snpower

Glideslope w/Autopilot

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With the 750 in LPV, APPROACH mode armed I am thus far unable to capture the glideslope. In fact, my Milviz aircraft do not even depict a glideslope on the HSI when not using the ILS... but I also have the A2A C182 and the glideslope works fine. Ideas? I've read on old (2009) posts elsewhere that at least early on the vertical mode was not supported due to sim limitations ?

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You may need to configure the GTN.  Perform a shift + right click on the top margin of the GTN and it should pop up the configuration menu.  If that does not bring it up from the VC GTN, then do that on the top margin of the GTN pop up.  The settings will be toward the top of the setups. Make sure you select Master Device (may be a default), Connect GPS to Autopilot, Connect GPS to HSI.  I also select Connect CDI Mode to NAV/GPS,and Automatic GPS/VLOC selection.  Scroll down and make sure the Radios are set to Com1/Nav1 if you only have one GTN installed.

The settings are aircraft specific, so you need to get into the Settings menu and make settings for each aircraft model.  There are also other options you should learn about in the User Manual.

I assume you engaged the APR mode when you were at the proper approach altitude and before the FAF.

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Thanks. I should have mentioned my settings. Attached are several screenshots. This is for the LPV RWY 21 @ KCHO. Approaching APUSE at 2,600 feet, Autopilot ON w/APPR armed. After APUSE the descent is down to 826' MSL. No Glideslope depection whatsoever. The aircraft remains on altitude hold and tracks laterally to the Missed Approach Waypoint.

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Just Outside the FAF, no glideslope indication:

 

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Tracking from the FAF to RWY21:

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Switching to A2A's C-182... the OBS shows the glideslope but the autopilot fails to capture in this instance as well.

 

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Here I am teaching myself again ;) I needed to select All options under "Panel Instruments" (SHIFT RIGHT CLICK the GTN 750) to track the glideslope...

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I will look at my settings again, but I am certain I do not have all of them selected.  Oddly enough I am flying from Asheville, NC, to Easton, Md today. I may take the C310 instead of the Turbine Duke v2, check my settings, and shoot that approach.  I flew in there for the Tom Allensworth memorial fly-in, but I was in my Milviz B55 Baron in US Army T-42 dress.  A Ron Attwood creation.

I believe I shot that approach into RNAV 03.

T-42%281%29-S.jpg

 

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5 hours ago, snpower said:

Thanks. I should have mentioned my settings. Attached are several screenshots. This is for the LPV RWY 21 @ KCHO. Approaching APUSE at 2,600 feet, Autopilot ON w/APPR armed. After APUSE the descent is down to 826' MSL. No Glideslope depection whatsoever. The aircraft remains on altitude hold and tracks laterally to the Missed Approach Waypoint.

Something is amiss with my C310's interface between the GTN and the instruments.  I attempted at least 6 passes, each time turning on or off options in the GTN Settings, Panel, section. For one approach I had all the selections, as you mentioned.  Finally, I switched to my Milviz Baron B55 and it flew the approach and V guidance as expected.  In the B55 GTN Settings, Panel, I only had the first three items selected, Master, Connect to AP, and Connect to HSI, and the last two in that section, Connect CDI mode and Automatic GPS/VLOC.  I have a separate instance of the C310 that is using RXP GNS v2 GPS's but did not take the time to try with it.

I must say I got a lot of practice today with the newer GTN feature to add holds at a waypoint.  I did that several times at FOMIV after breaking off the approach and starting another.  Way cool t be able to do that!

I'm off now to my TDv2 KAVL to KESN flight.  Enough recurrency training for one day!

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Let me try to shed some light on the settings (already posted somewhere in the forum, but I'll practice my memory).

First, the GNS V2 and the GTN will work the same regarding to the settings / simulator override / instrument links etc... This part of the product (the interface between the simulator and the device) is exactly the same, +- device specifics.

As an example of GTN only implementation: TAWS-A requires Flaps + Gear retracted/extended input information for the correct algorithm to work. The GNS V2 is only TAWS-B. However, the GTN features TAWS-A and properly takes this in account! (you can try dangerous vertical speeds near or far an airport, and see how the GTN will warn you differently as soon as you extend the flaps and/or the gear!

