Rob W Posted at 2016-4-11 06:03
I haven't flown with this firmware yet, but on the previous one I noted that if flying forward then  ...

just flew a few minutes ago- I have the new firmware and it did exactly as you stated, no change

Topviewpics Posted at 2016-4-14 03:15
Yes, it is the same place. And that's were my P4 keeps dropping height from forward flight and inc ...

We will!  

DJI-Tim Posted at 2016-4-11 23:20
We need the flight data to analyze it.  My P4 doesn't drop the altitude. Could you please post fli ...

it sounds like we may have a hardware issue, if some P4's drop and others do not, how can that be?
because mine for sure drops, and it is a real issue.

scfilmvideo Posted at 2016-4-13 23:26
Do they ALL do this, or just some of them? Is there any known correlation between the P4 versions wi ...

I can only speak from personal experience, but my cousin and I ordered our P4's approximately 2 weeks apart.  He ordered his on March 15 (release date), and I followed him 2 weeks later.  We are BOTH experiencing this same drop, and they have both been doing it from day one!  For me, it happens at low altitude, as well as high altitude (up to 400' AGL), so I don't THINK it has anything to do with the Visual positioning system...

I realize this is a new product, and so it is likely to experience some growing pains, but judging from what I've seen one SEVERAL forums, this is not an isolated incident.  On the Phantom Pilots forum, there are literally DOZENS of P4 owners experiencing this same problem.
  
And, I've heard rumors of a firmware fix for this situation, but at this point, they seem to be only rumors.  I HOPE this can be fixed by firmware, because if this is a hardware or flight model problem, this could spell doom for DJI.  I've already seen reports of mass returns to Apple stores, as well as returns direct to DJI.  
And, even if you choose to keep your P4, but it must go back for some sort of fix, this could bankrupt DJI.  I would much have preferred to wait a few more months and purchase a product that functioned correctly, then to purchase a device that is CLEARLY not yet ready for release.  Sometimes, scooping the competition can backfire on you, and this MAY be the case here...

  

robotizen Posted at 2016-4-14 02:36
An interesting bit of evidence would be how much does it drop vs. the forward velocity before the st ...

I noticed the same drop when going straight up, with no forward or lateral movement.  At the top of my climb, when my left stick was centered, it still settled back down roughly 6 to 8 feet...  So, I don't know that forward or lateral velocity makes much difference in this particular situation.  

kim.elitepp Posted at 2016-4-14 03:02
I am having the same issues with loosing altitude after stop with my P4 .  As much as 6 feet.  Was h ...

I think you just hit the nail on the head.  I was so excited to get my Phantom 4, and now, with this loss of altitude situation (not to mention a gimbal calibration error since the last firmware), I'm just really disappointed with the whole experience.  I realize this is a new design, and that I am an early adopter, but I almost feel that I've been cheated out of the excitement that I SHOULD be experiencing when I purchased a $1400 device!  This may seem a trivial amount to a multimillion-dollar company, but this was not a small expense for me to spend on an extravagance.

I only hope that DJI is paying attention to these forums.  I am a firm supporter of companies and businesses that support me.  However, I am JUST as willing to pull that support, if I feel that my concerns are not being addressed.

DJI-Tim Posted at 2016-4-13 22:29
We will!

When, on the P5 or P6?

Let's not be too hard on DJI, at least they've acknowledged the problem and must therefore be looking into working on a fix.  You can't moan that they shouldn't have rushed the P4 out and then expect them to rush a fix out can you?  I'd rather they took their time and got the fix right (as well as fix the gimbal problems) with the proviso that if anyones P4 crashes because of the dropping altitude problem in the meantime that DJI cover the repairs.

Sound fair? DJI?

Advocate Posted at 2016-4-15 05:15
Let's not be too hard on DJI, at least they've acknowledged the problem and must therefore be lookin ...

"You can't moan that they shouldn't have rushed the P4 out and then expect them to rush a fix out can you?"

Don't understand this statement at all!  

They shouldn't have rushed it out.  Now that they have they should rush out a fix at their expense.

Unfortunately if it is hardware issues back your craft will go.

How many people have already wasted a lot of time and money exchanging and returning P4s.

Am I the only one that hasn't experienced this issue?  I've not really flown that much yet, but apart from the initial problems (positioning) I had which got resolved by the first firmware upgrade.

I've not yet upgraded to the latest firmware.  I'll do some flights on the weekend to confirm, but I can't remember seeing this issue yet.

Craig Rogers Posted at 2016-4-15 13:52
Am I the only one that hasn't experienced this issue?  I've not really flown that much yet, but apar ...

if you keep your flight on the move you dont see it drop its only when you let the stick rest at the mid stop the P4 brakes then it drops, but if you slow it down it drops less

fast forward flight stop to take a pic it drops

mark.mwilliams7 Posted at 2016-4-13 15:52
Use the dji assist program on a PC and connect the P4 and its under flight data

thanks mark!

