CRASH on FBWA Takeoff (LOG FILE INCLUDED

Hi Everyone,
This my first post here but we are looking at the reason we had a crash today.

A little background on the plane. It is a Ritewing 70" flying wing. We have the Pixhawk system in with airspeed, GPS, external LED and USB connection. It has well over 100 flights on it without issues. Today we flew 3 flights which all went perfectly fine. The last flight the plane did was a 20 minute mapping mission where we were testing the Do-Cam-Trigg-Dist option (which we didn’t get working).

Because it didn’t work on the first mapping test we charged the battery and went out to test again. Our normal startup procedure is:

-Turn on radio (DragonLink)
-Turn on plane
-Wait for the plane to acquire GPS lock and show a solid green LED light.
-After green light, turn on the camera.
-Arm the plane
-Control and throttle check (run throttle up to 100% while moving control surfaces around for 5 seconds).
-Launch the plane in FBWA mode.

This time when we launched the plane it climbed for about 2 seconds then the motor shut off, and the plane rolled over and did a nose dive to the ground. When we got to the plane the plane was no-longer armed but the servos were still being supplied with power and were at full throws opposite each other (hence why it rolled over).

We are really confused by this and I don’t know exactly what to look for in the logs.

Any help would be greatly appreciated!

Josh

You said a 100 flights without problem ?
Did you change anything lately ?
Firmware update maybe ?

A week ago i crashed my go discover in a similair way. ( check my posts)
I see alot of people with delta’s with problems… Or it’s just coincidence…

Looking at the log you were flying in Manual the entire time. No other flight mode was selected so the APM wasn’t really doing anything

Have a look at the graph I have attached. It shows the RC channels both RAW in and out. The blue/black lines represent RC3 which I assume is your throttle. You throttle up just fine and then go banana’s on the sticks :slight_smile:

Does that seem right or have you attached the wrong log or am I looking at it incorrectly somehow? Because no where else in your log is the throttle running so I assumed that was the flight bit :slight_smile:

Thanks, Grant.

Hi again. Further analysis of the log has us intrigued. We can’t quite figure it out.

We find it hard to believe you were back and forth on the transmitter sticks that much. It could be that your DragonLink had an issue or transmitter had an issue? Probably worth checking before you fly again.

Its also possible there could be log corruption. Were you running a groundstation at the time? If so it would be GREAT if you could upload the tlog.

Actually any other logs would be interesting too - earlier logs where the flight was successful. But the tlog is the most important if you happen to have that again it would be GREAT.

Thanks, Grant