When can you start a circling approach

[Nanart]

lets say your doing a Rnav approach for one runway circling to another and your a B catgory aircraft, now lets assume you get the rwy visual at 5 miles at what point can you start circling for the rwy you intend to land on? since your a B catagory aircraft to you have to wait till your within 1.5 miles before starting the circling?

I was able to get this out of the AIM but it doesn't really explain when you can start the circling procedure:

The visual manœuvring area for a circling approach is determined by drawing arcs centred on each runway threshold, and joining those arcs with tangent lines. The radius (R) of the arcs are related to the aircraft category as follows: A, 1.3 NM; B, 1.5 NM; C, 1.7 NM; D, 2.3 NM; E, 4.5 NM. (Category E circling minima are published at DND aerodromes only.) The circling MDA provides a minimum of 300 feet above all obstacles within the visual manœuvring area for each category.

[Big Pistons Forever]

When you are at circling MDA you are only guaranteed obstacle clearance on the inbound track to the MAP and inside the arc for your category. The safest thing to do is fly the inbound tack until you are 1.5 miles (cat B) or closer to the runway threshold and then circle.

[TopperHarley]

You obviously need to establish visual reference too.

[Tim]

you can start circling once you have and expect to maintain visual reference. that may or may not be done at MDA. if i can circle at a higher alt than MDA and treat it more like a regular circuit, i will. like BPF said, there are specific ranges that MDA applies to based on cat of AC, so keep that in mind if you decide youre gonna start circling early and keep your eyes out.

http://www.tc.gc.ca/eng/civilaviation/r ... tm#602_128