Engaging A/P after takeoff

Hello!

Please, look at this video, since I don’t have a fluent english it will be hard to explain my problem only by using words. https://www.youtube.com/watch?v=fjpxj7RNP2U

I engaged the A/P at 1min 25sec (on the video), and as you can see, the plane if going down up, down up.
What can be the problem?

Happens to me also, If you fly the plane about 5 minutes manual after takeoff and then engage the A/P its does not go up and down, Don’t know why but yeah

Simply put your trim isn’t set right and your speed isn’t right if you have everything calibrated properly it won’t do that

So, what speed should I have?

I often do trim 20% on takeoff! What should i have then?

I need to search but there was a thread on this topic. It has to do with your rate of climb and the yoke position. Also how far apart the circle and line are in the HUD. Sorry to use the technical terms :)

It all depends on attack angle flap settings basically the yoke needs to be neutral or really close to it to engage the AP and not have it do that.

20 is fine unless you are still having to pull back on the yoke it needs to be in the nuetral position to engage AP if you recalibrate and the plane doesn’t go up or down then you know it’s in the neutral position or use the yoke on in your instrument panel