Is Prop Breakage in Flight an Issue?

sandblaster

Senior Member
Have seen more then one u tube video of prop breakage in flight causing the crash or loss of the copter. How big an issue is it. Did the prop fail without warning as in, it was not previous damaged by another crash? Are the slow fly prop's more pro to breakage because they are so light and flexible. Seems copter puts much more stress on the prop because there is not an air foil to carry the weight of the load, prop's must carry the full load all the time and are making lots of quick speed changes also increasing stress on prop's.

Thanks.
 

Tritium

Amateur Extra Class K5TWM
I had it happen to me twice on my ESky Big Lama Outdoor. Both times was with new blades. Once was from 150 feet in the air. Luckily it only cost me about $30 to fix it from that crash. I also have had bad blade strikes on my Double Horse.

I got rid of both copters because they were a pain to fly with constant blade strikes and repairs. I absolutely LOVE my quad with stock DJI motors and props. I have had no crashes even in 20 mph wind gust and no prop failures.

Thurmond
 

colorex

Rotor Riot!
Mentor
There is always a risk that you will hit a titanium reinforced spy bee-sized drone from the military causing you to nick a propeller - but there is way more possibility for other damage to happen. Losing a grub screw in my case.

A possible issue is weakening of cheap propellers due to UV radiation - so if your props start getting pale or have tiny fissures change them immediately.
 

Tritium

Amateur Extra Class K5TWM
I lost the entire cone nut from the rear prop adapter on my mini tri-copter. Good thing my wife has sharp eyes because I never would have found it.

I have seen talk over at RC Groups of the same DJI props I am using coming apart in flight but I have had no issues at all.

Thurmond
 

bmsweb

Site Moderator
I'm yet to have a prop break on me . . having said that, my friend had his TriCopter Rear Prop fail during flight . . . FPV flight . . . Oh and while flying over a lake lol


Its worth noting that after recovery, he discovered that the other two props had stress fractures developing.
 

Ak Flyer

Fly the wings off
Mentor
I have seen quite a few props leave their planes in flight or on take off, but I've never seen one break without hitting something. I did see my brothers Align 450 shed the blades while spooling up and parts of one shot between my legs. Not sure what happened there but there was a vibration he was chasing, we figure the vibration caused it or the blades were causing the vibration. I've never experienced a blade failure in my heli's yet. My brothers Sig Kadet LT40 lost the prop on take off. He was only going about ten mph when the prop shot off across the yard in front of him. One of the funniest things I've ever seen.
 

colorex

Rotor Riot!
Mentor
I lost my stock Bixler prop when the nut got loose and I lost power. Prop was never found again.
 

sandblaster

Senior Member
I'm yet to have a prop break on me . . having said that, my friend had his TriCopter Rear Prop fail during flight . . . FPV flight . . . Oh and while flying over a lake lol


Its worth noting that after recovery, he discovered that the other two props had stress fractures developing.

This is the one that makes me ask the question. Expensive loss due to a rather inexpensive part breakage. Wonder what brand of props he was running and how much flight time was on them. Sounds like they just gave up in flight for no reason other then stress.
 

bmsweb

Site Moderator
sandblaster:
We originally thought it lost power, but after recovering it 2 days later it turned out the prop broke off in flight. Upon inspection of the other two props they both had stress fractures forming. He has since stopped using them and now checks the condition of his props.

This is the video he did after the fact:
 

sandblaster

Senior Member
Very instructional video. Looks like the props had damage in several areas, around the hub and out on the blades. How much was done by impact with water at speed is hard to say. No question about the broken one and the stress marks on the others. Hard day to loose so much electronics. That is what I want to avoid by making wise prop choices.
 

bmsweb

Site Moderator
I've mainly been flying Aircraft so this hasn't been an issue for me. Its also worth noting that most quad, tricopters etc when taking off from grass their prop is striking some grass some times. This could also be a cause but no way of knowing for sure. These were the only props that John has used that showed stress cracks forming.

I have a strong feeling in this instance it was the props. Also going though all his hold props, none showed this type of stress.
 

michas

Junior Member
Hi there,

breaking props in flight happens 2 times for me this year. I started to analyze the situation. Here is, what I find out. Maybe you can confirm it?

- a third breakage was after a hard landing
- every time I was in "FPV"-mode (this means flight weight a little more then 1Kg)
- I use this props (9x4.7)
- flight was not too fast (no acro or so)
- all props where nearly new (without former cuts or contact to objects)

I think the smaller props are to weak for the weight (especially for my tricopter) so it can happen all the time. From now I will only use the bigger 10x4.7 props. Hope to get better "results"

Greetings from Germany
Micha
 

Ak Flyer

Fly the wings off
Mentor
I run the APC type props for everything I can. They are very hard which means better performance but they can also break. Almost always it's because of a bad landing or a rock in the runway I didn't see. Balancing props helps them live a lot longer as well.