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M600 pro propeller breaks in mid air

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Hello guys, today i had a m600 Pro propeller breaking at more than 100m altitude , the drone started spinning non stop but i could still managed to control it and landed safely.
1- there is no sign of being a bird because there are no blood splatter or feathers residue on the drone,
2- the propeller broke at exactly the same place on both sides
3- there are no signs of any wire that came lose and could had caused it
the drone has 2 years of flying around 2 times a week, i can confirm the total flying time later if needed. Do you think "material tiredness" can me applied here? i find it hard to believe as they are made of carbon but I will try to contact DJI to see if they have a recommended flying time limit to replace propellers. Anyway i just wanted to know if anyone had a similar experience. By the way just for information purposes when the drone started spinning the commands changed automatically to a "Home Lock flight mode" so pulling backwards on the direction stick brought it to me and not the backwards of the drone as with the constant spinning would have been very difficult to manage.
 

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Hello guys, today i had a m600 Pro propeller breaking at more than 100m altitude , the drone started spinning non stop but i could still managed to control it and landed safely.
1- there is no sign of being a bird because there are no blood splatter or feathers residue on the drone,
2- the propeller broke at exactly the same place on both sides
3- there are no signs of any wire that came lose and could had caused it
the drone has 2 years of flying around 2 times a week, i can confirm the total flying time later if needed. Do you think "material tiredness" can me applied here? i find it hard to believe as they are made of carbon but I will try to contact DJI to see if they have a recommended flying time limit to replace propellers. Anyway i just wanted to know if anyone had a similar experience. By the way just for information purposes when the drone started spinning the commands changed automatically to a "Home Lock flight mode" so pulling backwards on the direction stick brought it to me and not the backwards of the drone as with the constant spinning would have been very difficult to manage.
Glad you got it safely back to ground ok.
Yes - the flight controller has algorithms built in that enable you to still control the aircraft in the event of a prop loss.

Do you undertake a full aircraft inspection/pre flight check that includes props?

The problem with CF props is that they are very easily broken and can be brittle if even a prop tip is caught putting the aircraft away or taking it out of its flight case.

This is why, once on the ground and set up, I always then examine and flex each prop both on the leading and trailing edge.
 
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Glad you got it safely back to ground ok.
Yes - the flight controller has algorithms built in that enable you to still control the aircraft in the event of a prop loss.

Do you undertake a full aircraft inspection/pre flight check that includes props?

The problem with CF props is that they are very easily broken and can be brittle if even a prop tip is caught putting the aircraft away or taking it out of its flight case.

This is why, once on the ground and set up, I always then examine and flex each prop both on the leading and trailing edge.
I do this prop check from time to time, not before every flight, but will start to in the future...
 
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Hello guys, today i had a m600 Pro propeller breaking at more than 100m altitude , the drone started spinning non stop but i could still managed to control it and landed safely.
1- there is no sign of being a bird because there are no blood splatter or feathers residue on the drone,
2- the propeller broke at exactly the same place on both sides
3- there are no signs of any wire that came lose and could had caused it
the drone has 2 years of flying around 2 times a week, i can confirm the total flying time later if needed. Do you think "material tiredness" can me applied here? i find it hard to believe as they are made of carbon but I will try to contact DJI to see if they have a recommended flying time limit to replace propellers. Anyway i just wanted to know if anyone had a similar experience. By the way just for information purposes when the drone started spinning the commands changed automatically to a "Home Lock flight mode" so pulling backwards on the direction stick brought it to me and not the backwards of the drone as with the constant spinning would have been very difficult to manage.
Glad to know the 600 performed as advertised; a single prop/motor failure will not result in a crash. Thank you for sharing. Now off to check my props with a high intensity lite....😁
 
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.... By the way just for information purposes when the drone started spinning the commands changed automatically to a "Home Lock flight mode" so pulling backwards on the direction stick brought it to me and not the backwards of the drone as with the constant spinning would have been very difficult to manage.
Failsafe mode:
Great to hear the M600Pro performed as expected on the 5 motor mode.
We don't often get a discussion on the failsafe mode or prop failure of the M600Pro, so in-directly your contribution & 1st hand experience is insightful to most that have not experienced their M600Pro fail... personally, I find the M600Pro a rock solid platform and intrigued to learn more when it's not-so-rock-solid. o_O

That's good to know about the flight programming on prop/motor failure.
That brings up a good question to all, what are the failure modes of the M600Pro? Is that documented where we can read and is there only "one" failure mode program? Can the M600Pro loose 1 motor or 2 motors? I like the M600Pro for its redundent A3 Pro IMU/GPS, and the Hex... was wondering if there were additional safeguards on the craft. The M210 has redundancy not of motor, but electronics to the motors. Was wondering if the M600Pro had any other electronics (A3Pro, LB, Mainboard, etc) that worked with safeguards.

Also, as sour as this next one sounds (little ex-military attitude)... is there a method we can induce failsafe to verify the platform is fully functional? I'd rather "test" it without expensive cameras, ronin Mx gimbal attached and at a lower altitude if fails. Being able to verify fail safe would be nice to share with various parties that may desire to know if craft... of such large size, will correctly operate in fail safe mode.

Last curious point on failsafe mode, how fast was the rotational "spin"? The M600Pro with long strut landing gear under normal conditions can be a little tipsy prone in winds. With it spinning, and likely a faster rate of decent, how was the landing? Was the spin controllable, is the failsafe mode suppose to provide any significant RC input to perform a controlled landing?

Regarding the props:
On the M600Pro, with 21" props and the power of the motors... that is good to read it performed fail-safe correctly. That would be an alarming craft coming down uncontrolled.

By design, the folding props are 2 halves each bolted to center hub that mounts directly to the motor.
Other than carbon chip or split that normally initiates at the thinest section... being the tip section; carbon is very resilient to wear or stress damage. Carbon prop damage is normally a loss of a lengthwise sectional piece, followed by a possible loss of the remaining lengthwise section... but normally at a different break point. Resulting in an uneven, stair stepped break. If not damaged by strike or handling stress cracks (pack & unpack), the fatigue point failure of folding props is the pivot bolt and the associated prop mount "hole" that breaks. For the 2 halves to break nearly identical does indicated more handling stress than strike.

I'm not sure where the break occurred, but from your description I'm assuming more near the hub, not the tip and it sounds like it was a break across the width, not a lengthwise crack/break? Having a carbon prop break back in the thickest section of prop is very strange and even an abusive chip (ding while packing) wouldn't cause it to become a crack in the dynamics within the carbon material. Carbon's strength and weakness is directional... on a prop it's width is strength and weakness is normally lengthwise... thus the long cracks initiating from tip strike or packing stress.

I'm curious where was the failure break was on the props? May be too late, but any photos of the break or were you able to recover any of the separated prop sections? Prior to take-off, where the pivot bolts snug or did blades have any "looseness" movement in the mounts?

A method I apply preflight: I normally take note of blades when I unfold and straighten the props. That alignment mark on blade mounts is suppose to be correct if blade hasn't compressed. If you need to move beyond the alignment hash mark very much, it's a indicator of possible blade mount wear. Once the M600Pro is started, I walk around and examine the spinning prop dish, looking for 1 prop or 1 blade out of track... that could indicate an overlooked mount or hub tension... or damaged blade. One advantage of the M600Pro taller stance, it's easy for get eye level and examine the prop dish track. I again take a 2nd quick inspection of dish track when I first hover it up to my eye level. As a RC Heli flyer, it's pretty quick to spot a blade out of track. For the Heli it was swash plate adjustment, for the M600Pro it would be mount tensions or damaged blade.
 

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