Alex Perry writes: > A lot of approach plates, needing a course reversal, either use a > procedure turn or a hold. The former is easier, but needs a > depicted hold somewhere else in most cases, the latter. Thus, I've > been given radar vector, direct to navaid when able, then hold, efc > for the approach at specific time. So far, I've never had a hold > enroute, before getting into terminal airspace.
I haven't seen a hold instead of a PT yet in Canadian approaches, but then I haven't looked at approaches for mountainous areas. I can see where a hold (possibly with a shuttle descent) could be valuable near high terrain. By the way, here's an interesting bit of trivia: Canadian approaches have almost completely abandoned OMI markers (completely for middle and inner). Instead, at high traffic airports, they use an NDB a few miles from the threshold for the FAF (and often the IAF as well), so you have to use the ADF (or DME) together with ILS to establish the FAF; there's sometimes another NDB off the far end of the runway for missed approach. It looks like I'm not going to see a marker light at any point in my instrument training. Here's an example from the DAFIF (without a second NDB for the missed approach, since the VOR is nicely lined up): http://164.214.2.62/products/digitalaero/terminals/v0211/CANADA/OTTAWA_MACDONALD_CARTIER_INTL/V_ILS_OR_NDB_RWY_32.PDF I can think of three advantages to switching from OMI to NDB: 1. ATC can still allow instrument approaches using the NDB (to higher minima) when the ILS is U/S. 2. ATC can vector traffic directly to the IAF or FAF more easily. 3. VFR traffic can use the NDB to line up in marginal VMC conditions. Can anyone think of other benefits to throwing out the OMI markers? What are the disadvantages? As you might guess, it's rare to see an IFR Canadian plane without an ADF radio, especially since the majority of approaches at smaller airports are still NDB or NDB/GPS, and many smaller towns are joined by NDB air routes rather than Victor airways. Without RNAV, I could not even fly to Kingston from Ottawa IFR without an ADF. All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
