David Megginson <[EMAIL PROTECTED]> said: > This was just added to the Canadian AIP: > > Glide path installations generate a radiated signal resulting in a > normal glide path angle of 3deg (it can currently be anywhere from > 2.5deg up to 3.5deg). The normal antenna pattern, of glide path > installations, generates a side-lobe. The side-lobe pattern > produces a false glide path angle at three times the set angle > (e.g., at 9deg for a normal 3deg glide path angle). > > I've never been so high on an ILS that I've seen this, of course, but > it's interesting, and should be an easy effect to model. Any > volunteers?
Does this describe the problem in more detail? "This glide slope signal may be adjusted between 2� and 4.5� above a horizontal plane. A typical. adjustment is 2.5� to 3�, depending upon such factors as obstructions along the approach path and the runway slope. "False signals may be generated along the glide slope in multiples of the glide path angle, the first being approximately 6� degrees above horizontal. This false signal will be a reciprocal signal (i.e. the fly up and fly down commands will be reversed). The false signal at 9� will be oriented in the same manner as the true glide slope. There are no false signals below the actual slope. An aircraft flying according to the published approach procedure on a front course ILS should not encounter these false signals." Found at: http://www.allstar.fiu.edu/aero/ILS.htm So if you are 6 degrees or above you will get an inverted signal saying you are too low and then at 9 degrees it suddenly acts like you are right on? Does that hold true right down to DH? Oh my. That *would* be interesting. :-) Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
