ILS Approach and ADI Steering Needles

[cichlidfan]

The one link posted above will work just fine for you. It shows a headin of 125, it is close but not peffict like my spelling. :)

 

Actually the charts I linked show 119 for Batumi which seems right on approach (it is certainly closer to 120). You are thinking another set of charts by Shu77, I have those as well.

[cichlidfan]

I also noticed that the heading on the info bar in the F2 view does not match the compass heading in the plane while looking at these heading conflicts (about 5 degrees high I think).

[CAT_101st]

Actually the charts I linked show 119 for Batumi which seems right on approach (it is certainly closer to 120). You are thinking another set of charts by Shu77, I have those as well.

You are correct.:doh:

[cichlidfan]

I just found this...doesn't help with the sim so much but still cool.

 

Everything you ever wanted to know about Batumi.

 

http://eurocontrol.gryph.de/airports/UGSB.pdf

[Qazme]

Figured out my heading bars being stuck in the middle permanently was because both VHF radios where sent to ON instead of TR causing the navigation error. Knew I would find it!

[hassata]

Now tell me you don't love this sim :D

[mooshim]

Now tell me you don't love this sim :D

 

+1 :D

[Qazme]

Yeah I love it SSSSOOOOOO MMMMUUUUCCCCCHHHH I just want to kick it's hog's teeth in at times. Man, this thing just throws new things at you everyday.

[Fish]

I can't see much wrong with the ILS gauges, but then I'm not a pilot, so know no better.

 

ILS VIDEO

[GGTharos]

The needles should command your attitude - ie. they tell you 'pitch/bank to to the needle to intercept glideslope', not 'glideslope is here'. See the difference? It's actually kinda hard to grasp sometimes :/

[mia389]

I have never flown a plane where the needles told me to fly the intercept. Now I know the CRJ I fly you can make the fms fly intercepts. I have no problems flying an ils approach with the A10 analog gauges. Reminds me of a 310 I used to fly actually. Of course its a bit twitchy in the warthog.

 

You guys know it does not matter if your course is not set to the runway. Its just for your reference. For runway 09 I set my course to 090. Next time your lined up on the localizer, spin your obs knob and you will see your cdi will not change. Now a TACAN is a different story.

[BlueRidgeDx]

I have never flown a plane where the needles told me to fly the intercept. Now I know the CRJ I fly you can make the fms fly intercepts. I have no problems flying an ils approach with the A10 analog gauges. Reminds me of a 310 I used to fly actually.

 

So, in the CRJ you've never been in HDG mode on an intercept course with APPR mode armed in Green Needles and had the FD fly you onto the LOC? I find that hard to believe.

 

That's kinda the definition of a Flight Director, isn't it?

[Qazme]

The needles should command your attitude - ie. they tell you 'pitch/bank to to the needle to intercept glideslope', not 'glideslope is here'. See the difference? It's actually kinda hard to grasp sometimes :/

 

 

That's why they are called steering bars and not guide bars. lol, HUGE difference, almost 180 degrees worth ;)

[Frostiken]

Actually, for me the strangest part about the ILS system is that you can pick up the glideslope before / without a localizer.

 

ILS systems, at least American ones, don't give you glideslope without localizer present. The reasoning is that you can land hard, and you can land soft, but if you completely missed the runway it doesn't matter :D Makes sense to me!

 

This actually should be considered a bug. You can see it in Fish's video, he rolls out of the turn and instantly has glideslope, but no localizer.

 

You also shouldn't be hearing that Morse code unless you're in the localizer lobes either, as the code piggybacks on the localizer antenna signal.

Edited May 18, 2011 by Frostiken

[lobo]

I can't see much wrong with the ILS gauges, but then I'm not a pilot, so know no better.

 

ILS VIDEO

 

The ILS info as presented on the HSI and ADI is fine. The yellow steering bars (flight director) are not working properly. These bars should provide you with steering commands (direct you) to maintain the loc and slope. They do not do this they repeat the loc and slope info... this is the problem.

