Mavic dropped mid air -> destroyed

[m0j0]

I try now to make it a habit before every flight to check everything, no metal around & calibrate all the sensors. Have not crashed or maimed anyone since. .

I would advise against calibrating every flight. Get a clean calibration and leave it alone.

Don't be discouraged, Whether it is a $1000 Mavic or $30 copter... stuff happens so you just need to be on the ball !!.

Stuff happens with cheapos... rarely does "stuff happen" with DJI products. Set it up properly, make certain you understand RTH completely. Practice flying. Practice emergency situations and fly it. I have about 500 miles of flight without a single crash. Don't be scared to fly the thing, it is incredibly stable probably the most stable platform I have flown.

 

[dwallersv]

Just read this in the mavic manual. Number 7 on batteries

Over Discharge Protection: To prevent over-discharge damage, discharging automatically stops.
If was brought up about full forward on both sticks
Max draw from the battery
I agree
It shouldn't allow you to do this and back off. Not drop out of the sky

I don't see what you're claiming regarding sticks anywhere on that page. I can only find the point #7, as you transcribe it above.

However, I would say your reading/interpretation of item 7 is entirely wrong. The issue with full sticks is a current draw limitation, which the batteries themselves provide in a current limiter. In short, there is a maximum current that the battery will deliver, and cap it at that threshold.

The Mavic will not drop from the sky. Instead, you will get a warning message on the RC, "Batt Error", which will go away when you back off the sticks.

Item 7 above concerns over-discharge which has to do with how much you drain the battery. Lithium Ion chemistry does not like to be discharged below 3V, and if taken this low or lower, significant damage starts to occur in the battery. A LiIon battery (of which lipo and LiHV are part of the family) discharged below 3V should be discarded and not trusted, no matter how "okay" it seems.

Over Discharge Protection will drop your baby from the sky. But you've got to be stupid enough to run the battery dry, then fight the Mavic's instinct to critical-battery auto-land. Only then do you have a possibility of reaching the discharge protection cut-off.

No, the Mavic battery doesn't shut off when you demand too much current from it. It just doesn't give it to you.

 

[WaveJunkie]

I would advise against calibrating every flight. Get a clean calibration and leave it alone.

If that were the case I would have never calibrated in the first place as it was rock solid stable the first couple of days / flights.

Now If I do not calibrate before flight and just let it be, the unit still has drifting every 3rd or 4th launch. (after battery changes) I am having to manually correct with counter (trim) to maintain center. If it is too much for comfort ill down the sucker and recal.

I have found the unit is quite sensitive to pipes, rebar in cement and any other metal. As ill get a compass warning if underground pipe is too close to launchpad.

Stuff happens with cheapos... rarely does "stuff happen" with DJI products.

You misunderstood my point (or I didn't explain it properly). Just as in life.. stuff happens... be
prepared... be on the ball.

These forums are full of DJI products that have "stuff happen" all the time without any logical reason. Im not saying its junk, as I still love my mavic

 

[mig25]

I don't see what you're claiming regarding sticks anywhere on that page. I can only find the point #7, as you transcribe it above.

However, I would say your reading/interpretation of item 7 is entirely wrong. The issue with full sticks is a current draw limitation, which the batteries themselves provide in a current limiter. In short, there is a maximum current that the battery will deliver, and cap it at that threshold.

The Mavic will not drop from the sky. Instead, you will get a warning message on the RC, "Batt Error", which will go away when you back off the sticks.

Item 7 above concerns over-discharge which has to do with how much you drain the battery. Lithium Ion chemistry does not like to be discharged below 3V, and if taken this low or lower, significant damage starts to occur in the battery. A LiIon battery (of which lipo and LiHV are part of the family) discharged below 3V should be discarded and not trusted, no matter how "okay" it seems.

Over Discharge Protection will drop your baby from the sky. But you've got to be stupid enough to run the battery dry, then fight the Mavic's instinct to critical-battery auto-land. Only then do you have a possibility of reaching the discharge protection cut-off.

No, the Mavic battery doesn't shut off when you demand too much current from it. It just doesn't give it to you.

I was referring to the OP that he stated both sticks were full forward and it lost power and it fell. Just before impact he stated it restarted. I have used sport and don't get any warning and it runs fine. Yet we do have these issues that come up like our OP accident.

 

[smh]

Quick update about the (long) analysis process :

Answer from DJI

Upon checking your case, Here are the results of the data analysts:
【Flight control file fly17】
1)Aircraft worked at GPS mode in flight.

2)Pilot pushed throttle up and pitch stick forward, aircraft flew up and forward, then dropped at t=501s when it was 41 meters relative height due to battery power cut off.

Conclusion:
Batter power cut off, free RMA

 

[idiogenic]

Good outcome mate!

 

[m0j0]

If that were the case I would have never calibrated in the first place as it was rock solid

I have had mine since November. I have never calibrated it. Not once. It flies perfect. I really don't recommend doing what I do. I am a believer of calibrating and leaving it alone. It did come from China.. but mine has flown perfectly since day one and I have never calibrated the compass.

