FS98 737-400 AUTO LAND
APAGE646
Has anyone had problems with the 737-400 auto pilot, auto land (APR) facility
in FS98. The aircraft will lock on to the glideslope o.k. but for some reason
fails to follow the centre line needle, I've tried making sure the correct
runway heading is dialled up, but more often than not the 737 ends up anywhere
but the runway!!
Any suggestions?
Alan Page
Sentenza
Hi APAGE646,
Not all runways are suited for automatic landings. Try runway 27R at Chicago
O'Hare - works beautifully. You can even see smoke coming off the tires on
touchdown, and no mistake. Also make sure your barometer is set correctly by
pressing the "B"-key
HTH
Mike
Noble Air FRA
SCC 1312G
"No matter where you want to go ... one of our pilots will have the
appropriate scenery."
.
APAGE646 schrieb in Nachricht
<199804021909...@ladder03.news.aol.com>...
Henri H. Arsenault
In article <199804021909...@ladder03.news.aol.com>,
apag...@aol.com (APAGE646) wrote:
> Has anyone had problems with the 737-400 auto pilot, auto land (APR) facility
> in FS98. The aircraft will lock on to the glideslope o.k. but for some reason
> fails to follow the centre line needle, I've tried making sure the correct
> runway heading is dialled up, but more often than not the 737 ends up anywhere
> but the runway!!
> Any suggestions?
>
The "course" number must be the runway heading, and the VOR must be at the
correct frequency. The aircraft will not line up until it crosses the
glideslope (do it at a small angle to avoid oscillations). But from your
description, it HAS to be either 1) you don't have the right frequency, or
more probably 2) you don't have the right course setting.If it is on, the
"nav" AP light should turn off when the autopilot locks in to the approach.
You DID press the "apr" button on the autopilot panel, didn't you?...
If it still doesn't work, try another airport, in case the airport you are
using is screwed up (it does have ILS and you are not locking in to the VOR
instead of the runway frequency, are you? - the ATIS will give you the
runway frequency...).
Henri
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Walter J. Bertram, Jr.
Actually, all that is required is that the correct frequency
be tuned and that the APR button be pushed. The COURSE
number is convenient for the pilot in navigating to an
appropriate intersection wilth the localizer, but it does
not enter into the functioning of the autopilot.
Walt
APAGE646
Walt
I was under the impression that the runway COURSE heading was critical for the
aircraft to lock on and follow an ILS freq. centre line needle, rather like a
VOR COURSE heading the needle centres on the course punched in on the OBS?
another observation with this problem is when I select the APR function button
on the autopilot, the HDG light indicator on the autopilot does not go out, so
I can only assume the aircraft is still following the HDG as apposed to
locking in on the ILS signal!!
Regards
Alan
Walter J. Bertram, Jr.
As I said before, the COURSE setting is not critical to the
autopilot APPROACH function. Try it. After you are set up to
intercept the Localizer, turn the COURSE setting 90 degrees
East or West. The autopilot will still capture and follow
the Localizer.
APPROACH mode, using an ILS signal, works quite differently
than when using the VOR signal.
Using either manual steering or auto pilot, you should set
the direction of the plane so that it will cross the runway
centerline some 5, 10 or 20 miles from the runway (depending
on the speed and characteristics of the plane, and the
relative angle between ILS heading and the planes
heading.). Then turn on the APPROACH mode. As the plane
nears the centerline of the ILS signal*, the autopilot will
take control. If you had the HEADING mode on, that is when
the HEADING light will turn off. The autopilot should then
steer the plane down the localizer path. For correct
functioning of the Glidepath portion of the autopilot, your
altitude should be such that you are below the glidepath
when you turn on APPROACH mode.
* Note that I did not say centerline of the runway here.
Some ILS signals are not aligned with the runway. These
signals bring you near the end of the runway, where the
pilot must take over and manually steer the plane onto the
runway. These are usually called LDA (Localizer Type
Directional Aid) approaches. Other ILS approaches are
simply mis-aligned by a few degrees, and are still called
ILS approaches.
Walt
Bob Weber
APAGE646 wrote:
>
> Walt
> I was under the impression that the runway COURSE heading was critical for the
> aircraft to lock on and follow an ILS freq. centre line needle, rather like a
> VOR COURSE heading the needle centres on the course punched in on the OBS?
