Compass Calibration Required

[flyNfrank]

I am very procedural when I go flying, my check list is longer than my left arm. But I feel inappropriate to calibrate the compass at every flight (why not every battery?) DJI has been clear: They recommend calibrating at every new location (figures are 150 miles I believe.) not at every flight. If it was necessary, they would have mentioned it. So in the name of what someone decides and recommends (Based on what information?) that the calibration must be done at every flight? Put it simple, to each his own, but DJI DOES NOT recommend to calibrate at each flight. Any contrary recommendation is misleading and must be corrected. I wonder what's the point to spread wrong information on the forum, when all what we need is clear infos to avoid mistakes.
PS: I don't wait to be at 100 miles to recalibrate, but when I fly in a 10 miles radius I'm not bothered, and not taking any risk)

In all fairness, what makes you say DJI DOES NOT recommend to calibrate at each flight?

As it is also true that DJI DOES NOT recommend to NOT calibrate at each flight either.

Also there is no text or literature from DJI that says calibrating each flight will hurt or damage the aircraft.

They Do have it listed in the GO app as... calibrating your compass is crucial for the safe operation of your aircraft.

I brought this subject up for two reasons. One is because a number of new pilots have had issues that some refer to as Fly-away, some say Lost control, some like a Mind of it's own. And these things are obviously related to compass and gps. As I mentioned earlier I had never seen a flight log from one of these instances where the pilot did in fact calibrate the compass prior to the flight. A very good way to help eliminate the situation is to calibrate prior to flying. Who knows, it may be an issue with the device used to fly with, or certain devices, or devices with wrong settings, ect.
The other reason of bringing this up I recently heard when a diagnosis being made using flight logs, the 1st 3 data points looked at were compass calibration, gps, and certain battery data.

I then logged into the site here after not being online here a few days and see 3 threads had been recently created from different people with the same similar issue. That's when it appeared to be a good time to bring this up.

So of coarse everyone can and will do as they please with each of their own aircraft. But for myself, when I see DJI state that compass calibration is crucial for the safe operation of my aircraft, you can bet I will do simple calibrations with documented flight.

 

[brianb87]

The hinge is all plastic? The latches? The hinge in the handles? The wheels? It couldn't be more obvious that there is a magnetic field from SOMETHING that is giving you a need to calibrate constantly, and consistently. It don't care you look at it, or value anyone's advice.. it couldn't be more obvious that something is not totally legit with what you are doing or using.

Tomorrow I'll take off from the landing pads.. How far away are we talking from metal objects? Im usually 30' or so from my car.

 

[Meta4]

when I see DJI state that compass calibration is crucial for the safe operation of my aircraft ....

Frank, there's a huge difference between calibration is crucial to safe flight and calibration every flight is necessary.

Of course proper compass calibration is important. Your Phantom won't fly properly unless the compass is properly calibrated.
This forum is full of reports of flight difficulties that begin with, I calibrate every flight.
Calibrating every flight doesn't make you less likely to have flight problems.
But it often indicates a pilot that doesn't understand what calibration of the compass does.
And sometimes in their efforts to be safe, these flyers get a bad compass calibration which has a negative effect on their flight safety.

Fly safe.
Understand what compass calibration is, when it's necessary and how you can screw it up.

 

[Meta4]

Tomorrow I'll take off from the landing pads.. How far away are we talking from metal objects? Im usually 30' or so from my car.

Your compass is in the bottom of your landing gear.
Magnetic field interference depends on the size of the object and how close it is to your compass.
At 30 feet, your car shouldn't be a problem but a 50000 ton ship might be.
Much smaller pieces of steel can have an effect if they are close to the compass.

 

[brianb87]

Your compass is in the bottom of your landing gear.
Magnetic field interference depends on the size of the object and how close it is to your compass.
At 30 feet, your car shouldn't be a problem but a 50000 ton ship might be.
Much smaller pieces of steel can have an effect if they are close to the compass.

Thanks Meta4. I'm going to fly the same place tomorrow. So if it doesn't ask to calibrate then I'm good, even though I've possible been calibrating around metal previously?

 

[Meta4]

Thanks Meta4. I'm going to fly the same place tomorrow. So if it doesn't ask to calibrate then I'm good, even though I've possible been calibrating around metal previously?

I can't tell whether it's good or not but calibrating around metal isn't a good idea.
You can have compass problems that aren't strong enough for the app to advise you.
You want to calibrate your compass so your Phantom has a good picture of the magnetic environment up where it is flying ... not what the magnetic environment is in an area where the magnetic field is distorted by large steel objects.

 

[brianb87]

I can't tell whether it's good or not but calibrating around metal isn't a good idea.
You can have compass problems that aren't strong enough for the app to advise you.
You want to calibrate your compass so your Phantom has a good picture of the magnetic environment up where it is flying ... not what the magnetic environment is in an area where the magnetic field is distorted by large steel objects.

