On 5/11/07, Ron Jensen <[EMAIL PROTECTED]> wrote: > On Thu, 2007-05-10 at 21:16 -0500, Laurence Vanek wrote: > > One thing I have noticed is that if you leave the KNS80 in rnav mode > > when tuned to localizer freq & intercept you will follow a glideslope to > > a surprising place. I have mistakenly done this a couple of times. > > Needs to be in vor mode. > > In anything but VOR mode the CDI needles are slaved to the gps so the > RNAV code can drive them. The RNAV code doesn't drive the glideslope so > it remains centered always... currently without a warning flag.
According to the documentation (again #16), not entirely. Even when in VOR/PAR mode, tuning in a ILS frequency shall cause HSI or CDI deflection if in recieving range of the pertinent LOC or GS. So at least then the nav should be unslaved from gps, thus letting the nav(gs) receiver(s) do their own thing as in pure VOR mode. But it is a bit unclear what might be construed by thinking of a tuned in ILS, the sentence about "[...]VOR/PAR function will remain annunciated along with the active ILS function" and the following conditionial "[...]within receiving range[...]" and "(unless an ILS frequency is slected)"(last sec. of #16, p.19). Taken at its face value, I'd think of some sort of internal db (like in more modern gps instruments) because otherwise, how would it know about a ILS freq if not in receiving range. Since I find that not very probable I'm leaning towards the interpretation, that it would show the beahviour as described elsewhere and the special exception about ILS gets triggered only if (selected _and_ in-range(LOC or[?] GS)). So the qualifying "at least" I used above would become "(only) when". > > > Im not sure but when tuned to a localizer freq should vor/rnav mode matter? > > I think the right thing to do is set the ILS flag and un-slave the CDI > needles... Which brings me back to a question I've pondered before: how > do we know we're tuned to an ILS freq? There's a bit of silence in the documentation. Taking into account the nitpicking exceptions explained elsewhere, and the goal to avoid misinterpretations by the pilot, (flying to a wpt "established" by LOC and (pertinent(?) DME, descending on glidepath by GS) I would suggest the general rule applies without exception to ILS: RNAV modes would have to recieve VOR and (not HOLD) DME (or VORTAC) to not flag as invalid (stated end of #11, p.16 in general). This in turn would require an eventual ILS with paired DME. Is that a common setup? Or even possible? (seems not so here, ED*). Perhaps the ILS annunciator could show up when receiving a LOC signal, but it would remain the pilot's responsibilty to switch to VOR(/PAR) mode to use it directly (and only then to unslave the nav from gps). I hope I uttered all that guesstimations in a remotely comprehensible way. *g* regards K. Hoercher ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Flightgear-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-users