> another observation with this problem is when I select the APR function button
> on the autopilot, the HDG light indicator on the autopilot does not go out, so
> I can only assume the aircraft is still following the HDG as apposed to
> locking in on the ILS signal!!
The VOR beam is about 20 degrees wide and the ILS beam is 1/4 or 5
degrees. The HDG light indicator will only go out when you come within
the ILS beam width and you have APR selected. The HSI course pointer
doesn't have to be set to the runway heading for the ILS APR to work but
doing so helps you steer to the beam to capture it.
--
Regards,
Bob,
rweb...@wport.com
John Benton
The COURSE selection when using ILS (unlike VOR) has no effect on the operation.
As a general rule, the inbound course is set in the course selector to coincide
with the actual course being tracked/flown.
After selecting APR, the autopilot should remain in the HDG mode until within a
specified distance of the localizer. When such parameters are satisfied, the
autopilot should switch to the APR mode and localizer capture should begin. The
HDG light should extinguish at that time.
APAGE646 wrote:
> Walt
> I was under the impression that the runway COURSE heading was critical for the
> aircraft to lock on and follow an ILS freq. centre line needle, rather like a
> VOR COURSE heading the needle centres on the course punched in on the OBS?
> another observation with this problem is when I select the APR function button
> on the autopilot, the HDG light indicator on the autopilot does not go out, so
> I can only assume the aircraft is still following the HDG as apposed to
> locking in on the ILS signal!!
> Regards
> Alan
APAGE646
I think my problem lies when switching from flying the approach with HEADING (
"HDG" ) selected on the A/P, to keep the Localizer centred, and then selecting
"APR" for the final part of the approach i.e to put the aircraft over the
threshold. In my case the "HDG" light does not go out, therefore it will not
allow the Localizer to capture,and the aircraft steers to the right or left of
the Localizer, to regain and centre the Localizer I have to re-select "HDG" and
steer manually. Maybe I've got a bug in FS98??
Regards
Alan
Henri H. Arsenault
In article <199804061828...@ladder03.news.aol.com>,
apag...@aol.com (APAGE646) wrote:
I don't think so. Try turning AP "HDG" off before you hit the glideslope
with "APR" on. The glideslope should grab the plane. The altitude will not
lock in until you cross the vertical glideslope, so you should be slightly
below it or lose altitude so you can intercept it.
Just make sure that you course is set to the correct runway heading (and
not to the VOR, otherwise you will head for the VOR instead of the runway)
- and make sure that you have an airport with ILS. And not all runways at
an airport have ILS...
APAGE646
Thanks for all the advice guys I have just tried the following approach three
times with the same end product:-
LONDON HEATHROW ILS RUN 27L . FREQ 109.50 ILL
1: 8 miles out with the heading of 275 ( Runway Heading ), dialled up and
being flown on the "HDG " function on the A/P. The Localizer is centred and the
Glideslope has just started to move down.
2: Approach speed 150knots 25degree flap, wheels down.
3: 6 miles to run, reduce to 140knots full flap, the glideslope is just below
centre.
4: Select "APR" on A/P", glideslope captures, but "HDG" light does not
extinguish!! aircraft starts to drift to right of centreline, the
Localizer has not captured again, regain centre line by re -selecting "HDG" and
steering 273 degrees this brings me back on course, diss-connect autopilot (Z)
and continue approach manually, can anyone see what I'm doing wrong??
Regards
Alan
Sentenza
Hi APAGE646,
You should hit the APR button before you even capture the localizer. So
about fifteen miles out you should be flying at a heading of, say 265 to 255
with Heading Hold on. At that time, hit the APR button. The A/P will then
intercept both localizer and glideslope.
If you're approaching from, say, twenty miles out heading 275 with HDG Hold
on and it appears that you're on the localizer, that doesn't necessary have
to be the case, as the localizer beam is very narrow. Therefore, the A/P may
not intercept the localizer. To alleviate that problem, turn on the APR
button, then set a new heading of 280 with HDG Hold on. Wait until the
needle is just a little offset, then set a new heading of 270, also with HDG
Hold on. The A/P will then intercept the localizer (and the glideslope, of
course).
Speedwise it looks alright. 140 knots, full flaps and spoilers armed at six
miles out should give you a perfect autoland, provided the runway's ILS
system has the necessary capabilities.
HTH
Mike
Noble Air FRA
SCC 1312G
"No matter where you want to go ... one of our pilots will have the
appropriate scenery."
APAGE646 schrieb in Nachricht
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