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RookiePilot

Boeing 737 not following ILS course

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I am trying to land Boeing 737 on runway 27R using ILS at Heathrow, London flying from Paris.

 

The plane follows course until that morse code beep sound comes. After that when I change it from GPS to NAV, the plane starts to go somewhere else instead of runway. Here's what I am doing.

 

1. It is set to follow GPS and not NAV

2. ILS frequency 110.30 is set in NAV1 (screenshot below)

3. Course is set to 273 (screenshot below)

4. Before take off, I set my altitude to 4000, speed to 300 and enable auto throttle, VOR LOC etc. i.e. I keep plane ready in auto pilot mode

5. After take off I press auto pilot and the plane flies to destination by following that pink line. No issues here.

6. After a few minutes I enable the NAV1 freqency

7. When I am around 40nm from airport, I reduce speed to 170 and height to 2000.

8. When I around 30nm away from airport, I hear that ILS morse code beep. At this point I change from GPS to NAV. I can see the horizontal diamond in PFD.

9. Now here plane is supposed to follow the course I set earlier isn't it? But it doesn't and it just goes its own way.

 

What am I doing wrong?

 

 

WLOsPJl.png

 

 

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Did you press APP mode?  You need the VOR-LOC and APP mode for the airplane to execute the approach.  The default 737 is a bit weird, but I think that could solve the issue.

 

Hope this helps,

1251452

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No I didn't press APP because only one diamond came on screen and that too vanished after few minutes when plane went its own way. I read that you press APP when both diamonds are in center.

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FSX localizers only work about 20 miles out... Could be a factor here.

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I don't know how realistic your flight plan is, but in general, yes, when you receive the morse signal audio the localizer should be received by your radio-nav receiver and should drive the auotpilot in VOR-LOC.  You might try waiting a bit until you get closer to runway before activating NAV.  Note that radio nav does not follow a "course", rather it either follows a "radial" (VOR) or localizer (ILS).  It switches automatically depending on the frequency selected.

 

scott s.

.

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I'm not completely sure, but IIRC the plane can't handle the switch from GPS to NAV mode all that well. Perhaps try to disable and re-enable VOR-LOC mode after switching from GPS to NAV, at least I think that's how I usually did it.

Alternatively, you could try to enable the APP mode as soon as you switch from GPS to NAV, as Matthew (1251452) has pointed out before. That may not be the entirely correct procedure, but I think it could also solve the issue.

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Buddy, try it like this; 16 m out engage Vor-Loc just after you changed from GPS to NAV.  And at about 10m or so out, engage APP.      40  miles out is definitely  too far out.  You maybe picking up another airport's  ILS frequency as so far out.   Rwy 9L's range is 27 nm (31 miles). So you can see that you a bit out. 30 nm  is 34 miles.  Also rwy 27 has the same frequency value of 111.30 with a range of 27nm too. Remember in countries like the UK, USA, etc airports are very close together having the same ILS frequencies. This could be so...Check when you switch to NAV if your vor-loc  light goes off? Change to NAV earlier,so you can see what happens and correct it in time, but APP 12 or so miles out.

Check it out. Hope you come right.

 

Cheers

 

john

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Did you actually intercept the localizer? Like physically intercept it?

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I'm not completely sure, but IIRC the plane can't handle the switch from GPS to NAV mode all that well. Perhaps try to disable and re-enable VOR-LOC mode after switching from GPS to NAV, at least I think that's how I usually did it.

Alternatively, you could try to enable the APP mode as soon as you switch from GPS to NAV, as Matthew (1251452) has pointed out before. That may not be the entirely correct procedure, but I think it could also solve the issue.

 

You are right. After I changed to NAV, I disabled and enabled VOR LOC and the plane started following COURSE.

I'm not completely sure, but IIRC the plane can't handle the switch from GPS to NAV mode all that well. Perhaps try to disable and re-enable VOR-LOC mode after switching from GPS to NAV, at least I think that's how I usually did it.

Alternatively, you could try to enable the APP mode as soon as you switch from GPS to NAV, as Matthew (1251452) has pointed out before. That may not be the entirely correct procedure, but I think it could also solve the issue.

 

You are right. After I changed to NAV, I disabled and enabled VOR LOC and the plane started following COURSE.

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