
marine fog layer, some pilots depart IMC in Class G airspace in anticipation
of breakout out on top into VMC conditions before entering controlled
airspace -- not necessarily wise but legal nonetheless.