The number one reason for Phantom crashes (a little surprising)

[Mark The Droner]

I still consider myself a noob, but I have to agree with all content of each of msinger and meta4's posts in this thread. It's all spot on from what I've learned the past six months. If CSC was the number one cause of crashes, we'd be hearing a LOT MORE about it then we do.

 

[Jussaguy]

I agree too, but I would prefer to see a method that works on all remote controllers. Not all of them have a C1 and C2 button right now.

Fair enough. I was just giving an example but something like that. Maybe clicking the record button with the sticks?

 

[ObiDon]

There are some tabs that you can place over the sticks that when rotated correctly, will prevent the CSC from being initiated. That could give someone peace of mind.

 

[Jussaguy]

I still consider myself a noob, but I have to agree with all content of each of msinger and meta4's posts in this thread. It's all spot on from what I've learned the past six months. If CSC was the number one cause of crashes, we'd be hearing a LOT MORE about it then we do.

Again, I am only going by the way Tim at DJI wrote it. It might not be the number one reason and like I said, I was surprised to learn it was but even if it's not, its in the top 10 and he listed it at #1 for whatever that means. What's the difference? If you could remove one of the top 10 RMAs with programming an extra move to do a CSC like a button click, why not do it?

 

[msinger]

Maybe clicking the record button with the sticks?

The P3S remote controller doesn't have a record button either. While I agree with Meta4 that DJI will likely never change this, I would add a new kill switch to the remote controller if the decision was up to me. That way, there would be no question as to the function of the switch.

 

[Jussaguy]

I just went to youtube to look for something to show what I am talking about and found a perfect one without any searching.

Here is someone that is used to flying FPV speed multi-rotors and when you are used to being really loose with the sticks because you're always banking and curving and ****, this is what could happen. The person flying this is a good FPV pilot but he was not cautious of the CSC and friends bird died because of it. This is all I am saying.

 

[Jussaguy]

The P3S remote controller doesn't have a record button either. While I agree with Meta4 that DJI will likely never change this, I would add a new kill switch to the remote controller if the decision was up to me. That way, there would be no question as to the function of the switch.

You are probably right but we will always find something to complain about. I have a Q500 and it has a kill switch and people complain how easy it is to accidentally hit that too. I think a combination of a minor stick move (maybe just one stick) and a kill switch would suffice.

I agree with you though.

The ST10

That button in the upper left corner is the Q5 kill switch but third parties have created this to make it so you can avoid it by accident.

To me, a button with a lift lock like this would be just fine but that can't happen on our remotes, we need to make use of what's on the current remotes. The Phantom X, Tomato or whatever I bet will have something different. I hope anyway.

By the way, I don't want to start a thread on this so I'll just put it here. I have brand new batteries for $115 plus shipping. If you are in Cali you can come to my studio to pick it up. I have about 20 left so PM if you want one.

 

[Jussaguy]

No-one here works for or has any connection with DJI.
I have heard their people say many times (in response to suggestions that CSC be changed) that it is not going to happen.

I've heard a lot of things true and false about compass calibration but that's the first time I've ever heard it linked to altitude. I doubt it is related.

Reports involving bad calibrations turn up here every week.
The most common cause is unnecessarily calibrating the compass on a reinforced concrete structure.
For any more info on compass related stuff, read this excellent post: Compass Calibration, A Complete Primer

Well yeah, but what I meant was how do you send the bird up and not know you have a bad calibration?

About altitude or any location for that matter, did you read the manual I posted from DJI?

Read it. It says any time you change a location you should calibrate the compass (and it says it with a big old IMPORTANT on the heading)

 

[Meta4]

Well yeah, but what I meant was how do you send the bird up and not know you have a bad calibration?

Here's an example of someone who did it.

He was a calibrate-every-time guy and "successfully" calibrated on a pier with tons of steel sheet piling all around it.
While his Phantom was near the pier no problem was obvious but when he moved past the magnetic influence of the pier he found out.

About altitude or any location for that matter, did you read the manual I posted from DJI?
Read it. It says any time you change a location you should calibrate the compass (and it says it with a big old IMPORTANT on the heading)

Of course I've read the manual (many times).
I'm well aware of its inconsistencies and areas where detail is lacking as well.
Next time you're over on the DJI forum ask DJI-Ken about how often you should calibrate your compass.

 

[Jussaguy]

Here's an example of someone who did it.

He was a calibrate-every-time guy and "successfully" calibrated on a pier with tons of steel sheet piling all around it.
While his Phantom was near the pier no problem was obvious but when he moved past the magnetic influence of the pier he found out.

Of course I've read the manual (many times).
I'm well aware of its inconsistencies and areas where detail is lacking as well.
Next time you're over on the DJI forum ask DJI-Ken about how often you should calibrate your compass.

I've seen this video.

Two things, this guy is obviously not that smart so I have no idea if he knew he had a proper calibration but since he didn't return home the second he knew he didn't, he doesn't get a proper head from me in intelligence.

I'll ask again before we continue this conversation. Did you read the manual that I linked? Did you read what it said?

If you disagree with it then we just will agree to disagree but you realize you are going against what DJI had bolded and thought to put in their manual right?

