will CSC cause propellers to stop in mid flight?

[jeffrg270]

Hi all,

I have read the manual, and I know that the manual says not to perform CSC (bringing both sticks down and towards the middle) mid flight because this will shut the rotors off in mid flight.

Is that really true?

This seems a little dangerous because with the phantom flying around I guess there's a chance that I may want to fly it back and to the left, as well as yaw to the right and descend at the same time...

Would that turn off the motors and lead to the aircraft falling out of the sky?

Honestly, I never use CSC except to start the propellers spinning. Every time I try to do it to turn them off when the phantom is on the ground, it just wants to tip over.

So to power down I just hold the down stick until the propellers stop. But the phantom is smart enough to know that doing that inflight will not stop the motors - In other words, as long as the phantom is still descending, just holding the down stick will not shut it off.

Does the same apply for CSC? Obviously I'm not expecting anyone to try it, but I'm just curious what peoples thoughts are on this.

Thanks!
-Jeff

 

[xgeek]

Doing a CSC while in flight will stop the motors. Don't do it :lol:

 

[Jebus]

Yes. It happened to me last weekend.

While on the topic, does anyone know if any of the CSC positions will shutdown the motors (not just down & in)? I assume so, but thought I should check.

 

[jeffrg270]

Jebus,

Hopefully your phantom survived the crash!

That's too bad that this is a risk...you would think it would be an easy thing to build in the firmware that the motors cannot be shut off if the altitude of the phantom is still changing, meaning that it wasn't on the ground.

I can't think of any reason to allow CSC to still be functional while the phantom is in the air.

What are the other CSC positions that you speak of? The only one I know of is down and in.

-Jeff.

 

[Pull_Up]

Well I can think of one reason - a light aircraft heading towards your aircraft at the same height and you only notice late. I'd kill the motors straight away, personally...

The CSC move was chosen because whilst you may want to be coming back and rolling to the left whilst yawing right and descending (that's a hell of a manoeuvre, by the way!) it's highly unlikely you'll be wanting to do that at full throw in every direction - especially chopping the throttle to zero. Recipe for a falling brick anyway...

 

[Jebus]

I agree Pull_Up. I wasn't planning on coming back that quick, but because the quadcopter was far away, I was thinking that I could bring it down and back and the same time and never realized that I was pulling both sticks all the way back.

When it hit the ground the gimble popped off and I lost one of the rubber dampners. I just had to bend part of the gimble back and other than that everything else was perfect. Luckily it landed in some slushy snow.

In the manual, it describes all of the other CSCs. There's down and in, down and out, and then down and both sticks to the left, and down and both sticks to the right.

Lesson learnt. I'll now be paying more attention to hopefully prevent this from happening again.

 

[jeffrg270]

Hmm...maybe I'll try executing those CSC's with the props off and the phantom sitting on the coffee table...because in the phantom vision manual that I read it only shows one (the down and in), on page 31.

Are you sure those others aren't just for the previous generation of phantom? If not it would be good to know because I want to know which positions to definitely avoid while flying.

-Jeff.

 

[Jebus]

Sorry... I didn't realize this was the Vision forum - so it could be specific to older Phantoms. I've got a v1.1.1 and have only ever tried the 'down & in' CSC, but according to the manual I've got saved, there appears to be four different CSC.

 

[jeffrg270]

Hi Jebus,

Just to confirm with the Phantom 2 Vision, all of those other CSC combinations also cause the motors to start up and power down.

I tried it on my coffee table with the propellers off and they all seem to have the same effect.

So just wanted to post that because its not mentioned in the manual...

Pull_up, I agree, in an emergency you want to bring it down quickly, but I'd still rather be able to do that WITH control, rather than without. When you pull the throttle all the way down it actually descends quite rapidly, and the motors do not turn off until it's on the ground, and I have not had a situation where it's lost control because of too rapid a descent.

It bothers me that there's so many CSC's, and that they all are possibilities in flight, AND that you really only have to hold that position for very little time, only about a half second.

I think the saving grace is that for the left stick (throttle/yaw) rarely do I ever hold it in a "maxed out" position except when I'm raising altitude, but I personally would still prefer it if the CSC would turn the motors on, but not off. I think it's risky to use it to turn the motors off even when the bird is on the ground, because in the half second before the motors stop, it just wants to tip over.

I think that as pilots we just need to be careful, or if we're handing the remote to someone to fly around a bit.

-Jeff.

