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Missing Glide Slopes

PostPosted: Thu May 05, 2005 1:26 am
by fsjeffrey
I enjoy ILS approaches at various airports and have noticed that when lining up on certain runways, the glide slopes are missing when I punch in the localizer frequencies. As a matter of fact quite a few are missing. The localizer (left-right) works but not the glide slope.I can only assume that it is a scenery problem but don

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 2:40 am
by Bourgoignie
Hi,

Look in Afcad if everything is configurated as it should.

Greetz. Jos

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 10:31 am
by fsjeffrey
jose,

What does that mean?

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 11:26 am
by Bourgoignie
Hi,

Afcad is a free program (for FS2002 version 1.4) where you can configurate parkings and if you wish adapt the airport when you installed a new airport and there is a difference to see... or build a new one.
In this Afcad 1.4 all the airports are there and you find there the navaids. You can add or change this navaids.
So go looking to your airport KPHL if the navaids are there as it should be... and make the changes if necessary.

Greetz. Jos

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 11:49 am
by WebbPA
You may want to try the .bgl scanner here http://www.simviation.com/fs2002utilities_gen5.htm

If you have a bad file it will tell you.

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 2:01 pm
by microlight
Do you mean that the bug for the glideslope on the PFD isn't there? If it is then it may be that the glideslopes aren't missing. I discovered by trial and error that when you approach an ILS, you have to intercept the localizer before you intercept the glideslope, or else the autopilot does not recognize the glideslope.

If the bug isn't there, then I can't help. I must admit that I had not missed any missing glideslopes at PHL, although I'll go and check now...

:)

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 2:24 pm
by microlight
I just tried 9R at KPHL in FS2002 and the glideslope bug is active in the flight displays. Try approaching the localiser at around 4000 feet at say 20 miles out and makes sure that your plane centres on the localiser beam before the glideslope bug starts to descend. That way, the autopilot should pick it up.

:)

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 2:52 pm
by fsjeffrey
Jose and all,

This problem of no glide slopes isn't isolated to Philadelphia Int'l (KPHL) there are hundreds of runways with no glide slopes at almost every airport in FS2002. I'm surprised that this hasn't been brought up before.

Try it out if you're interested; access any large airport and go to world > map view and click on the airport.  You'll find the runway localizer frequencies. Slew around to a runway and put in the frequency. Look at the HSI or VOR gauge and see if there is a glide slope. Use any aircraft you want. The Learjet seems to be the only one that won't show a glide slope even on the runways that other aircraft do.

Somehow I feel that the problem is a localizer frequency issue and I don't quite understand how AFCAD can fix it as suggested by the following:

"So go looking to your airport KPHL if the navaids are there as it should be... and make the changes if necessary. "

I brought up Philadelphia Airport in AFCAD. What changes should I make in order to get a glide slope? I don't believe that I need to change the Navaids as they all seem to be OK.

What I need is a Glide slope. How?

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 4:52 pm
by fsjeffrey
microlight,

I tried what you did but was unable to get a glide slope. How do you coordinate autopilot with an ILS approach? I clicked on the autopilot and hit "apr" and things went a bit crazy.

I was, however, able to get a glide slope on runway 17 at 108.75 MHz.

I'm beginning to think maybe there's something wrong with my system, but I'm still able to get many glideslopes and many without.

BTW what aircraft did you use at runway 9R?

Re: Missing Glide Slopes

PostPosted: Thu May 05, 2005 5:52 pm
by beefhole
Yes, there are glideslope problems at KPHL, but only on one runway-27R (in my experiences, all the other glideslopes are fine).  It is my home airport and I fly out of it all the time.  Another example is Sydney, YSSY (I don't remember the exact runway).  AFCAD may help.

