Ran into an issue that Im hoping someone can help out with on my pixhawk. any time I put it into FBWA or B mode she pitches down hard and even with me giving full up elevator she still pitches down and i have to bring it out of the mode to prevent a crash. In stabilize she flies just fine and when I maidend her a few weeks ago she flew perfect, even was able to do auto flight and landing. I didn’t make any changes to her when this started happening last week when I had a crash, loss of RC control and because of the nose dip she went into some trees on RTL. Rebuilt her adding an airspeed sensor and Im still having the same issue. I tried to put the log in but at 20mb she wouldn’t load, if someone link its will help ill dropbox it and put the link up.
You can attach large tlogs or dataflash logs by zipping or by using Google Drive.
here is a link for the log file, thank you TCIII.
Thanks Tom for bringing this to my attention.
I haven’t looked at the logs yet but I will shortly. Off the top of my head you should check your pitot tube isn’t blocked in some way - either the tube itself or the hose having a kink. That would cause this issue.
Your log file is interesting. Its showing the flight modes as numbers and its not mapping to a mode so I can’t tell when you are in FBWA. How did you produce it from Mission Planner? Are you running the latest Mission Planner?
I downloaded the logs right from APM Planner 2.0 on my Mac, when I look at the logs I can see the modes themselves when it changed, if for some reason they can’t come up just look for the mode change and the altitude drop. I check the pitot tube and theres no kinks and its reading properly, I also had this issue before I installed the pitot tube.
If you could get the dataflash log directly of the SD card on your pixhawk that would help.
Does your transmitter support different trim settings depending on what mode your in? i.e. when you go into FBWA does your trim change significantly?