glide slope problem

[bobdawkins]

I have noticed that when I capture the glide slope it seems to be okay, I am actually under it to start with, ie above the centre line, if you think of it as a cone shape, when it should be loosing altitude, it does it at the last minute it as it where, it then takes a dive for the runway to keep on the glide slope, but of course by then I am too high to land, I am nicely lined up to start with about ten miles out, the radios are set right, etc, then it all goes wrong, this happens on all the airpots, not just one or two

[aerofoto - HJG Admin]

ILS coupled autolandings aren't perfect in FS .... and often become even less perfect the closer, and lower, one gets towards the RWY.

In FS, the further out from the RWY ones establishes themselves on the ILS .... then the the better.

Rigidly controlling airspeed .... during ILS coupled auto approaches so as to avoid too high a nose up AoA (i.e. too slow) .... or .... too much nose down AoA (i.e. too much speed) .... does seem to help .... a bit too !!!!

The aircraft we represent here, so far as I'm aware, would not normally perform fully automatic landings .... all the way down to RWY contact.

The AP should be disconnected .... and the landing then completed manually from at least 50FT.

AP controlled/attempted ILS coupled autolandings will always be "VERY FIRM" (if not "virtually fatal") in FS.

Hope that helps Bob !

In the meantime .... leave that AP alone and practice manually

Youi'll be a "PRO" in no time !!!! ;D

Mark C
BOG/CO

[bobdawkins]

thanks for your help, but whether I fly A/P or Manual, the glide slope cross on the panel doesn't seem to be lined as it should be, when I have 2 whites and 2 reds, which I believe is supposed to show you the right position on the glide slope,??

[skyking]

It appears to me that you're flying way too slow. Try it a little faster until landing assured. Like around 100KIAS.

[dirtybird]

Two things that have occurred while having the low glideslope dual red and dual white phenom have helped me in the past. Once on glideslope I inadvertantly forgot that my
assinged runway had two different ILS headings for the recipricating runaways giving
me the dead even centerline but off glideslope. I assume that your airport of choice is
not the only airport this is encountered and the remote aspect gives you no possibility
of having two receiprticating ILS's and radio frequencies So whenever it's obviously off visually as in photo I check the altimeter is set by pressing key B several times. I think
you have a lot of room to play with in the cessna with respect to height of glide more so
than the DC-8. To further clarify my possible assumption with recipricals the glides slope
on reverse beam could be right at either end of runway. Tell me what airport you are
at and I will experiment. I will check the cooridinates and try my theory out now if
you happen to know how to keep flight sim headings from sliding two degrees
off worldwide please let me know.....

[Mike Monce - HJG]

I also have noted over the years that there may be a bit of a bug in the GS for MSFS. I rarely fly without doing an ILS approach and I've notice that at all airports there seems to be a "dip" in the GS at about 1-2 miles out from the threshold. I can be holding the GS needle perfectly, then it will suddenly be below me and then as I correct, it bounces above. It also never seems to correlate with the VASI.

I've decided to ignore the bump and continue flying at the same vertical speed through the bump, and all seems to work fine.

I'm going to pay a bit more attention to this and see if I can determine where exactly this occurs.

Mike

[bobdawkins]

I fink I found me answer, silly me was fine tuning Afcad file FJDG and have realized that my glide slope beam width degrees was wrong, it was too big, and also my glide slope angle degrees was the same, it was 6 instead of 3, put it back to original setting, and every thing seems to be functioning as it should be, can't for the life of me think why I changed it, probably one of those experimenting moments and then forgot to put it back I know, stop experimenting, or try and remember better, I did a backup first, but couldn't remember where I had put it, what a plonker aye, ;D ;D thanks every one for your ideas anyway.

"The HJG Forum Clown" I have all copyright on this mistake ;D ;D

[skyking]

Glad you got it sorted out. I'd still like to see you carry a little more speed on final.

[Earl]

Jul 4, 2009 17:44:25 GMT Mike Monce - HJG said:

I also have noted over the years that there may be a bit of a bug in the GS for MSFS. I rarely fly without doing an ILS approach and I've notice that at all airports there seems to be a "dip" in the GS at about 1-2 miles out from the threshold. I can be holding the GS needle perfectly, then it will suddenly be below me and then as I correct, it bounces above. It also never seems to correlate with the VASI.

I've decided to ignore the bump and continue flying at the same vertical speed through the bump, and all seems to work fine.

I'm going to pay a bit more attention to this and see if I can determine where exactly this occurs.

Mike

I've noticed this also. There also seems to be a virtual wind around several airports which seems out of place. I've wondered if it affected the glideslope. I've definitely noticed both problems at KATL and KTTY in Knoxville. I usually have to go to panic mode and kill the autopilot and hand fly to the runway.

Any others notice this?

Thanks,
Earl

[viscount]

Like Mike said, the GS behaves a bit weird when you're close to the airport. I do the same as him, I ignore the GS if I have the runway in sight. Sometimes this leads the GPWS to get mad at me, but oh well...