G'day Bob,

if for some reason you intend on conducting an ILS approach but the runway for the ILS is not available(wind limits, U/S runway etc) and you need to circle to another serviceable runway, is the published minima for circling treated as an ILS DA or as an NPA MDA?

It makes sense to me to treat it as an NPA MDA with all the caveats for visual circling. The most important part of this would be to 'not descend' through the MDA, and circle at this altitude until you can affect a landing IAW the circling caveats.

Thanks in advance,

cheers!

In that situation the circling minima would be no different to any other approach. If it's safe to circle, it's safe to circle. It doesn't matter how you got into the circling area.

If you are in the circling area by day, you can circle as required keeping 300 feet clearance [Cat B], above any obstacle you fly over and maintaining visual contact with the runway environment.

By night, you must ramain not below the published circling minima until you intercept the normal approaach profile for your aircraft.

I wouldn't be too keen on circling at the ILS DA!!!

Thanks Bob, that makes sense. Have a good one!