A problem with the ILS at Aerosoft ENVA (Trondheim) airport scenery

[WebMaximus 372]

From what direction do you fly to FAF? Have you tried to intercept localizer with HDG SEL?It seems you're paralleled to LOC and have G/S inhibit before LOC capture option turned on. That's why it don't want to activate this modes.

ANP should be ok here, but the problem can also be in airport or airac coordinates in this case.

 

I was coming in from the SE in LNAV mode, haven't tried HDG SEL yet.

 

Reason I was not on the localizer but a bit left of it was simply because how LNAV was following the route until I disconnected the autopilot to fly the approach manually since the ILS didn't capture. Appearently the route flown by LNAV was not 100% spot on looking at the localizer.

I'd give the FSX registry repair fix a try.

 

Hmm...never had to try that one as far as I can recall but do you really think that would have anything to do with the NGX for some reason not capturing the ILS for one single airport?

 

I might be wrong but I thought that registry fix was something you can test if the path to FSX for some reason has become corrupt in the registry...don't see how that would have anything to do with an ILS approach...?

[Fabo 213]

 

 

Reason I was not on the localizer but a bit left of it was simply because how LNAV was following the route until I disconnected the autopilot to fly the approach manually since the ILS didn't capture. Appearently the route flown by LNAV was not 100% spot on looking at the localizer.

 

Then you probably never actually intersected the ILS as far as I can see, resulting in this behaviour. Annoying, but normal, in that that this does happen. Should you happen to run into this problem again, just make sure that you give autopilot a chance before turning to final. Just leaving it in HDG SEL before the last turn should do the trick.

[PatrickM 2]

The FAT to TD (109.9) is 268°. Could that be the fault?

[scandinavian13 5,192]

I'm with the others that, had you flown this in HDG mode, it would've captured.

[EDIT: Looked back at the charts on IPPC and they were different from the charts I found.  The suggestion to force the capture via HDG still stands, however.]

[marts747 0]

 

 

Very weird this indeed. I also have UTX installed and FS Global Ultimate X mesh for Europe but I haven't seen any crashes so far and if I must choose between that and a faulty ILS I prefer the ILS issue for sure ;-) Too bad though you have this problem yourself!

 

Sorry for bending the topic!!!

 

Check the Aerosoft Forums. I'm not the only one!!

 

Martin.

[WebMaximus 372]

Well, usually I never have any problems having the NGX capture the ILS following the LNAV route but I will definitely try HDG SEL instead tomorrow and see if that does the trick!

 

Will report back and let you know.

 

@ Martin - OK, guess I should consider myself lucky then only having problems with the ILS. Strange why this airport scenery would cause such big problems considering it's a fairly small and simple scenery compared to many other airport sceneries.

 

Another thing I've noticed with help from someone is that the developers behind the ENVA scenery to a certain extent seem to have chosen a path away from FSX standard such as where to place files and how to name them etc. For instance when I tried to disable the scenery by unchecking everything related to Aerosoft ENVA in the FSX scenery library I got major elevation problems and I couldn't understand why since I just unchecked everything related to the Aerosoft ENVA scenery and thought that would bring me back to default FSX scenery for ENVA but it didn't. The reason was that the developers have chosen to place one single file in one of the default FSX scenery folders and if I didn't disable that one as well manually by renaming it I would get these elevation problems...

[WebMaximus 372]

The FAT to TD (109.9) is 268°. Could that be the fault?

 

Got 267 from EFB and someone correct me if I'm wrong but I don't think one degree on the inbound course would cause the a problem capturing the ILS, only that I would approach the runway 1 degree from the wrong direction so to say.

 

I also have the setting in the NGX enabled where it will correct the inbound course to match what is in FSX since that and what you see on the updated charts isn't always the same.

 

Came to think of another thing about capture or not capture...wouldn't the fact that I saw both the LOC and G/S move on my PFD indicate I indeed was within the ILS distance and angle?

[WebMaximus 372]

Did some more searching on my problem and quickly found out I'm not the first person with problems capturing the ILS for runway 27 at Aerosoft ENVA. For example I found this old thread about the very same problem I have so something is definitely fishy with the Aerosoft ENVA scenery.

 

http://forum.avsim.net/topic/356209-enva-rwy-27-ils-localizer/

 

Will be most interesting to perform some more testing tomorrow!

