Parachute to rescue a drone, mounting questions.

[Hionimi]

Hi, it seems the law in my country (Netherlands) is about to enforce parachute systems on drones, I'm cool with that and would love to get something like that as not only does that qualify me to fly legally, but also prevents damage to anything and anyone which is great!

Now, there are a few things that trouble me about this system, first of all, it seems absolutely necessary to move sideways when deploying the chute to prevent hitting the chute on the way down when it is still below the multirotor.

Second, the system seems to only work when the multirotor is still hovering and not already falling. I imagine this could be a problem in case of an engine failure and the multirotor is already falling, especially if noticed too late.

Now, there's another issue but that mostly regards the model I fly. I have a DJI F450, which has rather short arms and large propellers. This manual shows that it needs to be put between two arms to make it work at its best. From there it can freely fall and perhaps even still be deployed successfully if the multirotor is already in free-fall. Now I guess you can see the issue coming, the plate to which the system is mounted is right underneath the propeller's blast of air, so it seems a good place to put it to make it work well, but a horrible place otherwise in the means of proper lift production...

I guess I could use the Flame Wheel's bottom plate as the mounting surface with a servo on top for the release mechanism and put the straps of the chute on the other side through the upper holes of the optional landing gear I have. But I wonder of the chance of ending up tangled in the chute wouldn't become a bit too high...

Thoughts?

 

[kah00na]

I don't know how this could be implemented, but I could have used it a few days ago when my tricopter fell over 300 feet and smashed into my neighbor's roof and then bounced down on to his driveway. I'm in for one when you figure it out.

 

[Hionimi]

Ouch, sorry to hear that, Kah00na... And of course will share my findings once I know more.

 

[Cyberdactyl]

From watching hundreds of videos and from personal experience, ~90% of mishaps and failures happen near the ground or at obstructions. Almost never do you have the multirotor simply fail in mid flight at a height where a parachute could offer assistance from hard ground impact. . . in time.

Most pilots are going to try and save it before deployment, and then it would probably be too late, since the pilot knows in the back of his mind successful deployment will still incur damage. Especially if it is an expensive MR and has hundreds to thousands of dollars of video equipment onboard. And isn't that the type of MR you would spend a couple hundred on a deployment system in the first place, unless required?

Now, what could raise the above percentage of deployment is from loss of visual orientation or fly-away with no RTH and the pilot decides to throw in the towel and say, "oh-crap, I have no control" when the MR is still flying condition, but that decision to deploy could be further reduced since the pilot knows the chances of the MR making it to the ground through trees, (or closer to the ground through trees) is reduced to almost zero with a parachute.

Where I could see it useful is flying over crowds when video recording and ANY odd behavior of the MR requires deployment. But even in the above situation, you can see the pilot would have to have Chuck Yeager type reaction times to have deployed the chute successfully.

I suspect having a parachute onboard is going to be 'successful' in an extremely very narrow band of failure scenarios, AND once deployed, the chances of the parachute being even partially successful is also average.