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ILS Approach problem

Pro Member First Officer
mdaskalos First Officer

First off, I found the sticky thread in the FS 2004 forun describing how to make an ILS approach. I though I had done everything right, but if I had, I wouldn't be having to post here...

Flying a CRJ-700 IFR from Princess Juliana (TNCM)to St. Thomas (TIST). My GPS took me there via my GPS waypoints. Switched it to "Heading" as I was vectored around on approach. I had NAV1 tuned to 110.100, and the CRS set to 100.

ATC brought me to 2100 feet at a heading of 70. When I got cleared to come straight in, I turned the AP off, switched the GPS/NAV switch to NAV (found on left side of cockpit, not with the radio stack or autopilot board).

Turned AP back on, with it set to NAV, somewhere about 10 miles out. Or was it seven? Both, probably, as I made anothe approach. Nothing happend/zip/zero/nada. Never heard any "Morse code", even though I had it set to give me the audio for some period of time.

Questions:

1. Should I have manually turned to heading 100 upon getting the clearance to go in straight? I didn't, so If everything else was done right, I was 30° askew when I engaged. Is this what is meant by being established on tyhe glide path

2. In addition to having the Autopilot on NAV and needing the the GPS/NAV switch set to NAV, is it necessary yo have APP (APPR?) enabled on autopilot as well? As I recall, on one approach I did, the other I did not (neither way was successful.)

3. Whether yes or no to #2 above, what is the difference between that switch on or off?

4. Why did I not hear the ILS signal on my NAV1?

5. If I'm doing something dumb on my NAV1 settings, is it possible to test what I'm doing by tuning to the ILS signal of my departure airport? (of course, I would need a different departure to do that.) I presume I would have to be aligned on approach with it to pick up the signal, or is it possible to hear it just sitting on a runway?

6. Since writing this, I read the "Approach Guides" sticky further; the part about GPS approach setup. Would I benefit from doing that? Can I do that when ATC is telling me where to go????

Thanks for any help.

mdaskalos

6 Responses

Pro Member Trainee
gheib1 Trainee

You did the right thing by switching back to nav...make sure you double check your ILS freq as well. Make sure your course obviously is set to the desired appr to the rwy...if you do not hear the morse, do not the the nav OBS line moving, or unable to see a glide slope indicator then you did something wrong. The thing with an ILS approach I don't quite get is why is everyone doing it through auto pilot. Lear to manually stay on the glide slope and keep the line. That make is so much more gratifying and fun to fly.

Another thing on tuning the aircraft's ILS nav freq make sure you actually switch the freq so that is the active one...not trying to sharp shoot ya...everyone makes little mistakes every now and again.

Pro Member Chief Captain
CRJCapt Chief Captain

1. No, the 30 degree intercept is good.
2. Yes, APR or approach mode allows the autopilot(AP) to capture the localizer(LOC) and the Glideslope(GS) on an ILS. NAV button on AP will intercept the LOC but not the GS. Nav button is used for enroute navigation, VOR, LOC and GPS approaches.
3.See #2
4a Ensure that the nav volume is turned up within the program settings
b.Ensure audio button NAV 1 is illuminated
c. Ensure computer speakers are turned up enough
d. There is a 8-10 second pause between ident codes
5. You should hear it on the runway.
6. Not sure if ATC will issue a GPS approach. TIST doesn't have a GPS approach.
http://www.navfltsm.addr.com/index.htm

Pro Member Chief Captain
Jonathan (99jolegg) Chief Captain

mdaskalos wrote:

Questions:

1. Should I have manually turned to heading 100 upon getting the clearance to go in straight? I didn't, so If everything else was done right, I was 30° askew when I engaged. Is this what is meant by being established on tyhe glide path

I'd personally turn on to the lateral localiser before engaging the APP. Its not essential but try it.

mdaskalos wrote:

2. In addition to having the Autopilot on NAV and needing the the GPS/NAV switch set to NAV, is it necessary yo have APP (APPR?) enabled on autopilot as well? As I recall, on one approach I did, the other I did not (neither way was successful.)

