DroneFlying Posted at 2017-2-2 10:22
"Heck yes of course DJI should be warning people about the things the drone CAN'T do. "

That would make for a very long manual, my friend.

Are we really going to devolve into arguing semantics now?

"The RTH estimate is for under ideal conditions and does not take into account current wind conditions and may result in the aircraft not having enough power to reaching the Home Point"

This single line of warning popup would've prevented my lost drone today, and probably tons of future accidents waiting to happen. I'm willing to bet they WILL add this to the manual/app in the future because it's stupid not to.

DroneFlying Posted at 2017-2-2 10:17
Are you sure about this? I know they did begin covering water damage around that time, but I was under the impression that you still have to recover and send in the aircraft. And the Care Refresh page still says that to start the process you have to "send your product to a designated DJI repair center under the instruction of DJI Support staff". Otherwise, as the OP himself has pointed out, they have no way of knowing that you really did lose the aircraft and would open themselves up to fraud.

That was my understanding, you need to recover a damaged Mavic to claim.  Maybe I'm wrong in my understanding but it would make sense otherwise they could be wide open to people being a bit less than honest possibly.

Psy Posted at 2017-2-2 10:27
Are we really going to devolve into arguing semantics now?

"The RTH estimate is for under ideal conditions and does not take into account current wind conditions and may result in the aircraft not having enough power to reaching the Home Point"

I'm sure they'll be adding a lot of things to the manuals and this may very well be one of them.

For what it's worth, I seem to recall that I have seen threads where they seemed to be willing to replace someone's drone even though it was completely lost. However, I believe that the only time I've seen that was in the case of a flyaway where they were able to determine that it wasn't due to pilot error. In other words, those were warranty replacements and not Care Refresh replacements: an important difference that I'm guessing you're aware of since you stated in your original post that you don't think Care Refresh applies here.

Psy Posted at 2017-2-2 09:41
It doesn't have to calculate for sudden change in wind - it just has to calculate how much tailwind it's getting and inverse that for headwind and tell me if it's likely I'll make it home. That's really not that difficult for it to extrapolate when it's capable of doing everything else already. Or at least tell me that it's a possibility!!

The whole reason why the Phantom from one generation to the next, and now the Mavic is so appealing to the mass consumer market is because the price is coming down while the intelligence is going up.

On your app you would have set RTH warning and critical warning you never said what happened with this.
You would have received first warning at whatever you had it set at, you could have cancelled that, but second critical warning , you can't cancel this, so as the Manual says if your current battery level can only support it to descend then that's what it will do

you  are well aware dji insists you read the manual , you have said you read the manual cover to cover, so can you explain how you missed this bit, it is meant for just the situation you found yourself in.

Low battery RTH :

The low battery level failsafe is triggered when dji intelligent flight battery is depleted to a point that may effect the safe return of the aircraft . USERS ARE ADVISED TO RETURN HOME OR LAND AIRCRAFT IMMEDIATELY WHEN PROMPTED.DJI. GO 4 app will display a notice when low battery warning is triggered. The AC will automatically return to Home Point if no action is taken after ten second countdown. The user can cancel RTH procedure by pressing RTH button on the controller. The thresholds for these warnings are automatically determined based on the AC current altitude and distance from home point.

THE AIRCRAFT WILL LAND AUTOMATICALLY IF THE CURRENT BATTERY LEVEL CAN ONLY SUPPORT THE AIRCRAFT LONG ENOUGH TO DESCEND From ITS CURRENT ALTITUDE. THE USER CAN USE THE REMOTE CONTROLLER TO ALTER THE AIRCRAFTS ORIENTATION DURING THE LANDING PROCESS.

A1000 Posted at 2017-2-2 10:29
That was my understanding, you need to recover a damaged Mavic to claim.  Maybe I'm wrong in my understanding but it would make sense otherwise they could be wide open to people being a bit less than honest possibly.

Sorry, I'm wrong. Whilst water damage is covered loss or partial loss is not.
You need to find the flight log, propose a treasure hunt for the local sub aqua club and get the drone back.

"Sorry, I'm wrong. Whilst water damage is covered loss or partial loss is not."

Ok, that's what I thought.

Psy Posted at 2017-2-2 10:00
Again, I am totally not understanding the hostility that you seem to have towards me.

