Well now there is a difference between the defined circling area for each category versus the minimum circling visibility for that category. So we have a defined circling area assessed to decide on the minimum circling altitude prior to descending on profile to the runway and a minimum visibility required during the circling manoeuvre. So for cat C we have a 4.2nm circling area generally with a minimum visibility of 2nm. So assuming that the runway lights (sometimes other lights clearly indetifying the runway environment) are to be kept within 2nm while conducting the circle. So there is nothing supernatural about circling within 2nm.
However the first rule about circling approaches is DON"T DO THEM IF YOU DON"T HAVE TO!! Generally there are other runway oriented approaches available.
The second rule is it is NOT a VFR/VMC procedure so it must be flown in a disciplined manner primarily on instruments with visual check points. Many have come to grief looking out the window at the runway especially on the base turn. Have in mind definite minimum target altitudes; at the end of downwind leg; at mid base and lined up and STICK To THEM.
The third rule is if out of position go around. Go somewhere else if need be.
Black Dawn,
120 TAS turn radius is nearer to .45nm I think. Think you gave us the diameter.
[This message has been edited by pterodactyl (edited 10 June 2001).]