Dear all,
Since a few pilots here (including one quite experienced one) have reported issues at take off time with their Mavic Air after the latest firmware update - namely sudden significant yawing or drifting without stick input right after take off - I have run a test myself today with all three take off modes:
1. Manual
2. Automatic with precision landing activated
3. Automatic without precision landing
In all three scenarios my Mavic Air behaved absolutely stable and as expected. Thus reported problems are apparently not a general bug in the latest firmware update, but might rather relate to a need to check VPS settings and/or maybe a required RC or IMU calibration.
And here below the screen recordings of my three tests. Please ignore the compass movements, which are a long standing issue with CrystalSky, just watch the video feed:

During your Manual takeoff, you can clearly see your MA drifting to the left starting at around 5.1m altitude, then again at the apex of the takeoff it drifts to the left again.
This is not normal behaviour if the MA had proper GPS lock (I see 14 sat locks) and a properly functioning VPS / IMU system. This is not stable to me, as even my MA does a better job of being like a Tripod on manual takeoff, when the firmware issues don’t kick in.

EdisonW1979 Posted at 2018-5-27 12:51
During your Manual takeoff, you can clearly see your MA drifting to the left starting at around 5.1m altitude, then again at the apex of the takeoff it drifts to the left again.
This is not normal behaviour if the MA had proper GPS lock (I see 14 sat locks) and a properly functioning VPS / IMU system. This is not stable to me, as even my MA does a better job of being like a Tripod on manual takeoff, when the firmware issues don’t kick in.

Come on, this is absolutely minimal and is nothing compared to the perceived problems reported by other pilots. They reported e.g. up to 45° yaw after take off. That is the level of problem I am referring to, not your few millimeters that you seem to perceive ;-)

Thank you so much for doing this my friend and I am pleased your MA takes off flawlessly. I will check my drone over again and try again in the morning. Weird little glitch in the yaw for me on take off but no other issues - I'll sort it now I know that it is not a universal issue. Thanks again - very much appreciated.

I also have had no issues with the latest update. The only issue I have had so far was the initial wobble when new and in cold weather. The update to fix that worked and I have considered this the perfect drone for me to date.

Wachtberger Posted at 2018-5-27 12:57
Come on, this is absolutely minimal and is nothing compared to the perceived problems reported by other pilots. They reported e.g. up to 45° yaw after take off. That is the level of problem I am referring to, not your few millimeters that you seem to perceive ;-)

I agree, looks normal to me. I floated my MA for a full battery (21 minutes ) in tripod mode for a timelapse (344 stills) with very little movement. I rarely use assisted take off mostly CSC, haven't really noticed significant yaw while doing it.

A CW Posted at 2018-5-27 13:03
Thank you so much for doing this my friend and I am pleased your MA takes off flawlessly. I will check my drone over again and try again in the morning. Weird little glitch in the yaw for me on take off but no other issues - I'll sort it now I know that it is not a universal issue. Thanks again - very much appreciated.

You are very welcome dear friend and I hope yours will be stable too after your checks!

Wachtberger Posted at 2018-5-27 13:21
You are very welcome dear friend and I hope yours will be stable too after your checks!

Fingers crossed. I'll let you know if I find a fix.

QuadKid Posted at 2018-5-27 13:06
I agree, looks normal to me. I floated my MA for a full battery (21 minutes ) in tripod mode for a timelapse (344 stills) with very little movement. I rarely use assisted take off mostly CSC, haven't really noticed significant yaw while doing it.

Same for me. And at least from my screenrecordings it is clear that there is no yaw at all. Thus the problems experienced by other pilots must have a different source and it will be interesting to identify it.

Thanks for posting, it seems only a few experience this problem.
Off subject do you think it is worth buying the crystal sky even with the compass problem that you talked about.
Do you see it being corrected.
Thanks
Rudy

Good job Wathcberger, have been using MavAir quite a bit in the last few days with no problems, just as a btw , I see your compass heading on your map is spot on, radar is a bit of an issue with Crystalsky I think , using my iPhone with MavAir I don’t have this problem, but with Crystalsky I have same issues.

Your tests are exactly the ones i've done before.  However, we achieved different results.  I don't know what the deal is, but it seems that some users are affected and others are not.  But I was definitely affected.

