Every airport has a "preferred" runway to use. I'd suggest using that one regardless. The surface wind goes into the equation to select which runway, but it doesn't kick in until crosses a threshold.
Of course, if you can find ATIS information online :) Alex Perry wrote: > +1. Reversible approaches should be configured like any other ATC controlled > ground system - such as runway lighting. I have no objections to an > automatic selector for which ILS end to enable, but it should be based on > surface wind (for example) and not the aircraft position. > > > > John Denker <[email protected]> wrote: > > >> Back in the 2nd week of September there was discussion of >> reversible ILSs. >> >> Maybe I missed something, but I thought there was rough >> consensus around the following ideas: >> >> a) FG behavior should be reasonably realistic. We should >> not make artificial assumptions that make approaches >> unflyable, when better alternatives are readily available. >> Conversely, we should not require FG to implement features >> that are not available in real life. >> >> b) An instrument approach procedure generally contains a >> "missed approach segment". There is a maxim that says >> "If you are not prepared for the miss, you are not prepared >> for the approach." The FAA says that half the time, >> a practice approach should include flying the missed >> approach segment. Real-world pilots take this seriously. >> Lives are at stake. >> >> c) You cannot show up at a real-world airport and expect >> both ends of a reversible ILS to be active simultaneously. >> The physics doesn't permit it. The signals would interfere. >> If runway 11 is active and you would prefer runway 29, >> you can ask Tower to reverse the ILS. They might or might >> be able to grant your wish. >> >> d) For years, FG has attempted to divine which end of the >> reversible ILS the pilot wants to use based on aircraft >> position and/or heading. This is both unrealistic (see >> item c) and impossible. There is no objective way to >> determine whether an aircraft is flying the "upwind leg" >> for runway 11 or the "downwind leg" for runway 29; the >> only difference between the two is the pilot's intentions. >> You've heard of problems that are so hard that they are >> classified as NP-complete ... well, this problem is much >> worse than that. It is ESP-complete. >> >> e) The current code is even more broken than that. At >> some airports, it gets the wrong answer 100% of the time, >> so that you cannot fly the inbound segments, never mind >> the missed approach segment. Bug reports on this issue >> have been discarded without comment. >> >> f) Code to fix all these problems has been available since >> September. It uses a "preferred-approach-deg" value >> in the property tree to decide which end of the ILS to >> activate. If you prefer the other end, you can easily >> change this property. All segments of the approach are >> flyable. Everything is predictable and well behaved. >> >> The same words that described the ILS service volume >> apply here: This is a significant departure from past >> FG behavior, but it is not wrong. It is feature, not >> a bug. >> >> This code was not committed. It was discarded without >> comment. >> >> =========== >> >> I was recently told [off list] that there was a >> "requirement" within FG to permit simultaneous approaches >> to both ends of a reversible ILS. This came as a surprise >> to me. I do not recall anybody suggesting this, even as >> a joke, much less any consensus in this direction. >> >> Let's be clear: We all agree it is important for both >> ends of the ILS to be available without undue hassle, but >> they don't need to be available at the same time. And >> "without undue hassle" doesn't mean without any pilot >> input at all, especially when the problem is ESP-complete. >> Most real-world instrument-rated pilots are content to >> fly the approach that Tower says is the active approach; >> they don't show up at an airport with inflexible pre- >> conceptions about which approach will be active. >> >> I was also informed [off list] that the code to make >> reversible ILSs usable had been "ignored" because it was >> "not good enough". That is not very informative, not >> very constructive. No clarification has been forthcoming >> as to what makes it "not good enough". >> >> Perhaps some folks on this list would be kind enough >> to look at the code and make constructive comments. >> Take a look at >> http://gitorious.org/~jsd/fg/sport-model/commits/sport >> in particular the item that speaks of "reversible ILS". >> >> If there are some requirements that I am not aware of, >> requirements that make unflyable approaches preferable >> to flyable approaches, please explain. >> >> ------------------------------------------------------------------------------ >> This SF.Net email is sponsored by the Verizon Developer Community >> Take advantage of Verizon's best-in-class app development support >> A streamlined, 14 day to market process makes app distribution fast and easy >> Join now and get one step closer to millions of Verizon customers >> http://p.sf.net/sfu/verizon-dev2dev >> _______________________________________________ >> Flightgear-devel mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/flightgear-devel >> > ------------------------------------------------------------------------------ > This SF.Net email is sponsored by the Verizon Developer Community > Take advantage of Verizon's best-in-class app development support > A streamlined, 14 day to market process makes app distribution fast and easy > Join now and get one step closer to millions of Verizon customers > http://p.sf.net/sfu/verizon-dev2dev > _______________________________________________ > Flightgear-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > -- “I am for doing good to the poor, but I differ in opinion of the means. 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