Yes, I would love if DJI were to give me a new drone after what happened today. I made a newbie mistake and I screwed up - that's why I spent more money and bought a the DJI Care insurance package. I knew the likelihood of me somehow messing up the drone was high. Surprise - that's why I bought the replacement plan.The only difference is that I was unable to retrieve the drone physically because it fell into the sea instead of concrete or into a forest somewhere where I am actually able to physically get it back. I'm fairly certain the main reason they have the physical drone replacement plan as part of the policy is because they want to prevent fraud (and also because they want to be able to recycle parts). That is obviously not what is happening right now.

You made a newbie mistake.

You made several newbie mistakes, first and most important one is you didn't read the manual.

This has nothing to do with dji letting you down , your whole approach to this was incredibly juvenile and without concern for others whether they were flying lying on the beach or swimming in the sea when your AC landed on them.

I think you should write to djicare and ask them to include allowing for newbie mistakes.

hallmark007 Posted at 2017-2-2 10:46
On your app you would have set RTH warning and critical warning you never said what happened with this.
You would have received first warning at whatever you had it set at, you could have cancelled that, but second critical warning , you can't cancel this, so as the Manual says if your current battery level can only support it to descend then that's what it will do

I think you are being confused.

There are actually four separate RTH warning, not two. Only two can be set  manually through the DJI app. (Since I don't have my drone with me now I can't confirm this. Someone else correct me if I'm wrong.)

1) My low battery warning is set at 30% (first manual)
2) My critical low battery warning is set at 10% (second manual)

3)The third RTH is a self calculated RTH warning which is a warning that is displayed when DJI thinks you will not be able to get home based on the distance it would need to travel back with the amount of battery that is left. This warning can happen at any percentage level and is not controlled by the user. THIS HAPPENED TO ME AT 50% BATTERY, WHEN I HAD STARTED OUT AT 85% AT THE BEGINNING OF THE FLIGHT. I did NOT ignore this warning and I began flying back IMMEDIATELY manually because I wanted to be in control of the aircraft and I wanted to make sure that I was flying full throttle (again, it does not seem to specify what throttle or mode the aircraft self flies back in).

**Again - I must emphasize that my whole issue is that it is ambiguous in the owners manual and shown nowhere on the app that the automatic RTH calculation does not include wind speed. That is what is at discussion here ..

4) The fourth, forced automatic landing only allows for descent and is the last ditch effort for the drone to land safely where ever it happens to be, and in my instance was 500M from where home point somewhere out at sea ...

I'm really confused at the level of hostility by the members of the community towards new fliers. Especially those that don't really know what they are talking about ...

hallmark007 Posted at 2017-2-2 11:05
You made a newbie mistake.

You made several newbie mistakes, first and most important one is you didn't read the manual.

I'm not even going to bother replying to you anymore because you add absolutely nothing to the discussion and are spreading misinformation.

And DJI does cover newbie mistake. That is LITERALLY what DJI Care is for !!!!!!!!?

"I did NOT ignore this warning and I began flying back IMMEDIATELY manually because I wanted to be in control of the aircraft"

That's one thing you did right; since you'd previously been flying (per your original post) in urban / suburban areas, I'm guessing (hoping) that your RTH altitude was set fairly high and that your over-water flight was lower than that. Had you allowed the automated RTH to kick in, you'd have used up even more battery life climbing, and the wind might well have been even worse at the higher altitude. It typically is stronger at higher altitudes over land, at least.

"I wanted to make sure that I was flying full throttle"

That, on the other hand, was a bad call, but I know we've already been over that and I won't belabor the point.

Psy Posted at 2017-2-2 11:14
I'm not even going to bother replying to you anymore because you add absolutely nothing to the discussion and are spreading misinformation.

And DJI does cover newbie mistake. That is LITERALLY what DJI Care is for !!!!!!!!?

Yes,  newbie mistakes when you recover the drone. But you didn't.

DroneFlying Posted at 2017-2-2 11:15
"I did NOT ignore this warning and I began flying back IMMEDIATELY manually because I wanted to be in control of the aircraft"

That's one thing you did right; since you'd previously been flying (per your original post) in urban / suburban areas, I'm guessing (hoping) that your RTH altitude was set fairly high and that your over-water flight was lower than that. Had you allowed the automated RTH to kick in, you'd have used up even more battery life climbing, and the wind might well have been even worse at the higher altitude. It typically is stronger at higher altitudes over land, at least.