 

[Pull_Up]

Pull_up, I agree, in an emergency you want to bring it down quickly, but I'd still rather be able to do that WITH control, rather than without. When you pull the throttle all the way down it actually descends quite rapidly, and the motors do not turn off until it's on the ground, and I have not had a situation where it's lost control because of too rapid a descent.

Oh yes, it's for emergencies only - risk to life and limb sort of thing. Just watch out when descending briskly straight down you don't get into a vortex ring state, aka "settling with power", or the ground might just keep on coming! I had it happen to me a couple of times back in the early days (you know, November ) where luckily I got away with it so I now always include a lateral element to any descent rate faster than autoland speeds. Spiralling works nicely if you can perform co-ordinated turns with a small forward element.

(I did a video about it for those, like me then, who weren't aware of the risks of a rapid descent with rotors powered up: http://www.youtube.com/watch?v=rUCc88vG9Us )

Sorry, drifiting a little off topic there but it might be relevant to anyone looking for the safest quick method to get down.

 

[gunslinger]

Sorry... I didn't realize this was the Vision forum - so it could be specific to older Phantoms. I've got a v1.1.1 and have only ever tried the 'down & in' CSC, but according to the manual I've got saved, there appears to be four different CSC.

Ummm.... I can see a few things in this document that I would never do. I'll bet this cost more than one newbie a blade or two... :shock:

-slinger

 

[AHill]

Hi all,


So to power down I just hold the down stick until the propellers stop. But the phantom is smart enough to know that doing that inflight will not stop the motors - In other words, as long as the phantom is still descending, just holding the down stick will not shut it off.

-Jeff

Doesn't holding the left stick down for more than 3 seconds while in flight also shut down the motors? When I hand catch the Phantom it is still flying and you hear the motors trying to correct as you move the Phantom by hand but holding down the left stick for 3 seconds shuts down the motors. At what descent speed and length of time does it determine it is ok to shut down motors?

 

[gunslinger]

Hi all,


So to power down I just hold the down stick until the propellers stop. But the phantom is smart enough to know that doing that inflight will not stop the motors - In other words, as long as the phantom is still descending, just holding the down stick will not shut it off.

-Jeff

Doesn't holding the left stick down for more than 3 seconds while in flight also shut down the motors? When I hand catch the Phantom it is still flying and you hear the motors trying to correct as you move the Phantom by hand but holding down the left stick for 3 seconds shuts down the motors. At what descent speed and length of time does it determine it is ok to shut down motors?

There was a post on this a week or so ago. It's a combination of the left stick being held fully down and the lack of descent over a three second period of time. I guess the reasoning is that if you're dialing in "descend" and it's no longer doing so, it must have landed...

-slinger

 

[ladykate]

Hi all,

Honestly, I never use CSC except to start the propellers spinning. Every time I try to do it to turn them off when the phantom is on the ground, it just wants to tip over.

When I first started flying a lot, I had a couple of tip-overs on landing when executing the CSC - and several near tip-overs. The trick (or... procedure) is to decrease the throttle to 0 for a second before you bring the right stick down and left/right. For that matter, just holding the throttle at 0 for 3 seconds will shut them off. With the motor speed to low idle, moving the yaw and pitch won't cause a quick wind up and subsequent flop over.

Huge stick movements that would cause a CSC in-flight seem very unlikely - although I could see it if you were in manual and trying to save it from an extreme maneuver - although in a situation like that, you should get mega-points for even knowing you had to have zero throttle, full left yaw, full pitch up and full roll right... wow... OK, I take it back - there shouldn't a reason.

Finally, you should be sure your Phantom (or other NAZA platform) is in 'Intelligent' mode. You get plenty of protection there.

Finally 2 - read the NAZA help documentation for the firm word on the other questions. Here is a short segment that answers some:

Intelligent Mode: By using this mode, different control mode has different way of stopping motors. In
Manual Mode, only executing CSC can stop motors. In ATTI. Mode or GPS ATTI. Mode, any one of
following four cases will stop motors:
a) You don’t push throttle stick after motors start within three seconds;
b) Executing CSC;
c) Throttle stick under 10%, and after landing for more than 3 seconds.
d) If the angle of multi-rotor is over 70°, and throttle stick under 10%.

 

[BrianRHoff]

This absolutely happened to me once. Left stick all the way down. Engines shut off about 100 ft up.

 

[N017RW]

This absolutely happened to me once. Left stick all the way down. Engines shut off about 100 ft up.

There's a setting in the Phantom Assistant that can affect this.

Look for intelligent engine cut-off or similar.