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Have you heard of a pilot accidentally doing a CSC power shut off in mid flight?

Dangerly

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If you enable emergency CSC power shut off, how likely is it that you'll accidentally shut the power off mid-flight? I don't think about not doing the CSC by accident, but now that I'm wondering about this for the first time, I'm wondering if it's safe to leave CSC power stuff off enabled by default? Leaving it on lets you drop the drone in emergency situations, like if a low flying helicopter comes out of nowhere in uncontrolled airspace flying low and fast. What are your thoughts in terms of flying safe? Safer to leave CSC power shut off enabled or not?
 
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What are your thoughts in terms of flying safe?
In terms of safety, it's a great idea to keep it enabled.

how likely is it that you'll accidentally shut the power off mid-flight?
Not likely. If it was happening often, you'd see people talking about it in this forum.
 
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There have been at least two instances/threads were it was deduced that inadvertent "Always/Anytime" CSC's brought the drones down. I think both drones were Air models and possible Air 2 models.
In both instances the flight log ended i.e. the motors stopped, after the CSC position had been held for around 1.5-1.7 seconds which appears to be period in Mavic style drones. One went into a lake but I can't remember where the other ended up.

It's a pretty radical flight path to command, a descending helix at maximum speeds if the option is Breakdown/Emergency_only but, with a Mini set to cine/tripod mode (to reduce the speeds to minimums), quite interesting.
Been there, done that but I don't think I was recording video and I only wanted to check/confirm that the motors would not stop, they did not stop.
With "always/anytime" set and starting from a height of about 6-8ft the drone was about 18" off the ground/grass when the motors stopped.
 
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I do not think there is any real risk with the 249g drones of causing and real damage or the FAA would not be as liberal as they are with that class.

I have had to crash my Inspire 2 into bushes once when it went out of control (the OA slowed it down to avoid any real damage). I would not be comfortable droping power on the larger drones .

For sure you would want it to be hard to accidentally trip. Yuneec H series have a switch on controller that can be easily tripped bad Idea.
 
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Leaving it on lets you drop the drone in emergency situations, like if a low flying helicopter comes out of nowhere in uncontrolled airspace flying low and fast.
I've seen you mention this in several threads and I have to tell you CSC is a terrible way to avoid a manned aircraft. You want to get out of the way as fast as you can and still maintain control of your drone. Maximum downward thrust is going to have your drone descend much safer than just killing your motors and relying on gravity for a descent. You also might need to descend and move in a lateral direction as well. CSC is a safety feature for killing a spinning prop that might be in danger of hitting a person, or in a fly away situation. Not a good Idea for aircraft avoidance!

**edited** Free fall is a faster way to descend, but being able to control your decent is much safer, IMHO!
 
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I've seen you mention this in several threads and I have to tell you CSC is a terrible way to avoid a manned aircraft. You want to get out of the way as fast as you can and in order to do this, you need to be in control of your drone. Maximum downward thrust is going to have your drone descend much faster than just killing your motors and relying on gravity for a descent. You also might need to descend and move in a lateral direction as well. CSC is a safety feature for killing a spinning prop that might be in danger of hitting a person, or in a fly away situation. Not a good Idea for aircraft avoidance!
Well said, and my thoughts exactly. Glad now I didn't reply earlier because you nailed it! Much better than I could have.
 
Maximum downward thrust is going to have your drone descend much faster than just killing your motors and relying on gravity for a descent.
That is simply not correct.

For a normal DJI drone the maximum controlled descent speed is severely limited .... unless the firmware has been hacked. This is possibly to avoid "Vortex Ring State".
With quite a few drones the maximum descent speed changes with flight mode, sports mode generally offering the fastest.
The Mavic 3 & Air 2s have the fastest I have noticed in a normal drone i.e. a non FPV drone, and that is listed as 6 m/s.
Some others are limited to 5ms e.g. Air2, Mini 3 pro.
Others are limited to 3m/s e.g. Mavic Pro, M2P/Z, Mavic Min (sports made), Mavic Air.
Those are just the drones whose manuals I have looked at.

