Problems with localizer

[davidngr]

I don't know what is going on but after a couple of touch and go's with my crj200, intercepting the localizer without any problems at all, I have experimented a strange issue: as soon as my aircraft intercepts the loc again and starts to turn to center the runway, it suddenly stops its turn and it goes off course: this occurred several times and I was not able to continue my descent to center the runway properly....? I don't know why but I have never experimented this issue before...any explanation?

Edited October 29, 2011 by davidngr

[philipp]

Are you sure you set the NAV source switch on the side panel to the right source?

Also, did you by any chance press the XFR button on the autopilot (causing the AP to use NAV2 receiver when source selector is set to NAV1 and vice versa)?

Philipp

[davidngr]

Thanx philiph for your quick reply! I will check it tomorrow and if the problem occurs again i will post some screenshot! I don t remember pressing the xfr button!

Davide

Edited October 29, 2011 by davidngr

[davidngr]

It seems to be working now. Maybe I pushed the XFR button inadvertently yesterday as you said and that s the reason why I had this problem....

[davidngr]

Hi Philipp and all! Unfortunately yesterday I experimented the same problem and I am pretty sure that I did not press any XFR button. I think there are some problems with the APP button. Again while I was doing some touch and go's, after a successful attempt to intercept the localizer with a good landing, the problem occurred again. The first time, the aircraft did not intercept the loc at all and I was forced to execute missed approach. During my second attempt, the aircraft intercepted the localize far too in advance causing the airplane to go off course....

Here some screenshots that describe what I have just mentioned above. I think you may way want to look at it, because even though it doesn't happen often (luckily), this problem is a little bit frustrating...

Thanx in advance for all...

Ps: I am in Alicante

Edited November 3, 2011 by davidngr

[Dhruv]

Try intercepting the localizer at a 30 degree angle or less. The plane's autopilot might have a hard time with a sharper intercept angle than that.

[davidngr]

Try intercepting the localizer at a 30 degree angle or less. The plane's autopilot might have a hard time with a sharper intercept angle than that.

It is not a question of angle: The problem is that in the first time the angle was 15 degrees or less and the Loc was not intercepted at all. (First picture, as you can see there Loc does not turn into green: why? It should have not occurred) In the second time, I was not in the condition to intercept the loc since the angle was more than 90 degrees, but the loc was strangely captured ( pictures second and third. I don't know how), causing the aircraft to go off course and not to center the runway.

Davide

Edited November 2, 2011 by davidngr

[woweezowee]

too close too high

hint: press the "O"-key 4 times to toggle an visual ILS aid in xplane.

Edited November 3, 2011 by woweezowee

[flyinhawaiian]

Protip: Hand-fly the approach like a boss!

[davidngr]

too close too high

hint: press the "O"-key 4 times to toggle an visual ILS aid in xplane.

Dear woweezowee it is not a question of being too slow or too high. First of all I perfectly know how to intercept a localizer and the glide slope (also manually), and consequently there is no need to to toggle a visual ILS aid since the problem now is quite different. As said above, the AP seems to be faulty and not working properly: I will to try better explain again why (sorry for my not fluent english): I was practicing some touch and go, being able to land successfully with no problem intercepting the loc with APP engaged. But when it came to intercepting the loc during my second attempt, I experimented the following issue: as you can see in the first picture, I have the same intercept angle used to capture the loc during my first attempt, and the aircraft is also the same distance away from the airport: so what happened? The AP ( and i don't why: same intercept angle, same distance as the first attempt) does not intercept the loc, which does not turn into green, and consequently I am forced to execute missed approach. But now a new stranger thing and behavior happened: after executing missed approach and turning downwind with APP engaged, my aircraft strangely intercepted the loc (turned into green now) in a position where it was impossible to capture it (pict 2 and three). And after intercepting it, ( I m now 10 nm from the airport downwind) the aircraft starts turning in order to center the runway. Unfortunately this did not happen ( as u you can see in the pict number three) and after a third unsuccessful attempt I decided to land manually. But my questions are the following: why did not the AP intercept the loc having ( I say it again) the same intercept angle, same distance as the first successful attempt? Why did the aircraft, then, strangely intercept the loc in a position (downwind) where it was impossible to capture it? I hope to have explained better my problem now. So that's why I think there are some problems with it.

Hope to hear from you as soon as possible

Davide

Edited November 3, 2011 by davidngr

[woweezowee]

As no one else, including me, ever saw that error, and because this is all just some lines of software code in xplane and the CRJ that's equal on all our systems, there has to be another reason why your ILS approach fails. I only guessed based on your screenshot:

You are 8nm out and not even have reached the altitude for initial approach yet (wich I assume shoudl be reached some nm more out, like 12 or 14 and wich should be 2700 if you dialed it in correctly). So please try again coming in from some more miles out and 2700ft.

Please also post the approach charts of the airport you are flying into in order for us to help you. Maybe you are that close because a procedure turn would be expected at that 8nm fix you are flying over. I don't know without the chart.

[davidngr]

The airport is Alicante rwy 10, but the problem is not the procedure though, ( the first attempt to land was successful with the same parameters as the second failed attempt) but the strange behavior of the aircraft and above all of AP with APP engaged. Again apart from the correct procedure or not to be followed, how is it possible that an aircraft, as mentioned before, can intercept the localizer (Loc Green), after executing missed approach, while being downwind? This couldn't happen and this is the strange behavior I am not able to explain and this is why I think there are some problems with it. Of course, I know that my pictures are not clear enough to help you out to better understand what is going on but what I am trying to stress is the fact that there is something going wrong with AP, otherwise I won't make a fuss !

