Mark Hansen wrote:


The circle to land is required anytime the landing runway is more than
a set number of degrees from the approach course (I can't remember the
exact number of degrees - maybe 10 or 30?). Obviously, the runway opposite
to the approach course would qualify ;-)

30 degrees for ground based, 15 for RNAV.

Also, descent gradient limitations, straight-has to be to TDZ; circling
just to MDA.

And, a third, less often an issue, are limitations on the electronic
guidance's proximity to the runway centerline, extended.