The free fall terminal velocity of a Phantom style or Mavic style drone seems to be between 14m/s and 16m/s and that appears to be reached with in the first few seconds, besides the initial descent would be at maximum controlled descent speed, or accelerating to it. It would be interesting to see what the free fall speed of a DJI FPV.

A 'normal' DJI drone can not pull itself downwards and, if you think about it, for a controlled descent at more or less constant speed and at less than free fall speed the props must be running at near hover speed otherwise the drone would accelerate.
I looked at this a while back and, from memory, descent motor speed is only slightly below hover motor speed, I assume the difference in speed/thrust takes vertical drag into account. Similarly I recollect ascent motor speed if fairly close to hover speed for the same reasons.

Think of travelling in a lift, your apparent weight changes only whilst the lift and you are changing speed, when the lift is travelling at constant speed your weight is normal

I do not argue that horizontal control would be good but in order to lose height free fall is the fastest.
 
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I've seen you mention this in several threads and I have to tell you CSC is a terrible way to avoid a manned aircraft. You want to get out of the way as fast as you can and in order to do this, you need to be in control of your drone. Maximum downward thrust is going to have your drone descend much faster than just killing your motors and relying on gravity for a descent. You also might need to descend and move in a lateral direction as well. CSC is a safety feature for killing a spinning prop that might be in danger of hitting a person, or in a fly away situation. Not a good Idea for aircraft avoidance!
"Downward thrust?" Isn't a drone descent basically just falling in a controlled way (which, basically by definition would be slower than simply falling)?

*that said I absolutely agree with your overall point. It's like motorcycle riders who want to know the "best" way to lay a bike down in an emergency, and it's like you generally shouldn't "choose" to lay it down.
 
I have had to crash my Inspire 2 into bushes once when it went out of control (the OA slowed it down to avoid any real damage). I would not be comfortable droping power on the larger drones .
I'd only be comfortable if the impact is likely to be worse than the crash from cutting the power. It's an option that should be used (or not used) wisely.
 
I have no idea if this is even possible, but if the props spun backwards, could not the drone pull itself downwards?
If the props could be driven in reverse then they would push the drone downwards, this is why drones flip on take off if props are fitted to the wrong motor ( a common mistake with the mini series drones) and, quite strangely, possible with the FPV.
Whoops, though the FPV detected my mistake and shut the motors down before the FPV could flip.

But I think, where quickly-detachable-propellers that require twisting to fit, there is a risk that the horizontal drag whilst turning props in reverse could twist quickly-detachable-propellers off the motors ...... unless the propeller click into locks when correctly fitted.
Where quickly-detachable-propellers that require twisting to fit they generally rotate in a direction such that the horizontal drag acts to twist them on.

I don't remember if FPV props 'lock' in place but m2p/z props do lock in place. I have no idea about the other 'Mavic' style drones with quickly-detachable-propellers lock in place.

With the likes of a Phantom 3 it is conceivable that driving the props in reverse could unscrew them.
That said, free fall with a Phantom 3 DOES drive the props in reverse but in those circumstances the forces are still acting to tighten the prop on its screw.
 
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I don't remember if FPV props 'lock' in place
One of my drones is the FPV and they twist-lock in place, similar to other Mavic drones I've flown. I suspect you are talking about a different kind of locking into place, that is not just the press-down-and-rotate type of lock. Is that correct?

I am wondering if the props could take being spun backwards without coming loose or other damage, if being able to do a powered descent would be useful for not only avoiding emergencies (maybe falling faster than free fall but with control?) and also might make for some very cool video? I know when I've been descending with the FPV at maximum descent speed, there are times I was wishing for a faster descent to get a better cinematic effect.
 
