Left stick down descent

[Landforms]

Can someone please confirm whether pulling the throttle fully down during craft descent on my P4 will or will not stop the motors in flight? The latest firmware added this CSC and I'm leery of pulling too far back on the throttle during descent at the end of the flight. I see older forum discussions on previous models but nothing on the current P4 firmware CSC. I don't want to learn the hard way

 

[Mark The Droner]

Pulling all the way down on the throttle will NOT kill the motors. Confirmed.

Disclaimer: I don't own a P4

 

[Roadking]

I think it will and have the same concern when descending. I don't hold it all the way down and try to only hold down for a couple of seconds at a time. Doesn't seem like a good idea to have left stick down fully for 3 seconds stops the engines, but it does.

 

[thunderbird]

I hold it down all the way when decending

Did it many times and no issue

 

[Roadking]

I hold it down all the way when decending

Did it many times and no issue

Good to know. I've been a chicken $hit to try it.

 

[thunderbird]

Most of the time on the way returning I push throttle down and hold and forward up hold

Sometimes when it's just right above me throttle down hold until it land

The motor will stop after 3 second when holding throttle down and no altitude drop

 

[Dirty Bird]

Pulling left stick all the way down does NOT kill the motors WHILE IN FLIGHT. If your bird is on the ground or otherwise stationary (like you grabbed it by the landing gear) then holding the left stick down DOES stop the motors.

Can someone please confirm whether pulling the throttle fully down during craft descent on my P4 will or will not stop the motors in flight? The latest firmware added this CSC and I'm leery of pulling too far back on the throttle during descent at the end of the flight. I see older forum discussions on previous models but nothing on the current P4 firmware CSC. I don't want to learn the hard way

 

[Landforms]

Pulling left stick all the way down does NOT kill the motors WHILE IN FLIGHT. If your bird is on the ground or otherwise stationary (like you grabbed it by the landing gear) then holding the left stick down DOES stop the motors.

Excellent. Thank you.

 

[Erised]

I hold all the way down, the phantom4 controls the rate of descent not to cause vortex ring state, it's all ways a good idea to have some horizontal travel, you can hear the difference in the sound the props make, this makes for a smoother descent. If you get in this vortex do not increase power you will only make it worse, full horizontal to get out of the vortex then increase power. I have a syma x5 and lived this vortex ring often and it came down like a rock. I also practiced how to get out of it and recognise the signs of a vortex developing. Often starts with a wobble.

 

[Romonaga]

I have found that in air holding it down does not cut the power. However, once on the land it does cut power, however I don't know how high in the air that would work as such I always make sure I have landed.

 

[msinger]

however I don't know how high in the air that would work as such I always make sure I have landed.

It has nothing to do with the altitude. The motors will shut down after your Phantom detects it has stopped descending. At that point, it assumes it has landed.

 

[cdusher]

CSC=combined stick command
From another post.
When I entered my "GO" program yesterday to fly my P4 I received a notice from DJI that in order to stop the motors in an emergency. Pull down on the throttle while pushing the "RTH". I would imagine that this change was made across the board. This should eleviate the accidental CSC shutdown. Now it has to be intentional. This does not affect a normal shut down once landed.

 

[MedinaTaylor]

I have found that in air holding it down does not cut the power.

That's because you have to hold it perfectly still for 3 seconds while holding the stick down.

If you let it move at all, it will think it's still in the air and it will not shut down the motors.

 

[WetDog]

That's because you have to hold it perfectly still for 3 seconds while holding the stick down.

If you let it move at all, it will think it's still in the air and it will not shut down the motors.

No. It will shut down if you hand catch on a boat which is moving up and down.

There seem to be two control loops involved. If it detects a pressure on the switch at the bottom on the leg, it will shut down. Presumably that happens only after the craft has landed. It will also shut down if 1) you hold the the left stick completely down for three seconds ** AND ** 2) the craft decides that it isn't flying. It can be moving - I shut down this way on a rocking boat all of the time. It somehow integrates it's knowledge of what the rotors are doing and how the P3 is moving and decides it isn't 'flying'. But absolute stillness of the RC or the craft is not needed.

