Very close call with Mini 2

[MavicFanBoy07]

Hello, so for the long weekend, I went up to the Blue Mountains (about 2 hours drive from Sydney) for about 2 nights. Great opportunity to try out the Mini 2's capabilities. So I get to the planed take-off area and take off as usual. Everything went pretty smooth for about 15 minutes. Now wind was about 15km/h but there were a few strong gusts every so often, probably not the smartest idea to send it off the edge of a cliff face, but I thought I might as well risk it. All of a sudden the drone started to sound like it was really struggling in the wind. At the time the time it was around 100m away from me. For a few moments there I had completely lost control of the drone and honestly I don't know how I managed to get it back. I tried RTH but it just would not work. I ended up bringing it home manually after the big gust of wind past but it still sounded like it was struggling and I kept getting the 'max power' error message. It wasn't until I landed it that to my horror, one of the props for the front left arm had com completely right off and the other had slightly cracked. There was no other damage to the drone at all. I am so thankful it was not a fly away case as the mini 2 is my only aircraft. I am also really surprised I was even able to get it home as I am a relatively new pilot. My only advise is to just stay calm and do your best to get it back.

Any ideas as to why the propeller came off? I had replaced the props only about a month ago after I flew into a brick wall. Do you think it was just me not screwing the prop on tight enough?

Thanks!

After landing ?

 

[Ashjuk]

Do you think it was just me not screwing the prop on tight enough?

That sounds like the most likely reason for a prop detaching itself in flight.

Glad you were able to get it back safely.

 

[DJayI]

I always check those screws before every session. There is very little material for those screws to thread in to and it concerns me. Also, it is not recommended to reuse those screws. May want to pick up some small fastener thread locker.

You may already be aware that cliff faces are associated with turbulent air, often creating significant down force. I have read that even larger, stronger drones can succumb to their down force.

Glad you got it back and did not panic.

 

[Phantomrain.org]

I think the Props hit the drone in the wind and got ripped off and the other cracked.

Phantomrain.org
Gear to fly the Mini 2 in the Rain.

 

[Gagey52]

Can’t believe it flew minus a set of props!
Regards

 

[old man mavic]

@MavicFanBoy07 what happened to you is one of the reasons for the thread lock on the screws,it is important when you change the props that you use new screws with the thread lock already applied ,and as has been mentioned check the tightness of the screws before flight
you were very very lucky that only one of the props came off and its a testament to the minis capabilities that it got back at all the overspeed warnings were because that one motor had to go full tilt with only one prop attached to keep the drone in the air ,make sure you always change both props on individual motors not just the damaged one
then go out and buy a lottery ticket before your good fortune wares off

 

[Paleomanjim]

Thanks for sharing. I do check my props from time to time, but admit I have reused the old screws instead of using the new ones that came with it. I'm gonna change out those old screws right now just to be sure. As others said, I'm shocked it flew with one prop missing!

 

[Mike Mas]

A lot of prop failures is due primarily for the fact DJI elected to use goofy screw rather than a hex.

Mike

 

[Dale D]

Thanks for sharing. I do check my props from time to time, but admit I have reused the old screws instead of using the new ones that came with it. I'm gonna change out those old screws right now just to be sure. As others said, I'm shocked it flew with one prop missing!

forgive my ignorance- can you please explain the screws? I only have a Mavic 2 Pro but when I replace a prop that is all I do, is remove he old prop and screw in the new one. What the screw am I supposed to change?

 

[GFields]

Greetings! What a story. I'm sure you will reconsider flying in high winds. Glad you got it back!!

 

[hiflyer201]

What the screw am I supposed to change?

no screws for your drone. They are a fixed assembly

 

[DJayI]

think the Props hit the drone

I have not had the Mini 2 long, but wouldn't that leave a corresponding mark on the arm or fuselage?

think it was just me not screwing the prop on tight enough?

The screws are a fine thread, very easy to cross thread fine threaded screws. I cannot really tell by looking at your picture, but those threads in the vacant hole look a little boogered up to me. You should check them with a magnifier before attempting to remount the props. If the threads in the hole are messed up, you will not be able to just replace the prop and screw.

PS Even if the hole was not cross threaded and you originally mounted the screws tight enough, vibration, heat/cooling cycles can loosen screws. Thread lockers help prevent that and is most of the reason new screws should be used with every prop change, as mentioned above, new screws have a coating of thread locker.
Check screws prior to every session, only takes a few seconds and could prevent a disaster. I used to be in to helicopters, same rule applies to them, however, there are a lot more screws to check on a heli and it could take a while.?

 

[NG Wildman]

forgive my ignorance- can you please explain the screws? I only have a Mavic 2 Pro but when I replace a prop that is all I do, is remove he old prop and screw in the new one. What the screw am I supposed to change?

Check out his pic on the top of this thread. The screws hold the props on to the top of the motor. Most replacements come with a dab of Loc-tite on the tip to stop the screw from coming out.

 

[hiflyer201]

there are a lot more screws to check on a heli and it could take a while

Isn't there something called a Jesus bolt...it comes out and you get to .......well you can guess the rest...

 

[DJayI]

Isn't there something called a Jesus bolt...it comes out and you get to .......well you can guess the rest...

Well, in the helis I had, that would either be the bolt that held the main gear to the rotor shaft or the bolt that held the rotor head to the rotor shaft. Losing either results in reduced lift by 100%.?
Of course there are very few parts a helicopter can do without and still be airworthy.
I once read that helicopters don't so much fly, as the do beat the air in to submission.?

 

[DJayI]

DJI elected to use goofy screw rather than a hex

Let's hope it was done in the interest of weight and not $$.

I assume from your avatar(Model Airplane News cover?) that you are "The" Mike Mas. You'll forgive me, in my early days I was quite envious of your helicopter skills and exploits.
We were both a bit younger then.

 

[KitDavenport]

Along these same lines, replacing props is important and new screws too. Finding those tiny screws was a struggle for me. Finding a good drone mechanic is impossible. Drone health is vital and you have to do it yourself. Find on Amazon a screw box of tiny screws just for this reason. Have them on hand in your drone shop. AND, make sure you're willing to take the risk. Usually I error on the side of caution and stop flights. Be Safe!

 

[hiflyer201]

I once read that helicopters don't so much fly, as the do beat the air in to submission

I heard that the only reason they fly is that the earth rejects them.. he said ducking...

 

[waltermitty]

A lot of prop failures is due primarily for the fact DJI elected to use goofy screw rather than a hex.

Mike

Can you clarify this - why would the fastener head make a difference?

 

[Galeforce1]

I always check those screws before every session. There is very little material for those screws to thread in to and it concerns me. Also, it is not recommended to reuse those screws. May want to pick up some small fastener thread locker.

You may already be aware that cliff faces are associated with turbulent air, often creating significant down force. I have read that even larger, stronger drones can succumb to their down force.

Glad you got it back and did not panic.

In the Blue Mountains there are very strong updrafts close to the canyon edges. I know because I used to fly light aircraft up into the mountains from Hoxton Park when the airfield there was still open. The updrafts can also draw the aircraft in closer to the canyon wall.

For a tiny aircraft like the Mini, it would be very risky to fly over the edge, and it seems the OP was very lucky indeed.