My new Phantom 4 appears to have an issue with altitude. For example,  when I fly to 180 feet in a straight line, it will drop all the way down  to 100 feet. sometimes it will start to go back up on its own but I  have lost confidence in this  unit. It's brand new, no crashes.  I have tried re calibrating the  compass before each flight, have also done several IMU calibrations on  perfectly flat surfaces. I have tried multiple batteries.  When I view  the flightrecorder log on the healthydrone website  I do not see signal loss or any "errors" that would suggest something  has gone wrong. When I watch the playback on the DJI GO app I see the  drone dropping 80 feet but the onscreen controller shows no downward  input from the controller. I have only had phantom 4 for 7 days and have made multiple flights but always seeing large declines (over 50 feet) around 180/220 feet. Thoughts on what could be going on? I will be the first to admit I am new to flying but something is very off here.


Flying in P mode
No gimble guard.
APP 2.8.4
Ver 01.02.0503
RC 1.6.0

flights are sync'd on the DJI GO app, most recent flight with issue is from today 8/29/2016

Are you flying with a gimbal guard attached?

I have just the opposite problem. When I go to center on the left stick my P4 continues to climb, sometimes over 100'. It then drops back to the altitude it was at when I centered the stick. Working through it with DJI online and some of the other members. All of my firmware is up to date.

It doesn't happen every time I fly and when it does it's only at the beginning of the flight when I first gain altitude.

It might have something to do with updating to the latest aircraft firmware. It started around then. I may go back one release if it continues to happen and give that a try.

mark82 Posted at 2016-8-29 21:21
Are you flying with a gimbal guard attached?

No gimble guard.
APP 2.8.4
Ver 01.02.0503
RC 1.6.0

Roadstar1700  After Watching my playback a few more times from today's test flight... I noticed that my drone is actually increasing in altitude even after I returned stick to center. Then I am seeing it drop back down. After reading your post, I may actually be seeing the same thing you are. Is there a way to share my flight for review?

Can you offer the general areas you fly?  Like is it over water, up in a mountain area, flat desert, very hot temperature?

MD_Icarus Posted at 2016-8-29 21:42
Can you offer the general areas you fly?  Like is it over water, up in a mountain area, flat desert, ...

In my backyard about an 1+acre of open space. Over land that is mostly flat. There are other homes in the area. There is a small pond nearby....I have also flown in a wide open RC park and issue happened there aswell. .. Issue has been present on cooler days like today 75 degrees and on hotter days of about 90 degrees.

jklingbe Posted at 2016-8-29 21:33
No gimble guard.
APP 2.8.4
Ver 01.02.0503

I'm not sure how to attach a flight log into a reply. I think I've seen it done in other posts, though. I'm going to fly again tomorrow. I refreshed the aircraft firmware and re-caled the sensors this afternoon. I'll post a reply on this thread on how the flights went.

MD_Icarus Posted at 2016-8-29 21:42
Can you offer the general areas you fly?  Like is it over water, up in a mountain area, flat desert, ...

I've had 5 flights in the last month with this issue. Flat land, near water, near hills.

Hello jklingbe,I cannot sync your flight record.Could you please sync it again?

DJI Mindy Posted at 2016-8-30 00:01
Hello jklingbe,I cannot sync your flight record.Could you please sync it again?

I have re'sync'd my flight records via the DJI GO app. It says it was successful and I see the cloud icon in the top corner of each flight.

There is no reason your aircraft should fluctuate altitude much at all. Especially since you do not have anything mounted on the P4
What is the exact date, flight time, max distance, and max heigh of the flight.I looked at your last flight and the altitude changes I see stick input. But for a few seconds I see the percentage go up but not a stick movement but the aircraft only changed a few feet.
Also, try a RC stick calibration and that may clear up some of it.

Roadstar1700 Posted at 2016-8-30 09:22
I have just the opposite problem. When I go to center on the left stick my P4 continues to climb, so ...

DO you have a gimbal guard installed?

