Hello everyone.  I posted a CSC theroy once before (see below for link) that if you were to take the AC up high enough, then do a CSC and let it free fall, then do another CSC and regain control before it hits the ground, would it be possible?

I did just this...even though I said in that 1st post that I would never do it.  I was out in Kansas, on my Uncles farm land in the midle of his 200+ acre land, took it up to 400' did the CSC, put the sticks back to center, then did another CSC and IT WORKED.  I had about 200' left before it regained control.

What was unexpected was, as it was free falling, the props began to spin the the opposite direction and make an unusual noise, similar to when it is operiating normaly, but a different sound.

I was able to do this because I was over an empty field with no one around.  I took a huge risk because I wanted to test my theroy with the thought in mind that IF I needed to do this in an emergency situation, that I could potentially recover the AC before it hit the ground, but given that there is a time delay in the process, each situation would be different.

So, your welcome for testing this theroy for you all, freeked me out a bit, but glad I did it to satisfy my curiosity.  Now I just hope DJI doesn't delet this post for some reason.


CSC Theroy
or
http://forum.dji.com/thread-89541-1-1.html

Plenty of youtube videos of this being done - could have saved yourself the risk!

Did you have CSC set to "breakdown" in the menu or not?  Ive not seen anyone test the "breakdown only" mode yet.

gnirtS Posted at 2017-8-23 07:03
Plenty of youtube videos of this being done - could have saved yourself the risk!

Did you have CSC set to "breakdown" in the menu or not?  Ive not seen anyone test the "breakdown only" mode yet.

What does that mode even do? This has always confused me.

Yep, just watched a couple of brosifs do this on youtube last night.  Not the brightest group of guys.

Ex Machina Posted at 2017-8-23 07:13
What does that mode even do? This has always confused me.

DJI are vague.

"Breakdown" apparently should allow CSC to kill the motors only "in the event of a failure" but it doesn't specify the conditions for allowing this.

Ive yet to see someone test that CSC in "breakdown" mode does nothing to a perfectly functioning drone.  Accidental CSC terrifies me more than anything else on the mavic!

So if i set to breakdown ...in theory if I was to accidentally hit the CSC command it would not come crashing down correct? I'm going to test it on the bench anyways

gnirtS Posted at 2017-8-23 07:22
DJI are vague.

"Breakdown" apparently should allow CSC to kill the motors only "in the event of a failure" but it doesn't specify the conditions for allowing this.

Right, w/o knowing how "breakdown" is defined, how do we know when it might be useful?  I find it hard to imagine what kind of failure where the AC would still be responsive to the RC this could address.

Another frustrating documentation fail. Maybe it's really another lost-in-translation thing?

Who is "Theroy"?

Anyway, shutting off the Mavic's motors in mid-air is nothing new anymore, since these fantastic young men have tried it:

$gambino$ Posted at 2017-8-23 07:31
So if i set to breakdown ...in theory if I was to accidentally hit the CSC command it would not come crashing down correct? I'm going to test it on the bench anyways

On a bench it'll shut off.  Because it knows its not flying.

Its the air as far as i can tell it hasnt been tested.  In theory if the translation is correct, if the drone is fully working then CSC should do nothing in that configuration.....but i don.t trust it until i see proof!.

Whats a breakdown?  A proper ESC or overload error?  A simple gimbal overload or brief over discharge warning?  A high wind warning?
I really wish DJI would give specifics.

Ex Machina Posted at 2017-8-23 07:45
Right, w/o knowing how "breakdown" is defined, how do we know when it might be useful?  I find it hard to imagine what kind of failure where the AC would still be responsive to the RC this could address.

Another frustrating documentation fail. Maybe it's really another lost-in-translation thing?

I am with you there!
I would love to know where a CSC of the Mavic in full flight would be useful?
Even if a CSC in mid-air would be executed to get away from birds, this is an illusion, the Mavic cannot possibly escape from angry birds.

MARSAN Posted at 2017-8-23 08:07
I am with you there!
I would love to know where a CSC of the Mavic in full flight would be useful?
Even if a CSC in mid-air would be executed to get away from birds, this is an illusion, the Mavic cannot possibly escape from angry birds.

One scenario where you might want to CSC in flight could be if the AC is being blown toward a group of people by winds too strong to overcome, and you want to ditch the craft before it hits someone.

Another risky move might be where you've flown too high to get down safely with remaining battery charge, and you want to CSC in the hopes it will recover in time to safely land.

Or you're flying in a commercial flight path and need to quickly get below an approaching helicopter or plane.

Ex Machina Posted at 2017-8-23 08:25
One scenario where you might want to CSC in flight could be if the AC is being blown toward a group of people by winds too strong to overcome, and you want to ditch the craft before it hits someone.

Another risky move might be where you've flown too high to get down safely with remaining battery charge, and you want to CSC in the hopes it will recover in time to safely land.

Nice examples, but there are other methods to avoid collision.
For low battery there is the automatic RTH.
Also, if your Mavic is suddenly disabled by executing a CSC in mid-air, it could hit someone on the ground.

