Phantom 4 altitude drop

XJoeyX · Apr 12, 2016

chris digata said:
are people only having this problem at low altitude? are the all in hot places? at what batt temp? is it a VPS problem due to more sensitive sensors
ive seen the odd drop now and then but only at low height due to VPS adjustment

This Sunday, I took my P4 all the way to 400' AGL, and at the apex, I STILL saw a noticeable drop (seen in the video...), and I'm estimating from 4 to 8 feet (that's what it looks like when closer to the ground.) It is SO noticeable, that I can see it in my videos. It was a nice cool day (in the low 70's), I can't speak about the battery temp offhand, but I had not been flying long that day... And, at 400 feet, the VPS would have no involvement... I did not notice this before the last FW update, but perhaps I was just so happy that I finally got my shiny new Phantom 4 that I didn't notice it the first day. I'll go back and review video...

Ok, I just went back and reviewed some of my First Flight video (before the FW update), and it DOES appear to be "sinking", although, it did not seem to be quite so severe... So, I guess I've had this problem from day one!

I wonder what the solution might be? I'd HATE to have to send this thing all the way back to China (I ordered direct from DJI)...

Ramphex · Apr 13, 2016

My altitudes are off too, the other day went out for a flight and when returning back to home and hovering at about 3 feet it said I'm 17 feet up.

chris digata · Apr 13, 2016

XJoeyX said:
This Sunday, I took my P4 all the way to 400' AGL, and at the apex, I STILL saw a noticeable drop (seen in the video...), and I'm estimating from 4 to 8 feet (that's what it looks like when closer to the ground.) It is SO noticeable, that I can see it in my videos. It was a nice cool day (in the low 70's), I can't speak about the battery temp offhand, but I had not been flying long that day... And, at 400 feet, the VPS would have no involvement... I did not notice this before the last FW update, but perhaps I was just so happy that I finally got my shiny new Phantom 4 that I didn't notice it the first day. I'll go back and review video...

Ok, I just went back and reviewed some of my First Flight video (before the FW update), and it DOES appear to be "sinking", although, it did not seem to be quite so severe... So, I guess I've had this problem from day one!

I wonder what the solution might be? I'd HATE to have to send this thing all the way back to China (I ordered direct from DJI)...

Yes mine does seem to adjust height by itself when flying fast and at one point i was at 50m in height 2 mins later 54m and i had not adjusted it, but i fly slow most of the time and keep a close eye on it.. so im good with it and will see what happens.. so yes their does seem to be a problem with them All...

XJoeyX · Apr 13, 2016

Well, hopefully, this is something that can be addressed through firmware. Since we are less than a month since release, we can only HOPE that the P4 is just going through growing pains, and it will stabilize in the next couple of updates, and the next few months... I'm keeping my fingers crossed!!

Archer911 · Apr 13, 2016

The thing is I would have sworn my P4 didn't do this with the firmware it was shipped with. The trouble started after the latest update.

XJoeyX · Apr 13, 2016

Archer911 said:
The thing is I would have sworn my P4 didn't do this with the firmware it was shipped with. The trouble started after the latest update.

Archer, I thought much the same thing. However, I went back and looked at my first flight videos, and there IS a noticeable drop even in my first videos (and I didn't even notice it that first weekend). Perhaps the drop wasn't as prevalent before this latest firmware update, but for me, at least, the drop was there.

Archer911 · Apr 14, 2016

XJoeyX: You could be right. I can tell you today when I flew over water I made **** sure I had enough altitude before braking.

XJoeyX · Apr 14, 2016

Archer911 said:
XJoeyX: You could be right. I can tell you today when I flew over water I made **** sure I had enough altitude before braking.

You got that right! I SURE don't want to give my new $1400 toy a bath!!!

Aquacop · Apr 16, 2016

Same here

skyeboysteve · Apr 16, 2016

I'm having the same problem too but I'm seeing not only up to 10 feet of drop (within VPS range) when braking but also 20 foot drop while letting it drift in ATTI mode over a short distance. This afternoon was my first time to fly outdoors in daylight and the wind was not ideal as it was gusting from 15-25 mph. I purposely didn't fly higher than 30 feet due to wind velocity, but noticed while trying the tracking feature with orbit that the P4 would rise 20 feet on one side of the orbit then descend down 25 feet on the other side. A cool effect but not when it's not predictable.

