VTOL went on a slow suicide

Hi guys,

Someone in my team crash a VTOL today, here are the items I was able to see looking at the log.

  • No electrical failure
  • No terrain data missing
  • Battery was ok
  • Motors were running
  • No Baro failure
  • first descent from 106 to 59, cruise for couple of seconds, then crash, at an average rate of 4.07m/s, so a descent of 12 degrees
  • No bad command from the RC
  • Pitot working and not blocked
  • Constant terrain following at 120m

I am scratching my head, but the only thing that could be the cause, is the wind, constant 35 km/h headwind.

Please, feel free to check those logs, because I can’t find a reason

https://drive.google.com/file/d/1pp8d7a-QpEZY9Y7EA5e2dlupCbXsYx1y/view?usp=sharing

Thanks

By the way, is there any way on mission planner to have the following, once you are in FBWA or B, AUTO, etc… and the ter_curalt is inferior to 30m it will trigger an alarm, like a GPWS

Or even better, this alarm and a vertical profile display on the map, like on a EGPWS

Found a way for the alarm using control - F / Warning manager, but still nothing on the cause of the crash :thinking::roll_eyes:

I’m new to this but with a 35km/h headwind your relative airspeed may have been messed up. Not too sure if the a/s sensor is the primary a/s reading or if it uses the INS If there is a large enough discrepancy between the two. Like I said new to this stuff but just a thought.

Hi Benjamin,

I looked at your log and also got confused as to what happened. I suspect a loss of receiver signal but it could also have been a flight controller reset during the AUTO mission.

The AS Sensor, GPS, and BARO all seemed fine and then just quit. I think the logging after the initial event is nonsensical. One other thing I noticed was the odd number of Mode changes. You can see the summary of mode changes in the Google Maps image.

Fortunately, it seems that you were able to retrieve the VTOL. Cheers!

Hi Kevin, I thought also before that the wind speed was the cause of the crash, but looking at previous ones with same or stronger wind and no issue

Hi Greg

Thanks for your reply, the weird part is I lost the vertical guidance but not the horizontal one.

Also, where could I report it has a possible bug?

Lastly, I setup those mission planner parameters on all our laptop for future flights

Ben,

Report your issue in the Plane v3.9.x release that you are using. The threads that Tridge start.

Good luck!