Need help. DJI won't cover flyaway crash. Ignores flight data.

[IIIDaemon]

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...I'd like to preface this by saying I've seen and read about DJi doing some pretty rotten $!#$%, but I gotta say I don't think i've ever seen a post crash or incident video or flight-log that showed any pre-flight-flight checks, these new guys get these drones and just take off, typically like a bat out of hell and alot of the times right over water!! I cannot get all my checks done without using 7-9% battery.. I've tried, I've told myself it's flown great the the last two batts in a row.. the nxt batt i'll just take off.. but once i start the craft.. i just cant make myself do it.. I do all the pre-flight checks on the ground, then capture Main, Status, Sensors & Batt Scrns, verify RTH settings then start motors,set rem-crtl as home -point, listen, lift off, get clear maybe 20ft agl, yaw right, yaw left, listen, look, slide right, slide left, scan the screen and slowly climb out to typically 210ft, once up there I scan the horizon, adj cam angle, and then only then do I start my trek with a gradual increase in speed, again 7-9% battery gone, but i feel confident that all systems are go.. I do this every single flight, once i land, I capture Main, Status, Sensors, Batt, Map Scrns.. then dump the flight-log at Healthy-Drones and gather the rest of the data...
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IIIDaemon
www.GasRecovery.net

 

[syotr]

This is incorrect.
The Phantom still requires a properly calibrated compass to be able to fly in atti mode.
The compass does not provide any position data but it supplies heading data which is necessary to fly properly

I have to disagree. You can completely remove the GPS board and compass and the Phantom will fly just fine in ATTI mode. It will drift with the wind but will hold its orientation by gyros. If you try to rotate it, the Phantom will fight to hold its heading.

 

[sinxa]

another food for thought, . .

Disable compass

what i understand from this, when one of gps either compass is not present (malfunction / not locked yet), phantom will automatically switch into ATTI and ignore any data from both of them, and rely to the barometer only just to keep its altitude, and let the pilot to take full control on the orientation and direction of movements.

Sent from my SCL23 using PhantomPilots mobile app

 

[AlecW]

So it sounds like the OP's issue was caused by a poorly calibrated compass prior to flight to me.

 

[dwallersv]

You need the compass to fly straight in ANY mode, including atti mode.

No, you don't.

The gyros in the IMU are more than sufficient to keep straight, level flight. GPS and flux compass are completely ignored in ATTI.

 

[dwallersv]

Actually, there is another opinion on this.
If compass really needed on every mode, why DJI recommend to exit P-GPS mode when compass error happen? To what mode we should switch??

ATTI, as DJI recommends.

Meta4 is simply wrong. A compass is not necessary to achieve straight flight. IMU gyros are more than sufficient to achieve this.

As DJI states in the manual, in ATTI mode the only sensors controlling flight are the IMU and the barometer, for altitude.

 

[Les Davidson]

Just goes to show compass calibration is vitally important prior to every flight. Also keeping updated with software.

Sent from my SM-G935F using PhantomPilots mobile app

 

[AlecW]

Just goes to show compass calibration is vitally important prior to every flight. Also keeping updated with software.

I'm sitting here thinking the polar opposite. The OP said he calibrated at this location prior to flight, my gut feeling is that calibration near the bridge or in that parking lot let to this accident. If you have a good calibration there's no need to keep doing it.

 

[With The Birds]

Just goes to show compass calibration is vitally important prior to every flight. Also keeping updated with software.

Sent from my SM-G935F using PhantomPilots mobile app

As has been pointed out- it has been clearly demonstrated that calibration prior to first fligh of the day is not required and likely to cause problems. It is much better to fly with a last known good calibration than to potentially replace it with a bad one. I haven't calibrated my compass for over 10 months and haven't had an issue.

 

[eatpasta]

As has been pointed out- it has been clearly demonstrated that calibration prior to first fligh of the day is not required and likely to cause problems. It is much better to fly with a last known good calibration than to potentially replace it with a bad one. I haven't calibrated my compass for over 10 months and haven't had an issue.

Can we have a synthetic vs. regular oil discussion next as this one seems to be just as contentious....