Roadstar1700 Posted at 2016-8-30 10:04
I'm not sure how to attach a flight log into a reply. I think I've seen it done in other posts, tho ...

You can also connect it to the Assistant2 and perform a factory reset.

DJI-Ken Posted at 2016-8-30 12:20
You can also connect it to the Assistant2 and perform a factory reset.

I don't have a gimbal guard. I flew it this morning after refreshing the firmware and did re-cals with the same problem. After the second increase in altitude I brought it down to 10' off the ground and the GO app said I was 58' high. I'm currently rolling back 1 firmware version on the aircraft and will try again today. I have another thread started called Altitude Drop. This is not my thread, but the member who started it is having the same issues.

Roadstar1700 Posted at 2016-8-31 00:25
I don't have a gimbal guard. I flew it this morning after refreshing the firmware and did re-cals  ...

OK, thanks for the report.
Try a RC stick calibration first to see if it helps.

DJI-Ken Posted at 2016-8-30 12:46
OK, thanks for the report.
Try a RC stick calibration first to see if it helps.

Just came back and still have the problem. I tried the stick cal a couple of times over the last 3 days, but not today. When I came back down GO said I was 50+ feet high when I was only 10' up.

I changed the resolution on my computer screen, but still can't get the VPS calibrated. It fails at 66%.

I'm not sure what to try anymore. I know I can't fly it the way it is.

Roadstar1700 Posted at 2016-8-31 01:15
Just came back and still have the problem. I tried the stick cal a couple of times over the last 3 ...

Ok, what's your Go app login email and I will look at the last flight.
Also, when you start the aircraft and wait until it says "Safe to fly GPS" the altitude is reading correctly?
So the altitude gets incorrect during the flight and not while it's on the ground right?

DJI-Ken Posted at 2016-8-30 13:45
Ok, what's your Go app login email and I will look at the last flight.
Also, when you start the ai ...

My login e-mail is sgussert@charter.net   I just did a sync on all of my flights and they all show the cloud icon. Both flights today had altitude problems.

The altitude reads correctly at 0.0' just before I take off. Not sure what the actual altitude is when its up high, but it shows quite a bit higher number when I bring it down to a physical 10'. You'll see the incorrect ending altitude when I pull the stick down to stop the motors at the end of the flight.

Roadstar1700 Posted at 2016-8-31 02:10
My login e-mail is sgussert@charter.net   I just did a sync on all of my flights and they all show  ...

OK thanks, I'll take a look in a bit.

Roadstar1700 Posted at 2016-8-31 02:10
My login e-mail is sgussert@charter.net   I just did a sync on all of my flights and they all show  ...

Your flight is 15 minutes, where in the flight does it show the altitude fluctuate. I'm sorry but I can't watch a 15 minute flight.

DJI-Ken Posted at 2016-8-30 14:38
Your flight is 15 minutes, where in the flight does it show the altitude fluctuate. I'm sorry but ...

My last flight was today with a time stamp of 11:58:11 and it's a 3 minute flight. The altitude increase happens
at the 16 sec mark.

Roadstar1700 Posted at 2016-8-31 02:43
My last flight was today with a time stamp of 11:58:11 and it's a 3 minute flight. The altitude in ...

You didn't sync the latest ones then or my device is not updating to the latest.
The last entry was 7/26 with a time of 16 minutes and max dist of 4720ft.
If you've synced and it's my device then start a ticket with support and have them evaluate the flight and provide them the same info here.

This is exactly what happened to me with my P4 when new - details on my fix here - please let me (and DJI) know if something similar fixes it!

http://droneflyers.com/talk/thre ... ips.1806/#post-6272

DJI-Ken Posted at 2016-8-30 12:19
There is no reason your aircraft should fluctuate altitude much at all. Especially since you do not  ...

Today I did these steps. Restarting the aircraft and RC between each one

refreshed the firmware.
Calibrated the VPS  (had not done this before)
Calibrated sticks on RC (had not done this before)
Calibrated IMU on perfectly flat surface
Calibrated Compase

Took it for a test flight up to 100 200 and 300 feet. No drops. Landed the aircraft. Powered everything off. Then tried another test flight up to 200 fee, still no drops.

