DJI Drone Help Forum

Phantom 4 Pro propeller spin-off


#1

My drone mysteriously dropped out of the sky immediately upon selecting the RTH function on screen of the DJI Go 4 app (iPad). I contacted DJI support but they said it must have been because I hadn’t fitted the propeller properly. My argument is that it’s sprung loaded therefore how can it come off by my mistake!? I had already been flying for 5 minutes and up to 300ft before it fell. I’ve uploaded the flight log to http://www.phantomhelp.com/LogViewer/6NGV3HOG1Z9K2687NWXZ/

Any feedback and advice would be appreciated, thanks.


#2

Props can fly off mid-flight if they are damaged around the hub area and/or the prop lock on top of the motor is damaged. I’ve also seen a few cases where 3rd party props snapped off where they meet at the hub. If you don’t use 3rd party props and you carefully inspect the props and prop locks prior to each takeoff, you’ll greatly reduce the chance of something like this happening again.


#3

I had one do the same thing, but I knew exactly what happened when it did. It was a newby mistake. I was in a hurry and one of the props just didn’t feel right when I put it on, but I flew anyway. It was half a mile out and a couple hundred feet up when the prop finally came off. I don’t know your situation, but I can tell you it absolutely can happen. BTW, I was using carbon fiber props. Never have used them since.


#4

It can definitely happen. A friend of mine has had it happen to his Mavic Pro twice because he was in a hurry and not paying attention. He didn’t seat the props in the lock all the way and they spun off.
It’s typical user error.


#5

It certainly has all the signs of loosing a prop. If you look at these charts, they pretty much confirm that. This is the last 25 seconds of data. Props can come off, even with the most detailed of installation and inspection. This is about as certain as you can be without having the aircraft log file.


#6

Thanks for your reply. The props are all original supplied and in good condition. I actually performed a few new tests, test 1 was with the prop semi-connected (midway between on and off). the prop snapped into the locked position as soon as the motor spun. Test 2 was with the prop just sitting on the motor. as soon as the motor spun the prop flew off, as expected. Test 3 was with all 4 props in semi-connected position. Again, when the motors spun, all 4 props snapped into the locked position. This confirms the default is for the prop to lock into position if it is not snapped into position correctly. When the prop fell off originally I had already performed about 25 minutes of flight time over 3 flights. This issue only occurred when the batter level dropped to 20%, the RTH alarm sounded and I automatically selected the RTH function on the screen. Everything else was working perfectly up to that point.


#7

Thanks 04red6 but the props were all locked under spring control. I check the prop locks before every flight.


#8

Hi Fly_Dawg, Are the charts from my flight data or from somewhere else?


#9

Yours…


#10

Please can you explain how I look at the same chart data, thanks


#11

You can’t directly. You can import the .csv in to CSV View or in Excel. In this case I used Excel with external graphing software.


#12

Thanks. If you don’t mind it would be great to know the graphing software you used and also which parameter(s) you looked at.


#13

The parameters are listed on the Vertical Axis. The two at the top are customized in Excel from True/False Values. The bottom chart should be self explanatory. I use a program called Dat Plot, for the graphs, but you can also do these in Excel itself. I just prefer the external software.


#14

Did you find the prop that spun off? If so, did you see any damage on that prop and/or on the prop lock it was attached to?


#15

Yes I located the prop in 10ft of water, about 50ft from the drone. Both the prop and the prop lock are perfectly good. Falling into water saved mechanical damage but the drone was completely immersed for a couple of hours until I could get a boat and skipper to help find it. I spent 3 weeks drying the drone and dismantled it to try and clean all the accessible connectors, etc. I have managed to get virtually everything working except the gimbal and the left vision sensor.