I pull down all the way on the left stick all of the time. I typically give it some horizontal motion because it's a bit safer (although I have not heard credible evidence of a P3 or P4 entering a vortex ring state) and more fun.

 

[N017RW]

No. It will shut down if you hand catch on a boat which is moving up and down.

There seem to be two control loops involved. If it detects a pressure on the switch at the bottom on the leg, it will shut down. Presumably that happens only after the craft has landed. It will also shut down if 1) you hold the the left stick completely down for three seconds ** AND ** 2) the craft decides that it isn't flying. It can be moving - I shut down this way on a rocking boat all of the time. It somehow integrates it's knowledge of what the rotors are doing and how the P3 is moving and decides it isn't 'flying'. But absolute stillness of the RC or the craft is not needed.

I pull down all the way on the left stick all of the time. I typically give it some horizontal motion because it's a bit safer (although I have not heard credible evidence of a P3 or P4 entering a vortex ring state) and more fun.

There's no switch on the bottom of the leg(s).

It is believed the barometer is the sole sensor or detector for this. This may be corroborated by your observations that a rocking motion doesn't seem to be a factor which rules out other sensors in the IMU having a role in the 'decision' on whether it has landed or not and allowing shutdown with just the left stick down.

 

[Ibmftw]

There's no switch on the bottom of the leg(s).

It is believed the barometer is the sole sensor or detector for this. This may be corroborated by your observations that a rocking motion doesn't seem to be a factor which rules out other sensors in the IMU having a role in the 'decision' on whether it has landed or not and allowing shutdown with just the left stick down.

It would make sense that it uses the barometers reading, why do you think the left stick has to be completely down? If it worked at 25% throttle, your aircraft could be in some kind of up draft wind etc and your 25% would be just enough to keep the bird hovering at exact altitude and your rotors would power down so DJI uses full down throttle and 3 seconds of no altitude change to know for sure the phantom SHOULD be descending (in any weather conditions) but isnt. This is what makes catching and powering off the phantom, even at a different height from take off, possible. I don't think it has anything to do with the vps system because you can catch the drone keeping your hands away from all/any sensors and the power down will still work even if your hand was over a balcony and the phantom couldn't even sense the ground because it's at 35 meters altitude.

 

[techmyjustin]

Thanks for the discussion, I was just going to ask this question. I hand catch my P4 every time, and I hold the throttle down for 3 seconds to turn the motors off. I was afraid to descend too fast for fear the motors would shut off, but it makes sense now that they only turn off after 3 seconds of no altitude change while holding the throttle down.

Which begs the question, what if the altitude isn't measuring correctly and you decide to hold down the throttle to land it, and it shuts off 100 feet high in the air?

What is the margin for error on detecting the altitude change?

 

[Mark The Droner]

Ain't gonna happen.

 

[ray rokni]

Can someone please confirm whether pulling the throttle fully down during craft descent on my P4 will or will not stop the motors in flight? The latest firmware added this CSC and I'm leery of pulling too far back on the throttle during descent at the end of the flight. I see older forum discussions on previous models but nothing on the current P4 firmware CSC. I don't want to learn the hard way

Csc is combined stick command, which means more than one command, so pulling down %100 on the throttle stick will not kill motors. The only time it will kill motors is when it does not sense any change in height, e.g.: If landed, if hand caught, if caught on a tree branch, etc.. In normal flight descending at full throttle for any length of time will not kill motors


Sent from my iPad using PhantomPilots mobile app

 

[snowghost]

I hold all the way down, the phantom4 controls the rate of descent not to cause vortex ring state, it's all ways a good idea to have some horizontal travel, you can hear the difference in the sound the props make, this makes for a smoother descent. If you get in this vortex do not increase power you will only make it worse, full horizontal to get out of the vortex then increase power. I have a syma x5 and lived this vortex ring often and it came down like a rock. I also practiced how to get out of it and recognise the signs of a vortex developing. Often starts with a wobble.

Yes you can hear it and see it. The X5C is very susceptible to VRS if you're not careful.