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![]() "John R Weiss" wrote in message news:_biPb.92428$5V2.241427@attbi_s53... "Gary Drescher" wrote... Sure, but if the fix in question is your destination airport and your clearance limit, then you might have equipment that lets you navigate to that fix by a published approach to the airport (say, via an off-field NDB or VOR), but not have any way to identify the fix as a holding fix. If you can navigate to a place once, you can do it again. If your navigational ability is so degraded that you cannot find your position via VOR/DME, VOR/VOR, VOR/NDB, or similar means, then you probably should declare an emergency and navigate any way you can to any place you can identify. I disagree that the ability to navigate to a place once means you can do it again. AIM 1-1-9.b clearly states that localizer goidance is only valid out to 35 degrees each side of the course, and that the back course is specifically not to be used for guidance unless a back course procedure exists. Assume a 90kt holding speed and an NDB colocated with the localizer antenna to identify the fix. If there were a 20kt wind blowing across the holding course and you did not correct for it in the hold, then 3 minutes later when you begin the inbound segment of the hold you will have been blown about 1 mile to the left or right of where you want to be. At 1.5 miles from the airport, that is just about 35 degrees off of the inbound course. Any stronger wind, or unfavorable errors flying the pattern, and the localizer may be giving incorrect guidance. [I'm not trying to upset anyone with this admitadly academic exercise, but as "homework" after passing my last BFR I was given the friendly advise to go a read a page a day from the AIM. I found the section on localizers interesting because I had previously had the incorrect idea in my head that they are a special form of VOR. They use the same frequencies, but operate on a totally different principal and their behavior outside of that 35 degree window can be quite bizarre.] |
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