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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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