This might be the key to your problems. You should have the APP button engaged, not the NAV on approach. See point 9 of the ILS guide.

mdaskalos wrote:

3. Whether yes or no to #2 above, what is the difference between that switch on or off?

The APP button primarily deals with approaches. The NAV button primarily deals with navigational aids (NDBs, VORs) or even heading hold, but isn't essential for that.

mdaskalos wrote:

4. Why did I not hear the ILS signal on my NAV1?

Try another approach. Make sure you have actually turned the NAV1 radio on, don't just input the frequency, you need to select it. Cross check the frequency with the approach plate or the Map in FSX. If you don't hear the morse code frequency then you aren't tuned into the right frequency or you don't have the NAV1 radio selected.

mdaskalos wrote:

5. If I'm doing something dumb on my NAV1 settings, is it possible to test what I'm doing by tuning to the ILS signal of my departure airport? (of course, I would need a different departure to do that.) I presume I would have to be aligned on approach with it to pick up the signal, or is it possible to hear it just sitting on a runway?

If you are within range then you can hear the Morse Code of any ILS. It sounds to me like you just don't have it switched on. See Point 4 of the Approach Guide.

mdaskalos wrote:

6. Since writing this, I read the "Approach Guides" sticky further; the part about GPS approach setup. Would I benefit from doing that? Can I do that when ATC is telling me where to go????

You can either ignore ATC and use the GPS or follow ATCs instructions. They get grumpy if you attempt both. Note that the GPS doesn't control a descent, only a lateral guidance. You could use the lateral guidance and then descend in visual conditions - not a practice used in the real world though.

Pro Member First Officer
mdaskalos First Officer

gheib1 wrote:

The thing with an ILS approach I don't quite get is why is everyone doing it through auto pilot. Lear to manually stay on the glide slope and keep the line. That make is so much more gratifying and fun to fly.

At the stage I'm presently at, it's more like I fight the thing like a bucking bronco (only partially induced by low near-ground FSX framerates, which seems to be a common complaint), which invariably results in a last minute abort of the landing, or a need to ID via dental records.

Getting a conclusion to a flight where the only parts of the aircraft touching the ground are made of rubber, is gratification enough for now. Learning to crawl before I walk.

"A man's GOT to know his limitations." - Clint Eastwood, "Magnum Force"

Thanks everyone for the input. I'll double check on these things and try the suggestions, and read up some more.

I've had FSX since only monday, and the demo for about a week before that. My last flying sim (if you could call it that) was Strike Commander, an F-16 shooter, over ten years ago.

mdaskalos

Pro Member Chief Captain
Jonathan (99jolegg) Chief Captain

Maybe try a few visual landings until you are fine with those and then go on to the instrument approaches.

It'll make them a lot easier.

Pro Member First Officer
mdaskalos First Officer

Thanks again for the input guys.

Had some "success" over the weekend. Found out that my NAV1 was apparently mis-tuned. I tried things again, and was able to hear it.

When I say "success", it is a very narrowly limited definition: I stayed on the glide path nicely in all attempts, but at the end, I'm having difficulty judging when to slow the plane down and bring it nose up:

1. On the first attempt, I got jittery about high airspeed too early, cut the throttles, barely made it over the river/stream on approach to TJSJ, touched down just outside the airport perimeter fence Anyone in their 40's remember the old Kool-Aid commercials where the pitcher comes busting throught the fence? Yeah, it was kinda like that, and rolled up casually onto the runway. ("What? What??? You mean it ain't supposed to be like that?") But at least it was a nice soft touchdown.

2. Wasn't gonna let that happen on the next try, so I came boring in at a solid 175kts, all the way to the pavement. The rear gear musta' been about five feet in the air when the nose wheel hit.

Actually, 99joleg, getting on top ot the instrument landings is helping me with visual landings. (at least the way I'm approaching it). By watching the descent rate, when on instruments, I have a pretty good idea of what descent rate will keep me close to the guide path for a visual (provided I come in at the same speed, but I can adjust my descent rate for differences in speed). All I have to concentrate on when it's on auto pilot is when to slow down and when to nose up.

Once I get better at making my touchdown, I think I'll back off to just using the autopilot to get me aligned with the runway and handle the vertical control myself. Then sometime after that, I'll try to gain greater mastery over lateral control. (By that time, perhaps my hardware will permit better control, as well).

So, it looks like I gotta read up a bit more on my aircraft and on technique as well.

mdaskalos

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