Anyone had props come off in the air?

srchadwi · Feb 23, 2015

Hi

A few months ago my Phantom died 50 meters in the air and fell to the ground. After it landed I discovered that two of the props had come off in mid air.

I haven't started this thread to discuss why this happened I would just like to know if anyone else on the list has had an incident of props flying off in mid air. You would be doing me a big favour if you could get in touch.

Thanks

rexster314 · Feb 24, 2015

I would imagine that the only way props come off in midair is if the motors stopped and the props backed off. I guess the hub could separate from the prop as well

jonstatt · Feb 24, 2015

rexster314 said:
I would imagine that the only way props come off in midair is if the motors stopped and the props backed off. I guess the hub could separate from the prop as well

That's correct. If the motor stalls the props could unspool and fly off. Typically this happens due to an ESC failure. It can also be a motor failure (less likely), or a wiring failure (catastrophic solder failure, overheated and broken single core wire etc). To lose two at the same time is a bit odd though, unless there was some of cascade issue.

happydays · Feb 24, 2015

The Inspire comes with prop locks...

Mori55 · Feb 24, 2015

I really don't think you need prop locks on the phantom. If you have to motors fail prop locks aren't going to help.
The inspire is a whole different animal.
Everytime I install my props i snug them up with a wrench.

Meta4 · Feb 24, 2015

Mori55 said:
Everytime I install my props i snug them up with a wrench.

The props are self tightening. This is not necessary.
If that was important DJI would have recommended it.
As it is they make no mention of using a wrench to tighten propellers.
They do however say that the wrench is to use in loosening stuck props.

mendezl · Feb 25, 2015

ohhh dang that is how to use that wrench, I thought it went on the actual propeller for the Phantom 1 so I threw it away

albatross911 · Feb 25, 2015

It has happened to me. One prop flew off on the 3rd flight of the day and the quad just flipped and crashed down. Luckily it was just at the beginning and hovering just a few meters up. Brought back to the shop and they said it was due to the ESC and replaced it. I still fear it can happen any time since then.

Mori55 · Feb 25, 2015

Yes I know the props are self tightening. But just for piece of mind I snug them down.

rbhamilton · Feb 25, 2015

Mori55 said:
Yes I know the props are self tightening. But just for piece of mind I snug them down.

If it gives you peace of mind it's worth doing but there's really no need. The way the threads work, while the motor is spinning the prop is held tight. The only way the prop is going to come off in flight is if the motor suddenly stops. Your quad can't fly on 3 motors so if one stops it's coming down - tight prop or not.

syotr · Feb 25, 2015

I had it happen once, not on my Phantom but on my Dex quad. It uses the E300 kit. One prop spun off when a bullet connector came loose. If a motor stops suddenly, the inertia of the spinning prop will unscrew it. If you snug them up with a wrench the prop may not come off in this situation, but you will still crash. In my crash, the only prop that survived was the one that spun off. I found it in the yard. The others cracked when it hit the roof of my house.

srchadwi · Feb 25, 2015

albatross911 said:
It has happened to me. One prop flew off on the 3rd flight of the day and the quad just flipped and crashed down. Luckily it was just at the beginning and hovering just a few meters up. Brought back to the shop and they said it was due to the ESC and replaced it. I still fear it can happen any time since then.

Thanks for getting in touch.

albatross911 · Feb 25, 2015

hi srchadwi, somehow I have no way to reply your PM, maybe I'm still too new on the board?

anyway, I didn't discuss much with the shop about the prop coming off. at the time I thought maybe I didn't put the prop on properly before taking off. the prop went missing after the crash and I couldn't find it after searching the area for an hour. my attention was on the motors as there were sands inside after the crash and once I was home I opened it up to clean and found one of the motors stuttering. I was going to the shop to get a new motor when they told me it's more likely to be the ESC. I was still thinking the crash had caused the problem rather than the other way around. The next day they called me and said they found the problem to be the ESC and they had replaced it for me. When I picked up my quad I did ask if the ESC could had caused the prop to fly off and they just said "maybe...". They were quite busy at the time so I didn't ask much more.

