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Citation X autopilot.

Controlling your aircraft, using the autopilot etc.

Citation X autopilot.

Postby dilbert » Wed Apr 07, 2021 5:19 pm

The horizontal modes work o.k.; but the vertical modes do not.
Altitude does not hold in either ALT or FLC ASEL modes. Instead pitch seems to be controlled by throttle. Desired altitude can be reasonably well held with 1/2 flaps, using an rpm range of 52 to 52.3 %.
Not ideal; but workable.
The biggest problem is that the Primus 2000 glideslope doesn't initiate until around 4.4miles and 1000 ft. If the plane has already descended to that level at time of engagement, it works fine.
However, if the pilot has maintained a higher altitude at time of initiation, the plane will dive to intercept the glideslope. This is true in LOC/ALT/GS or LOC/FLC/GS modes.
Since the glide slope code seems related to the Primus2000, the internal workings of which I'm not familiar with, I have been unable to find a way to extend the initiation point to 2000 ft and 9.5 miles, which would render it practical for regular use in FG.

Is Syd Adams still maintaining the plane? f not, is there a current maintainer?

Thanks and kind Regards. :)
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Re: Citation X autopilot.

Postby WoodSTokk » Wed Apr 07, 2021 6:05 pm

There are more than one Citation X.
We have one in the FGAddon Hangar.
There is another one from PAF-Team: https://github.com/GDsouza/CitationX-PAFTeam
And i think our pirate has also a modified Citation X.
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Re: Citation X autopilot.

Postby dilbert » Wed Apr 07, 2021 8:33 pm

Thank you, WoodSTokk.

Glide slope works correctly in the PAF-team version.
Also, ALT is sought and held in either version, provided it's entered in hundreds of feet-40 for 4000; 22 for 2200, etc. Seems a bit strange, but it works.

Thanks again for the link and Kind Regards. :D
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Re: Citation X autopilot.

Postby Johan G » Sun Apr 11, 2021 3:10 pm

dilbert wrote in Wed Apr 07, 2021 8:33 pm:[...] ALT is sought and held in either version, provided it's entered in hundreds of feet-40 for 4000; 22 for 2200, etc.

Ah, so in flight levels rather than feet.
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Re: Citation X autopilot.

Postby dilbert » Mon Apr 12, 2021 12:28 pm

Thanks. Was testing at prop levels and not thinking too clearly. :)

The autopilot works nicely.

I'm still a little confused, thinking that with Primus, Alt would hold altitude at the point set and FLC would effectuate climb to or descend to the ASEL flight level. Currently, both Alt and FLC effectuate
climb to and descend to ASEL-which may be correct. When FLC is employed, mode switches to HDG/ALT when ASEL is reached. Anyway, the current arrangement works fine for me. :)

P.S. I've been engaging the Localizer at 4000 AGL ; and switching from HDG/ALT to NAV/ALT, which then displays LOC/ALT. Also, I then enter the anticipated Glideslope initiation level in ASEL (corresponding to 2400 AGL) ; but have found it necessary to wait until the glideslope bug activates before clicking APP. :)

Well, the good fortune didn't last. Now when I engage the glideslope the throttle goes full automatically and jams. Killing AP doesn't unjam it; and the only remedy seems to be to alternate
reverse thrust to prevent overspeed. :(

So now after the throttle jammed I waited to see what would happen; and when a/s reached 250 with the overspeed alarm blaring, the throttle unlatched where it could be reduced to idle.
Nevertheless, a/s remained stuck at 250 K; regardless of idle throttle. Only reverse thrust enabled enough speed reduction for normal landing, as before.

Also tried deleting the CitationX in roaming, which made no difference. Using different model stick made no difference, either. Don't know why everything seemed to work well initially; whereas throttle jamming problem now persists. :cry:
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Re: Citation X autopilot.

Postby dilbert » Wed Apr 14, 2021 1:27 pm

Well I'm back in the FGaddon version, which works fine, provided you drop ASEL from 40 AGL to 20 AGL after Localizer interception; then drop it to 10 AGL at the regular GS point (around 9.5 miles).and click APP to arm GS. 50 % at 15 degrees flaps works well most of the way-maintains 150 K at level and doesn't overspeed during descents, so you don't have to jockey the throttle. I go to idle at 500 feet, or so, and click DEL to arm reverse thrust. :)

The PAFTeam version has a number of improvements, especially the audible overspeed alarms and the correct GS initiation point; but the throttle
sticking problem is a negative feature for now.
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