When can I turn?

[Ryan B]

Guidance on legal IFR procedures...

I'm approaching the OLM vor from the west, I want to turn outbound on the 201R to OZEYO. Do I have to wait until crossing the VOR to start my turn, or can I turn before the vor so I'm rolling out on the 201R?

Vor Ry 35 KOLM
http://tiles.skyvector.com/sky/files/tp ... 45VD35.PDF

[Orest Skrypuch]

OLM in this approach is not designated a flyover point, so you can negotiate it much like any other turn at a VOR.

Ideally you should lead the turn so as to pick up the correct radial when rolling out, on the other side. Rule of thumb, at 100 knots, with no wind, a standard rate turn for 90 degrees needs a lead of 0.5 nm. If using VOR DME, don't forget to allow for the slant distance.

* Orest

[Keith Smith]

OLM is actually not part of the approach at all (other than being the holding point for the missed), btw. You would not be cleared for the approach from OLM, unless they gave specific instructions to fly along the OLM 201 radial and kept you above the MVA until the IAF.

[Orest Skrypuch]

Keith makes a good point.

Ryan, were you flying /A?

* Orest

[Ryan B]

Thanks for both responses... yah I knew OLM wasn't an IAF but I was asking the question mainly for the theory behind what I can and can't do.

I was flying /G but did not want to go directly to that fix on the 201R.

You seem to mention the circumstances would be different in OLM wasan iaf... are you saying I would have to overfly the VOR then turn outbound (say a 245 heading or so) to intercept the 201R?

I am especially interested in the answer/theory behind that because on my GNS530W/430W - the unit will turn me a little early (if on autopilot) when approaching a common "T" barb for an RNAV approach. I wanted to know what is legal....

RE: Turns to rollout on a radial - I use the same methodology I use irl to vector aircraft onto the localizer/final app course:

I'll turn them 1 mi (from final) per 100 kts ground speed if perpendicular to final. So a common fast mover such as our beloved F16's would get a turn about 3 miles from final, they usually do 300ish over the ground. This method usually works fairly well for me when I fly in flightsim and just like in this example I turned a little earlier because the degree of turn was tighter than 90. (I arrived on the airway from HQM).