Also, if he had read the manual, he would have known not to calibrate there.

EDIT: In the video he also said he "rushed the take off to catch the boat and calibrated it really quickly". To me, this proves only that this guy was fool headed and it almost cost him. He did about 3 stupid things in 3 minutes. Some of the terms HE USED "rushed take off, not thinking about it because we wanted to record the ship" and then he was too stupid to know what to do with the bad calibration. This guy is an example of an idiot and nothing more.

 

[Jussaguy]

Here is another video from a DJI F550 and read the comments. Never calibrates and flies all the time and then this happened. He was actually a smart enough flier to realize to take control, didnt panic but because he had to fly at 10K he didn't have enough juice to get home but if he had a calibrated bird, he would have still had it in one piece. His actions at least saved the bird somewhat. From now on, he calibrates.

The reason I won't touch a Solo by the way is because it has a 16 rotation calibration of the compass.

I have no problem with you flying without calibrating, not sure why you do if I do (according to the recommendation of the DJI manual). I must admit, I like your tenacity to stand by your conviction in the face of the DJI engineers who wrote the manual which again is posted above. Can you please explain to me why they are wrong?

 

[Meta4]

I'll ask again before we continue this conversation. Did you read the manual that I linked? Did you read what it said?
If you disagree with it then we just will agree to disagree but you realize you are going against what DJI had bolded and thought to put in their manual right?.

Again .. YES I have read the manual (even the current version) many times.
It's far from a perfect document and the compass calibration section is possibly the worst part, possibly due to language difficulties?

You are not just disagreeing with the fine people at the DJI forum (which I don't always agree with) but the engineers who created the thing and made the manual.

You aren't going to take any notice of anything I say and I'm tired of typing the same stuff over and over so I won't say any more.
You seem to respect the DJI guys opinions.
Ask DJI-Ken how often you need to calibrate the compass sometime.

 

[Jussaguy]

Again .. YES I have read the manual (even the current version) many times.
It's far from a perfect document and the compass calibration section is possibly the worst part, possibly due to language difficulties?

You aren't going to take any notice of anything I say and I'm tired of typing the same stuff over and over so I won't say any more.
You seem to respect the DJI guys opinions.
Ask DJI-Ken how often you need to calibrate the compass sometime.

I love how you are doing the same thing I am, repeating yourself over and over and not agreeing and saying I'm being stubborn. Besides, do you think the techs (who they are hiring like gang busters to match the meteoric rise of the need for these things) know more than the Chinese counter parts who build them??? I actually respect Ken's opinion but it's not the end all and also when someone says "you don't need to calibrate every time", I don't disagree with that comment, I just choose to.

The document is quite clear about calibrating the compass every time. I don't need to ask DJI-Ken. I know what he thinks. Ask DJI-Tim. He think differently.

Apparently the difference between you and I is that you are sure you are right and others that think differently are wrong. Before this post, I said, you are allowed to think what you want and I don't begrudge you but since I've been flying for years without anything close to a crash, I'm not changing my routines but I respect your opinion and have no problem and frankly don't care what you do but for the people that come to this forum and read this stuff, I'd like them to know what DJI says you should do rather than what you say so I am reporting it.

 

[TheRealNick]

Something I read earlier was that the CSC requires 2 sec of the sticks in that position which is not the case. It is instant. I saw this in a .dat file, as soon as both sticks hit the position the motor's commanded speed when to zero and then it took some time for them to stop....

I don't care if other people calibrate compass or IMU all the time, but I don't. I have 60 flights on 1 compass calibration and factory IMU. All my flights have been within 30 miles of each other.

What I do think is important is to check the sensor readings before every flight, even if you just did a calibration....

 

[Jussaguy]

Something I read earlier was that the CSC requires 2 sec of the sticks in that position which is not the case. It is instant. I saw this in a .dat file, as soon as both sticks hit the position the motor's commanded speed when to zero and then it took some time for them to stop....

I don't care if other people calibrate compass or IMU all the time, but I don't. I have 60 flights on 1 compass calibration and factory IMU. All my flights have been within 30 miles of each other.

What I do think is important is to check the sensor readings before every flight, even if you just did a calibration....

Great post!

I only wanted to discuss CSS to begin with.

You are dead on, it's instant. Try in the SIM. It's correct.

You should definitely calibrate the IMU after a firmware update. 60 flights is not a lot and nobody thinks they will lose their connection or have a spin out/fly-away. Do yourself a favor and don't wait until I'm right.

 

[Jussaguy]

At the end of the day this is the problem with me and the CSC if I'm being honest. Lol.

 

[Mako79]

http://download.dji-innovations.com...en/Phantom_3_Advanced_User_Manual_v1.0_en.pdf

The above link is the DJI Phantom official manual.

Page 44 under the title of "CALIBRATING THE COMPASS"

IMPORTANT: Always calibrate the compass in every new flight location. The compass is very sensitive to electromagnetic interference, which can produce abnormal compass data and lead to poor flight performance or flight failure. Regular calibration is required for optimal performance.

it DOES also say that you should not calibrate where there is magnets and electronic interference but unless you are taking off from the same spot EVERY time you fly the bird, you are not just disagreeing with the fine people at the DJI forum (which I don't always agree with) but the engineers who created the thing and made the manual.

