Intercepting the ILS

wrote:
I agree with everything you just wrote. But, you have not addressed
my question. In what way does/can following the glideslope from 2000
to 1800 feet at SCK violate the regulatory implications of the SCK
ILS's 8260-3?

In the specifics cited for Stockton there is no issue of legality. My
understanding was that the CFII in question was making a general
statement about the limitations of the G/S prior to the PFAF; that is,
it is advisory only. Although using it as advisory at Stockton and
using 1800 as the floor prior to the PFAF would be both legal and
permissiable technique, it will not work where there are intervening
stepdown fixes between the point at which the approach clearance is
received and the PFAF.

It is also permissible technique to disregard the G/S and simply drive
it down to 1,800 to intercept the G/S from below, assuming there is
sufficient distance to do that.

I surmised that the CFI was thinking in global terms, and failed to
provide a complete explanation. Then again, my understanding about what
was (in) the CFI's mind is fragile at best.

In general terms: it is not legal to use the G/S as primary prior to the
PFAF. That is an important concept for the pilot to understand. It has
been proven more than once that a lot of air carrier pilots don't
understand it.

"In the specifics cited for Stockton there is no issue of legality."

We're agreed then.

I had attempted to emphasize in my long series of messages to you that
*I* was talking about Stockton, whatever might have been in the CFI's
mind.

Ed

Doug wrote:

What did your CFI tell you to do? Decline ATC's instruction?

*** Actually, he didn't tell me to do anything. He mentioned it after
I had already started down the glideslope. At that point, I was pretty
busy, so I just said "Let's talk about it on the ground".

Then on the ground, it slipped through the slats.

- Jerry Kaidor (
)

Gene Whitt wrote:
Jerry,
It's been a few years since I flew down to San Jose to watch your first
solo. This thread of some 46 responses made my late arrival all the more
interesting.
*** Greetings Gene! I still have the photos you took up on my
refrigerator!


There is an interesting side light to the SCK 29 ILS that I learned before I
had my instrument rating which was not required for my CFI back then. I was
flying as safety pilot in VFR as a rated pilot was shooting the ILS to 29
when somewhere about 600' the localizer needel went crazy and all the way to
the right side even though the runway was directly ahead. This was some 30
years ago.

Interesting as to why this might be and happen and I will tell you why but
make your best guess now.

It could be that equipment was not as sensitive as it is today

*** Or it could be that it was more sensitive. I have two NAV
receivers: a
KX170B and a GNS430. The 170B is definitely more sensitive.


but suggest
those of you who
want to see what happens I suggest that you set the localizer to 110.1
instead of 109.1 and fly the procedure and see how the localizer works, if
at all. Under the right conditions it
should give the same response as I have described. 110.1 happens to the the
Localizer
frequency at one of the two runways (21RL) at Travis AFB.nearly 30 miles
away but in line with Stockton's 29.

*** The localizer signal is AFAIK produced by two transmitters, both
amplitude
modulated. One has a 90Hz tone, the other one has a 150Hz tone. It
looks
like a sort of positional diversity took place where one of the signals
had an
obstruction way out there in the Valley somewhere.

When I did my Private X-country, I tuned in the wrong VOR and
merrily
navigated on it for about 10 miles. These days, I try to be very
disciplined about
always ID-ing navaids before using them.

- Jerry Kaidor ( )