Re: Missing Glide Slopes

PostPosted: Fri May 06, 2005 3:50 am
by microlight
It was the FFX 737-300 (what a sweet model that is!) with a home-built panel that uses the default M$ gauges. The routine I always use with jetliners is:

- autopilot is switched in following the takeoff and climbout and is active until touchdown

- get ATIS as far out as possible from your destination airport so you know which runway is in use

- tune NAV1 to the ILS frequency at that runway, and align the 'course' setting to the runway heading

- switch in the APR as soon as BOTH the localiser and glideslope bugs are detected. The glideslope bug should be above the centreline at the top of its travel, or should be getting there as you descend to approach height

- use the local navaids to plot a heading to intercept the localiser at around 4-5000 feet altitude around 15-20 miles out so that the glideslope bug is still at the top of the display. The autopilot will turn the plane onto the localiser beam and the autopilot 'heading' light will go out

- when the glideslope bug reaches the centreline as you fly along the localiser the altitude light will go out and your plane will begine to follow the glideslope down. Reduce speed and extend flaps as necessary to maintain attitude and stay centred on localiser and glideslope

- go to manual throttle control at about 4-500 feet

- cancel APR and autopilot over the runway threshold, flare and touch down

Two things to remember really - switch the APR in sooner rather than later, and keep it steady - rapid control changes are often disastrous.

Good luck!

Re: Missing Glide Slopes

PostPosted: Fri May 06, 2005 8:57 pm
by fsjeffrey
microlight,

Got it. Thanks for the lesson.

Re: Missing Glide Slopes

PostPosted: Fri May 06, 2005 9:04 pm
by fsjeffrey
beefhole,

I too have glideslope problems at KPHL but on two runways; 27L/9R and 27R/9L.

I have compiled a list of selected airports showing all runways with ILS and ILS/DME capability. Yesterday I checked these runways for workable glideslopes. I was particularly surprised to discover that no glideslopes worked at any runway at Denver Int'l (KDEN).

I case anyone is interested, I'll summarize some of my findings below:

NO GLIDESLOPES WORK AT:

-Denver Int'l (KDEN)
-Indianapolis Int'l ( (KIND)
-Newark Liberty Int'l (KEWR)
-Portland Int'l-Oregon (KPDX)
-Seattle-Tacoma Int'l (KSEA)

ALL GLIDESLOPES WORK AT:

-Atlanta Int'l (KATL)
-Charlotte/Douglas Int'l (KCLT)
-Dallas-Fort Worth Int'l (KDFW)
-Hong Kong Int'l (VHHH)
-Los Angeles Int'l (KLAX)
-Memphis Int'l (KMEM)
-Orlando Int'l (KMCO)
-Phoenix Int'l (KPHX)
-Raleigh-Durham Int'l (KRDU)
-San Francisco Int'l (KSFO)
-Tulsa Int'l (KTUL)

SOME WORK, SOME DON'T

-Chicago O'Hare Int'l (KORD)
-Dulles Int'l (KIAD)
-Kansas City Int'l-Missouri (KMCI)
-Philadelphia Int'l (KPHL)
-Salt Lake City Int'l (KSLC)
-Tampa Int'l (KTPA)

I'm currently checking at the Scenery Forum to see if the scenery bgl's contain anything about glideslopes.

I'll nail this thing down yet.

Re: Missing Glide Slopes

PostPosted: Sat May 07, 2005 4:55 am
by microlight
fsjeffrey,

Well, I'm stumped. I just fired up FS2002 and flew an approach to runway 35L at Denver, and I got the glideslope perfectly - see pictures. Red rings in the cockpit tell the story. So on my system at least, it's working as it should. Perhaps a re-install would fix your problem as the default bgls seem to be working - at KDEN 35L anyway?

Image

Image

Anybody else out there with any ideas?

???

Re: Missing Glide Slopes

PostPosted: Sat May 07, 2005 11:59 am
by WebbPA
I just landed at 35L in Denver too.  No glideslope problems.

Since you know your MS .bgl files are all good I'd suggest you start disabling some addon sceneries - you might want to just disable all of them at first and see if that clears up the problems.  Then start enabling them one at a time until you find the culprit.