Glideslope intercept

[Scupper 6]

Has anyone managed to intercept an ILS glideslope in the C90 using the ProLine avionics?

 

The localiser function seems fine, and in another post on this forum there's a suggestion that you have to be around 1,200ft agl to pick up the glideslope but I don't think any real world interception would be that low. 

 

So far, when I do an ILS, I sail majestically over the airfield unless I wait too long, cut the autopilot and wrestle the thing down myself. It's just not very satisfying to fly a great plane badly. 

 

[Jim Robinson 122]

I successfully did one off off an FMS arrival/approach last night, I've noticed twice now though when you switch from FMS to VOR1 you can lock onto the localizer but the APR button wont stay on when you try to arm it for the glideslope. It just keeps turning itself off. Last night I clicked VNAV briefly and then after that for some reason I was able to click APR and it stayed on. It did a good job on the ILS once I got the combination right.

[Scupper 6]

Thanks Jim. I tried that just now, hitting VNAV before APPR and for the first time got a glideslope indication (vertical scale on the right of the PFD). I sailed over the airport again but I guess I need to change the ALT to zero instead of my intercept height so I'll try that later and report back.

[Jim Robinson 122]

It seems to me the problem is that when you switch between FMS and VOR1 using the Preset button on the PFD the NAV switch stays stuck on FMS Nav, I think just turning that off and back on again lets it switch from FMS NAV to VLOC NAV and then the APP button becomes available. I've made ILS landings with my FAF altitude value still entered on the ALT knob, APP seems to successfully override that once you manage to tickle everything in all the right spots.

 

Also it appears once you switch the Preset button from FMS to VOR1 you also have to choose the correct CDI needle by clicking the NAV/BRG button on the DCP, then select the VOR1 needle with the Menu/ADV knob. Click the NAV/BRG button again to get back out.

 

You'll notice I use a lot of terms like "it seems", "I think", "it appears", etc. :smile: I'm still trying to get this all figured out myself and the problem is every practice session is an hour flight at least, lol.

[Scupper 6]

Interesting. I just tried again with the same result, - no glideslope capture. At least we know the FAF altitude isn't the problem and is overridden if the ILS is set up properly. 

 

I'm doing very long finals and higher intercepts to give myself a chance to sort things out but it does take a while to get onto an approach, - particularly as this plane doesn't seem able to save flight plan data.

 

Perhaps if/when you feel you've nailed it, you could put together a short dummy's guide, - which buttons to press and at what stage? I think a lot of people would appreciate it and you're certainly further along that track than me.

[300hp.GT 4]

Interesting. I just tried again with the same result, - no glideslope capture. At least we know the FAF altitude isn't the problem and is overridden if the ILS is set up properly. 

 

I'm doing very long finals and higher intercepts to give myself a chance to sort things out but it does take a while to get onto an approach, - particularly as this plane doesn't seem able to save flight plan data.

 

Perhaps if/when you feel you've nailed it, you could put together a short dummy's guide, - which buttons to press and at what stage? I think a lot of people would appreciate it and you're certainly further along that track than me.

Forgive me for asking a really obvious question, but are you putting the ILS freq in the Nav radio? If you use the FMS to enter an approach, you'll track with LNAV, but it won't intercept the GS. 

 

Certainly not trying to insult your intelligence. Simply trying to troubleshoot.

[Jim Robinson 122]

OK here's an example I just did, going into KGEG Spokane, WA from the west, I started at KEAT Pangborn/Wenatchee and did the ZOOMR1 arrival and ILS21 approach. To put that in the FMS you make a flight plan between KEAT and KGEG, then on the DEP/ARV page you select ILS21 followed by the ZOOMR1 arrival and EPH transition. I didn't mess with any waypoint altitudes in the FMS, I just climbed straight to 19,000' for cruise and descended manually to hit the FAF at 5500'.

 

Charts here:

 

ZOOMR1

ILS or LOC/DME RWY 2

 

If you load that in the FMS it sends you from GANGS to LUCEV which is the IAF and the chart says to hit LUCEV at 5500'. Since the turn between LUCEV and SIGYO is nearly 180° you'd do a procedure turn there (at least the GTN750 does one there). Apparently the FMS doesn't do procedure turns so it tries to double back on itself and swings so far off course it doesn't have time to line back up again before touchdown - anyway I expected this so I took over at LUCEV and did the procedure turn manually. I spun the HDG bug left to 360° (reciprocal HDG minus 30°) and turned on HDG hold crossing LUCEV, flew out for 1 min, and then turned back right to 210°.