Awesome! Thanks again for the info Meta4.

 

[III% Streve]

The only indications WE have to know that a calibration is good or not is a verification that the aircraft nose, in the radar, is pointing as close to perfectly the same direction its actually sitting, and the compass MOD value. The MOD value CAN be a poor gauge though. If, for instance, you calibrated you P3 while standing on a metal plate, it would likely "pass" the calibration. If you then went trait to the compass MOD it would indicate near 1500 or higher. Now take that same P3 out to the middle of 40 acres and look at the MOD value. It will be totally out of whack, and my not even let you spin up. Go back to the metal plate and its all good. But go to fly, and the second you get outside that plates magnetic field you will see all the signs of a fly-away.

Moral to the story... calibrate three times a year and you have 3 chances to have a strange calibration due to something you might not know about. (Like a steel pipe under ground) Calibrate 365 times a year and you have 365 chances to get screwed. Which is more safe?

 

[ianwood]

As it is also true that DJI DOES NOT recommend to NOT calibrate at each flight either. Also there is no text or literature from DJI that says calibrating each flight will hurt or damage the aircraft.

The amount of bad information out there is huge. Even from DJI employees. Their support people are laughable. And the countless "instructional" videos on Youtube show people calibrating their compass in the street, with a wedding band on, with a watch on, with the controller 2ft away, on a beach, etc.

Most of DJI didn't know what declination was until I beat them over the head with it.

My point being that I would be careful with even what DJI says. There is a language barrier and unless you're talking to the engineer who wrote the algorithm, you're probably getting slightly incorrect information.

 

[RedHotPoker]

Monday morning, right after the updated firmware and new Go App version are installed, I will perform & complete all Phantom 3 calibrations and have all of my battery updated before I fly those four consecutive intelligent flight batteries. Showing that the new Phantom 3 is still a cake walk in the park. Hahaha
I wish I had a different color for each day of the week...

RedHotPoker

 

[Mordor]

flyNfrank


Please advise why.

The last place it flight was the same. (At my house garden).
The launch first 40 seconds, it stays above the ground without oscillations or turns, so, stable...
All indications were perfect. Control on any direction was perfect.

Then i fly way, normally.

What could exactly go wrong?

P.S. Im also radio ham, so i consider have a good idea about local magnetic camps such antennas, transmitters, cars, generators, train metal passages, electric cables, etc,etc...and when i do it, i go another places...

 

[flyNfrank]

Frank, there's a huge difference between calibration is crucial to safe flight and calibration every flight is necessary.

Of course proper compass calibration is important. Your Phantom won't fly properly unless the compass is properly calibrated.
This forum is full of reports of flight difficulties that begin with, I calibrate every flight.
Calibrating every flight doesn't make you less likely to have flight problems.
But it often indicates a pilot that doesn't understand what calibration of the compass does.
And sometimes in their efforts to be safe, these flyers get a bad compass calibration which has a negative effect on their flight safety.

Fly safe.
Understand what compass calibration is, when it's necessary and how you can screw it up.

It's a shame how so many are eager to jump into something to twist around what is actually being said. If you go to the OP and read the 2nd paragraph, you can see how so much gets twisted by the time it reaches this point. People read and read then likely forget who actually said what and before you know it someone has been stepped on for no reason. I never said calibrating every flight was necessary. I tried pointing out it was required if the bright yellow "?" was included. I then posted what it says when the "?" is clicked on. On my P3 the "?" appears on each flight. And since learning compass calibration is documented and looked at, I have made it a habit to calibrate when the aircraft status ask me to.

Now aside from that, I believe it is someones theory that there are good & bad calibrations. Where that ever came from I don't know. But the P3 has set values it needs to see during the calibration process, and if it does not receive them it will fail the test and give blinking yellow lights. At that point you must repeat the process until it gets those values.

 

[Meta4]

I never said calibrating every flight was necessary.

Sorry Frank, I must have been confused.
I thought that was you that said ......

The main purpose for this thread is to inform you to calibrate the compass prior to each flight. Other then laziness, there is no excuse to not calibrate before each flight.

Now aside from that, I believe it is someones theory that there are good & bad calibrations. Where that ever came from I don't know. But the P3 has set values it needs to see during the calibration process, and if it does not receive them it will fail the test and give blinking yellow lights. At that point you must repeat the process until it gets those values.

Frank ... the Phantom compass calibration adjusts the compass sensors to deal with the earth's local magnetic field.
You can adjust the compass to deal with any magnetic field, whether it's the normal field generated ny the planet - or a distorted local field generated by magnetic interference from a large steel object.

Either way you can get the mod values adjusted to around 1500.
But if you have calibrated for a distorted field, you have a BAD calibration.
It's not theory, it's fact whether you understand it or not.
And if you have calibrated for a distorted field, once your Phantom gets away from that distorted magnetic field and back to the earth's regular field, your compass is not adjusted for it and oops ... your Phantom is no longer flying properly.

