v0.1.3 AP Problems
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@martyn I'm encountering a possibly related issue in descent, using version 0.1.4. So far I have only been able to reproduce it when descending by more than 1000ft from the previously held altitude.
Steps to reproduce:
- Starting in ALT HOLD at 7000ft, LNAV, AP on
- Set ALT SEL to 2900ft, select ALT ARM => The horn sounds (not sure if that's supposed to happen)
- Status as shown by the annunciators is now: ALT HOLD (green), ALT HOLD armed (white).
- Select IAS, reduce thrust to idle (TMS set to DESC mode).
- About 400-500ft above the selected altitude, the aircraft will start to level off, reducing the descent rate to only about 200ft/m. IAS annunciator is still green, ALT annunciator is still white, but Airspeed starts to reduce rapidly. Adding thrust to keep airspeed at the desired value will cause the plane to keep a rate of descent of only about 50ft/m, while still indicating IAS green, ALT white.
- My current workaround when this occurs: Selecting VS mode, pitching down using SYNC, the AP will capture the selected Altitude as desired.
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@martyn Tried it again today. Twice it worked perfectly. The third time it again went all haywire. At 22000feet, I set the target altitude to 16000feet and armed it, set VS mode, followed by SYNC switch (TOGGLE AFTERBURNER mapped to a switch on a keyboard), then set pitch down 1500feet/min. As soon as I pressed SYNC switch again, the vertical speed shot right up to +1500feet/min or more, then settled back down to zero. I tried this a number of times, then had to turn off the AP and hand-fly it down.
Guess I will submit a support ticket like you suggested. -
I can confirm these autopilot problems. Yesterday I made a flight without any problems (version 0.1.4) and today the autopilot did not wanted to descent. Plane used, 146 200
The first stage of the decent went well, from 23000 ft to 15000 ft. As I was almost at 15000 ft I had to go to 3000 ft. While I was still descending (about -500) I selected 3000, Armed, set VS, SYNC on set vs -2000, sync off. Autopilot did not keep vs, came back to 0. Tried a few times to set the vs, but did not work. So I did de descent manually. Plane used 146 300
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@martyn I did another flight (by the way I am using the 100 version), but this time it worked perfectly. I will post screenshots the next time the problem occurs.
However, one thing I would like to note is that the instant I set a new altitude (6300ft) and armed it (current altitude was 16000ft), there was a long beep like when the altitude reaches within 1000ft of the target. Every time I had the AP problem, this beep has been there. But this time, AP descent worked perfectly. -
I too seem to have encountered an issue with the AP when descending with version 1.4. Pressing ALT ARM triggers the horn to sound and the plane starts its descent immediately from ALT HOLD and quite violently too. In order to descend properly I have to hold the plane in altitude hold, start the descent with vertical speed mode then adjust selected altitude and press ALT ARM.
Cheers :)
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@martyn
I made a couple of test flights. The first flight went well, no problems did show up. But the sound of the horn was there as soon as “ALT ARM” was selected.The second flight I tested if the horn also was heard as I selected a higher altitude.
In levelflight I selected a higher altitude and as soon Alt ARM was selected the sound was there. So I deselected Alt ARM, and then the plane went up while “ALT” is stil selected.
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I just tested the new gauge, could not find any of the problems we had. The horn works as it should when setting a new altitude and arm it. No sound, only when in range of the target altitude.
I made several descents in my test flight, and all went well.
Thanks for solving this problem so quickly.
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@martyn managed to record what has been happening with me the last couple flights. Apologies if it is hard to see, don't usually record things.
First video when on ascent out of the airport the plane refuses to hold 2000 fpm, and instead kept pitching up despite me trying to set it multiple times. This was recorded after I first attempted to correct it. I tried setting VS both by manually clicking it on the FCU and on my Bravo hardware (tried toggling between IAS and VS as well on the hardware).
https://www.youtube.com/watch?v=FzFmPo2RmUMIn this clip I was attempting to slow the plane down, any attempt at using the speed brakes just resulted in the plane pitching downwards to maintain the ~250 knots IAS.
https://www.youtube.com/watch?v=R4yeW3OkFE8The only thing different in my settings between 1.2 and 1.3/4 is that I rebound SYNC from Afterburner to ELT. I have noticed that the button light for IAS is lit on my Bravo, and not on the FCU when loading in to the plane. I don't think it was doing that prior to 1.3. It kind of feels like IAS is forcing itself on in the background, perhaps. Which wasn't an issue in 1.1/2.
Unless I am doing something fundamentally wrong that wasn't causing an issue previously that I am just missing?
Shall DL that gauge to try too, since I did have the above mentioned altitude bug as well.
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So far I haven't encountered the exact problems as described in this thread with the WASM you supplied, but unfortunately I'm encountering the early level off first encountered in 0.1.2 again. Just took off, selected an altitude of 9000ft, ALT ARM => No altitude horn this time, white ALT annunciator turned on.
Set IAS, used Sync (using the ELT binding if that has any impact) to set the desired airspeed. At about 8000ft the horn sounded, as intended, but at 8600ft the green ALT annunciator came on, the green IAS annunciator turned off, and the plane levelled off at about 8500ft, even descending a little to get back to that altitude. -
Downloaded the 0.1.4 update and applied the WASM patch and it’s much better. Still seems to arm the ALT mode too soon in ascent though, meaning I had to adjust up a couple of hundred feet, but all the weird descent issues I was having seem to be fixed (only one flight though), and altitude capture seemed to work fine in descent. Will try a couple of additional flights in coming days
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@melon said in v0.1.3 AP Problems:
I was attempting to slow the plane down, any attempt at using the speed brakes just resulted in the plane pitching downwards to maintain the ~250 knots IAS
That is exactly what it will happen and is intended. You have selected the vertical mode of IAS thus telling the autopilot that you want to maintain the speed when you pressed the button.
By deploying the airbrake and inducing drag, the autopilot is unquestioningly obedient and will do its very best to maintain the speed you commanded earlier - and it can only do that by lowering the nose.
What you get is no reduction in airspeed but an increased rate of descent.
There are situations (all too common) where you need to go down and slow down and it's a fine art in manipulating the automatics to achieve this. In the 146, descent in icing conditions with anti-ice on, particularly in the terminal environment, was, shall we say, a challenge at times.
If you want to slow down, set the aircraft off at a modest rate of descent circa 1000fpm and the VS mode will maintain that - you can then deploy the airbrake to slow down (rapidly) or bring the thrust back. -
@toozin Please watch the video. I know what it should do, but it was not doing that because if you watch the video you'll see that I was in VS mode not IAS. I was using IAS as the term not as the mode in the sentence you quoted. To reiterate, I was in VS mode yet it was acting like it was in IAS mode when it was not.
I previously had been using VS to maintain 2000fpm while slowing from like 280 to 250 or whatever. That is not working now.