[scandinavian13 5,192]

 

 

Came to think of another thing about capture or not capture...wouldn't the fact that I saw both the LOC and G/S move on my PFD indicate I indeed was within the ILS distance and angle?

 

No.

 

You were within the correct service volume to receive a signal, yes.  Just because you can see the indicators move however, doesn't mean the autopilot knows to switch from the one commanded mode to the other.

 

Remember, computers a dumb.  They can't think for themselves and read minds.  There are several movies that describe why (they take over the world and kill everyone - as in Terminator, Matrix, and so on).  Having the aircraft on LNAV is telling the aircraft that it should follow the LNAV course and keep doing it.  If the LOC remains to the right side of the aircraft (as is in your picture), probably down to about the threshold, it won't arbitrarily decide to jump off of its stable tracking of the LNAV course, to jump onto the LOC course.  The computer is just following what it's being told: follow LNAV until you intercept the LOC (within some tolerance - but you apparently didn't hit that tolerance.)

 

As I mentioned earlier, had you been on HDG SEL, and on an intercept heading, it probably would've been just fine.

 

I know that side of the pond is all about magenta-lining-it, but sometimes you gotta step in and ensure the computer does what it needs to do.  Automation is meant to assist you in tasks, not do the job for you.  If it starts to screw up, step in (take it off LNAV), backhand it (put it on an intercept heading via HDG SEL), and tell it to get with the program (and make sure APP is armed.)

[Don t moderate me this way 882]

Plus one for Kyle's explanation:

 

I remember my NGX in LNAV flying so precisely that it would NOT cross the extended centreline. That is, it would not intercept the LOC, just flying parallel to it with a very small offset.

 

I can confirm it takes a genuine interception to activate the LOC mode.

[WebMaximus 372]

Thanks a lot for all great input guys, you were 100% correct that the problem indeed was I stayed in LNAV just like Oliver describes in the post above. When I switched to HDG SEL instead to make sure I would actaully cross the extended centerline everything worked just perfectly.

 

Sorry to waste your time guys when in fact there was never a problem only me not doing things in the correct way. It was just that I didn't even think about this even if it's perfectly logical because for all other airports I usually fly to I'm fine staying in LNAV but that of course has to do with the alignment of the final fixes in your route and how well they match up with the ILS.

 

Here's a screenshot and I think it speaks for itself...

 

 

Thanks again to everyone who contributed !!

[Michael Moe 494]

Sometimes LNAV makes shortcuts on approach making the ILS LOC not available. I realised this on 27L in egll coming from southeast.

 

Michael

[Don t moderate me this way 882]

The contribution was Kyle's so ....

 

You never wasted my time, WebMaximus. It's fun to help and from most issues posted I learn something myself.

[hopskip 253]

Looks like the new scenery is a few metres offset compared to the AIRAC. Due to this, interception in LNAV from the left of the localizer won't cross the centreline. The Approach mode won't take over till the ILS is centred, and the Glideslope won't follow the descent path till the Localizer is centred and active.

 

There is an option in the FMS/Settings to allow the Glideslope to capture without Localizer capture, however this is not realistic, and can potentially lead to the situation of the aircraft following the Glideslope in LNAV instead of on the localizer. This could lead to a landing on the grass to one side of the runway if followed all the way through to an autolanding (which is why it is inhibited in the real aircraft).

 

I wonder why there is such an offset in the scenery vs Airac, and I wonder which one is more correct. (My money's on the AIRAC).

Nevertheless, when you look out the window and see the Airac runway position doesn't match the actual runway, it's going to be best to land on the actual runway rather than the grass, even if Aerosoft put the runway in the wrong co-ordinates location. Obviously the ILS is part of the scenery (as a ground-based navaid) and not the AIRAC (which only displays the centreline on the Nav display).

 

When you are on the Localizer ILS and zoom the Nav display all the way in (2.5nm) I bet you will see yourself "right" of centreline by a few metres.

[WebMaximus 372]

Yep, I'm pretty sure the problem is with the scenery.

 

What I learned from this is that I'll from this point always make sure to actually cross the LOC before I decide whether it's a problem with the ILS or not.

 

One thing though I still find strange is that I'm pretty sureI've had the NGX capture the LOC even before actually crossing it at other airports. What I mean is how I see VOR/LOC becoming the active lateral flight mode.

 

Well...never mind, I'm just happy I can feel confident when flying the ILS approach into 27 @ ENVA from now on :-)