Davide

Edited November 3, 2011 by davidngr

[Japo32]

Have to fly more... But in my flights (and believe me that there are a few already) I never saw this problem. Maybe because I followed the procedures as described in maps.. maybe because I was lucky.

The real thing is that the failure is not easy to reproduce (if exist).. but we will try to find it (if exist)

thanks.

[davidngr]

Now I am doing touch and go procedure to better practice my landing training! So it is more likely to experience this problem while doing that kind of training procedure. I know it is hard to replicate this type of failure, but believe me Javier I am a pilot with a decent experience on flight and it has really happened. Try it out when you get time by doing the same training (maybe in alicante) and let me know if you happen to experience it. But I am quite sure that the problem exists!

Thanx for your kind support:-)

Davide

Edited November 3, 2011 by davidngr

[woweezowee]

For anybody interested in helping to solve the issue, spanish charts are available here:

http://www.aena.es/csee/Satellite/navegacion-aerea/es/Page/1078418725163/?other=1083158950596#ancla3

2800ft at 8nm out seems to be ok. My second guesses (as I also fly to Alicante often, I "own" this airport in FSE and use the scenery by Eiresim, converted by myself) are:

Some error with the scenery and/or ILS data in xplane?

or

You use some hardware to trigger the CRJs approach mode, and although showing it would work, something is not tuned correctly. For eample for me, for various reasons (wrong systems reaction), I can not use alss the options of my Saitek or Goflight Panels with the CRJ. Some commands just don't "get through" or change a setting that was not intended to change.

[davidngr]

I am not using any converted scenery. I have Proflight Saitek Pedal and and x-ciborg as yoke...

Many thanx for all

Davide

[davidngr]

Hi all! Sorry to bother you again. I was able to upload a video while approaching alicante ryw 10. You will note that the aircraft is not able to intercept the loc with APP engaged even though the intercept angle is correct... So hope you can better understand this issue..Hope to hear from you asap

[Japo32]

Hi.

I have just emailed Philipp to know what could happend there. It seems that there is something missed.. but I don't know if it is because the plane or x-plane.. or the way you flought.

What I can see is that you try to catch the VOR almost 8nm out of the VOR. I don't know if that is enough for intercepting. Maybe is ok, because usually I only catch that distance when following to the ILS, and never had any problem.

If I try to catch a VOR usually is more distance.

For me the speed, the angle are good enough... Maybe the turbulences.... but well.. have to investigate, because if every VOR was not catched then it would easy to find the error.. but if only a few or little are not intercepted... then how to solve it will be difficult.

[davidngr]

Many thanx Javier for your quick reply! The thing is that i was trying to intercept the localizer, not the VOR.In fact, Nav 1 was set to the Alicante ILS frequency (110.30) as you can also see at the end of my video on the FMS. Anyway, thanx for your help and support. Hope to hear from you asap

Davide

[Japo32]

Ahhh so it was a localizer. So you tried to catch it with NAV mode with the autopilot, because I didn't see the Gs armed. Or did you press the APPROACH mode button?

Also could you please try with the localizer frequency in both nav1 and nav2 radios? Like a CATIII (but it won't be a CAT III. Only CAT II)

[davidngr]

Yes exactly! I was trying to capture the localizer! Nav1 was set to 110.30 and the AP was engaged. After reaching a good intercept angle, I pushed the APP button, but nothing happened, no loc intercepted. I will try to do as suggested to see what happens as soon as the problem occurs again. Just a question: when both nav 1 and nav2 are tuned to the same ILS frequency, should I switch from nav 1 to nav 2 or just stay tuned to nav1?

Thanx again

Davide

[philipp]

In the video I see you armed the LOC1 while there was NO RECEPTION on the localizer: You see in the FMA the white LOC1, while at the bottom you see the HSI needle is NOT deflected. Then, at about 1:30 in the video, you get a needle deflection.

Could you try :

Navigate to intercept with using only HDG mode, LOC not armed, until the HSI needle shows a deflection. Then, when you are on intercept course, and the needle is deflected, press APPR button.

I'm sure it works then, as I have flown a thousand ILS approaches myself already with the CRJ

[davidngr]

In the video I see you armed the LOC1 while there was NO RECEPTION on the localizer: You see in the FMA the white LOC1, while at the bottom you see the HSI needle is NOT deflected. Then, at about 1:30 in the video, you get a needle deflection.

Could you try :

Navigate to intercept with using only HDG mode, LOC not armed, until the HSI needle shows a deflection. Then, when you are on intercept course, and the needle is deflected, press APPR button.

I'm sure it works then, as I have flown a thousand ILS approaches myself already with the CRJ

Ok I will try this and let you know. BTW your aircraft is amazing and I love flying it. I am so crazy that I have purchased the real CR200 manual from Bombardier and I am just studying it:-)

Thanx for all:-)

Thanx a lot

[davidngr]

Just to let you know that I was able to solve this mystery by having the localizer frequency both tuned to nav1 and nav2 radios as suggested by Javier; when the problem had occurred again I used the XFR button to switch the frequency to Nav 2 and it worked......

Edited November 30, 2011 by davidngr