When using the auto take off I noticed that my P4 got to about 4' then slowly dropped down to about a foot off the ground. Also when I was hovering it will drop a few meters and then settle into place. Hope a fix comes quickly.

I've experienced similar issues, not just with braking but also when manually orbiting in active-track mode, and also in ATTI mode. While using the latter today in strong winds (20 mph) the P4 would drop 20 feet while drifting with the wind. I kept having to switch back to P (and extra throttle for good measure) to keep from descending into the ground--I didn't go much higher than 30 feet due to the high winds aloft (forcast for 45mph at 400 feet).  While using active-track, it would track and follow the target pretty well, but when I'd try orbiting (using the roll stick); it would climb about 30 feet above where it started 90 degrees (upwind of the target), then as I contintued around 180 degrees from that point (downwind of target), it would descend to about five feet lower than it's original alitude.  Kind of a cool effect, but not commanded; and often on the downwind side of the orbit I'd either pause or add throttle to make sure I wasn't going to hit the ground.
Yes, I've calibrated everything I can think of: IMU, Compass, and the four vision cameras.

Anyway, since apparently not ALL P4s do this; I may just return this unit to Amazon and exchange for another one.

Mine does that also.

parkgt Posted at 2016-4-15 13:05
"You can't moan that they shouldn't have rushed the P4 out and then expect them to rush a fix out  ...

Let me explain that statement that you don't understand.  You're moaning that the Phantom 4 has this altitude drop problem because DJI rushed to get it out, so you're saying that rushing was the cause of the problem.  So you're answer to this problem, is to ask DJI to rush again and get a fix out.  Now IF rushing the P4 out is the cause of the problem(s) how do you think rushing a fix is going to turn out?  Get me?

I apologise if this post comes across as confrontational, that's not my intent at all, I just think we should give DJI the time to investigate this problem and fix it properly and thoroughly, instead of turning into the teeming internet mass of complainers with pitchforks at the ready.  I've only been a member of this forum for just over a week but so far I've found its members polite, knowledgable, and above this sort of thing.  For the most part ;)

While typing this I'm sure I remember seeing a post by one of the DJI guys explaining that the altitude drop was caused by the Ultrasonic altitude sensors and their angle in relation to the ground, if that's the case isn't that a fairly easy fix, mathematically I mean? You already know the angle of the P4, and therefore the angle of the Ultrasonic sensors.  Everything can be calculated from there can't it?  As you didn't have this problem with the P3P I'm assuming you've already solved this once.

I'll try and get some drawings up to explain what I mean once I've finished my morning coffee

DFWdude4DJI Posted at 2016-4-11 17:06
I have the same issue with losing altitude as well. You can check out this video that someone review ...

Maybe this guy is not on Yuunec's payroll but he is pretty biased anyhow. It's just not a good or fair comparison. He admits that it's the first time he flies a Phantom and that he has owned, operated and modified Yuunec's for years...
Furthermore the light conditions 'and height) of the video's of the Phantom and it's competitor are not the same.
Far from scientific and/or fair.

mark.mwilliams7 Posted at 2016-4-13 15:52
Use the dji assist program on a PC and connect the P4 and its under flight data

thank you mark!!

Visual Air Posted at 2016-4-13 16:36
All the P4s do this and countless other issues have also been reported and noted.
There is truly a ...

it's a brand new, state of the art piece of hardware/software. Of course it's going to have some bugs. Every new product with new technology that comes out has some bugs, unless the developers keep it in testing for years (which nobody does for obvious reasons), and it always takes a little time to iron out the problems. Everybody knew they were buying a brand new piece of technology. Nobody thought there might be a few issues at first? I saw this coming a mile away. You think every new iPhone that comes out is perfect and doesn't have flaws? Wrong. With new technology (especially technology this smart) comes new problems, with new problems comes new programming to fix it. Patience is key.

FWIW, I flew again in the same location this afternoon but with my iPhone that has its own barometer (which I think the Go App uses to benchmark the P4's barometer real-time).  I still saw sinking in P-mode when stopping from full speed flight (though flying sideways or backwards didn't seem to drop as much).  ATTI mode was fine this time--no altitude loss; and orbiting with active-track also maintained altitude just fine; so I'm wondering if it was coincidence or if having a mobile device with its own barometer is more critical than it was for the P3?

I also flew higher this time, (150 feet) and noticed the same drop well out of range of VPS; although the altitude readout on the Go App showed a slight climb--granted it's hard to tell that high what exactly is going on; and even any horizontal drift away from you can be perceived as dropping, as the angle with the horizon changes.  However, when I reviewed my log from yesterday it showed my altitude while braking, was staying within about a foot, when I clearly saw it sinking over six feet each time I stopped while flying low and close to where I was standing!  So, it makes me wonder if there isn't something wrong with the whatever primary altitude sensor it relies on (GPS, VPS, barometer, accelerator)?

