I was preparing for another flight with my Phantom 3 Professional early this morning. As always, with my preflight check-up everything was normal but when I started to put on those propellers to my phantom, I noticed one propeller that I can't seem to tighten and just keep on turning. So I removed it and inspected. What I saw somehow scared me and I believe that this might be the reason why some propellers got loose while in the air and as a result a crash. Good thing I brought a spare with me and the flight was a success. Should I change my propellers to those carbon fiber reinforced ones? I know I didn't tightened the prop too much, just enough that it wont get loose and result in a crash.

Lucky you, with that kind of quality control I think I'd try something different.

Prop was over tightened, probably more than once.   
Plastic threads strip easily if torqued too high.

I tighten mine with the lightest of pressure. I deal with self-tightening threads in the automotive world all the time (rear wheel drive vehicles with mechanical cooling fan clutches) and never is there a need to tighten anything to keep it in place (because it is SELF-TIGHTENING). All you really need to do is make sure it is all the way down.

Hello pixelperspectiv, propeller might be over tightened. Please change the propeller and double check it before your flight.

DJI-Jessie, I did. I just gotta be more careful from now on.

"Should I change my propellers to those carbon fiber reinforced ones? "
That wouldn't make any difference.
They have the same hubs and can also be damaged by overtightening.
You should closely examine your other propellers for possible thread damage too.

The props are self tightening.
Don't tighten at all. Just spin them until they stop on their own.

But I do wonder if you remove them after every days flight session ?
I'm leary of doing that. Plastic ain't forever.

This was my primary concern when there's a necessity to remove the props when stored in a bag. That's why I bought a bag that can fit the aircraft with the props installed. Shorter setup time and the props last longer.

If you frequently remove and install props, only finger-tight them. Spin them on until they stop and then apply a little bit more (less than a quarter turn) or until you 'start' to feel it can't turn any further. Don't use the included tool when tightening... use it only to loosen the props if needed.

Just finger-tight is the correct torque required.  Even though they are self tightening, make sure they start off snug so they can't come off if for example the motor goes from spinning to stopped suddenly and the inertia unwinds them.  Just like screwing the cap on a soft drink bottle -- just enough to seat the cap and form a seal.  No need to overtighten.  Like a mechanic friend once told me, some people have gorilla hands and tend to tighten threads with the rule "keep tightening until the threads strip, then back off a quarter turn."   These threads, like any plastic thread, will last a lifetime if they are not damaged or overtightened and stripped.

Thanks all for the replies. I may have overtightened this one a bit, checked the other props and they are all fine, just replaced the one that got stripped and loose.

OrlyP Posted at 2016-8-28 06:04
This was my primary concern when there's a necessity to remove the props when stored in a bag. That' ...

Yeah, I remove them often as my bag does not allow me to keep them on. Might be a longer setup rather than keeping them on most of the time while inside the bag, but I can't find any other bag that can fit 2 cameras, 3 lenses and 2 flashes along with the P3, RC and 3 extra batteries.

Anyway, thanks for the advise. I will have to finger tight them from now on, Used to think that I need the tool whenever I place the props on.