A different location doesn't mean like in Phoenix instead of New York, it means your front yard vs. your backyard.

The reason for that is because the compass, as all compasses work by the magnets in the earth and they are different in every location. I almost never fly in the same location so with all due respect, I will listen to DJI over your opinion. You are right though, a bad compass calibration can lead to catastrophic failure but you know before you send it up if you do your checks if your home point is set right and if your compass is set right.

Again, don't get me wrong, I don't think everyone needs to do a per flight calibration but if you don't want to find yourself in a "fly away" which is almost always a bad compass, then you will do it especially when you change altitudes, change altitudes or make a major location difference.

Although I said front yard and backyard, I don't think you need to do that (although I would). But there is DJI in black and white saying if you change your location, calibrate. Listen to them or not. Matters not to me but I thought the official word should make it's way into the conversation.

Final thought, you know how your iPhone tells you to calibrate every now and then for what is apparently no reason. It's because it needs a calibration of the compass and the phone knows it. If that happened while flying, you better get out of GPS mode and get in to ATTI and fly it back and hope that your cached map is just fine if you are out of line of sight.

CSC will be left as is. I'm sure they would have revised it in the Phantom 1.1 if it was a problem.
What is the chances of full stick descending and yawing right whilst flying backwards banking left? This is not a first person shooter game! And why would an FPV drone racer/stunt perform this manoeuvre?? Those who do CSC are the ones that are curious or have not read the manual.

CSC should be left as is as it is a safety feature. If you added an extra step in stopping the motors, it will definitely cause more injury in an emergency as you have to fumble around looking for the button and then triggering the CSC. Think of this.. you have landed in a park and the props are still spinning. An interested child/animal runs towards the Phantom. If your fingers are on the sticks, the reaction time is immediate and threat minimised immediately.

What DJI needs to change is the Manual. They have published the CSC as the first method of shutting down the motors. Most users would just skim through this and ignore the second option of down stick for 3 seconds. They should just publish the down stick for 3 seconds as landing and separate CSC for EMERGENCY in the manual!!

And in regards with compass calibrations, its best to use your common sense. Look at the environment and judge what's best. You need to remember that the phantom when flying spends more time in the sky then on the ground. If you do a compass dance at ground level where there is heaps of magnetic influences and you get airborne, the compass North will be conflicting and you will get compass errors. If it detects compass errors, it will switch to ATTI and turn off the GPS to prevent flyways.

I check my compass mod values before flight, and if needs to be done, I would google map the closest open field. The open field will reflect the compass when the Phantom is in the sky.
And also remember, there is rebar in the concrete so be careful with driveways and foot paths and take off from a cardboard box.

 

[JKDSensei]

So who has used the CSC in an actual, people might get hurt, this is the BIG one... emergency (while IN FLIGHT) ?

 

[kandelin16]

Tip: it is possible to restart your motors during free fall but unless you are above 250 meters and do it right away, no chance of saving and even if you manage it, you need some luck based on how it's flying. The move is restart motor and IMEEDIATELY ascend up (no thottle forward). Test it in the sim.

Any real world proof for this? I've done it in the sim from 275 feet but I'm skeptical about it in the real world, and I've never heard of anyone doing it.



Sent from my iPod touch using PhantomPilots mobile app

 

[Jussaguy]

CSC will be left as is. I'm sure they would have revised it in the Phantom 1.1 if it was a problem.
What is the chances of full stick descending and yawing right whilst flying backwards banking left? This is not a first person shooter game! And why would an FPV drone racer/stunt perform this manoeuvre?? Those who do CSC are the ones that are curious or have not read the manual.

CSC should be left as is as it is a safety feature. If you added an extra step in stopping the motors, it will definitely cause more injury in an emergency as you have to fumble around looking for the button and then triggering the CSC. Think of this.. you have landed in a park and the props are still spinning. An interested child/animal runs towards the Phantom. If your fingers are on the sticks, the reaction time is immediate and threat minimised immediately.

What DJI needs to change is the Manual. They have published the CSC as the first method of shutting down the motors. Most users would just skim through this and ignore the second option of down stick for 3 seconds. They should just publish the down stick for 3 seconds as landing and separate CSC for EMERGENCY in the manual!!

And in regards with compass calibrations, its best to use your common sense. Look at the environment and judge what's best. You need to remember that the phantom when flying spends more time in the sky then on the ground. If you do a compass dance at ground level where there is heaps of magnetic influences and you get airborne, the compass North will be conflicting and you will get compass errors. If it detects compass errors, it will switch to ATTI and turn off the GPS to prevent flyways.

I check my compass mod values before flight, and if needs to be done, I would google map the closest open field. The open field will reflect the compass when the Phantom is in the sky.
And also remember, there is rebar in the concrete so be careful with driveways and foot paths and take off from a cardboard box.

And like that I have found a level minded poster. Well said and I don't agree with all you said but you did it elequantly and kindly. Bravo!