First APM flight, problem with stabilization mode?

Hooray, got to the point where I've got APM set up and in a plane (Hawk Sky).  Now I need a bit of help diagnosing a flight problem.


I took off and got some altitude, and then flipped into stabilize mode. As you can see from the video, as soon as I did this, the plane started spiraling down and to the right.


I brought the plane back in and recalibrated gyros, but still couldn't get it to work.


Any advice appreciated!


Update:  As noted in the comments, I had the ailerons reversed.

Revised ground test and setup notes here.


Following that, here's what I did to reset and try again.

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  • HeHe. Same thing happened to me with the HawkSky (makes a great platform). I Recommend using the bixler params as a starting point. Cheers.
  • Moderator

    It looks like I've got everything working correctly.  I've make a new blog entry with some notes:

  • Moderator

    Cool Dude, what size batteries do you use? I'm using 3S 2200 mAh, so it needs to sit pretty far back for to balance COG.  Thanks!

  • Moderator

    For my own edification, I made this chart to drill myself on aileron motion.  (I've just recently switched from my RET EZ*, so I'm just getting started in aileron control).  Would somebody mind double-checking it?  It would be most appreciated!


    Aileron Motion
    Here's the aileron controls spelled out.  Apparently my brain constantly works backwards on this.  Ironically I do all right when flying,...
  • Moderator

    Cool Dude, I like how your mod moves the APM into the fuse. Do you notice any weak spot where the battery bay or slots are cut?

  • Moderator

    Thanks Guys!  Embarrassingly, it was my fault in getting the aileron visualization backwards.  I looked at it a dozen times, thinking "when the left aileron lowers, the plane will roll left."


    I redid the setup, getting the ailerons correct... but I had incorrectly fixed the reversed rudder in the transmitter, so it was reversed when controlled by APM.  I didn't notice it while testing stabilized mode, since that doesn't use rudder.  My newest test includes fly-by-wire-a, which revealed that problem.

    I'm having another unrelated problem... as soon as I resolve that, I think I'll be ready for another air test.

    Thanks again!

  • Hi Mark,  I am also trying to build an APM using Dynam hawk. Although I do not have the answers to your questions, I do want to share with you some of my experience. As you can see in the pic below I have made a slot at the side of the fuselage and inserted a piece of thin wood. The APM is attached to this wood using double sided tape. The GPS is attached on the top using velcro. I used hot glue to attach the velcro. This setup  enables all the electronics to be inside the protective hatch.


      To enable easy power connect and disconnect, I have cut a part of the belly which is then fastened using velcro. This gives me access to the back of the fuselage where I install the small batteries for the APM. The batteries for the motor are at the front under the APM.



     I have still not flown mine using any of the auto modes. However it flies great in manual mode. BTW what config parameters did you use. I used the one for Bixler which Chris uploaded recently. I am hoping that it will work fine for this as both planes are very similar.

  • Mark, I think you should check whether your dip switch settings are correct.  This looks like an Elevon setup.  Please check DIP switch 4.


  • 3D Robotics

    Mark, did you go through the flight setup process in the manual to check servo direction before you flew?


    As we say (many times!), failure to check your servo direction before flight is the #1 cause of failure. (That's true for regular RC control, too)

  • Developer

    The video shows that aileron reversal is definitely wrong. I'd suggest you set SWITCH_ENABLE to 0, which will disable the dip switches, then use the planner to set the reversals. Your video shows the left aileron giving more lift when you tilt the plane to the right, which is backwards. That means RC1_REV is incorrect. You probably want to set it to -1.

    Check the elevator and rudder reversal as well. If you have some rudder mixing enabled, then tilting the plane right should engage some left rudder. Pitching up the noise should give some down elevator.


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