ILS instrument accuracy? Help......

The 'preferred' option is to have a loc frequency automatically force the
NAV/GPS switch to go to nav mode.


Almost all wiring suggestions imply that as the deafult mode.

So you barrel along with your gps upto the IAF cros tracking your favourite
VOR then swap frequencies
on nav1 and bingo your automatically lined for a loc intercept.

Personally I find it it irrating and also if P2 happens to tune the ILS/DME
for cross references
purposes and the A/P is on then you can do a beautiful intercept of the ILS
for an airfield you just
happen to be passing!!


Peter


"Stan Gosnell" wrote in message
...
(Ben Jackson) wrote in
news:PeIab.524381$uu5.87404@sccrnsc04:

What ACUs will allow you to select GPS display when a LOC
frequency is tuned in on the NAV? I know UPSAT's won't
actually select the GPS until you tune a normal VOR on the
associated NAV.


With the installations we have, the HSI has no idea what's
selected, or what frequency. There's a push/push button, which
cycles between VOR & GPS, and the HSI just gets voltage from
whichever is selected. There is no logic at all to prevent
using either one. The nav radios and the GPS are completely
independent, and have no relation to each other in any way.

--
Regards,

Stan

In article , TripFarmer
wrote:

I'm just starting to work on my Instrument Rating and yesterday when doing an
ILS approach I was keeping the localizer centered and my instructor told me
to
look up about a mile out. We were maybe 200 yards off the centerline. Next
one we stayed on the centerline (visually) and the needle was 1/2 deflection.

When was the last time the required VOR checks were performed?
This is an instrument requirement, isn't it?
Check your AFD for a VOT in your area.
If no VOT, perform and airborne check with two VOR receivers, if
installed.

On Sat, 20 Sep 2003 16:24:18 GMT, EDR wrote:

When was the last time the required VOR checks were performed?

That check does not verify the accuracy of the localizer and/or glide path
receivers in the unit.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

EDR wrote

When was the last time the required VOR checks were performed?
This is an instrument requirement, isn't it?
Check your AFD for a VOT in your area.
If no VOT, perform and airborne check with two VOR receivers, if
installed.

VOR checks have nothing to do with LOC accuracy. Two separate
receivers sharing the same tuning head and CDI.

Bob Moore

In article , Robert
Moore wrote:
VOR checks have nothing to do with LOC accuracy. Two separate
receivers sharing the same tuning head and CDI.

So what happens when both nav's are dialed in to the same localizer
frequency?
Do the indicators read the same?
Or is there a difference?
Which one yields a more accurate track?

On Sat, 20 Sep 2003 23:31:56 GMT, EDR wrote:

In article , Robert
Moore wrote:
VOR checks have nothing to do with LOC accuracy. Two separate
receivers sharing the same tuning head and CDI.

So what happens when both nav's are dialed in to the same localizer
frequency?
Do the indicators read the same?
Or is there a difference?
Which one yields a more accurate track?

If you are interested in doing a flight check of your LOC and GP receivers,
the procedure is outlined in AC91-16.

But to just check the accuracy of the LOC & GP receivers and indicators
systems, I would do a portion of the test which consists of flying directly
over the OM at the GP intercept altitude, and at approximately a 45° to the
LOC course. The GP needle should go from full up to full down deflection;
and the LOC & GP needles should be centered when passing over the OM.

This procedure does not check the LOC flag alarms or deviation sensitivity,
but if it's grossly abnormal, it is additional evidence that the unit
should be bench-checked.



Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Peter Bondar" wrote in
:

The 'preferred' option is to have a loc frequency
automatically force the NAV/GPS switch to go to nav mode.

Well, maybe preferred by some, but I may want to tune in the
localizer while I'm a long way out, getting ready for the
approach, but navigating on GPS until I'm inbound, or at least
on vectors. Forcing VOR mode just because a localizer is tuned
is simply a stupid way to do things.

--
Regards,

Stan

Which approach was it, 24 or 06?
My last approaches at BHM seemed to be spot-on, except for pilot induced
variation of course. (about 3 mo ago for 6, 2 mo for 24 in heavy smoke).

Ben
N26RR
KBHM


Any thoughts about what to do? It seemed like a practice ILS I did at
another
airport didn't do this a couple of weeks ago. Could it be this one
facility
(BHM)? Do I need an avionics shop to look at it?

I'm new at this so I'm not really sure what step to take next. Any help
will
be appreciated.


Trip



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In article , Ron Natalie
wrote:
The glide slope transmitter is often separate.
It's always separate. The glide slope transmitter is down approximately
where the touchdown is (and obviously off to the side of the runway).

Not only is the G/S transmitter separate, the signal is bounced off the
ground from the transmitter toward the approach end of the runway. That
is why TERPS requires a specified distance of flat empty ground ahead
of the runway threshhold.

"Stan Gosnell" wrote in message
The 'preferred' option is to have a loc frequency
automatically force the NAV/GPS switch to go to nav mode.

Well, maybe preferred by some, but I may want to tune in the
localizer while I'm a long way out, getting ready for the
approach, but navigating on GPS until I'm inbound, or at least
on vectors. Forcing VOR mode just because a localizer is tuned
is simply a stupid way to do things.

Agreed. My Garmin 300XL is setup to force the switch and it is a procedural
pain for approaches with with course reversal.

And if you switch to NAV mode while GPS is in Hold mode, the moving map goes
a bit crazy (I guess it's looking to the indicator for intended direction
info but it's been disco'd).

May be time to go back and have it configured to 'non-preferred' mode.