Let us press. Let us hold. Let Us Drone. CSC stands for Combination Stick Command and it refers to the method of starting and stopping the motors on a drone. You may have heard horror stories about CSC, and this typically stems from people who accidentally executed a CSC while in mid-flight.
In this post, I will discuss when a CSC should be performed, and how to avoid accidentally shutting off your motors in midair, as catching your free-falling drone is the last thing you want to do on a Saturday morning.
CSC to start the motors
There is one thing you absolutely must do every time you launch your drone. Can you guess what that is? If you guessed “start the motors”, then you get a gold sticker.
Although there seems to be a certain amount of fear surrounding acronym CSC, you actually perform a CSC (Combination Stick Command) every time you start the motors.
The dreaded CSC that people fear is the one where the motors shut off while in flight, and we will talk about that later in this post.
There are two Combination Stick Commands to start the motors on every DJI drone:
- You can either press both sticks down and in and hold until the motors start, or
- Press both sticks down and out until the motors start.
See, not so scary, right? So that is the Combination Stick Command to start the motors, but how do we stop them once the drone has landed safely?
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CSC to stop the motors once landed
Once landed, there are two different Combination Stick Commands that you can use to stop the motors from spinning.
- Push and hold the left stick down and the motors will stop spinning after 3 seconds.
- You can use the same method you used to start the motors to also stop them. Either press both sticks down and in, or down and out, and the motors will stop immediately.
So now that we have gone over the Combination Stick Commands that you use every time you fly your drone, let's talk about the Combination Stick Command that has downed many an unsuspecting pilots drone.
CSC to stop the motors in mid-flight
On most of DJI drones, the Combination Stick Command for starting the motors is the same CSC used for stopping the motors while in flight. So by pressing the sticks down and in, or down and out while the drone is in the air will cause the motors to shut off and the drone will free-fall to its death.
There have been firmware updates along the way that have changed the way some of DJI's drones execute a midair CSC, as to minimize the chances of accidentally performing a Combination Stick Command.
Furthermore, DJI has allowed some drone owners to completely disable the CSC for the duration that the drone is in the air. This option may be appealing for some people.
Later in this post, I will get more into firmware updates and how to find out if your drone model will allow you to disable the in-flight CSC.
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Why would you want to stop the motors in mid-flight?
You may be wondering why on earth you would want to shut off the motors while in mid-flight, as this will all most certainly cause irreparable damage to the drone.
Here are some instances where it would be wise to perform a CSC while in mid-flight to prevent further damage to surrounding structures or people.
- If the drone is heading towards people and you are unable you control it for whatever reason.
- If the drone is ascending rapidly on its own while not under your command.
- If the drone collides with a tree or something and you need to stop the motors to prevent further damage.
- If the drone is out of control and you don't have command of it.
Related post: How to Use DJI’s Find My Drone Feature – Find My Drone is a feature in the DJI GO 4 app that allows you to locate your drone in the event of a flyaway or crash.
What to consider if you have to perform a mid-flight CSC
If you have found yourself in one of the unfortunate scenarios listed above and you deem that a CSC maneuver is absolutely necessary while in-flight, wait just one second.
When panicking, we don't often think things through. Before instantly shutting the motors off, take a second to think about where your drone will fall. Are there people beneath the drone? Is there a lake beneath the drone that could be avoided if you wait for another ten seconds? Shutting the motors off before first looking beneath the drone could have serious consequences.
Drones often receive a bad wrap from the public, and a Mavic Pro landing on the head of Tom will certainly not help Tom's perception of us drone pilots.
Now that you have learned how and why you may want to perform a CSC while in flight to stop the motors, let's talk about some of the controversy surrounding the methods used to perform a CSC.
Controversy over CSC
DJI felt strongly enough about having a CSC to stop the motors while in flight to add it as a fail-safe, but does its importance warrant its initiation methods?