Now, for the 'needles', the problem doesn't exactly lie into the device, but most likely into the aircraft gauges. Some developers 'assume' their gauges work with any data input, some others don't have a choice (to fake a readout for example).

In this case, there are multiple data sources for needles in the simulator, that a developer can choose from, mostly in 3 groups: GPS vars, HSI vars and VOR vars. Each of these groups provide H and V CDI data (GPS not directly, but you can use XTRK in GPS mode for example). The problem lies in the group the developer use, as well as the assumptions.

For example about data sources, a developer could choose the VOR group vars to drive the HSI gauge needles. It will work fine with the default GPS. However, for this to work with the GTN/GNS V2, you have to select the "Connect GPS to VOR indicator" option. This option says 'override the VOR group vars', accordingly, the "Connect GPS to HSI" option overrides the HSI group vars.

Another example about assumptions: the default GPS does not provide vertical guidance. A developer might choose to 'park' the VCDI out of view when in GPS mode, otherwise, the default simvar reads the value '0' which means 'centred'. Of course, such developer should have used the simvar 'VCDI valid' and park not based on 'gps mode' but on 'cdi validity'. This would work fine with the default GPS in any case. With the GTN/GNS V2, both VCDI and validity are properly overridden, but the gauge might fail if not coded along these 'natural' guidelines.

Of course, should FLT V2 and FLT V2 fly the sky, someday, you'd get accurate gauges for accurate GPS devices!

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1 hour ago, RXP said:

As an example of GTN only implementation: TAWS-A requires Flaps + Gear retracted/extended input information for the correct algorithm to work.

Confused here.  Are you saying it requires a notch of flaps and gear down to capture vertical guidance?  I routinely depending on conditions, come up on the FAF with a notch of flaps. As soon as vertical guidance engages and the AP starts me into a descent, I bring in another notch of flaps and lower gear.This works for me famously except today in the C310.  My TDv2, Milviz Baron B55, Carenado Baron B58, and remainder of my many aircraft conform to this.  Would you please explain further?

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5 hours ago, RXP said:

TAWS-A requires Flaps + Gear retracted/extended input information for the correct algorithm to work.

This is what it relates to. What I'm saying is the Reality XP GTN 750/650 Touch correctly connects the flaps extended and the gear extended signal to the GTN TAWS-A, so that it warns the pilot correctly, per TAWS-A specs, depending on the flight conditions. The TAWS-A also adapts the algorithm based on airport proximity.

IIRC, this affects:

  • Excessive closure rate to terrain alert
  • Flight into terrain when not in landing configuration alert

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Jean-Luc. That sounds to apply to warnings, not to engagement of guidance.  Is that correct?

The issue he was having yesterday was coupling the vertical guidance of the approach. He appears to have overcome it by selecting all of the options under Setup, Panel.  I found a similar difficulty today with that same one aircraft, and no other.  That does not spell an issue with your product at all as your product works perfectly with all my other aircraft. 

That said, it is also important to point out here that i worked extensively on that C310 panel to fit in beyond the conversion from the Milviz F1 GTN installation to RXP GTN a transponder and a NAV2/COM2 radio set. It is more probable the inability to couple to vertical guidance is on me for all that I tried, via trial-and-error, to accomplish with the panel.

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This is ok, I know the OT is about vertical guidance. I was just using the TAWS-A example as a specific difference between the GTN and the GNS V2 implementation in regard to the simulator, all other things being equal otherwise! Of course, mentioning the TAWS-A example gives me the opportunity to also cite its distinctive difference compared to other products ;-)

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28 minutes ago, RXP said:

This is ok, I know the OT is about vertical guidance. I was just using the TAWS-A example as a specific difference between the GTN and the GNS V2 implementation in regard to the simulator, all other things being equal otherwise! Of course, mentioning the TAWS-A example gives me the opportunity to also cite its distinctive difference compared to other products ;-)

Have not experienced the TWAS warnings. Great! Am as proficient as I think I am....  Oh my!My thinking there is a recipe for disaster!

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