Crash when selecting 'fly to here'

My quad is flying fine in stab, loiter, circle and RTL. So I thought I would try ‘fly to here’ started from the Mission Planner via 3DR telemetry link.As soon as I selected this (default 10m altitude) it pitched hard right and dived into the ground. Attached is a Telemtry log showing all this.The change from loiter to ‘guided’ can be seen about 92% of the way thru the log. Any ideas?



Hi Phil,

I have analyzed your tlog and found what caused the crash and another issue.
On you first bettery it was pretty low when you took off. I have speech on my MP set to warn off low voltage at 14.6 V. It was warning low batt most of the time. You were dangerously low when you landed. You need to use your battery failsafe. Then you landed and put in a fresh battery. I also noted a huge voltage drop when you started flying, and that it dropped off pretty quickly. Conclusion : Your battery is too small for the 16 - 17 amp draw you have.

OK, The part you have been waiting for. Looks like when you whent to Guided mode the copter tried to pitch down and roll left, there by revving up motor # 4. In fat # 4 goes to max and 2 & 3 drop 1 kind of the same.

The action happens at 2:24:40 . Either your # 4 motor stalled (lost sync) or some thing failed with # 4. The reason it happend when you hit Guided is it called for a quick tilt. Do you have low kv motors with large props & Simon K. They have been known to stall. If the motors work after the crash, I would go with a stall being the cause.

Let us know what you find and what your equipment is, batt, motor, props, esc’s, ect.


Thank you very much for your prompt and comprehensive reply. I will post more details.Incidentally, which parameters did you view to get the info re what EACH motor was doing at that instant?

This for Greg Fletcher - have just made new post of this as well - as the original got inadvertently marked as ‘solved’.

Greg - point taken re battery. Some more info for you regarding hardware:

Yes, I am using low kV motors - Sunnysky V2216- 11Kv 900. with 10 X 4.7 props.

ESCs are HobbyKing 20A ‘Blue’ Series.

Two queries : 1) How do you get the log info which shows what each individual motor is doing at any time?
2) Why did it not happen when using circle or RTL? - Is there something different about autoguided mode that calls for more radical changes in pitch/roll?.



Ha - reply to myself ! - realise now I was misinterpreting the CH1,2,3,4 outputs - realise now they refer to the MOTOR numbers(not to be confused with the control channels - all makes more sense now… :wink: