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From: ths@lanl.ARPA (Ted Spitzmiller)
Newsgroups: net.aviation
Subject: Re: Out to dry on the glideslope
Message-ID: <1524@lanl.ARPA>
Date: Wed, 26-Feb-86 11:28:49 EST
Article-I.D.: lanl.1524
Posted: Wed Feb 26 11:28:49 1986
Date-Received: Sat, 1-Mar-86 00:55:52 EST
References: <2473@pixar.pixar> <474@gcc-milo.ARPA> <2493@pixar.pixar>
Organization: Los Alamos National Laboratory
Lines: 36

> > I'm just a low time VFR pilot (so I could be wrong), but isn't the usual
> > procedure to intercept the localizer before following the glideslope down?
> 
> ..... in many of
> the approaches we have flown during training we have intercepted the GS
> *before* reaching the localizer.  This is actually quite handy since you
> can already have the rate of descent established by the time you have that
> other little needle to center.
> 
> 		--Craig

As I mentioned in a previous posting, you should NOT begin the descent UNTIL
you are established on the inbound course (LOC needle off the peg).  If you
are getting the GS before the LOC then one of a number of situations has
occurred:

      o   If you are on vectors, the controller is required to bring you
	  into the LOC before GS intercept.  This position is outside of
	  a point 2 miles from the GS intercept, at the GS intercept altitude.
	  This point is called the "approach gate".  A controller may NOT
	  position an aircraft to intercept the GS from above.

      o   If you are flying a PT, you are not going out far enough from the
	  OM before starting the PT.  Generally 90 seconds is acceptable
	  unless you have a lot of altitude to loose or there is a
          significant headwind on the outbound.

	  One technique is to begin your OB timing over the OM but do not
	  start the PT until the GS comes off the vertical peg and preferrably
	  not until the GS needle centers.  This will assure that even with a
	  stiff headwind during the OB you will have enough time to intercept
	  the GS from below and on the LOC.

Perhaps some of the other "old salts" might have some other suggestions.

Ted Spitzmiller