I did suffer from the sudden yaw and spin.  I've since been able to almost eliminate that.  I had to go through a factor reset, then firmware refresh of .400 on the aircraft, then refresh the .100 on the RC, then a reset of my Note4 and then an  upgrade of the DJI Go 4 App.  Then i did calibration of EVERYTHING using the Assistant 2.  It was a lot to go through, but it seemed to correct the instability.  As i've said in a few other threads, my problem now is distance.  I don't get anywhere near the distance that i got when i first launched.  My first firmware was .300.

sky6105 Posted at 2018-5-27 13:54
Thanks for posting, it seems only a few experience this problem.
Off subject do you think it is worth buying the crystal sky even with the compass problem that you talked about.
Do you see it being corrected.

You are welcome. I certainly do not intend to play down the problem that some are experiencing and did this test to see if I am myself affected although already in previous flights after the firmware update I had not experienced the yaw issue. Thus the root cause seems to relate to other factors yet to be identified.
Concerning CrystalSky I definitely do not regret the purchase. The compass issue is the next thing I want to explore further and I am optimistic that it can be fixed by DJI.

hallmark007 Posted at 2018-5-27 14:01
Good job Wathcberger, have been using MavAir quite a bit in the last few days with no problems, just as a btw , I see your compass heading on your map is spot on, radar is a bit of an issue with Crystalsky I think , using my iPhone with MavAir I don’t have this problem, but with Crystalsky I have same issues.

Thank you dear friend. I hope that compass issue can also be solved one day.

3-D Posted at 2018-5-27 14:34
Your tests are exactly the ones i've done before.  However, we achieved different results.  I don't know what the deal is, but it seems that some users are affected and others are not.  But I was definitely affected.

I did suffer from the sudden yaw and spin.  I've since been able to almost eliminate that.  I had to go through a factor reset, then firmware refresh of .400 on the aircraft, then refresh the .100 on the RC, then a reset of my Note4 and then an  upgrade of the DJI Go 4 App.  Then i did calibration of EVERYTHING using the Assistant 2.  It was a lot to go through, but it seemed to correct the instability.  As i've said in a few other threads, my problem now is distance.  I don't get anywhere near the distance that i got when i first launched.  My first firmware was .300.

Good to hear that at least the yaw issue is solved for you and I hope you can solve the distance problem too.

Wachtberger Posted at 2018-5-27 22:08
Good to hear that at least the yaw issue is solved for you and I hope you can solve the distance problem too.

thanks.  I've been giving serious thought to trying to downgrade using some of the tools i've found.   This problem has put a serious damper on my flying.  and it's a really bad look for DJI.  I couldn't fly more than 600 feet today without signal failures

Thanks for evidence, that yaw problem is not a common issue for MA

Great test
That also applies to my mavic air with all the latest updates / firmware never had any issue flies perfectly stable.

3-D Posted at 2018-5-27 22:21
thanks.  I've been giving serious thought to trying to downgrade using some of the tools i've found.   This problem has put a serious damper on my flying.  and it's a really bad look for DJI.  I couldn't fly more than 600 feet today without signal failures

My strong advice would be not to try downgrading. The fact that the .400 firmware does not allow downgrading indicates that very serious issues have been fixed with it.

nixuspix Posted at 2018-5-27 22:22
Thanks for evidence, that yaw problem is not a common issue for MA

You are welcome. Nevertheless we should aim to identify the cause for those who are affected.

FIXED!!!! No sudden yaw movements at all on all four flights today I refreshed the FW on just my app using v. 16 on my iPhone 7+ and calibrated everything except the VPS. Not one glitch today.
Perhaps it may have something to do with the FW in Assistant 2 on IOS or may be I had a bad calibration on the RC - difficult to gauge but very pleased with the performance of the MA today - no more calibrations needed for a while now.

A CW Posted at 2018-5-28 07:13
FIXED!!!!  No sudden yaw movements at all on all four flights today  I refreshed the FW on just my app using v. 16 on my iPhone 7+ and calibrated everything except the VPS. Not one glitch today.
Perhaps it may have something to do with the FW in Assistant 2 on IOS or may be I had a bad calibration on the RC - difficult to gauge but very pleased with the performance of the MA today - no more calibrations needed for a while now.

Great to hear! Now we hopefully can track down which action fixes the issue. Do I understand correctly that you did not re-calibrate the sensors, but only compass, IMU and RC?

