B&H sent me the propeller locks (after being back ordered for several weeks) but UPS delivered them to who knows where. It definitely was not at my front door. I work at home and my mom whom I take care of lives with me all day long so we would have heard the bell ring from UPS. Anyway, B&H is on backorder again and I don't want to wait a few more weeks before testing my I1. Do I absolutely need the propeller locks to fly th I1? Thanks!

Mate
  Read this topic and the sad crash of Howie 121218  "My I1 damage photos from propeller fall off automatically" 24 Feb 2015

I have 20+ successful flights without prop locks (hand-tightened well of course). I now have my prop locks and use them with each flight, but before they arrived I never had an issue. Based on others experiences and videos, I wouldn't push the quadcopter hard or in windy conditions. Ultimately it's your decision. It's less safe than having prop locks, but most likely you won't have an problem.

This is a post from RC Groups forum:
Originally Posted by srandall25  View Post
"Something I thought would never happen to ME, happened today. I launched the inspire and did a hover test about 15' high... It was hovering fine, I was doing gentle movements on the stick just making sure everything was responding fine as I always do... it was responding fine... then, while it was only just hovering after maybe 30 seconds or so, out of nowhere, the right rear prop flew off, inspire flipped upside down, landed in the snow with 3 props still on and spinning. I immediately stopped the motors and was amazed no damage was done except for the scraped props... I was not using prop locks! My dealer hadn't received them yet...

Pre-flight:
Before each flight, I'm always paranoid about cross threading these props... and just like every other flight, i place the prop on the motor shaft and spin it on so that it spins freely until it stops... once it stops, i do one final little manual hand torque to ensure it's tight..

The fact that the inspire was hovering fine tells me the props were properly secured. This was not caused due to a speed brake and the prop backing off because of an opposing force that was greater than the torque could handle. Unfortunately I could not find this prop anywhere... I will go back tomorrow to try to find it again so I might get a clue as to how this happened. I'm not a rookie when it comes to self tightening props. I flew the Vision+ since it was released in April... I have flown my inspire many hours with no issues. I've also flown an S900 for the last 5 months... has nothing to do with this issue, but the point is, i'm not a rookie when it comes to flying the DJI products. Every time I've read about someone's prop flying off I always swore they didn't properly torque it or they cross threaded it... I could never have dreamed that this would happen after a successful hover and happen while it was only still hovering and not speed braking....

This makes me wonder if there is more to this reason for prop locks than just the speed braking issue... DJI never released prop locks for the Vision+... but I do realize the Vision+ doesn't brake as quickly as the Inspire... but this prop flying off in a successful hover after ~30 seconds just has me really wondering! One thing is for sure, I will not be flying this bird without prop locks in the future!"

This post has cured me of flying without prop locks. From now on I WILL ALWAYS FLY WITH PROP LOCKS!

We have a huge pile in stock at http://multicopterwarehouse.com if you need to order some, they are only $2

Embelish Posted at 2015-2-26 02:10
I have 20+ successful flights without prop locks (hand-tightened well of course). I now have my prop ...

I second that. Have a couple of successful flights without the locks as well but I wouldn't push it. There's something not right with the black props. They clog up, preventing them from being tightened properly. This in combination with a couple of conditions will cause the props to come off.  Pherhaps you could order a set at the links provided above. Better safe than sorry!

I tend to agree it appears that the black props have and remain the problem. Mine never have spin down to the base and have to be turned manually three or four spins to make sure they are tight .. the silver props spin on like a charm.. not so with either black prop .. I could not wait and bought prop locks and hope they get here this week ..

Koavog Posted at 2015-2-26 02:37
This is a post from RC Groups forum:
Originally Posted by srandall25  View Post
"Something I thought ...

Spinning the black prop doesn't let it go all the way. This is due to anodizing residue being built up on the threads. That way when you give it a final tightening turn it would not actually be tightened all the way. You can check this by measuring the distance from the prop nut to the motor. Furthermore I find the inspire making small corrections with quite aggresive motor input. For instance when traveling at 3-4 m/s and releasing the sticks would cause the inspire to turn back quite a steep angle. There are a lot of situations where the props can yank loose, even when flying at low speeds or altitude.

Has anyone found that having prop locks installed causing any change in stability or performance?

I put mine on today and noticed a difference in stability, however, it was also windy today and that could be the cause.

I will never fly without prop locks simply because the force and inertia placed on the blades seems very powerful I can see how props would fall off without them. I'm sold on using them. IMO.

I have mine on order and I had few flights without problems. I hand-tightened props well first time when I got the bird and never remove them. I check the drone every time before flight and pray not to come off. I fly in warm condition and I think the cold temperatures could contribute to the prop fell off as also screwing and unscrewing them too many times. So until I get my prop locks I will not take the props off.

Yes, use the prop locks. Having your prop *possibly* fly off is bad.