Lost a Motor or ESC


So…I was out flying, around 430m height, and all of a sudden I lose directional stability. Then I notice the altitude decreasing? Weird. I push up more to maintain, and the craft responds. Direction steady, all good. 10 seconds later… All heck breaks loose and I’m just seeing props, body, Sun… And I know something just hit the fan. Altitude is plummeting. I’m at like 40mph… Going down. Then nothing. I’m in a snow bank.

Thank God I got the 8" of soft fluffy snow otherwise it would be a write off.

Post mortem: one Chip missing from the ESC, solder melted clean off. Wires to front left motor got toasted, all melty. Burnt windings in motor.

Question: what was first… Blown ESC or damaged windings?

Is there any way to see?

Stupidity first and foremost. Your altitude was WAY and FAR above limits…Second, there is nothing in this data that will tell you what you want to know. The question is ridiculous for this data set. Even the aircraft files won’t tell you that. I apologize for being blunt, but flyers who exhibit “wreckless” and " careless" abandon of flight safety simply get under my skin. 400 meters is not the same as 400 ft…

For what its worth, your attitude values at the time of the incident.

Duly noted, and thanks for the graphs.


I’ve never seen a log like this one. You managed to blow from 12.6 v to under 10 volts in less than two minutes. I see you were in sport mode. You must have been deliberately trying to launch straight up like a rocket to achieve that kind of drop in voltage. If I wanted to deliberately wreck my drone, I don’t know of a better way to do it than the way you did it. The drone should have gone to critical autoland when the cells dropped below 3.3 volts, but I’m betting the motors burnt up before it had a chance. I’m surprised the whole thing didn’t catch on fire. I’m thinking after the motors burnt up and locked up, the ESC blew. But by that time you were already in a free fall. Craziest flight I’ve ever seen.

Let’s take a look. @m.mcnaught can you provide the AC .DAT via Dropbox or GoogleDrive? Look here for info on retrieving the .DAT.


BudWalker, I’ve looked for an appropriate FLYxxx.DAT file, but they all appear empty - like zero’s in all of the data fields. It’s wierd, and they are all dated 11-1-2014 9:00am. Any idea why?


Can you be more specific? Did you follow the procedure shown here?


I did the data retrieve, as per the procedure. Here’s an example of one of the DAT files:

They are the earliest DAT files on the craft (001-003 are just really small, like kb), and later DAT files are equally as empty.

I’m not sure I’ll ever know exactly what went on.