Another Naza H help thread, aggressive pitch when switching modes

[earhythmic]

Hey everyone. Long time lurker, first time poster. Yesterday I completed installation of the NAZA H and ran into some issues, hopefully you guys can help me out! The following is an email I sent to China tech support, which I don't expect much help from:

I have a question/problem regarding the mode selection and flight behaviors on the NAZA-H.
First some background:
- I installed the latest NAZA H software and driver and did all updates to the software and firmware.
- I set up the NAZA according to the software instructions. Double and triple checking every step.
- Checked and confirmed all of the proper movements in the feedback screen many times.
- Bench tested and confirmed correct swash movement in all modes.
- Test flew the helicopter in manual mode and flew fantastic
Here is the issue:
- After successful manual mode flight, I entered into a stable hover to check my attitude mode. I centered all gimbals before hitting the mode select switch. As I hit the switch and the helicopter entered attitude mode, the helicopter aggressively pitched backwards instantly (perhaps to 45 degrees, it’s hard to remember from the terror!) and eventually ran itself into the ground. (Luckily minor damage: blades and a couple stripped gears). Why did this happen? Is there a setting in the transmitter that was overlooked, or perhaps a setting in the NAZA setup software? I have fully reset the NAZA and transmitter and gone through the entire setup process again, but, as you can imagine, I have my reservations on attempting another test flight until I KNOW why this happened.

Additional information:
- Helicopter is Align T-Rex500 WITH flybar (confirmed and set up properly in the software)
- Radio is Spektrum DX9 with Spektrum AR8000 receiver
- NAZA is mounted on the rear receiver tray (gyro held the tail steady in manual mode, so I do not believe it is getting excessive vibration)
- I am NOT running the GPS module. Does any additional calibration need to happen even when not using the GPS module?

Please advise and thank you in advance.

[nightflyr]

Suggest you bench it, power it up (without blades ) and test it to see if it is repeatable....
If so there is a section for trimming the swash in the software to correct for this..
In the first version, many had issue(s) when the helicopter would lean when put in ATT mode.
DJI release the next version release with a fix.

[pril250]

Not a NAZA expert by any sreach of imagination but any aberration on a control system that is only expressed during flight as opposed to bench testing in my mind would be associated with excess vibrations or poor isolation on 3X gyro.