 

Oops, according to the chart I should have gone counter-clockwise, but something like this:

 

 

Here's where I think the problem is, after clicking the HDG button to take over manually, the tooltip over the NAV button still says "FMS NAV (on)". Somehow HDG and NAV are both on at the same time, so just click the NAV button once to turn it off.

 

So then I do this procedure turn at 5500', 200 KIAS and more or less roll out on rwy heading. While I'm turning I set the ILS freq 111.10 and change the nav source with the Preset button on the PFD (make sure it says VOR1 and not VOR2 before you click it, if you need to change it you can scroll it with the DATA knob on the DCP). Crossing LUCEV a second time I descend to FAF altitude 3900' before SIGYO, and hit the APP button. From there the AP captured the GS and flew a beautiful approach right to the inner marker.

 

Maybe try that one and see if you can get it to work.

 

Jim

[Scupper 6]

"Forgive me for asking a really obvious question, but are you putting the ILS freq in the Nav radio? If you use the FMS to enter an approach, you'll track with LNAV, but it won't intercept the GS."

 

I'm putting the ILS freq in the Tune part of the CDU. If that's wrong, I'll be delighted if you can tell me the right place to put it. 

 

Jim, you seem to have this down. Too bad Carenado couldn't be bothered to write a manual for how to use their complex product.

[ryanbatc 12,803]

The avionics in this plane are so effed up ugh...  They work only if you play by Carenado's rules bah

[Scupper 6]

Tried again tonight and managed a landing by using vertical speed mode to roughly stay on the glideslope before disengaging autopilot. This time I set the frequency in the small panel to the right of the MFD but that didn't seem to make any difference, - it showed up in the TUN page of the CDU anyway.

 

I noticed a few more things:

 

The preset (left of the PFD) is odd: selecting Loc 1 was impossible, - it did select with the rotary switch it but it continued to display 'Loc 2' (although the course it was showing was Loc 1). Loc 1, although programmed as to frequency and course, wouldn't engage despite being in the ILS zone of influence, but switching to Loc 2 called up the expected ILS deflection bar so I tuned the ILS course and went with that, which gave me the horizontal and vertical ILS bars. Again, no GS intercept so I did the vertical part using Vertical Speed mode. I might have forgotten to press VNAV along the way, - have to try that next time (I normally do it but it hasn't engaged GS so far). 

 

Next time I'll try it at a different airfield, - it's possible that East Midlands' glideslope just isn't working.

[Icon 22 11]

 

 

Oops, according to the chart I should have gone counter-clockwise, but something like this:

 

You need to watch those PT's. There is a B-52 planted in the area of your PT. Mount Spokane is around 6000' in that area. OUCH!

[Jim Robinson 122]

The preset (left of the PFD) is odd: selecting Loc 1 was impossible, - it did select with the rotary switch it but it continued to display 'Loc 2' (although the course it was showing was Loc 1). Loc 1, although programmed as to frequency and course, wouldn't engage despite being in the ILS zone of influence, but switching to Loc 2 called up the expected ILS deflection bar so I tuned the ILS course and went with that, which gave me the horizontal and vertical ILS bars. Again, no GS intercept so I did the vertical part using Vertical Speed mode. I might have forgotten to press VNAV along the way, - have to try that next time (I normally do it but it hasn't engaged GS so far). 

 

Next time I'll try it at a different airfield, - it's possible that East Midlands' glideslope just isn't working.

 

Note that what shows in the Preset field is what mode you'll be in after you click the button, not the mode you're currently in. It should say VOR1 before you click it, after you click it it'll probably say FMS. You have to use the DATA knob to make it say VOR1 first, then click the Preset button.

 

 

You need to watch those PT's. There is a B-52 planted in the area of your PT. Mount Spokane is around 6000' in that area. OUCH!

 

TBH it was VMC and as Amelia Earhart (sorta) said "Left seemed the most attractive at the time", lol.