And one more thing Frank ... you are quite confused about this and don't seem to understand it at all. Read Ian's primer again.
Your input on this topic goes a long way to causing unnecessary confusion for readers that may be unsure what the real situation is.
I'd really like to move on from this thread and not have to keep correcting misinformation.

 

[flyNfrank]

The amount of bad information out there is huge. Even from DJI employees. Their support people are laughable. And the countless "instructional" videos on Youtube show people calibrating their compass in the street, with a wedding band on, with a watch on, with the controller 2ft away, on a beach, etc.

Most of DJI didn't know what declination was until I beat them over the head with it.

My point being that I would be careful with even what DJI says. There is a language barrier and unless you're talking to the engineer who wrote the algorithm, you're probably getting slightly incorrect information.

My statement you quoted was made in reference to someone when asked why they didn't calibrate the compass, they say cause it didn't say I have to. And because of that, they feel it doesn't need to be done. And my point is there is nothing telling you not to do it either. As we know, dji will leave it in your own hands to interpret it for ourselves. So then you drop out of the sky or crash it's on you. We see here in the logs you didn't calibrate the compass when a message stated to do so. Well sorry for your luck, but we will offer you a 30% discount towards a new unit.

So it's no sweat off my nads to make sure to do it prior to flight. I have bought more then enough phantom's. Look at my signature.

 

[III% Streve]

Copy/Paste is a bugger sometimes!

 

[III% Streve]

I think its funny that so many have made such a ridiculously simple thing into some crazy rocket science/voodoo/ black magic kind of thing.

Calibrate your stupid compass in a place far away from metal, including crap that might be buried.
Before each flight check 4 thing..
1. Are you beyond 100 miles from your last calibration?
Yes - Calibrate that POS
No - Fly that POS
2. Is your compass MOD value between 1400-1500? Closer to 1500 is better.
Yes - Fly that POS
No - Calibrate that POS
3. Is your radar indicating that your P3 is in fact facing the direction it is facing?
Yes - Fly that POS
No - Fly that POS
4. Have you been smoking dope?
Go home and think about how you screwed your day up
Now move on the scary complicated part...

Take off, observing tendencies to drift as you loose contact with the ground and possible rotation.
If you see either of these things, land and calibrate that POS. Then start again at #1

Its that **** simple! If you follow those steps I am REALLY close to guaranteeing that you will not have a compass fault related crash.

 

[flyNfrank]

Sorry Frank, I must have been confused.
I thought that was you that said ......



Frank ... the Phantom compass calibration adjusts the compass sensors to deal with the earth's local magnetic field.
You can adjust the compass to deal with any magnetic field, whether it's the normal field generated ny the planet - or a distorted local field generated by magnetic interference from a large steel object.

Either way you can get the mod values adjusted to around 1500.
But if you have calibrated for a distorted field, you have a BAD calibration.
It's not theory, it's fact whether you understand it or not.
And if you have calibrated for a distorted field, once your Phantom gets away from that distorted magnetic field and back to the earth's regular field, your compass is not adjusted for it and oops ... your Phantom is no longer flying properly.

And one more thing Frank ... you are quite confused about this and don't seem to understand it at all. Read Ian's primer again.
Your input on this topic goes a long way to causing unnecessary confusion for readers that may be unsure what the real situation is.
I'd really like to move on from this thread and not have to keep correcting misinformation.

I do plan to read Ian's thread. But as for me being confused, on this, I don't believe so. Now others posting around what I have may make me appear to be confused. But I feel pretty good about calibrating my aircraft when the app states for me to. And after 70 flights at 70 miles that include a ton of beta testing, I never had the 1st inkling of what has been referred to as a bad calibration. How do you explain that? And believe me, if something acted wacky I would be on here with in the hour explaining the situation in detail. Btw, before buying the P3, I calibrated the compass about once every 6 or more weeks. Sometimes less if there was an update in there somewhere. But I never had any compass related issues doing it that way with the old technology.

 

[Meta4]

I do plan to read Ian's thread. But as for me being confused, on this, I don't believe so.

That's obvious

And after 70 flights at 70 miles that include a ton of beta testing, I never had the 1st inkling of what has been referred to as a bad calibration. How do you explain that?

Most likely it's because you are calibrating as you should .. in an area away from things that would give you a bad calibration ... just like it says in the manual.

 

[flyNfrank]

I'll give you one other thing to ponder on. In the new app if your IMU settings are with in spec, it will no longer allow you to calibrate. If it don't need it, it wont allow it. But now the compass as we know has put more emphasis on the calibration. I know what you're thinking, but I had to point that one out to you.

 

[snerd]

........................ In the new app if your IMU settings are with in spec, it will no longer allow you to calibrate. If it don't need it, it wont allow it.........

I didn't know that. I'm off to go check now!