Left Throttle down -> cut off

[gluton]

Hi everyone.
I just got a FC-40 and I crashed it today, on first fly ...

I put the left stick to full down position to make him go down.
The drone was going down then after few seconds, the motors cutted off.
I wasn't touching the right stick.

I've read that this behavior isn't normal. (I hope so )
It's only happen if the drone detect it stop loosing altitude for few secondes.
The drone was loosing altitude.

Does anyone would know what to check to try to fix this issue ?

Thanks

 

[Fly Dawg]

The drone was going down then after few seconds, the motors cutted off.

Not sure about an FC40, but all the Phantoms use left stick full down for 2 seconds to shut the motors down.

 

[gluton]

I barelly readed everywhere that it's something that shouldn't happen during flight.
And if it's the case, I don't understand this choice because It seem to me very dangerous when you want to loose altitude .

 

[Fly Dawg]

And if it's the case, I don't understand this choice because It seem to me very dangerous when you want to loose altitude

It is indeed the case. No one that I know of ever uses full down throttle in any circumstance other than an emergency flight abort. It is just not something that is done during normal flights. As I said, I am unsure about an FC40's control parameters, but don't try that with a Phantom or you will get the same result.

 

[N017RW]

It is indeed the case. No one that I know of ever uses full down throttle in any circumstance other than an emergency flight abort. It is just not something that is done during normal flights. As I said, I am unsure about an FC40's control parameters, but don't try that with a Phantom or you will get the same result.

What is your point of reference?

I can attest that at least since the P2 (2014) ‘Phantoms’ will not cut the motors with full left stick down alone.
Saying it is not used normally (paraphrase) is in correct.

You must combine left stick and right stick positions, or button push,’ (a.k.a. CSC) or aircraft must be stationary to cut off motors.

 

[gluton]

This is at least a Phantom 2 and the engines doesn't stop :

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and this is from P3P manual :

So I'm not sure to understand

 

[Fly Dawg]

You must combine left stick and right stick positions, or button push,’ (a.k.a. CSC) or aircraft must be stationary to cut off motors.

This is incorrect. I always use left stick full down to shut off the motors. CSC to start motors, yes. Left full down to stop. Using CSC while stationary can cause a flip over. This has been noted many times. That was all I was referring to. As I said am unsure of FC40 parameters.

 

[Fly Dawg]

Just a quick addendum to Post#7.....I have never tested full stick down during flight. I know for certain that this does indeed shut the motors down after landing. But it is too much of a risk to try and "Prove" a theory by doing that during flight. Just like doing CSC during a flight. A disaster waiting to happen. If anyone can disprove this, I welcome those to chime in. I am not going to risk it personally.

 

[N017RW]

There’s obviously a communication gap.
If you choose to be superstitious about certain stick combinations I respect that.

 

[Fly Dawg]

There’s obviously a communication gap.
If you choose to be superstitious about certain stick combinations I respect that.

Point taken. Not necessarily being superstitious about the combinations. But personally, I have not seen anyone to attempt ( At least not purposefully) Either CSC or Left stick full down during flight, to prove the theory. It wont be me I can promise you that......All I am saying is that I know for a fact ( And even in your post from the manual) that left stick down performs the same function as CSC, in regards to shutting down the motors. No arguments here, it is just a simple thing I thought of from the OP. May have no bearing at all.

 

[N017RW]

Please stop trying to explain me to me.
There are still a few errors in your paraphrasing.

 

[Fly Dawg]

There are still a few errors in your paraphrasing.

Please explain to me what these are. I have no issues whatsoever about any errors I make. Which in particular are you referring to? I am at a loss as to which one, or one's?

 

[N017RW]

This:
“All I am saying is that I know for a fact ( And even in your post from the manual) that left stick down performs the samefunction as CSC, in regards to shutting down the motors.”

CSC is intended to be an Emergency Stop and will occur even if descending/moving.
Lefy stick full-down at rest is not CSC.

 

[Fly Dawg]

CSC is intended to be an Emergency Stop and will occur even if descending/moving.
Lefy stick full-down at rest is not CSC.