 

I hadn't looked at the chart and I had "Left" stuck in my head, I was sitting there waiting for the AP to do something and when it broke right I assumed it was trying to double back on rwy heading so I turned on HDG hold and took over manually. Maybe the AP was trying to initiate the procedure turn correctly to the right [mild skepticism], I didn't hang around to see what happened. I'll have to try that one again and see what it does.

 

EDIT: Nope, no procedure turn.

[Scupper 6]

Finally... I've done it!

 

Here's what you have to do, and remember this is nothing to do with any route or arrival procedure that you have programmed into the FMC: I think I was getting mixed up with that. In the end I just set up the nav properly in the Primary Flight Display (PFD) and hit the right buttons in the autopilot controls. Jim's advice in the post above this clarified for me what the Preset does (the clue is in the name).

 

First tune VOR1 in the TUN page of the CDU (flight computer) to whatever the ILS frequency is, then head towards a point on the extended runway centreline far enough away so that you can have a long final approach and intercept the glideslope (GS) from below at a higher height than normal (to give you lots of time to stabilise your speed during your approach). Use Heading Hold for this, (with the autopilot on). I tuned VOR2 to the same frequency but that step most probably isn't necessary. Make sure that VOR1 is selected in the PFD display below the attitude indicator/artificial horizon. Note, as Jim says, that while the "Preset" indication will say VOR2 at this point (or LOC2), the display shows VOR1 or LOC1, which is what you want. Adjust the course using the round knob on the grey vertical panel thing to the right of the PFD (the tooltip will confirm that you are selecting the course on NAV1) and aim to intercept at about a 30 degree angle on Heading Hold (e.g. if the runway is 27, intercept the localiser at about 240 or 300 degrees).

 

Soon the horizontal and vertical deflection bars will appear on the PFD, showing that the ILS signal is being received. When the ILS deflection needle on the HSI starts to move towards the centre, hit the NAV button on the autopilot panel. this changes the mode from HDG to LOC1, the localiser.  When the localiser is more or less centred, hit the VNAV button on the autopilot panel. At this point you can still be on ALTS (altitude hold) because the autopilot will override that when it intercepts the GS. Now hit APPR on the autopilot panel, which engages both flight computers. At this point, accross the top of the PFD you should see APPR LOC1 AP in green capital letters. As the glideslope bar starts to fall down the verical ILS deflection bar, you will also see GS above the PFD in green, - which means you've successfully captured the glideslope.

 

Now you just need to control the speed with the levers and put the flaps and gear down (assuming you're a lazy pilot like me who doesn't bother too much with pre-landing checklists).

 

Thanks to all who posted on this thread, and if you have any more advice, perhaps how to do it better, I'm sure it will be well received. 

[ryanbatc 12,803]

Probably the best way to do it in Carenado's plane.

 

The real one you'd just be on a heading, ATC would clear you for the approach, and you'd simply press APR/APPR/APCH whatever the real button says.

[KenG 492]

I think P3D has more issues with this then FSX. I have successfully done manual FMS to ILS approaches in the C90GTx. I have used the FMS to fly an arc to intercept and a full procedure turn and when on the inbound course prior to the FAF switched over to the ILS and flew a coupled approach. 

 

The Careando "Pro Line" will not do the NAV to NAV automatic switch over nor will it automatically set the inbound course for the LOC. I also have not tried to fly a missed approach reselecting the FMS on the missed.

 

I have found numerous coding errors with the Navigraph database in how procedures are coded. I am not sure if this is an error in the database or a failure of Carenado to correctly interpret the data.

 

You do not want to use Carenado's VNAV function on any approach. This is an area Carenado just got so wrong and they have made it worse with update 1.1 and 1.2.

 

Carenado also failed to model the Landing Gear Warning System gear warn silence button on the left power lever. It is quite normal to pull power to a couple hundred foot pounds to slow down on approach. In the real airplane we hold the gear warn silence button when reducing power to slow down. Thus we don't have to listen to the annoying beeping of the warning system. Carenado did get some of the propeller drag in but I promise you with those swept turbofan propellers, when you close the power levers to flight idle the airplane slows down in a hurry. (This is a problem with every turboprop due to a fundamental flaw of propeller aerodynamics in FSX turboprops.)