What I mean is that there have been so many people that have crashed their drones because they have unintentionally executed a CSC while in flight. Since all it takes to perform a CSC is a couple of simultaneous stick movements, the chances of those stick movements occurring simultaneously are not that low.
You don't have to look long on YouTube to find videos of people accidentally performing a CSC and their drone suddenly drops from the sky.
If you have been flying DJI drones for a while now, then you probably are familiar with CSC, but the newbie is liable to press the sticks in every which direction while getting familiar with the drone, which is usually what causes the Combination Stick Command to be accidentally activated.
It looks like DJI watched those same YouTube videos because they have changed the methods for initiating a CSC while in flight for some of their drones to prevent unintentional CSC executions.
With all of this being said, it does require you to hold the sticks in the same position for 3 seconds for the motors to be stopped while in air. The average individual is not likely going to unintentionally hold the sticks in that configuration for that length of time, so I wouldn't be too worried about an accidental CSC happening.
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Firmware updates have changed CSC maneuvers
As mentioned above, DJI has changed the way to initiate a CSC on some of their drones. Currently, for the Phantom series, you need to press the left stick down and in while pressing the Return-to-Home button with your right hand.
This new method of stopping the motors while in flight makes it's a lot less likely for someone to accidentally perform a CSC.
There have been the firmware updates that have changed the way to perform a CSC. I would recommend regularly checking updates so you can stay informed with changes such as how to stop the motors while in flight on your particular drone model.
In fact, some drones allow you to disable the CSC while in the air. If you are curious as to whether your drone allows you to disable the CSC, go to settings>main controller settings>advanced settings>”do not stop motors in the air”.
Let's review
- CSC stands for Combination Stick Command.
- You perform a CSC every time you start the motors before launching and when you stop the motors after landing.
- DJI allows us to turn off the motors while in-flight by performing a CSC in the event of an emergency (drone out of control, after it has crashed to prevent further damage, etc).
- There has been a certain amount of fear surrounding “CSC” in the DJI community because of the accidental drone free-falls that have happened.
- It takes the operator holding the sticks in the same position for three seconds for a CSC maneuver to be executed.
- DJI has changed the way a CSC is executed on some of their drones with recent firmware updates.
- DJI has given us the option to disable the in-flight CSC maneuver on some of their drones.
- If you are going to perform a CSC while in-flight in the event of an emergency, ensure that there are no people, water, or other things you don't want your drone to drop like a rock on.
Trevor’s Take
You should now have a better understanding of what a combination stick command is, when and how to perform a combination stick command, and what mistakes to avoid that could lead to a free-falling drone. I, fortunately, have never accidentally executed a CSC while in-flight and I will certainly be kicking myself if I one day do since I just wrote a post on how to use Combination Stick Commands correctly. Have you ever accidentally performed a CSC while in flight? What's your story? Let's hear about it in the comment section below!
Hi Trevor,
I have just been a victim of this particular piece of twisted thinking on the part of DJI and others who proclaim that there is a good reason for it. Whilst I welcome your piece, as a way of drawing threads together to inform and educate, and admitting I am a little bitter : there is twisted logic in your piece too.
You quote 4 instances where you may ‘need’ to initiate a motor off. The only vaguely valid one there is ‘in a tree to prevent more damage’ : not an emergency as it is only the props/kit that gets damaged : not people. The other 3 are totally spurious as in each case you claim ‘loss of control’ – so if you have no control then how will the CSC command get through? It uses exactly the same control link as flying : if you have No Control then CSC WILL NOT WORK.
Argument = ‘you’d never use that control combination’ Utter rot. Quite apart from the FACT that any control combination is valid, how do you perform a fast downward rearward corkscrew spiral? Do not claim this is not a valid flight profile : it is as both I and others have DELIBERATELY and FOR OVER 3 SECONDS initiated this manoevre. Unfortunately, as some dipstick decided ‘you’ll never need to do this’ and set it to kill the drone, it cost me a potentially lethal crash – had anybody been underneath the drone when that situation occurred. NOTE : UK legislation requires 50m separation (which means vertical is OK) and also only requires you not to fly over basically ‘crowds’ – not individuals or pairs of walkers for example.