Completely agreed......My point was as I said, I have yet to see anyone test the full stick down during flight ( For 3 seconds ). It may or may not shut down the motors. CSC after landing has caused many a "Flip Over" after landing from the many posts and data I have seen. That is basically all I have been referring to as far as this thread goes. I have no disagreements other than wording. Operationally wise, I think you would agree. I am not trying to convince nor persuade. As I also said, If I am mistaken, I have no problem with that. I think we all look at facts, and adjust accordingly.

 

[barefootbeachcombing]

Completely agreed......My point was as I said, I have yet to see anyone test the full stick down during flight ( For 3 seconds ). It may or may not shut down the motors. CSC after landing has caused many a "Flip Over" after landing from the many posts and data I have seen. That is basically all I have been referring to as far as this thread goes. I have no disagreements other than wording. Operationally wise, I think you would agree. I am not trying to convince nor persuade. As I also said, If I am mistaken, I have no problem with that. I think we all look at facts, and adjust accordingly.

Holding the left stick fully down for 3 seconds (or any other length of time) will NOT cause the motors to stop on current/recent model Phantoms will the Phantom is in flight. I do it all the time.

Holding the left stick down will only stop the motors once the Phantom senses that it is on the ground (ie no longer moving downward).

 

[gluton]

Thanks for the anwsers.
I've readed that the altitude is measured by a barometric sensor and, if available, by GPS.
And I've also readed IMU calibration is to calibrations differents things like the barometric sensor.
I haven't done an IMU calibration and it was the first fly of this Phantom since something like 3 year.

I'm ordering news propeller then going to check with a IMU calibration.

I keep you updated

 

[Fly Dawg]

Holding the left stick fully down for 3 seconds (or any other length of time) will NOT cause the motors to stop on current/recent model Phantoms will the Phantom is in flight. I do it all the time.

Thank you for confirming that. As I said before, something I have never tried nor even remotely had an interest in trying. The only other entry would be the fact that I never use VPS. I find it useless. Now, if the AC calculates any values in reference to that lets say 20 ft AGL or thereabouts, what would be the outcome of a full down throttle, at roughly that altitude, for 3 seconds? Assuming no VPS? Just pondering the question honestly. My flights are generally speaking slow and methodical, so I have no use for any sort of excessive speed, distance ( I use that with a grain of salt ) or any other drastic manuevers, other than in an emergency situation which I do practice on occassion.

 

[gluton]

By navigating into the NAZA-M assistant, I found this :

Yes a DJI PHANTOM FC-40 and any others Phantoms which you can modify this parameter can have the motors cuted-off during a flight by putting the left stick (Throttle) full down.
It's just depend of the settings of this parameter.

Obviously I didn't wanted this and I still don't want this settings to be into "Immediatly".

I switched to Intelligent and it seems to have fixed my issue by testing my Phantom into my room without propellers. I'll do some in flight tests when I'll get my new propellers.

So every second hand owner of any phantoms which you can modify this parameter should check this before flying to don't have the same issue as me .

 

[N017RW]

By navigating into the NAZA-M assistant, I found this :
View attachment 98965

Yes a DJI PHANTOM FC-40 and any others Phantoms which you can modify this parameter can have the motors cuted-off during a flight by putting the left stick (Throttle) full down.
It's just depend of the settings of this parameter.

Obviously I didn't wanted this and I still don't want this settings to be into "Immediatly".

I switched to Intelligent and it seems to have fixed my issue by testing my Phantom into my room without propellers. I'll do some in flight tests when I'll get my new propellers.

So every second hand owner of any phantoms which you can modify this parameter should check this before flying to don't have the same issue as me .

Please understand this feature is not available on the NAZA Phantom and its Assistant.
Since the Phantom NAZA is not a true ‘M’ firmware wise many features are disabled and there are a few which are unique to
Phantom NAZAs such as the battery communication.

 

[gluton]

Please understand this feature is not available on the NAZA Phantom and its Assistant.
Since the Phantom NAZA is not a true ‘M’ firmware wise many features are disabled and there are a few which are unique to
Phantom NAZAs such as the battery communication.

I can affirm that this feature is available for my FC-40 by the NAZA-M assistant I downloaded from DJI.
Maybe my NAZA has been changed by the previous owner, I can't tell and I don't know how to check.

I just made new tests switching the settings from "Inteligent" to "Immediatly" and It's changing the behavour as describe into the description from my screenshot.

Without any doubt my issue came from here.