[mia389]

So, in the CRJ you've never been in HDG mode on an intercept course with APPR mode armed in Green Needles and had the FD fly you onto the LOC? I find that hard to believe.

 

That's kinda the definition of a Flight Director, isn't it?

 

Of course but the FD is only flying the heading I told it too until it captures the localizer. It does not automatically give me an intercept heading.

[BlueRidgeDx]

Of course but the FD is only flying the heading I told it too until it captures the localizer. It does not automatically give me an intercept heading.

 

Ok, I see what you're saying.

 

The Flight Director Computer used in the A-10 (and other fighters/trainers) actually does generate it's own intercept heading. The selected angle depends on the amount of course deviation, but nominally it's set at 45 degrees.

 

Depending on range-to-station and deviation rate, you might never achieve the nominal cut-off angle before the FD starts the lead-turn onto the localizer or TACAN course. But initially, that's where it's trying to point you.

[mia389]

That is really sweet. I never realized that the A10 did that. Really I dont use the FD much in the A10 until I am already on the localizer.

 

I would of been really confused if I seen the FD telling me I am on course and my localizer full scale deflection.

[Fish]

The ILS info as presented on the HSI and ADI is fine. The yellow steering bars (flight director) are not working properly. These bars should provide you with steering commands (direct you) to maintain the loc and slope. They do not do this they repeat the loc and slope info... this is the problem.

 

I'm sorry I know it is probably simple, but a still don't understand the difference. ?

 

For say the localiser, currently the yellow line is a measure of the actual distance from the approach line, and thats why its so techy?. But it should only be directing the pilot in what heading he should turn to to intercept the line. Is that correct ? So the deflection is based on angle off, rather than distance.? Or some combination of the two.

[hassata]

The way I understand it, when the thing works, if you keep the yellow line centered you will be banking at the correct angle, and pulling the right amount, to intercept the localizer (as opposed to eyeballing it by angling off 20 degrees and starting the pull when the localizer is 5 degrees from center and such).

[BlueRidgeDx]

Don't feel bad, Fish, until you've seen it first hand, it's a difficult concept to grasp. Once you see it moving and reacting as it does on an approach, that's when the light bulb usually comes on - "Oh, I get it!"

 

As presently modeled, the yellow steering bars on the ADI are a simple repeater of the localizer and glideslope deviation pointers. They are not behaving as a flight director. This is a known issue.

 

I assume you know how the localizer and glideslope pointers work, right? They simply tell you how far you've deviated from the desired course and glidepath. There is no steering involved, it shows only the magnitude of deviation.

 

A flight director, on the other hand, provides actual pitch and bank commands in order to return to (or maintain) the desired course and glidepath.

 

How the computer determines where to position the command bars is pretty involved. It uses present pitch and bank as supplied by the EGI, the current localizer and glideslope deviation, as well as range-to-station as supplied by the ARN-108. It calculates the rate of deviation change, and then determines the pitch and bank angles required to null the deviation. Those required values are then displayed on the ADI by the command steeering bars.

 

Take the following example:

 

Flight Condition: Aircraft centered on the localizer, but 1 dot below the glideslope as seen on the localizer and glideslope deviation pointers.

 

Flight Director reaction: The roll command bar will remain centered, and the pitch command bar will be above the waterline symbol. As you increase pitch toward the command bar, it will descend toward the waterline symbol.

 

At this point, the glideslope deviation pointer is still 1 dot above center, but the pitch command bar is centered. As the increased pitch attitude gradually corrects the "below glideslope" condition, the command bar will begin to move downward away from the waterline symbol. If you decrease pitch to keep it centered, you will smoothly capture the glideslope.

 

The same thing happens with the bank steering bar when you deviate from the localizer. It's a relatively simple matter to pitch and roll as necessary to keep the steering bars centered, which in turn will correct any deviations.

[Fish]

:(

Don't feel bad, Fish, ........................

 

I feel soooo much better now....

 

:megalol:

[lobo]

Thanks ED. The command bars are much more realistic and useful now!

Edited July 24, 2016 by lobo**