Consistency : one thing you rightly touch upon is that not all DJI drones behave the same. Whilst it is easy to snipe at so-called ‘noobs’ (as the pretentious loudmouths on the web tend to) you can be an absolute expert at flying 2 or 3 different models yet still get caught out when you use the same App to fly another of DJIs family : exactly what happened to me.
Given that DJI (and I have never seen ANY criticism of their thinking here) changed the CSC combination to be ‘stick + RTH button’ to prevent such accidental initiations : WHY IS THIS NOT COMMON ACROSS THE WHOLE DJI FLEET ??? (Not fair to ask you that – just venting 🙂 )
On a more minor note – regarding your piece – you said “Later in this post, I will get more into firmware updates and how to find out if your drone model will allow you to disable the in-flight CSC.” But – you didn’t. I appreciate it would be a major task to collate and cross- correlate all the DJI model / firmware / behaviour characteristics – I did read your article mainly based on that claim. Like I said – a minor point – not a criticism of your piece as at least you DID try to pull some of this stuff together.
So – in summary (as I am indeed a professional working in the Air Traffic Management safety environment as well as a CAA registered Commercial Pilot) : I challenge wholeheartedly the so-called logic behind having a function to kill a flying object mid-air thus transforming it into a fast moving lethal projectile. To have that dubious function initiated by what are a perfectly legitimate set of control inputs is insanity and verging on criminally irresponsible. It is not beyond the wit of man to have an auxillary button / buttons combination (after all we have a pretty useless ‘Pause’ button on our conreollers?) similar to the RTH + stick function WHICH OUGHT TO BE STANDARD ACROSS ALL THE DJI RANGE.
Incidentally, a friend who flies racing drones tells me that ‘stick kill’ has been banned in their sport for over 3 years . . . . . ?
Happy to take online response or be contacted offline by you. Let the flames commence.
Ray,
First off, thank you for the well thought out and detailed post. That’s a real bummer about your drone, I’m sorry to hear that. I’ll do my best to cover your main points.
You quote 4 instances where you may ‘need’ to initiate a motor off. The only vaguely valid one there is ‘in a tree to prevent more damage’ : not an emergency as it is only the props/kit that gets damaged : not people. The other 3 are totally spurious as in each case you claim ‘loss of control’ – so if you have no control then how will the CSC command get through? It uses exactly the same control link as flying : if you have No Control then CSC WILL NOT WORK.
There are a couple of instances that come to mind when I think of “loss of control”. The first, and likely most common would be a midair collision with a bird or something of the like. If physical damage is inflicted on the prop(s) or another component of the aircraft, there is a good chance you will have little to no control of the flight behavior, but the RC will still be connected with the drone if you need to perform a CSC due to an unsafe trajectory of the drone.
Secondly, a drone that enters ATTI mode on a very windy day is very difficult to control. If image transmission is lost and the drone is barely within VLOS so can’t tell which way it is traveling, it may be wise to perform a CSC if the battery is low and the wind is pushing hard away from you. Granted, you could simply lower the height of the drone to below 30’ to allow the VPS to kick in, but a new drone pilot may not be aware of this feature.
Albeit less likely, the third occasion that comes to mind is if there is an error in the compass or IMU. More often than not you will get an error on your screen and will still be able to control the drone, but I have seen reports of people that claim to have had “no control” of the aircraft. You are correct though that a CSC will not go through if the RC has no connection with the drone. We’re assuming though, that there is a connection, but the behavior of the drone is erratic.
And of course the idea is to prevent injury to anyone around, so a CSC should only be done if you know there is no one directly beneath the drone.