Actually, I had manually changed to only 15 meters up since I was flying out at sea. That is part of my pre-flight check.  It wouldn't have made a difference because my altitude was already higher than that

DroneFlying Posted at 2017-2-2 11:18
Yes,  newbie mistakes when you recover the drone. But you didn't.

You seem strangely focussed on wishing that I don't get a replacement drone and I'm not sure why. But hey, whatever rocks your boat ¯\_(ツ)_/¯

Psy Posted at 2017-2-2 11:10
I think you are being confused.

There are actually four separate RTH warning, not two. Only two can be set  manually through the DJI app. (Since I don't have my drone with me now I can't confirm this. Someone else correct me if I'm wrong.)

Critical battery warning cannot be cancelled RTFM, below is what happens in critical battery, also that warning is NOT RTH warning but a warning that you may not have enough battery to get to home point so land somewhere safe,
I think people are being hostile with you because your rude and making no sense , if you don't like the answers you seem to be aggressive in your reply, you also seem to answer only what suits you on two occasions I posted how you were putting others at risk but you failed to answer any of these points.

And this to me says a lot about you , I don't think your going to get a lot of sympathy around, mostly because you don't deserve it..

THE AIRCRAFT WILL LAND AUTOMATICALLY IF THE CURRENT BATTERY LEVEL CAN ONLY SUPPORT THE AIRCRAFT LONG ENOUGH TO DESCEND From ITS CURRENT ALTITUDE. THE USER CAN USE THE REMOTE CONTROLLER TO ALTER THE AIRCRAFTS ORIENTATION DURING THE LANDING PROCESS.

"You seem strangely focussed on wishing that I don't get a replacement drone and I'm not sure why. But hey, whatever rocks your boat ¯\_(ツ)_/¯"

You seem strangely focused on how this is really DJI's fault for not warning about it in the manual and I'm pretty sure why. But hey, whatever rocks your boat. ¯\_(ツ)_/¯
And I'm not wishing anything: I just don't agree with your attempting to blame DJI for what happened to your drone.

This guy, I'm pretty sure has the record on a stock mavic one way at least. 13.5 miles

Psy Posted at 2017-2-2 04:31
Thanks for all the opinions and feedback. I welcome the discussions so that we can all collectively learn from my experience. Like others have pointed out, I think it would be good for DJI to weigh in on two questions so far:

1) Does the RTH estimation battery life take wind speed (and to a lesser extent height) into consideration when making calculations ?

1.  No and to assume it does is a mistake.  If you think the manual is ambiguous then you should have taken it as a no as well.  Wind can change in speed and direction all the time and I frankly wouldn't believe DJI if they claimed they could incorporate that into their range calculations.

2.  The aircraft will have less range in sport mode as power to speed conversion is not linear.  You will require more than twice the power from the battery to do 40 mph than to do 20 mph.  Look up aerodynamic drag.  I think that DJI state that the max flight time is 27 minutes at 15 mph.  This is due to the aerofoil (wing) lift effect you get from the rotors moving forward through the air, just like in a helicopter.  You will actually get less flight time just hovering.  So duration rises from 0 to 15 mph and then reduces again at speeds higher than 15 mph.

DroneFlying Posted at 2017-2-2 11:29
You seem strangely focused on how this is really DJI's fault for not warning about it in the manual and I'm pretty sure why. But hey, whatever rocks your boat. ¯\_(ツ)_/¯

Yeah, because I'd love a replacement drone since I lost mine due to an honest newb mistake? So what's your problem?

Psy Posted at 2017-2-2 16:47
Yeah, because I'd love a replacement drone since I lost mine due to an honest newb mistake? So what's your problem?

OP: I feel your pain. Last year while on a trip I lost a brand new Sony RX100 IV camera which costs almost as much as a Mavic.  I had purchased accidental damage insurance on it and it was under warranty of course. But I lost it due to my own error, just as you did with your Mavic. There is no grounds for a claim.   

Regardless, good luck!

I am also sorry to hear it is gone.
I do think though that this is a pilot misjudgment, the fail safe's the software put in place are great but no replacement for good judgement.
4klms was a bit of a push, maybe out to 2, hover for a while - test the RTH function on one battery, then PERHAPS, if you needed push it further at your own risk of course.

