Hi,
On first, sorry for any errors, but this is my first post. I wanted to bring to your attention the crash of my drone DJI Phantom 2 with GoPro 4, seemingly unexplainable, which occurred August 29, 2015 on the mountain Gran Sasso of Italy, on the summit at 2,914 meters above sea level.
Perfect weather, no wind and gusts, temperature + 23 / + 25 degrees Celsius, batteries to 65%, compass calibration performed, GPS status OK (can not remember the number of satellites available), excellent video signal. The movie shows only the final part of the video. The first 7 minutes, in fact, no problems or malfunctioning. Suddenly, just 20 meters from the transmitter, the Phantom starts pitching, and does not react to commands. He begins to drop quickly.
Before touching down, it looks resume stability, but returns to pitch and crashes to the ground slipping into a gully where it is impossible to go for his recovery. I would appreciate if you would like to expose your ideas here about a possible cause.
I have already written to the DJI, at least to take a discount on the purchase of another Phantom but, of course, absolute silence from them!!
this really looks like a VRS (vortex ring state) issue to me. Before it started to crash to the ground you were decending near full speed. The props will have lost lift, it's not easy to regain control again, especially if you have not got much hight. The altitude where you were flying the air is a lot thinner and will increase the chance of a prop wash. Just before the ground it almost recovered, but lost in the end.
You said: " it is impossible to go for his recovery". How did you get the footage then?
Nice video though.
Hi Markus,
Thank you for your reply.
Yes, in fact the VRS could be the cause, but I did not explain how it is possible that the Phantom has regained stability for a moment, and then lose it again near the ground.
The camera, the battery and a propeller broke away from the phantom to the first impact with the ground, and it was possible to recover them. The phantom, meanwhile, continued to roll into the ravine, beyond the sight.
Beautiful. You guys have a lot of brass on the top ledge. Fantastic views . To bad about the quad after that I would be out picking up cans to buy another. Good luck!
Thank you for reply and for your deductions . I agree about the altitude, the thin air but not for the descent speed.
The rate of descent for the phantom 2 is maximum 2 m/s . One of the latest firmware upgrade had limited the speed of descent , just to avoid the VRS . I was aware of this and never passing 1.8 m/s , so that I did not fly too high for the risk of running out of batteries . I never went down faster by 1.5 - 1.8 m/s . Anything can be , but I doubt about the excessive descent speed.
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