Re: Turn onto xwind and final at 500' - why 500'?
Depends on Where You're Doing the Circuit
If you are not conducting legal low level ops such as training or aerial work in an approved area, (CAR's 141,. 157), then my understanding is that you cannot make turns below 500 ft as these constitute low flying. Yes, you can descend below 500 ft legally [I]on approach to land[I], where on approach means on final approach - not elsewhere.
So, if you were training at a CTAF/CTAFr, and making 500 ft circuits,then you should be 500 ft at the turn to x/w, and 500 ft at the turn onto final.
Once untrained pilots begin making 250 ft turns, or lower, then there is a very good chance of them suffering the wind illusion, and for this reason I'd recommend against it. If you do this stuff for a living, then the compensation is made instinctively. If you don't - then get some training in it first.
Yes, there is a certain logic about beginning your descent to land from the base turn, but I'd suggest that at lower levels, you should be flying a racetrack circuit - so that you make 180 degree turns from upwind to downwind, and a descending 180 from late downwind onto final. This pretty much ensures that you don't overshoot final, and it also keeps you 'in sight' of the threshold when in gloomy wx.Once you get down to 200 ft circuits, it must be racetrack or you can lose contact very quickly.
I'd therefore be thinking that the 'new' 500 ft circuit for light and slow aircraft is very likely to bring them onto final at the very same point as for the 1000 ft circuit. In practice it seems to be well inside the 'normal 1000' circuit, probably due to the lighties beginning a descent on the base leg rather than after turning final.
happy days,