I recently made a similar test but had put extensive hours in overland prior. I nearly lost my drone, I thought It would not make it back. I also misjudged the wind.

I at no time would have put the responsibility onto DJI - I knew this prior to flight, and if lost I knew it was my mistake.

Sorry to hear but this is not a warranty claim. I hope DJI may extend you courtesy and offer a replacement via care refresh and your flight log data but this would be EXTREMELY GREAT CUSTOMER SERVICE - it should not be expected as the policy clearly states thhat the drone must be recovered.

It sux though man.

My video of my near loss below

https://youtu.be/NjUuOaFXSzo

Just so that we are all clear, there were no Thermal Wind.

I'm truly sympathetic to mistakes (I make them a lot) and I'm really sorry that you lost your drone, but the key is to be prepared to put up with the potential downsides of any risk that you take and use it as a learning experience.
  
DJI can't tell users everything that a product can't do.  This borders on the 'Caution, contents may be hot' warnings they have to put on coffee cups.

I have edited the original post to avoid what I feel is unnecessary connections and hostility which detracts from discussing this problem. I already stated why I feel like there is a possibility of a Care Refresh claim in subsequent posts, but will accept if DJI gives me a thumbs down.

But, at the end of the day there will be hundreds if not thousands of new pilots getting into this new hobby of UAV, and I can guarantee that I won't be the last to try to push this toy to it advertised limits and abilities. As a community we should focus on that instead.

Psy Posted at 2017-2-2 19:11
I have edited the original post to avoid what I feel is unnecessary connections and hostility which detracts from discussing this problem. I already stated why I feel like there is a possibility of a Care Refresh claim in subsequent posts, but will accept if DJI gives me a thumbs down.

But, at the end of the day there will be hundreds if not thousands of new pilots getting into this new hobby of UAV, and I can guarantee that I won't be the last to try to push this toy to it advertised limits and abilities. As a community we should focus on that instead.

I really appreciate your good humor in what must be a sucky day, and also your willingness to help educate others.

All I'd say is you did a 'test'.  You made a hypothesis and tried to test that hypothesis.  The result was 'false' and there were consequences that are attached to that.  I truly do stuff like that all the time.  I just don't think there's blame to be shared.  Fair play to you for continuing this thread and educating.  Upvote from me to you.

I'm sorry for your loss, but it has nothing to do with RTH, it's your fault because you switched to sport mode which consumes a lot more battery.

BuzzCut Posted at 2017-2-2 19:23
I really appreciate your good humor in what must be a sucky day, and also your willingness to help educate others.

All I'd say is you did a 'test'.  You made a hypothesis and tried to test that hypothesis.  The result was 'false' and there were consequences that are attached to that.  I truly do stuff like that all the time.  I just don't think there's blame to be shared.  Fair play to you for continuing this thread and educating.  Upvote from me to you.

Thanks for the sentiment, but I would like to make a small counter argument.

My test was for range, not for battery life. In terms of range test, my test was a huge success - I got up to 4KM which I was more than happy with, because my Mavic did not have the same range manuafacure defect that my brothers P4 suffered. It did not even occur to me that I had to worry about the battery life, because in other environments and flights RTH estimations were extremely accurate. This is what this thread is really about right now

"I'm sorry for your loss, but it has nothing to do with RTH, it's your fault because you switched to sport mode which consumes a lot more battery."

Give PSY a break. So he responded to criticism that may have been knee jerk reaction, but after all he's just lost his drone. I haven't found his responses to be overly offensive and throughout he's been open and honest about what he did and the consequences he suffered. Repeating what has already been said is pointless and reactionary. For the benefit of others it's a great warning of what can happen, but I don't think there's much more that can be said that hasn't been said already. If there is then I look forward to reading it.

Psy Posted at 2017-2-2 19:54
Thanks for the sentiment, but I would like to make a small counter argument.

My test was for range, not for battery life. In terms of range test, my test was a huge success - I got up to 4KM which I was more than happy with, because my Mavic did not have the same range manuafacure defect that my brothers P4 suffered. It did not even occur to me that I had to worry about the battery life, because in other environments and flights RTH estimations were extremely accurate. This is what this thread is really about right now

For the sake of learning and us all losing as few Mavics as possible I think there's still a little left on the table here...  Apologies for the essay.