Then I searched on forums (both DJI's and here) and found a few similar cases then I realised it could have been the ESC's failure to cause the motor to stop or reverse and making the prop to fly off. In one of the posts I read the OP also couldn't locate the prop afterwards. Can the prop be broken into pieces in such situation?

Again knowing now that a ESC can fail at any moment without prior warning and lead to a crash I just hesitate to fly comfortably. On the day it happened to me it was on my 3rd battery and I did not have any crash during the day. I did come very close to a waterfall because the wall had probably blocked the GPS signals and it was drifting. I didn't notice until it came very close to the waterfall but was able to correct before hitting the wall. Not sure if water could have creeped into the hull and damaged the ESC in the process.

Here's the video I made about that day's flight and at the end I included both the close call to the waterfall and the final crash: https://www.youtube.com/watch?v=IO4XZOx2IEE

fastsmiles · Feb 25, 2015

Nice video, but that's a hard ending

srchadwi · Feb 25, 2015

albatross911 said:
hi srchadwi, somehow I have no way to reply your PM, maybe I'm still too new on the board?

anyway, I didn't discuss much with the shop about the prop coming off. at the time I thought maybe I didn't put the prop on properly before taking off. the prop went missing after the crash and I couldn't find it after searching the area for an hour. my attention was on the motors as there were sands inside after the crash and once I was home I opened it up to clean and found one of the motors stuttering. I was going to the shop to get a new motor when they told me it's more likely to be the ESC. I was still thinking the crash had caused the problem rather than the other way around. The next day they called me and said they found the problem to be the ESC and they had replaced it for me. When I picked up my quad I did ask if the ESC could had caused the prop to fly off and they just said "maybe...". They were quite busy at the time so I didn't ask much more.

Then I searched on forums (both DJI's and here) and found a few similar cases then I realised it could have been the ESC's failure to cause the motor to stop or reverse and making the prop to fly off. In one of the posts I read the OP also couldn't locate the prop afterwards. Can the prop be broken into pieces in such situation?

Again knowing now that a ESC can fail at any moment without prior warning and lead to a crash I just hesitate to fly comfortably. On the day it happened to me it was on my 3rd battery and I did not have any crash during the day. I did come very close to a waterfall because the wall had probably blocked the GPS signals and it was drifting. I didn't notice until it came very close to the waterfall but was able to correct before hitting the wall. Not sure if water could have creeped into the hull and damaged the ESC in the process.

Here's the video I made about that day's flight and at the end I included both the close call to the waterfall and the final crash: https://www.youtube.com/watch?v=IO4XZOx2IEE

Thanks for all the information. Don't suppose you can remember in which thread you read about the other cases?

Great video as well.

syotr · Feb 26, 2015

albatross911 said:
Can the prop be broken into pieces in such situation?

I did come very close to a waterfall because the wall had probably blocked the GPS signals and it was drifting. I didn't notice until it came very close to the waterfall but was able to correct before hitting the wall. Not sure if water could have creeped into the hull and damaged the ESC in the process.

It seems unlikely that the prop would be be broken by the motor stopping. I have read several accounts of cheap carbon fiber props failing in flight.

As far a water getting on the ESC when you were close to the waterfall, that is possible. The vents in the Phantom are designed to direct airflow around the ESC's and it looked like you were right in the mist at one point. You may have indeed discovered the cause.

rbhamilton · Feb 26, 2015

Where your ESC's the new ones with the yellow dot on the capacitor? If you have one of the older ESC's hooked up to one of the new motors (skinny wires) then it's a factory defect that DJI is well aware of. If you have one of the new yellow dot ESC's or one of the very first batch hooked up to the fat wire motors then it could be the mist I guess.