So today I got curious, everyone asks if it's possible to start the engines in free fall after doing a CSC, well I didn't take my bird up and let it drop, however, I took the blades off and started it, then while it thought it was in flight I did the CSC,I then started lowering it while making it tumble then did the CSC to start the motors, and they did! I'm not saying that it's a sure thing, but I'm slightly less scared of destroying my bird if I ever have to use the CSC while in flight.

Maybe someone that has a building with an elevator could try the same thing?

I tried this in the flight simulator a while ago at it worked but only if I went up to 400 feet.

Yes, they will restart after a CSC by doing another CSC.
In the P4 simulator you can test it out and if you go up about 300ft you can do a CSC then restart not crash.
I certainly wouldn't try it in real life.

I tried that too, but hopefully this means we can do it when it really counts.

kenbaileyphotog Posted at 2016-8-12 04:17
I tried that too, but hopefully this means we can do it when it really counts.

In the real world I would think that you would panic for a second or two and then you wouldn't have enough altitude to recover from.

This topic never ends.

Another concern you may want to consider with a "dead bird" after a CSC is that, like most copters, the Phantom is (most likely) top heavy. This would result in the aircraft becoming inverted (to some degree) and a restart of the motors may cause it to speed the process of destruction. I have not seen or read anything stating these aircraft will right themselves when inverted and I am not keen to try it.

You know what came to my mind, drop the phantom in a free fall from an airplane, person on the ground control it and test the CSC mid air couple of times, this is some redbull experience through, hope they try it for the sake of all phantom pilots.

dak162 Posted at 2016-8-12 17:36
Another concern you may want to consider with a "dead bird" after a CSC is that, like most copters,  ...

I saw a video on YouTube where they'll right themselves even when upside down, but they were only doing them from about 10 feet/3 meters,I don't know how much the drop speed affects it though, and their motors were already running.

Michael89 Posted at 2016-8-12 20:07
You know what came to my mind, drop the phantom in a free fall from an airplane, person on the groun ...

Oh yes, and that's totally legal and the FAA will love that.

DJI-Ken Posted at 2016-8-13 03:12
Oh yes, and that's totally legal and the FAA will love that.

As long as it's at 400' over the desert on a Sunday I don't see a problem

knobbydave@hotm Posted at 2016-8-13 03:25
As long as it's at 400' over the desert on a Sunday I don't see a problem

Your still not allowed to throw objects out of an airplane.
And explain the logistics of how you throw an aircraft out of an airplane and the person flying it has control of it whether that are in the plane or on the ground.

DJI-Ken Posted at 2016-8-13 03:46
Your still not allowed to throw objects out of an airplane.
And explain the logistics of how you t ...

Ken - I wasn't being serious

knobbydave@hotm Posted at 2016-8-13 05:10
Ken - I wasn't being serious

No problem. I do know of someone (my flight instructor 20yrs ago) who threw bowling balls out of the window and try to hit targets they set up earlier. Surprised they never got in trouble.

What is a CSC?

DJI-Ken Posted at 2016-8-13 05:46
Your still not allowed to throw objects out of an airplane.
And explain the logistics of how you t ...

Not suggesting you do it but there isn't a blanket ban on dropping objects.
Here's the rule:

Sec. 91.15 — Dropping objects.
No pilot in command of a civil aircraft may allow any object to be dropped from that aircraft in flight that creates a hazard to persons or property. However, this section does not prohibit the dropping of any object if reasonable precautions are taken to avoid injury or damage to persons or property.

labroides@yahoo Posted at 2016-8-13 05:50
Not suggesting you do it but there isn't a blanket ban on dropping objects.
Here's the rule:

Yes, but I'm sure with all the drone stuff going on the FAA wouldn't be pleased if they knew about it.

If it's done professionally it wouldn't hurt a fly.

I dunno, my bird often comes back with flies attached...
Poor guys.

Michael89 Posted at 2016-8-12 07:07
You know what came to my mind, drop the phantom in a free fall from an airplane, person on the groun ...

That's different though.  Dropping from an airplane will introduce considerable forward speed into the situation.  You also have to miss the tail of the plane.  It's not heavy like a sack of flour so may not drop below the tail fast enough.

Please dont do csc on platinum, platinum can not restart reliably, when it goes down in high speed 18mps then the props move invert also(drone not inverted position) , in this case the drone try to power on and spin normal, but when the motor try to power on, the wind from ground very strong and can not restart, because the props moving inverted is stronger than the esc power to spin corect position to recovery, and it will make the esc cut off and make the battery off also, loss power, and lost conection due to battery shut off, no power and crash

There is a reason for the 2 - 3 second delay when you command CSC .... its to avoid it accidentally happening in the air.

I have used CSC in the air - but that was when I hit a tree and considered it better to stop the props as it fell through the branches ... in that short delay - the screech of forcibly stalled props was horrendous.

I have done a mid air CSC, the drone fell in a flat spin the right way up. Looking at the DAT file there is some wobbling but the camera view was stable. There was no problem with the restart other than you must throttle up to halt the fall, the motors start at idle. Note the restart resets the homepoint to where the drone was at the time of the restart.

One interesting point to come out of this thread,
Can some one try blowing air upwards through the props of switched off phantom, e.g. with a fan or another drone or stick it out the window of a moving car etc. to see which way the props do turn?

When I have tried previously I would have sworn the direction of rotation was the normal one associated with powered flight etc. but I have just done it again and think that might have been a mistake.

I will see if I can find my prop balancer and try on that where the speeds of rotation can be slower

You only have to imagine the air flow direction ... lift means airflow is directed downward ..... if the AC is falling and props are then spun by airflow - they will turn opposite direction because airflow is upward.

If you fly fixed wing .... because the glide direction is same as powered flight - freewheeling props turn same direction as if power is applied. Our Phantom's / Mavics do not have same - the props freewheel reversed.

Thanks, having just tried it on a prop balancer I now realise I had confused myself as to the question I had previously asked  myself and what I had seen. I had looked at whether the direction of freewheel rotation tended to tighten or unscrew the props, it tends to tighten. I had not taken note of the fact that the actual direction of rotation reverses, a Homer masterclass moment I fear

I recall seeing a Youtube video where someone flew a Mavic up to 1000' and did a CSC and then a second CSC and was able to successfully restart the drone before it hit the ground.

This sounds like something Jerry Rig Everything's channel  would try. He's not afraid to destroy $1100 smartphones for the sake of science.