MARSAN Posted at 2017-8-23 08:43
Nice examples, but there are other methods to avoid collision.
For low battery there is the automatic RTH.
Also, if your Mavic is suddenly disabled by executing a CSC in mid-air, it could hit someone on the ground.

Welp, the wind can suddenly come from nowhere, hitting one person on the ground is better than a crowd, updrafts can throw off emergency RTH math, etc. Edge-cases, certainly, likely irresponsible piloting, agreed.

I'm glad it's there, not sure how many people would be able to actually successfully use it in the heat of the moment.

Ex Machina Posted at 2017-8-23 08:54
Welp, the wind can suddenly come from nowhere, hitting one person on the ground is better than a crowd, updrafts can throw off emergency RTH math, etc. Edge-cases, certainly, likely irresponsible piloting, agreed.

I'm glad it's there, not sure how many people would be able to actually successfully use it in the heat of the moment.

Your last sentence is the key!

Mavic pilots will find themselves in a panic situation when the going gets extreme.
When riding a bike, they say "Look there, go there", but when flying a drone in extreme situations, it does not always work like this.

gnirtS Posted at 2017-8-23 07:03
Plenty of youtube videos of this being done - could have saved yourself the risk!

Did you have CSC set to "breakdown" in the menu or not?  Ive not seen anyone test the "breakdown only" mode yet.

The only 2 that are in there are emergency and CSC.  I had it on emergency.  
The last time I checked there was no video's on this, but this was quite a wile ago.  Thanks for the update.

Thanks everyone for posting on this post.  Kinda feel stupid now and should have looked on YouTube first, but in my defense, when I tried to look this up quite a while ago, there were none.  I did see one from my original post that was preformed on a P4 but it was really high up.  Anyway, I don't know really what the differences are on the two settings when the AC is in the air.  Didn't want to push my luck.

You could have just watched the youtube video of someone that did that last year.

Bill in Ohio Posted at 2017-8-23 15:18
You could have just watched the youtube video of someone that did that last year.

Yes....Yes I could have...didn't think about it at the time...bla

So was your CSC setting set to "breakdown" or not for this?

I already did this over a school last month while searching for Bald Eagles with my Mavic.  I did it at a much lower altitude so it would be more interesting, of course.  

What are your thoughts on performing a CSC with some forward momentum through a waterfall?

ProQuad Posted at 2017-8-23 14:46
The only 2 that are in there are emergency and CSC.  I had it on emergency.  
The last time I checked there was no video's on this, but this was quite a wile ago.  Thanks for the update.

If you had it set to "Emergency/Breakdown" and the CSC command still stopped the engines then surely it means that option isnt working correctly?

My take on "emergency" is CSC will only stop the motors if its got another system error.

Anyone from DJI support care to elaborate?

gnirtS Posted at 2017-8-25 05:54
If you had it set to "Emergency/Breakdown" and the CSC command still stopped the engines then surely it means that option isnt working correctly?

My take on "emergency" is CSC will only stop the motors if its got another system error.

Yea, I just double checked what I had it on and it was on "For use in emergencies only"...I did not want to try it in the "CSC" mode and see if it will do the same thing.

It is not an easy decision to make.
Or better: it is an expensive decision.
At least the drone is ok.

ProQuad Posted at 2017-9-1 09:55
Yea, I just double checked what I had it on and it was on "For use in emergencies only"...I did not want to try it in the "CSC" mode and see if it will do the same thing.

I think that's just sloppy interface application -- someone decided there needed to be a warning on the function's usage and the developer implemented a menu control where he or she just added the warning as the first menu option label. IOW, there's actually only one option, and that option is to enable the CSC response.

This is a screeengrab of the latest iOS version of the app that shows the menu options, older versions of the app used to have even more confusing labeling:



All this confusion could have been avoided had the developer chosen to use one of the sliding on/off controls instead of a menu.

I continue finding it difficult to think of a scenario where you'd still have control over the AC in an emergency system breakdown as opposed to just an emergency. I mean, if the AC is doing a fly-away, haven't you likely already lost the ability to send it instructions from the RC? I'm feeling pretty certain now this was actually just an interface design fail.

i have been flying RC helicopters for the last 4 years before purchasing the Mavic.
As part of learning to fly these helis (some of which can have a rotor diameter of over 1.5M!) one learns to "Auto" which is the same as CSC.
This is in case there is a malfunction of the nitro engine or a malfunction in the ESC in an electric machine.
These helis use collective pitch to ascend and descend which means the angle of the blades can be adjusted for varying degrees of lift or even reverse lift enabling you to fly inverted.
When an auto is initiated the pitch angle is changed to point downwards.
This causes the blades to spin up by forcing the air through them during decent.
As the heli approaches the ground the pitch is altered to provide enough lift to bring the machine down gently before the energy stored in the blades is diminished.
Here is a video of a tree 700N doing one
https://m.youtube.com/watch?v=-1moclKmruM