I'm wondering if the gusty wind was affecting the barometer and since I was using an iPad Air that doesn't have a barometer, if it didn't have a good reference for varying air pressure. However, even GPS is more accurate than that for vertical height I think.. I'm going to try again tomorrow (if winds aren't stronger) with my iPhone 6S plus (which does have a barometer) and see if that helps.

Perhaps I should send this back to Amazon and hope for a better model in return, if others have no issue.

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Archer911 · Apr 16, 2016

skyeboysteve
My P4 doesn't like gusty wind at any altitude or its own turbulence when just a couple of feet of he ground. Essentially with gusts it gets pushed in the same direction the wind is blowing.

skyeboysteve · Apr 16, 2016

Interesting Archer, one thing I was impressed by with my P4 was how well it hovered even in ground effect indoors--rock steady unlike my P3 which would wander a bit. But maybe my P3 was a bit of a lemon after all I never saw any difference in low altitude hover with VPS on or off.

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lonjsnyder · Apr 17, 2016

Per Frank at CarolinaDronz.com, here's how the P4 should hover in wind:

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Drivesector · Apr 19, 2016

I noticed it out of the box with mine but once I did new firmware it seems to have decreased dramatically. It's not as scary now unless I hit the breaks doing 40mph.

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spitando · Apr 20, 2016

I have the same issue in my P4 notice today after few breaks. Looks like the drop is higher in high altitude. Any solution. Do you guys think this can be fixed with fw update?

dallaslott · Apr 20, 2016

I exchanged the one I got from DJI because mine was doing the same thing. New one is being mailed back to me currently. I also bought one from Apple Store. It's worked fine so far after about 15 flights. Knock on wood.
The Apple store had different stickers and the VPS cameras were covered, the DJI version was not. May or may not make a difference, but I've heard similar results and I can attest to the difference from my account. Just FYI

KevMo Photog · Apr 21, 2016

dallaslott said:
I exchanged the one I got from DJI because mine was doing the same thing. New one is being mailed back to me currently. I also bought one from Apple Store. It's worked fine so far after about 15 flights. Knock on wood.
The Apple store had different stickers and the VPS cameras were covered, the DJI version was not. May or may not make a difference, but I've heard similar results and I can attest to the difference from my account. Just FYI

So you have one from Apple Store that does not have any altitude drop at all?????

WWK888 · Apr 21, 2016

I bought mine from Apple, it had all the stickers on the sensors and camera but it also has the same problem. I contacted DJI and they wanted me to send a video showing the problem. I specifically asked if this is a firmware problem that could be corrected with an update and she said no it is not a firmware issue.

Sim597 · Apr 21, 2016

crashburn said:
Done it that way also, didn't work.

Of course the refrigerator didn't work, as it's not a "thing" with the Phantom 3 or 4s. All of us who think chilling IC boards and heating them to 140* or so is super hard on connections, and the boards themselves, are correct. This cycle of low to high temps is the NUMBER ONE CAUSE of premature failure, and also the number one cause of wear and tear. Even not chilling IC boards this isn't the best thing for them. Sure they'll work, they are made to be flown in cold environments, and heat up as they fly, but any engineer worth his/her salt will tell you, the heating up cycles are best kept to a minimum. This is why it's better to leave a computer running, the cold start cycle is hard on electronics. Also Diesel engines, even your gas car engine has the most wear when it's "cycling" thru warm up.
Mine seems to do it right after startup a little bit, but then after a few minutes the height is stabile.
Good luck

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KevMo Photog · Apr 21, 2016

WWK888 said:
I bought mine from Apple, it had all the stickers on the sensors and camera but it also has the same problem. I contacted DJI and they wanted me to send a video showing the problem. I specifically asked if this is a firmware problem that could be corrected with an update and she said no it is not a firmware issue.

Wow! That doesn't sound good. Really weird that some P4's are having this issue and some are not. It really does not bother me too bad as I have just adjusted for it when flying tbo. If I'm flying 2 ft off the ground for a shot I am always pulling it up as I end the shot anyway. I would never put on the brakes at full speed that close to the ground ever! But I can't wait to see how they are going to address this problem though! Thanks for the info from DJI!