I am going to test one more time at sunset but it would appear that I am not seeing this any longer. Hoping for another good flight!

Roadstar1700 Posted at 2016-8-30 14:10
My login e-mail is sgussert@charter.net   I just did a sync on all of my flights and they all show  ...

My Sunset test flight was a success!!!! That makes 3 take offs with no drops what so ever. By the end of the flight I was actually enjoying myself instead of worrying about the aircraft falling out of the sky! The drop issue does appear to be resolved now. If I should see the drops return (god I hope not) I will repeat what i did above and report back to this thread.

Roadstar1700 give the process I tried above and see if your problems go away. I sure hope they do!

jklingbe Posted at 2016-8-30 18:49
Today I did these steps. Restarting the aircraft and RC between each one

refreshed the firmware.  ...

Thanks jklingbe, I worked with DJI support in an online chat today and performed most of the procedures you listed, but not in that order. I still have the problem where it increases altitude then slowly comes back down.

One thing I can't get is a good cal on the VPS. It always fails at 66%. I've even tried a lower resolution on my computer screen with no luck.

I'll try your procedure as you have it listed tomorrow. Restarting the aircraft and the RC between each step may be the clue. I hope it works because I'm afraid of flying it as it is.

jklingbe Posted at 2016-8-30 20:21
My Sunset test flight was a success!!!! That makes 3 take offs with no drops what so ever. By the  ...

Also glad to see you were able to get yours to fly stable again. I've read where the SD card may be at fault, but I'm not sure how it could cause any flight problems. I asked DJI support today in my chat, but I didn't get an answer on that question. Have you heard anything about this? Do the firmware upgrades store data on the card unrelated to pictures or video? I am going to put the original 16gb SD card back in tomorrow before trying your procedure.

Roadstar1700 Posted at 2016-8-30 22:21
Also glad to see you were able to get yours to fly stable again. I've read where the SD card may b ...

I have only ever used the SD card that it came with. I have intention of switching it out for larger one but since it was so new and never flew correctly I haven't swapped it out yet. I have seen other posts including the one in this thread of bad SD cards causing issues. I have a feeling the VPS calibration is what fixed mine but I did all of the steps I listed before testing so I can't be sure. I would really be curious if that would fix yours. Do you have another computer that you could try it on?

jklingbe Posted at 2016-8-31 06:49
Today I did these steps. Restarting the aircraft and RC between each one

refreshed the firmware.  ...

I'm thinking calibrating the VPS has done it.

Roadstar1700 Posted at 2016-8-31 10:21
Also glad to see you were able to get yours to fly stable again. I've read where the SD card may b ...

Try that and also really try to get the VPS calibrated and factory reset.
Try different screen resolutions and also try a different computer if possible.

jklingbe Posted at 2016-8-30 18:49
Today I did these steps. Restarting the aircraft and RC between each one

refreshed the firmware.  ...

Success !  I followed your list and it flies like a dream. Stops immediately when you let off the stick. Stable and the altitude readout is correct. I swapped out my monitor with a Dell 24" 1200X1920 res and it calibrated the VPS on the first try. I thought, this must be a fluke, so I tried it again and it passed again ! Interesting that my 20" Dell 1200X1600 wouldn't work. I'm a happy camper now. Thanks again jklingbe.

DJI-Ken Posted at 2016-8-31 01:01
Try that and also really try to get the VPS calibrated and factory reset.
Try different screen res ...

Thanks DJI-Ken. A different monitor did the trick with the VPS cal. Flies great now.

Roadstar1700 Posted at 2016-9-1 03:31
Thanks DJI-Ken. A different monitor did the trick with the VPS cal. Flies great now.

That's great, glad your a happy camper now.

Roadstar1700 Posted at 2016-8-31 15:29
Success !  I followed your list and it flies like a dream. Stops immediately when you let off the  ...

Man that's great news! I'm glad this worked for you too!