You make a great point.  I don't know what your 'test' was.  I presumed to know but I clearly guessed incorrectly.

So, I infer from your response that your test was for 'range, not for battery life' and that it was a 'huge success' that your test was purely for RF transmission range and was therefore something like:

A) Can I fly my Mavic on this day in this place and in these conditions and maintain RF signal, including video transmission, for a distance of 4KM?

In that case it was indeed a success.  You proved to yourself that that Mavic on that day, in that place, at that flying height, and in those RF conditions could do that (I'll get to all the caveats in a bit - they're important).

That's a very expensive test though, since it doesn't factor in the ability to travel out and then travel back again (both RF signal and battery).  I would argue there would have been a much less expensive way to approximate that test by simply turning on your Mavic and leaving it hovering above a field with someone watching it while you got in a car with the controller and drove to different distances and periodically got out and tested signal that way.  Using that method you also would have been able to keep going til you found you max RF trasmission distance (again, with all of the previous caveats)

The more typical range test I've seen is:

B) Can I fly the mavic out X far and get it back again?  This is RC and battery, throttled by the weakest link.  Ususally that's done incrementally until someone feels like they've gotten close to what they consider to be a maximum without losing the drone (or they go one step farther and lose it).  This is still a risky 'range test' but definitely a much less risky type of range test than the one you performed.  I want to point that out to anyone that's looking to get their bird safely back.  I'm not trying to be facetious here.  I think it's important to distinguish the two and highlight the risks if we're trying to get our Mavics home at the end of the day.

Now, the most important point in my opinion which needs to be understood if we're to fly our drones for fun and still get them back:

DJI can estimate how far the Mavic can go, but they cannot guarantee how far it will go.  Never confuse an extimate with a guarantee when it comes to RC.

Why?  RC range depends on RF conditions.  RF conditions not only vary significantly from place-to-place, but vary significantly in the same place for a whole myriad of reasons.  To take it to an extreme, you could prove that 'your' Mavic in 'your' chosen location could go 4KM on a given day with the given RF conditions.  You could test the same Mavic in the same place on a different day and get completely different results, maybe resulting in losing your bird.  Why?  Tranmission distance depends on RF conditions, and a drone manufacturer only has control over the frequency, transmit power, receive power etc. of the craft and controller.  It cannot guess or control all the other RF signals in the area, the atmosphere (e.g. moisture in the air), the temperature, radiation from the sun, the tilt you have your antennae at vs. where the bird is, etc.  No control at all.  All of these factors and more go together to determine whether you have good RF conditions.  Again, estimates; not guarantees.

The same goes for battery life (though that wasn't part of your test it did have an effect on your day).  The Mavic uses sensors to estimare how much usable battery power is remaining, and an algorithm to churn that with sime limited other variables (how fast you're going, motor RPM, who knows what...) to estimate (again just a guess) how long that charge will last you.  That algorithm doesn't know future variables such as whether you're going to speed up, change flying modes, fly higher, or whatever.  Further the algorithm that tries to estimate whether - based on the current distance between the controller and the craft - you need to start heading back can't know future wind direction or speed, or the previous things that might happen to change the speed that the battery will be drained.  Other things can afftect the battery as well, such as temperature changes affecting the conductivity of the materials.

Bottom line: if you see a video where someone tells you 'The mavic will travel X far' or 'The Mavic's battery will last Y long' in such blanket statements they are being simplistic and innaccurate.

Since I don't walk around with a drive test team with spectrum analyzers I cannot gauge current RF conditions and therefore wouldn't consider performing a range test.  Line of sight is my personal choice for a limit for multiple reasons that are personal to me.

Energy = mass x velocity^2  -  it is the same thing going in when you are driving your car. Going 80km/h at 5L/100km compared to going 120km/h at 10L/h, double the fuel consumption, but not double the speed. The speed is squared and that is why sports mode can not be advised for range tests.

BuzzCut Posted at 2017-2-2 22:30
For the sake of learning and us all losing as few Mavics as possible I think there's still a little left on the table here...  Apologies for the essay.

You make a great point.  I don't know what your 'test' was.  I presumed to know but I clearly guessed incorrectly.

I was too focused on whether or not I could, as opposed to whether or not I should. Doh!