 

[N017RW]

Just goes to show compass calibration is vitally important prior to every flight. Also keeping updated with software.

Sent from my SM-G935F using PhantomPilots mobile app

I appreciate your experience. Mine is different. I have not calibrated my P2 in over two years now. I have flown as far as 600 miles from the cal location as well.
So long as nothing is added, removed, or relocated on the aircraft then the on- board distortions are un-changed. These hard and soft-iron distortions is what is being compensated for during the calibration procedure. Taking the non-polar response and creating a polar one is the result.
One must do what they feel is important, vital on the other hand is dubious.

 

[eatpasta]

I appreciate your experience. Mine is different. I have not calibrated my P2 in over two years now. I have flown as far as 600 miles from the cal location as well.
So long as nothing is added, removed, or relocated on the aircraft then the on- board distortions are un-changed. These hard and soft-iron distortions is what is being compensated for during the calibration procedure. Taking the non-polar response and creating a polar one is the result.
One must do what they feel is important, vital on the other hand is dubious.

Where do you suggest getting a solid compass calibration? I'm guessing in the middle of a field somewhere and not on an aircraft carrier.....?

 

[N017RW]

Me?
My front yard, on my concrete driveway, in suburban south Florida, on my tiny 1/4 acre lot.
There is enormous superstition regarding compass compensation.
It's mostly between the ears.

 

[eatpasta]

Me?
My front yard, on my concrete driveway, in suburban south Florida, on my tiny 1/4 acre lot.
There is enormous superstition regarding compass compensation.
It's mostly between the ears.

is that like compass envy?

 

[AlecW]

Can we have a synthetic vs. regular oil discussion next as this one seems to be just as contentious....

Dino or you will crash and burn


I calibrate in my neighbors backyard. Mine has a septic system in middle of it and I'm not sure if the leach field used PVC or metal pipes.

 

[eatpasta]

Dino or you will crash and burn


I calibrate in my neighbors backyard. Mine has a septic system in middle of it and I'm not sure if the leach field used PVC or metal pipes.

Almost certainly plastic...

 

[AlecW]

Almost certainly plastic...

The house was built in 1949, I think it's all the original system and I don't know what they used back then. The house has an interesting history, a widow lived on her own for about 40 years and the guy I bought it from owned it for 25 years but average one weekend a month occupancy, he also had a house in Florida. I've lightly got a big 20K bill coming up when it fails and I swap to city water/sewage.

 

[eatpasta]

The house was built in 1949, I think it's all the original system and I don't know what they used back then. The house has an interesting history, a widow lived on her own for about 40 years and the guy I bought it from owned it for 25 years but average one weekend a month occupancy, he also had a house in Florida. I've lightly got a big 20K bill coming up when it fails and I swap to city water/sewage.

if it's close to post-war there is a chance it could be paper (orangeburg) believe it or not. That stuff.... It's trash. It could also be clay if it's that old

 

[AlecW]

if it's close to post-war there is a chance it could be paper (orangeburg) believe it or not. That stuff.... It's trash. It could also be clay if it's that old

Could be clay, the house was well built for the time period, probably better than the crap that was built in the 80s and 90s etc. Anyhow, my neighbor's field is a 100 feet away so I calibrated it there just in case

 

[MacPhantom]

Just my 2 cents...

Compass calibration only puts the compass in the correct orientation for the local region that it is in for the calibration. If you get on a plane and fly somewhere different, geographically speaking you will need to calibrate the compass again. If you calibrate and always fly in the same general geographical area, you should not need to calibrate your compass.

That being said, nothing can help you in an area of strong magnetic interference. If you calibrate your compass there, you will be in worse shape than if you had left the current calibration because your baseline will be off and everything from that point is crap. If you didn't calibrate there, you could simply try to fly the device in ATTI mode away from the suspected object and you should have full P control back.

I calibrated my compass when I first setup my Phantom. I will not do it again unless I move it to a much different area, or the unit tells me there is an error that requires me to calibrate my compass. Again, I think I would introduce more risk in always calibrating than continuing with a known good calibration.

If my P3 started acting like these videos, I would immediately switch to ATTI mode and increase the altitude to buy me some time to sort it out. (The bridge would be my first suspect in this video)