Advocate Posted at 2016-4-17 04:01
Let me explain that statement that you don't understand.  You're moaning that the Phantom 4 has th ...

"While typing this I'm sure I remember seeing a post by one of the DJI guys explaining that the altitude drop was caused by the Ultrasonic altitude sensors and their angle in relation to the ground, if that's the case isn't that a fairly easy fix, mathematically I mean? You already know the angle of the P4, and therefore the angle of the Ultrasonic sensors.  Everything can be calculated from there can't it?  As you didn't have this problem with the P3P I'm assuming you've already solved this once."

First I never owned a P3.  
Second if it was the ultrasonic distance sensor then this should never happen above it's working height.
Third if this was a simple angular geometry issue you would think the solution shouldn't take to long.

And as far as there being bug to be worked out in all new products; there are.  That doesn't mean the the owners that paid good money should stand as quiet sheep waiting on the assurance of a company (with a track record like DJI has to) that it is working on a fix for an issue that can destroy their purchase.
Not many bugs in a a new IPad likely to sent it crashing into the ground.

Happened to me wasn't there before upgrade

Happens on my 3 advanced

This is happening to me, and it's really really starting to annoy me. Here's a video of the exact problem.

The P4 should not have been released before these problems were sorted out. It is not good for anybody that this was released earlier than should have been.

A brilliant piece of technology let down by misjudged management,  As far as I can see there is no direct competition with the DJI range, or at least not at this moment. So another couple of months spent on smoothing out known problems wouldn't have gone amiss.

Geebax Posted at 2016-4-11 01:08
You will be returning your P4 then. This is a user forum, meaning it is for users to help other user ...

Wrong!  This forum is for users and support to interact and help making the product better.   Nothing wrong with OP coming in here and seeking advise from fellow pilots and DJI support team.  

Behshad Posted at 2016-4-19 09:47
Wrong!  This forum is for users and support to interact and help making the product better.   Noth ...

Wrong what? The OP came here delivering an ultimatum. Do you know of any company that responds to ultimatum's? He was not seeking advice at all. Try reading the post again.

Geebax Posted at 2016-4-19 10:05
Wrong what? The OP came here delivering an ultimatum. Do you know of any company that responds to  ...

He was trying to get help from DJI.  They have not responded to being nice about this issue.  They are essentially telling all the previous people complaining about this issue that they don't know what they are talking about or they wouldn't keep asking for logs.  

Richard in Bois Posted at 2016-4-19 13:41
He was trying to get help from DJI.  They have not responded to being nice about this issue.  They ...

You, like the other member, have not read the posts in this thread. DJI-Tim responded asking for information from the OP, which to my knowledge he has not provided. Tim also said they are working on the issues. That counts as a response.

Over the last 18 months I have bought 5 new products from DJI close to their release dates. Everyone of them has had problems which DJI has eventually fixed.
I agree that the P4 also has its problems which I'm sure DJI will fix.
The good thing about these forums is that there is plenty of publicity being given to the problems that the P4 has so we can all be aware of them and take appropriate action to avoid flying into the dirt.
I'm going to be patient as I know they will do whatever is necessary to fix the problems because they always have in the past.

On a positive note I noticed in the last upgrade that they've fixed the problem with only being able to pinch or move the screen on the right hand side of the screen(eg on the map screen with apple devices).  

petevandra@msn. Posted at 2016-4-18 23:33
Over the last 18 months I have bought 5 new products from DJI close to their release dates. Everyone ...

Beta hardware and software that you only have to pay $1399.00 to try.
Heck of a deal!

Aardvark Posted at 2016-4-19 00:08
The P4 should not have been released before these problems were sorted out. It is not good for anybo ...

I decided to send the video to DJI Support last night, they told me they could not see the Phantom dropping... I honestly don't know what to say to that.

ItsMarky Posted at 2016-4-19 10:22
I decided to send the video to DJI Support last night, they told me they could not see the Phantom ...

a number of us have sent flight data to DJI and DJI tim has said they are working on it so lets hope they get to the bottom of this soon.

Hello DJI,

bouncing P4...reported since the "early days".

http://forum.dji.com/forum.php?m ... 4&fromuid=21627

Please DJI could you fix it?

Thanks
Alex

The altitude meter also not changing when it descend..right?

i think Dji will fix it.. I dont believe the rest dont have this issue... I just noticed and test it when i read this thread,..

But its not show stopper to me..

mark.mwilliams7 Posted at 2016-4-19 10:36
a number of us have sent flight data to DJI and DJI tim has said they are working on it so lets ho ...

thanks for the reply. yeah, hopefully in the coming days. I think I will be grounded and just fly my P2 until then..