Return-Path: Sender: (Marvin Kaye) To: lml Date: Thu, 20 Mar 2003 17:04:36 -0500 Message-ID: X-Original-Return-Path: Received: from [63.150.227.63] (HELO admsmxsint01.jocoks.com) by logan.com (CommuniGate Pro SMTP 4.1b1) with ESMTP id 2081096 for lml@lancaironline.net; Thu, 20 Mar 2003 10:47:42 -0500 Received: by mail1.jcnc.info with Internet Mail Service (5.5.2650.21) id ; Thu, 20 Mar 2003 09:47:42 -0600 X-Original-Message-ID: <4B9B1B1833408C40AE2F14A881F276F610B2EE@admsmxs2usr10.ad.jocoks.com> From: "Metcalfe, Lee, AIR" X-Original-To: "'lml@lancaironline.net'" Subject: [LML] Re: LNC2 in IMC X-Original-Date: Thu, 20 Mar 2003 09:47:37 -0600 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C2EEF8.0ABB4E46" This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C2EEF8.0ABB4E46 Content-Type: text/plain Grease: I hope you mean you are dropping the gear when the glide slope needle is one dot above center on the indicator. That is the normal procedure for most retractable flyers. If you are approaching the glide slope from above, you are doing it wrong. And if your CFII taught you that, you should find another CFII. Standard ILS approach design sets you up to approach the glide slope from below. If you look at the profile view on an approach plate you'll see an altitude with a line under it near the final approach fix. That is the "glide slope intercept altitude." You should be at or very near that altitude, preferably in stabilized level flight, as you approach the FAF. As most approaches are designed, you should intercept the glide slope (from below) at the FAF, which is denoted in the profile view by the "lightning bolt" arrow from the glide slope intercept altitude to the glide slope intercept point. In addition to making the approach much easier to manage, there is another reason for approaching the glide slope from below. There are ghost signals (aka "false lobes") above the real glide slope at multiples of the angle of the glide slope. For the standard 3 degree glide slope there would be a ghost signal at 6 degrees, 9 degrees, etc. Each ghost signal is progressively weaker by a considerable factor, with the characteristics of a particular glide slope antenna installation being the main determinant. With the more modern "capture effect" glide slope installations, the ghost signals are not a factor, but there are still a lot of the older technology ILSes out there. So if you are approaching the glide slope from above, you could inadvertantly intercept the ghost glide slope instead of the real one, at least in theory. I personally have never seen this happen, but I know pilots who claim to have experienced it. Fly safe! Q-Tip (now that I have a new, stragiht-bladed prop, I guess I need a new handle, eh?) N320WH - 472 hrs. - Kansas City (IXD) ------_=_NextPart_001_01C2EEF8.0ABB4E46 Content-Type: text/html Message
Grease:
 
I hope you mean you are dropping the gear when the glide slope needle is one dot above center on the indicator.  That is the normal procedure for most retractable flyers.  If you are approaching the glide slope from above, you are doing it wrong.  And if your CFII taught you that, you should find another CFII.  Standard ILS approach design sets you up to approach the glide slope from below.  If you look at the profile view on an approach plate you'll see an altitude with a line under it near the final approach fix.  That is the "glide slope intercept altitude."  You should be at or very near that altitude, preferably in stabilized level flight, as you approach the FAF.  As most approaches are designed, you should intercept the glide slope (from below) at the FAF, which is denoted in the profile view by the "lightning bolt" arrow from the glide slope intercept altitude to the glide slope intercept point. 
 
In addition to making the approach much easier to manage, there is another reason for approaching the glide slope from below.  There are ghost signals (aka "false lobes") above the real glide slope at multiples of the angle of the glide slope.  For the standard 3 degree glide slope there would be a ghost signal at 6 degrees, 9 degrees, etc.  Each ghost signal is progressively weaker by a considerable factor, with the characteristics of a particular glide slope antenna installation being the main determinant.  With the more modern "capture effect" glide slope installations, the ghost signals are not a factor, but there are still a lot of the older technology ILSes out there.
 
So if you are approaching the glide slope from above, you could inadvertantly intercept the ghost glide slope instead of the real one, at least in theory.  I personally have never seen this happen, but I know pilots who claim to have experienced it.
 
Fly safe!
 
Q-Tip (now that I have a new, stragiht-bladed prop, I guess I need a new handle, eh?)
N320WH - 472 hrs. - Kansas City (IXD)
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