There have been at least two instances/threads were it was deduced that inadvertent "Always/Anytime" CSC's brought the drones down. I think both drones were Air models and possible Air 2 models.
In both instances the flight log ended i.e. the motors stopped, after the CSC position had been held for around 1.5-1.7 seconds which appears to be period in Mavic style drones. One went into a lake but I can't remember where the other ended up.

It's a pretty radical flight path to command, a descending helix at maximum speeds if the option is Breakdown/Emergency_only but, with a Mini set to cine/tripod mode (to reduce the speeds to minimums), quite interesting.
Been there, done that but I don't think I was recording video and I only wanted to check/confirm that the motors would not stop, they did not stop.
With "always/anytime" set and starting from a height of about 6-8ft the drone was about 18" of the ground when the motors stopped.
Since I have both Air models this makes me a bit alarmed, though I agree that's such a radical flight path I can't imagine doing that on purpose. But I don't think about not taking that flight path. It's now making me think that DJI should incorporate a new feature into their software: If it detects a CSC, everything should start beeping at full volume with a "Warning - about to shut off power!!!" message from the controller. This seems like such an obvious and important feature suggestion now that I think about it.
 
When fitting a prop to an M2P/Z it is necessary to depress the prop to the extent that the motor's shaft projects slightly above the prop's hub. When the prop has been sufficiently depressed it can be twisted on. If the prop is released before it is fully home the prop's hub remains fully depressed with the motor's shaft still projecting above the prop's hub.
However if the prop is twisted fully home, it hits a stop, when the prop is released it 'rises' so that the top of the prop's hub is flush with the end of the motor's shaft, as if the prop's lugs were rising into recesses or detents. When the prop is fully home and the prop's lugs are in their recesses, this design acts to create an 'undo' stop which prevents the prop being twisted off by sudden decelerations i.e. the prop has to be depressed before it can be twisted off.
These recesses etc. are what I refer to as a "lock", I do not remember if the FPV has this feature and do not know it the other 'Mavics' have it.
 
My approach to avoidance is primarily to descend. After “tuning” Sport mode on my MPP, the fastest controlled, motors on descent speed I can generate is 22 mph (about 32 feet per second). It’s very stable, and responsive if lateral movement is necessary. However, executing such a maneuver demands eyes on the AC, not the screen, as you have be ready within the last 100 ft to slow it down (3+ seconds).
That’s all well and good, but the problem is that such “tuning” is not available to all aircraft, and I think it should be. But that’s me.
 
When fitting a prop to an M2P/Z it is necessary to depress the prop to the extent that the motor's shaft projects slightly above the prop's hub. When the prop has been sufficiently depressed it can be twisted on. If the prop is released before it is fully home the prop's hub remains fully depressed with the motor's shaft still projecting above the prop's hub.
However if the prop is twisted fully home, it hits a stop, when the prop is released it 'rises' so that the top of the prop's hub is flush with the end of the motor's shaft, as if the prop's lugs were rising into recesses or detents. When the prop is fully home and the prop's lugs are in their recesses, this design acts to create an 'undo' stop which prevents the prop being twisted off by sudden decelerations i.e. the prop has to be depressed before it can be twisted off.
These recesses etc. are what I refer to as a "lock", I do not remember if the FPV has this feature and do not know it the other 'Mavics' have it.
Yes, the FPV has these recesses too. Thanks for the detailed info.
 
My approach to avoidance is primarily to descend. After “tuning” Sport mode on my MPP, the fastest controlled, motors on descent speed I can generate is 22 mph (about 32 feet per second). It’s very stable, and responsive if lateral movement is necessary. However, executing such a maneuver demands eyes on the AC, not the screen, as you have be ready within the last 100 ft to slow it down (3+ seconds).
That’s all well and good, but the problem is that such “tuning” is not available to all aircraft, and I think it should be. But that’s me.
Can you say what you mean by tuning sport mode?
 

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