What in the World is Going on With the Autopilot!?!

[rodtod11]

And....its back. You get to altitude, have the Autopilot set for that altitude, soon as you hit the AP button, it pitches up wildly, nose is straight up to the sky, then a stall and you can never pull out of the stall. Did Overhaul...same result. I really do not want to go into a de install / reinstall again. Something is just not right here. Why does it work a few weeks then just stop working??? Bo changes were made...just flew the plane and here we are again. As soon as I push Autopilot I tried to check the climb rate, if I set it for 500, it will go instantly to 3500, 3300, always over 2000 foot per minute. It becomes unflyable even with autopilot off.....Sad to say, loved the CHerokee...deleting this one and just calling it a $50 loss. FRUSTRATED! You cannot tell me a Cessna flies this way....if so, I live close to an airport...I'm moving before they start falling out of the sky .

[Gault_Seven]

Have you ensured the flaps are up? I had a similar issue when I forgot to retract flaps after takeoff and upon activating autopilot, the aircraft would pitch up quickly. Disengaged autopilot and retracted the flaps, re-engaged and everything was fine.

[DrumsArt]

And....its back. You get to altitude, have the Autopilot set for that altitude, soon as you hit the AP button, it pitches up wildly, nose is straight up to the sky, then a stall and you can never pull out of the stall. Did Overhaul...same result. I really do not want to go into a de install / reinstall again. Something is just not right here. Why does it work a few weeks then just stop working??? Bo changes were made...just flew the plane and here we are again. As soon as I push Autopilot I tried to check the climb rate, if I set it for 500, it will go instantly to 3500, 3300, always over 2000 foot per minute. It becomes unflyable even with autopilot off.....Sad to say, loved the CHerokee...deleting this one and just calling it a $50 loss. FRUSTRATED! You cannot tell me a Cessna flies this way....if so, I live close to an airport...I'm moving before they start falling out of the sky .

What was the weight of the load of the aircraft? If you exceed the weight limit with the Cessna, you will have the problems you describe.

Regards,

Richard Portier

[iefbr14]

C182 cruise flight; AP is ON & altitude is set to 7500 everything is fine.
Then doing -> AP OFF -> AP ON : Display now showing [ROL] [AP] VS [-200] 2-3 secs later it switches to VS 7500 (!), but it had no effect, it still is in levelled flight. But what will happen after FS or flight cold start, when it is not initialised?

Sorry, I don't want to interrupt my current flight, to test it also with c172. FS is P3Dv2.4

Regards
Andreas

[Nick - A2A]

Andreas,

What you're describing is the normal operation of the KAP 140 autopilot. If after disconnecting the autopilot your aircraft descends (because of a power reduction say) when re-engaged it will enter vertical speed mode. The commanded vertical speed is then displayed for three seconds after engagement, before the display reverts to the selected altitude which in this case was 7,500 feet. (i.e it's not showing "VS 7500" and isn't in "levelled flight" - you're descending at -200 fpm in ROL mode! )

For more info, look at page 83 of the manual which is here: https://dealer.bendixking.com/servlet/c ... 0000_3.pdf

Cheers,
Nick

[iefbr14]

Hi Nick,

Andreas,
What you're describing is the normal operation of the KAP 140 autopilot.
...
before the display reverts to the selected altitude which in this case was 7,500 feet. (i.e it's not showing "VS 7500" and isn't in "levelled flight" - you're descending at -200 fpm in ROL mode! )

Thanks foor pointing, you are alright. Pic on page 89 shows really VS 12.500 .

Could it be, that is some of the fixes on the last update? I can't remember, this behavior was also before .

Cheers
Andreas

[Nick - A2A]

Hi Andreas,

No - I don't think anything changed in the last update with respect to autopilot mode selection. You just need to be aware that the caption 'FPM' or 'FT' is displayed under the numeric indication to show what it's currently representing. (i.e. There aren't two separate displays like the autopilot in the default Cessna which is presumably fictional!)

Actually, I think the software design of the KAP 140 is a little odd. It seems to me it would make more sense for it to show vertical speed by default in this display whenever the selected altitude isn't armed. This would act as an added indicator that the autopilot isn't set to capture altitude.

However, this obviously isn't A2A's fault - they just programmed it to replicate the real thing!

Cheers,
Nick

[cessnaman]

And....its back. You get to altitude, have the Autopilot set for that altitude, soon as you hit the AP button, it pitches up wildly, nose is straight up to the sky, then a stall and you can never pull out of the stall.

This happens to me only when in a climb. I'll be climbing at 700fpm and if I turn on the autopilot the plane will pitch up well over 1'000fpm. When I use the autopilot to set my fpm it will show 700fpm, so I'll set it at 400fpm and when the nose starts to drop I'll set to the desired fpm climb. Now if I'm at Alt. and I set AP, then all is good, so most of the time I'll wait till I'm at Alt. and once I'm stabilized for cruise flight, then I'll turn on autopilot.

The only thing I can think of for this nose up pitch, is I'm not in a good stabilized climb. I need to try getting the aircraft on a stabilized hands off climb and the turn on autopilot to see what happens.

[Lewis - A2A]

Have you tried being set in level flight prior to using the AP and then setting the AP for the climb?

thanks,
Lewis

[cessnaman]

I have set the AP at cruise and I will at times select the alt and set a new alt and the plane will climb or descend beautifully. No problems at all that way.

[Lewis - A2A]

Ideally thats what you want to be doing anyway, getting her trimmed and flying before turning on the AP.

thanks,
Lewis

[Gypsy Baron]

I echo Lewis' comment there.

I always trim out in level flight before engaging the AP and beginning the ascen, descent or continued level flight.

Severe wind changes, up or downdrafts will require your attention!

Also, I never, and I mead NEVER, use time acceleration. I have flown trans Atlantic and Pacific routes in my A2A B-17G and B-377 all in 'real time' and one 'sitting'. Also long hops in both Civilian and Military P-51's and shorter hops in the A2A GA aircraft. But then I am retired and have the time and will to do so

[cessnaman]

Yes, I also agree with Lewis. I do recall in my short 40 hrs of flying, my flight instructor would only have me activate the AP once we were in level flight and only when my workload was heavy. I would engage the AP so I can work out fuel calculation, times to next checkpoint, ect. in order to see if i was close to what I had figured in my flight planning. The rest of the time I was hand flying. i never had the chance to actually check the potential of the autopilot due to my short time flying RW.
I was so close to completing my flight lessons, when the economy took a dump. Oh well, it's been 7 years since I've seen a raise. maybe one day when I can make more money, I'll start again.

At least I can say thanks for the A2A C172, this is as close to flying the real thing, and I can at least try and keep up with some of the skills that I learned. Now if I can only get my CH yoke and peddles to work like the real thing. LOL

Thanks,
Gabe

[aprewett]

Cessnaman, lets start another thread, as I have the same yoke and peddles. It would be great to get some help with them.
Allan

[cessnaman]

Sounds good. You should go ahead and start one.