Psy Posted at 2017-2-2 10:16
It was a range test! How else would I know what the drone can and cannot do, until the aircraft told me to stop, right?

Although in hindsight, this mindset could've very possibly cost me a good chunk of change ...

I suppose that's the same as the microwave and tumble dryer manufacturers having to put warnings about not drying your cat in their products or Macdonalds having to warn people that coffee is hot.

If i need to fly from Location A (take off point) to Location B (Target), what is the best mode to arrive faster with less battery used, P or Sport Mode

Depends on wind

bmbk Posted at 2017-2-3 04:19
If i need to fly from Location A (take off point) to Location B (Target), what is the best mode to arrive faster with less battery used, P or Sport Mode

Which is it? Faster or minimal battery drain?  If covering the distance as fast as possible is the goal, then of course full throttle in sport mode (assuming you've got enough battery to make it)..  But if covering the distance with minimum battery use is the goal, then a more moderate amount of throttle--consistent with P mode--is probably needed.

FWIW, every aircraft manufacturer publishes this kind of data for their aircraft--power settings for maximum speed, maximum distance, and maximum duration (max time in the air)--all of which are different. If you want to get there in a hurry, you maximize speed.  If you're running low on fuel and want to make sure you can make it to the airport, you select a power setting to maximize distance. If you're circling over an airport waiting for the fog to clear, you select a power setting to give you maximum duration. But I'm not aware that this kind of info is available for drones.

bmbk Posted at 2017-2-3 04:19
If i need to fly from Location A (take off point) to Location B (Target), what is the best mode to arrive faster with less battery used, P or Sport Mode

As posted earlier in this thread, P mode at 15mph air speed has been suggested as the most efficient speed to fly with zero wind or a tail wind. The point at which sport mode should be enabled must be down to the pilot to determine the point at where the drone is fighting a head wind and making little or no ground related progress. For example, at this said point the drone could have an airspeed of 20mph but with a low or negative ground speed if the wind speed were around 20mph or above. GPS will give you ground speed.

Psy Posted at 2017-2-2 19:11
I have edited the original post to avoid what I feel is unnecessary connections and hostility which detracts from discussing this problem. I already stated why I feel like there is a possibility of a Care Refresh claim in subsequent posts, but will accept if DJI gives me a thumbs down.

But, at the end of the day there will be hundreds if not thousands of new pilots getting into this new hobby of UAV, and I can guarantee that I won't be the last to try to push this toy to it advertised limits and abilities. As a community we should focus on that instead.

Sorry you lost your drone.

Thanks for sharing your experience here - This information will be useful for others and has highlighted how critical wind speed is in affecting drone range.  I also wonder about your battery - mine really do not drop much even after a few days in the bag.

The attitude of some is a little odd - not sure what they get out of it, but it is best ignored.

"I was too focused on whether or not I could, as opposed to whether or not I should."

It's good to see that you're accepting the responsibility for what happened; learning from mistakes is what makes people better pilots.

LarsDK Posted at 2017-2-3 00:38
Energy = mass x velocity^2  -  it is the same thing going in when you are driving your car. Going 80km/h at 5L/100km compared to going 120km/h at 10L/h, double the fuel consumption, but not double the speed. The speed is squared and that is why sports mode can not be advised for range tests.

Drag is the elephant in the room - how aerodynamic is the Mavic ? I haven't seen any wind tunnel tests on the Mavic. Based on car & bike aerodynamic principals the Mavic's square arms and hard edges doesn't bode well for aerodynamics. So if we assume the Mavic is not particularly aero then increasing speed by using sport mode will have a massive effect on battery life as the drone will require increasing levels of power to overcome the drag/wind resistance. I'm not sure what the coefficient would be for the Mavic but for bikes it's roughly to go twice as fast requires 8 times the energy

Think one of the biggest problems with this thread , what exactly happened on this flight how it all went at the end, what exactly happened with RTH was it cancelled , what happened when it went into critical battery, we know RTH is automatic at this point.

Why would the OP not put up logs here if his outlying reason for posting here was to help others. I think it would help a lot more if he uploaded his logs to phantom help or even healthy drones.and posted them here.

As many have mentioned, seems like a wind-related issue.  Use the Rule of Thirds:  1/3 of your battery to get there, 1/3 of your battery to get back, 1/3 of your battery for contingencies.