Michael Moe

Navigation help (VOR and ILS)

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Hi. 

Bin a while since i tracked down radials and was wondering after an episode with EKRN ROE VOR 112.00 radial 270 setting course to 090 and tracking inbound with no issue. 

But after crossing ROE VOR the aircraft starts to bank left and right. Why is that? The Nav gauge is showing outbound. 

Next about the glideslope. 

Is there a common procedure? If i am stable on the localizer with alt hold and the needled GS is moving i tried moving to Aproach mode but it does not capture. 

 

Thanks Michael Moe 

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Just now, Michael Moe said:

Why is that?

Sensing is more sensitive closer to the VOR, and you're using a 60 year old autopilot.

2 minutes ago, Michael Moe said:

Is there a common procedure? If i am stable on the localizer with alt hold and the needled GS is moving i tried moving to Aproach mode but it does not capture. 

Did you try turning off ALT HOLD?

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Normally when getting close to a station You should reveret to heading hold. As Kyle says, the close the more sensitive. There is also a vertical cone where You will loose signal, called "Cone of silence".

Read about that here: https://aviation.stackexchange.com/questions/35255/how-wide-is-the-cone-of-confusion-above-a-vor-and-ndb

 

Some more modern Autopilots (modern is relative :-D) has the ability to shift to "Dead reckonning" mode, which means if tracking a VOR and the frequency isn´t changed, then as signal is los, the AP will shift to heading mode by itself, with the heading that existed at signal lost, and then resume NAV mode when signal is recieved again. But the DC-6 is definitly too old for this feature.

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"Cone of silence" aka cone of confusion.  You can think of VOR and NDB radio coverage as existing within a donut with the antenna at the center of the hole.  The donut is stretched out in the horizontal axis, each radio has slightly different distortions to the donut dependent on frequency but the analogy might help with this question.

As for the glide path capture, I'm not sure I understand Kyle's comment that the ALT switch needs to be turned off, this certainly isn't the case when I've flown; however, make sure the approach ready light is lit before you switch from LOCALIZER to APPROACH. See POH 81 where as it turns out it mentions disengaging the beam coupler control as you pass the radio station (I enjoy the old terminology, glide path and beam couplers).

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Thanks guys,

Guess i am to "young" still. :cool:

As for the GS in the DC-6 i tried with both Alt hold on and off and the Approach light is on (blue right ?)but as i said my procedure is wrong.

Should i be a Flaps 50 degree allready ? That is not normal in the "jets" to be at landing flaps allready (i know sometimes for a Autoland etc ) but i am at FLAPS 20. Read some of the intro and POH but cant find a ILS section (not that fun anyway but still)

The Autopilot´s may not be that advanced to control pitch if i am slowing her down with flaps on late final ?

Thanks

Michael Moe

 

PS!

And for the record - Oh boy i just love her - makes it so fun to catch um small routes like EKCH-EKRN etc - 

Tried a ENVA-EKCH but that was to advanced i guess (regarding fuel management)

 

 

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You'll probably hear many different techniques, first we haven't mentioned that you should be below the GS until intercept.  It should capture and descend regardless of configuration but  160 KIAS and some flaps is a good place to start. When the GS needle is alive lower gear and increase flaps and fly down the GS at 140 until about 2 nm then slow and put out full flaps for the final approach.  Watch out, she seems to want to die mid-air when all the flaps come out and you are normally carrying some power all the way to rotation.  The props are not pushed to high RPM and are usually left at 2200 unless you are heavy then leave them at 2400.  If you have to go around the electric props take no time at all to go to full fine pitch so just push the cue ball then the throttles.

She really is a joy to fly.

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17 hours ago, downscc said:

I'm not sure I understand Kyle's comment that the ALT switch needs to be turned off

Re-read it, please. I didn't imply anything. I simply asked if there was a difference between the two positions.

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3 minutes ago, downscc said:

Now it makes sense, thanks Kyle.

Welcome - sorry, it was somewhat vague. I was just trying to chase down alternate avenues, though, just in case something was behaving oddly.

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