 

[m0j0]

Now If I do not calibrate before flight and just let it be, the unit still has drifting every 3rd or 4th launch. (after battery changes) I am having to manually correct with counter (trim) to maintain center. If it is too much for comfort ill down the sucker and recal.

What you describe is uncommon. There is no way you should need to recalibrate from battery to the next at the same location. If that is happening you are flying in a bad area or.... you have a defective Mavic.

 

[m0j0]

I have found the unit is quite sensitive to pipes, rebar in cement and any other metal. As ill get a compass warning if underground pipe is too close...

If you are getting a compass error on the ground in an area you have already flown on a properly calibrated Mavic you have chosen a bad launch location. Move the Mavic to another location and try again. Sometimes that can mean moving it a few feet. Or launching it above the ground. I have done that to avoid interference from a pier.

 

[m0j0]

These forums are full of DJI products that have "stuff happen" all the time without any logical reason. Im not saying its junk, as I still love my mavic

No it is not. Most of the time "stuff happens" there is a reason that can be isolated to operator error. I'm not saying it always is the operators fault but my experience of the past few years on the board most of the errors can be explained by an error of the pilot. Didn't set home point, didn't set RTH properly, launched from a partially charged battery, flew beyond their experience - e.g. Too much wind and a host of other problems that were initially blamed on the aircraft but later after inspection of the flight data found to be operator error. I read most lost drone threads. I don't know how many times someone reports a flyaway only to find that they lost signal and had the RTH set lower than the building the aircraft flew into.. or found that they never really lost signal and their aircraft did exactly what it was programmed to do. So I disagree.. the board is full of issues but most are explainable and preventable. I have seen very few unexplained catastrophic issues.

MY .02
Darryl

 

[SeaComms]

Quick update about the (long) analysis process :

Answer from DJI

Upon checking your case, Here are the results of the data analysts:
【Flight control file fly17】
1)Aircraft worked at GPS mode in flight.

2)Pilot pushed throttle up and pitch stick forward, aircraft flew up and forward, then dropped at t=501s when it was 41 meters relative height due to battery power cut off.

Conclusion:
Batter power cut off, free RMA

Excellent news and corresponds with what the gurus on here deduced. What I wonder about though is if the gurus on here (obviously being monitored by DJI in some way) had not come to any conclusion of hardware failure would have DJI?

Anyway enough of my conspiracy theories, good news at the end and a weight off your shoulders confirming you did nothing wrong.

 

[SRJ_Mavic_PRO]

DJI would be lucky to conclude themselves out of a wet paper bag!! The so called programmers at DJI are the worst ever to touch a keyboard!!! Just look at the POS software they have released in the past three months!!

 

[dwallersv]

DJI would be lucky to conclude themselves out of a wet paper bag!! The so called programmers at DJI are the worst ever to touch a keyboard!!! Just look at the POS software they have released in the past three months!!

Wow. That's really unfair, and pretty nasty.

As for my part, I have a lot of respect for the DJI engineers and what they've accomplished -- hardware and software. Having managed many software projects, I understand the schedule mandates driven by marketing, competition, and customer demand that force out buggy code against the wishes and better judgement of the engineers. I've been one of those engineers too.

In fact, this is pretty much the case with almost every release of every complex software product.

 

[m0j0]

DJI would be lucky to conclude themselves out of a wet paper bag!! The so called programmers at DJI are the worst ever to touch a keyboard!!! Just look at the POS software they have released in the past three months!!

My experience with other manufacturers has been far worse. DJI has the best interface and by far allows the most customization. It really isn't close in my estimation. I have no complaints with DJI as compared to their competitors. I suppose if you compare them to apple computers or tablets they are behind.

 

[SeaComms]

Wow. That's really unfair, and pretty nasty.

As for my part, I have a lot of respect for the DJI engineers and what they've accomplished -- hardware and software. Having managed many software projects, I understand the schedule mandates driven by marketing, competition, and customer demand that force out buggy code against the wishes and better judgement of the engineers. I've been one of those engineers too.

In fact, this is pretty much the case with almost every release of every complex software product.

Could not agree more! I too have been managing a software development team for the last 2 years and I too understand exactly the sales/technical battle.

Personally I think DJI are doing a great job considering the complexity of the system vs the size and stability. Yes there are a few bugs but it still is far above most others out there.

We also have to remember that they are building in features to suit the whole world, with different restrictions, power and permissions for different countries. This is not simply a remote controlled toy, it is an extremely complicated flying software system.

There are a couple of complaints of loss of control and autonomous landings over water, but these are the exception and seem to be a fault rather than by design. I give them 2 thumbs up for the work they have done rather than bagging t hem for software bugs.

If I compare it to my Jeep Cherokee, a 4000lb death trap on wheels, I would highly recommend that Jeep hired some of those DJI software engineers... (in the 18 months I have owned my Jeep it has had around 15 to 20 software updates on various systems to fix things, some quite serious like total loss of power entering a freeway or intersection)

 

[jimapp]

Cannot resist..."Just Empty Every Pocket"...do not mean to offend...