P4P Crashed upside down, motors did not shut down?

[With The Birds]

This would have been good to know (always learning) in this case the standard CSC would have been crucial.

Left stick all the way down. Same as what I tried when it was on the ground.

Coming from a P3P I did not know the Phantom 4 Pro CSC command is left stick down to the center and RTH button. Definitely feel foolish for not knowing this, and some how overlooking it in the settings.

Anyone have thoughts on overloaded motors? I did not receive any error messages, and the motors seem to be physically fine, bearings spin smooth and evenly.

You say you saw sparks in the motors? Spinning freely and smoothly is not a conclusive indicator of the electrical condition. You may have one or more poles with an open circuit in the field coil and/or shorted windings. In a 12 pole multi phase motor it may still run however less efficiently. I would expect to see a CSC error reported if there is an open circuit (increases resistance on one or more phases) shorted turns may go unnoticed however and could lead to a later failure. I would disassemble the motors and check for signs of dmamge to the windings. They will be obviouslybdiscoloured if the temperature rating of the insulation has been exceeded.

 

[DanMan32]

It's the new and improved version of the Kill Switch, but DJI still calls it CSC in Chinglish or Englese.[emoji14] I can confirm that on the P3P, there was no delay on the real CSC. It was instantaneous and intentionally so. Any delay would not have helped, as the trigger of flying backwards from a boat while descending and orbiting while slowing down would last more than 3 seconds anyway!

I guess you didn't realize DJI added a 3 second delay to CSC in recent P3 firmware. Attempting CSC last few times on my P3A appeared to fail, particularly on the last two recent crashes where it then flipped. That's probably because I didn't allow for the 3 second delay.
I haven't used CSC on a normal basis having learned about shutting down by throttling down after landing and the danger of tipping the aircraft on CSC pending CSC actually taking effect.
CSC delay was added to P3 at least since Christmas, possibly Thanksgiving.

 

[DanMan32]

The motors since 2312a are very difficult to get apart as the shaft is tightly fitted to the bearings.
I'm looking to find or make a tool to press the shaft through.

 

[GadgetGuy]

I guess you didn't realize DJI added a 3 second delay to CSC in recent P3 firmware. Attempting CSC last few times on my P3A appeared to fail, particularly on the last two recent crashes where it then flipped. That's probably because I didn't allow for the 3 second delay.
I haven't used CSC on a normal basis having learned about shutting down by throttling down after landing and the danger of tipping the aircraft on CSC pending CSC actually taking effect.
CSC delay was added to P3 at least since Christmas, possibly Thanksgiving.

Thanks for the clarification. Haven't flown my P3P's in ages. The P4 and P4P and Mavic Pro have consumed all my attention. DJI might as well remove CSC completely. I only needed it once, and it worked, but that's so rare, I would rather make it impossible, like the P4P allows!

 

[DanMan32]

If there's a way to shut the motors besides CSC when it hasn't properly landed such as flip I'd like to know.
I guess I could try throttling down but I hope I won't have to test this anytime soon.

 

[GadgetGuy]

If there's a way to shut the motors besides CSC when it hasn't properly landed such as flip I'd like to know.
I guess I could try throttling down but I hope I won't have to test this anytime soon.

Hand catching is the solution. Works every time. No flips!

 

[DanMan32]

Well it didn't flip because I was landing but rather because I accidentally bumped into something. P3's don't seem to right themselves as well as P4's seem to do.
When it crashes, it always seems to end up on its head and I can't quickly shut it down. The last minor crash had the props with the most damage and that was mainly because they kept spinning.

 

[GadgetGuy]

Well it didn't flip because I was landing but rather because I accidentally bumped into something. P3's don't seem to right themselves as well as P4's seem to do.
When it crashes, it always seems to end up on its head and I can't quickly shut it down. The last minor crash had the props with the most damage and that was mainly because they kept spinning.

Oh! Been there. Done that. The original P3P CSC shutdown, after a wild hooking compass error crash, into a roof deck, prevented it from cartwheeling off the roof, and falling 30 feet onto concrete below. Just prop damage luckily! Glad I stopped updating my P3P firmware and apps before the CSC change. If there isn't anything necessary, on older aircraft like the P3P, best to leave well enough alone!

 

[BarryWilson]

I would think that that the "Left Stick down/right" coupled with the RTH button is a universal "Stop Motors" command on the P4 series.

I believe it replaced the previous CSC commands.

AD

I was operating my P4P indoors and lighting wasn't enough for the aircraft to sense obstruction from a table leg and upon striking the leg I lost half the left rear rotor blade. This immediately caused unstable flight. I immediately initiated moving both sticks down toward center of the controller which normally would shut down the motors in Atti mode. This did not stop the motors and the aircraft inverted. I then initiated the left stick down center (lower right corner) while pressing the RTH button. Let me tell you that's a long 3 seconds while your aircraft is under power. (Analogy here was like a fish flopping on the ground out of the water.)

LESSONS LEARNED:
1. Always install the rotor guards. They can protect you, the aircraft and other nearby objects even in those landings when the aircraft tilts to one side.
2. Always make sure there is ample ambient light for the sensors to detect obstructions.
3. Practice the purposeful motor shutdown sequences so they are second nature.

"Practice doesn't make perfect. Perfect practice makes perfect!"

In other words if you don't practice the right way to do something you may just be learning a bad habit.

Thankfully the only loss was a single rotor blade and one scared dog!