Argument = ‘you’d never use that control combination’ Utter rot. Quite apart from the FACT that any control combination is valid, how do you perform a fast downward rearward corkscrew spiral? Do not claim this is not a valid flight profile : it is as both I and others have DELIBERATELY and FOR OVER 3 SECONDS initiated this manoevre. Unfortunately, as some dipstick decided ‘you’ll never need to do this’ and set it to kill the drone, it cost me a potentially lethal crash – had anybody been underneath the drone when that situation occurred. NOTE : UK legislation requires 50m separation (which means vertical is OK) and also only requires you not to fly over basically ‘crowds’ – not individuals or pairs of walkers for example.
I do not claim that it is not a valid flight profile. To be honest, though, I’ve never felt the need to perform a fast downward rearward corkscrew spiral. May I ask when this would be functional, or desirable? Let me be clear that I am not saying that this particular flight path is “nonsense”, I just don’t know when it should be used. I know I mentioned that a newer pilot may perform a CSC in the post, but what I am learning from this part of your response is that an accidental CSC does happen to the experienced pilot as well.
Given that DJI (and I have never seen ANY criticism of their thinking here) changed the CSC combination to be ‘stick + RTH button’ to prevent such accidental initiations : WHY IS THIS NOT COMMON ACROSS THE WHOLE DJI FLEET ??? (Not fair to ask you that – just venting 🙂 )
I don’t know why this isn’t consistent with DJI’s entire fleet, but I agree with you that it should be.
On a more minor note – regarding your piece – you said “Later in this post, I will get more into firmware updates and how to find out if your drone model will allow you to disable the in-flight CSC.” But – you didn’t. I appreciate it would be a major task to collate and cross- correlate all the DJI model / firmware / behaviour characteristics – I did read your article mainly based on that claim. Like I said – a minor point – not a criticism of your piece as at least you DID try to pull some of this stuff together.
I did address this under the heading “Firmware updates have changed CSC maneuvers”.
Instead of listing every drone that you can currently disable the in-flight CSC on (as future firmware updates may change this), I stated “If you are curious as to whether your drone allows you to disable the CSC, go to settings>main controller settings>advanced settings>do not stop motors in the air.”
Again, thank you for the response. No need for flames to commence ;). I know there is a certain amount of bickering that goes on amongst drone pilots out there on the web, and I really just want this blog to be a platform where I (and others) can share helpful information in an easy to understand, respectful way. I know that I have a heck of a lot more to learn about flying, and there are others (likely yourself) that have more flight experience than I do, but I’m doing my best to provide quality information!
-Trevor
Thanks for your detailed post about this. I did a really stupid thing with my Tello drone at night. It was a little windy and it started to drift away from me, the only LED is on the front camera, so it was hard to spot if i was conteracting the wind or not. I really wish my drone had a “emergency stop” swipe, maybe from edge to edge or something (with a smartphone controller).
It got stuck in a tree and i was forced to wait for daylight to be able to get it down.
( Tello SDK 2.0 lists a “emergency” command and i think this is possible with the Tello EDU variant )
Hi Jonas, thanks for the comment. I’ve wanted the same option while flying my Tello. The wind is such a factor with this little drone that it’s easy to lose control of it while outdoors. Did you find out if an emergency shut-off option was available for your drone? Sorry for the late response!
Trevor
Thanks for a very interesting article. I was flying my Phantom 4 yesterday and whilst in midair the motors suddenly stops and it fell from a height of approximately 30 metres. I was using my DJI goggles and it did not show any footage when the motors stopped. I was changing the battery shortly before the flight and I thought that it might have been that the battery has fallen out.
Hi Marius,
You’re welcome, and I’m sorry to hear about the crash. Do you think it was an accidental CSC that caused the crash?
Trevor
Hi Trevor, no I do not think that it was an accidental CSC that caused my crash since the power went dead and I could not see any picture on the screen. Thus, communication to/from the drone was interrupted… As I understand, the CSC just shut down the motors and not the communication to and from the drone?
Kind Regards.
DJIGOpro