208 Altitude autopilot

[swk1959 21]

It seems no matter what I do, when I set the altitude the aircraft continues to climb, even when I set it to a lower altitude and engage -vs speed it continue's to climb the only way to stop it is to disengage the AP and hand fly it. As soon as the AP is engaged regardless the plane climbs.

any help would be appreciated,

 

Thanks

[DaveS 144]

Do you have a target altitude already set with the alt knob? I have been flying the C208 pretty exclusively lately and here is what I typically do

Set target altitude with alt knob when still on ground 

Engage the flight director before takeoff

When in the air and ready to engage AP I sync the heading with my current heading by pressing the hdg knob then I engage the heading mode

I then will engage f/c mode and finally the AP

f/c mode should provide pitch to maintain the current airspeed which you can then increase or decrease with the vspeed wheel until reaching target altitude

I haven't had any AP issues doing this other than there is a bit of a nose down pitch when within about 500ft of target altitude which it then slowly climbs back to reach target altitude but I think this is a bug with the latest update 

 

Dave

Edited October 7, 2020 by DaveS
additional info

[swk1959 21]

Thanks Dave for the speedy reply I will give it a shot and see what happens

 

Scot

[swk1959 21]

Thanks for the suggestion Dave but I followed your directions exacally tried it 4 times to make sure, the aircraft just continues to climb regardless

 

Scot

 

[swk1959 21]

It seems this is an issue with the 208, the 172 and the mooneybravo's autopilots are functioning as expected.

[BusheFlyer 87]

What you are describing has not happened to me ever and I have around 88 hours in my logbook on the c208. I wonder if it something else causing it on your setup. Perhaps a control issue?

[DaveS 144]

That is strange..do you have any mod's in the community folder that may be interfering? 

 

Dave

[swk1959 21]

I don't disagree, it just seems odd that it just the 208, I suspect it may be an issue between my machine and the latest update as I never had the trouble before. Oddly enough before the update I had issue's with the 172 autopilot but since the update it works fine.

[swk1959 21]

No mods at all Dave, strictly the same as I bought it with the exception of the patches

[desbean 357]

Same problem for me with the C208, on FLC or VS modes it always shoots past the set altitude. No problems at all with the AP on either of the 172's. Once the C208 is at a set AP altitude, you can then change altitudes using VS with no problem, so I reach set altitude with a 172, then switch to the 208 using developers mode.

[vgbaron 3,491]

I haven't had that problem. I set the desired alt. I set the vspeed and enable VS. I set the FD. I set the proper NAV mode. Then after take off, I trim to get close to my rate of climb and then engage the AP.  It just continues the climb and engages ALT hold at correct level

[swk1959 21]

It must differ from machine to machine I guess, it had worked for me when I first bought it but seems broken now, trying all the Ga's I have in the deluxe version to see which one's are affected for me, so far just the 208.

9 minutes ago, vgbaron said:

I haven't had that problem. I set the desired alt. I set the vspeed and enable VS. I set the FD. I set the proper NAV mode. Then after take off, I trim to get close to my rate of climb and then engage the AP.  It just continues the climb and engages ALT hold at correct level

 

[desbean 357]

22 minutes ago, vgbaron said:

I haven't had that problem. I set the desired alt. I set the vspeed and enable VS. I set the FD. I set the proper NAV mode. Then after take off, I trim to get close to my rate of climb and then engage the AP.  It just continues the climb and engages ALT hold at correct level

I just tried it in the same order you describe, and still no Alt hold. Had VS set to 500fpm and it steadily climbed between 500 and 1200 fpm and went passed the set Alt. The Altimeter started blinking when it got close to the altitude, but kept going.

[vgbaron 3,491]

41 minutes ago, desbean said:

I just tried it in the same order you describe, and still no Alt hold. Had VS set to 500fpm and it steadily climbed between 500 and 1200 fpm and went passed the set Alt. The Altimeter started blinking when it got close to the altitude, but kept going.

Now that IS strange.  I assume you are starting on the runway with engine running. I say that because if you did a manual start, perhaps "something" didn't get initialized properly. If you have any mods installed in community folder, try removing them all and see if the AP works then add back one by one.

[desbean 357]

7 minutes ago, vgbaron said:

Now that IS strange.  I assume you are starting on the runway with engine running. I say that because if you did a manual start, perhaps "something" didn't get initialized properly. If you have any mods installed in community folder, try removing them all and see if the AP works then add back one by one.

Yes, started on the runway and running. AP holds heading, but not Alt. Once again I switched to the 172 G1000, established altitude with AP then switched back to 208. When back in the 208 the AP is still on, but have to re-select and re-adjust both Heading and Alt., but then no problems with AP. On a brighter note I have no crashes using VFR map...