3-D Posted at 2018-5-27 14:34
Your tests are exactly the ones i've done before.  However, we achieved different results.  I don't know what the deal is, but it seems that some users are affected and others are not.  But I was definitely affected.

I did suffer from the sudden yaw and spin.  I've since been able to almost eliminate that.  I had to go through a factor reset, then firmware refresh of .400 on the aircraft, then refresh the .100 on the RC, then a reset of my Note4 and then an  upgrade of the DJI Go 4 App.  Then i did calibration of EVERYTHING using the Assistant 2.  It was a lot to go through, but it seemed to correct the instability.  As i've said in a few other threads, my problem now is distance.  I don't get anywhere near the distance that i got when i first launched.  My first firmware was .300.

There really is something wrong with DJI's .400 firmware if after upgrading, a person has to go through all those steps (gyrations) to get their drone to fly properly.

HedgeTrimmer Posted at 2018-5-28 08:45
There really is something wrong with DJI's .400 firmware if after upgrading, a person has to go through all those steps (gyrations) to get their drone to fly properly.

This assumption would be correct if all were affected, but this is not the case. Only relatively few users seem to have this yaw problem. You can see this effect after each release of a new firmware. Any problem that might arise, is quickly attributed to the new firmware but in many or even most cases is just coincidental. Therefore it is important to take the time tracking down the root cause.

Problem still may be .400 firmware itself.  

Complicated, but a bug in code may be accessing a memory location that in most people's drone has stored value that causes no problems.  But on a few people's drone has a stored value that results in Yaw problem when bug access's that memory location.

The numerous steps (gyrations) those who are having problems, finally results in getting that memory location set to a value that bug in code does not result in in Yaw problem.

If you have ever work with Language like "C"; you know about mistakes that can be made when using Pointers.

Wachtberger Posted at 2018-5-28 08:55
This assumption would be correct if all were affected, but this is not the case. Only relatively few users seem to have this yaw problem. You can see this effect after each release of a new firmware. Any problem that might arise, is quickly attributed to the new firmware but in many or even most cases is just coincidental. Therefore it is important to take the time tracking down the root cause.

I agree it is important to take time to track down the root cause.

But when several people report different problems after upgrading to .400 firmware, there is something related to either upgrade process or firmware itself.

As for assumption would only be correct if all were affected, not true.  A software bug can effect only a few people, and yet not all.  How?  Code that accesses wrong memory location.  It most people's drone the value stored there has been previously set to a value that is of no consquence.  But for a few people, value at that memory location is set to a value that does casuse problem.  It could be a case of Bug accessing a memory location that holds a user setting, with a value that very few people change.

Wachtberger Posted at 2018-5-28 08:33
Great to hear! Now we hopefully can track down which action fixes the issue. Do I understand correctly that you did not re-calibrate the sensors, but only compass, IMU and RC?

Yep - RC, IMU, gimbal then finally the compass before take off at my flight location.
Before the calibrations I refreshed the firmware on both the AC and RC via GO4 on my iPhone 7+ only.

I did all of this before I flew on Saturday too then the yaw glitch happened... Did the same calibrations yesterday and all is fine today! The only thing I did differently is that I didn't refresh the FW using Assistant 2 and took my time doing the RC calibration - repeated stick movements. I didn't experience a single glitch on all 4 flights today. Very strange! I think there is either a glitch in the FW affecting some users or I did a bad RC calibration before. I see a few have far more problems than what I had which was a simple 45 degree yaw on takeoff with no input from me before everything else was perfect - others are having major drift issues and yaw turns during flight whilst a number clearly have no problems at all. It's hard to say what the best fix is as i think each case needs to be addressed separately as obviously not a universal problem but from my perspective - my drone is flawless once more! Would of been quite ironic for my MA to suddenly malfunction on the day I sold the MPP

I really appreciate the scientific approach you took to looking into this issue, and the fact that you took the time to post this. Thanks for that! I too have not had any of these yaw issues on take off.

What we need now, is for someone to post a similar set of videos that can demonstrate the problem in a reproducible way, at least reproducible on their own drone.

#1 Wachtberger

Nice to hear that  YOUR Mavic Air has no problems..
but as conclusion to say hundreds of pilots
with suddenly giering problems(as mine too) has nothing to do with update..
i cannot understand...only if your Air is OK!!!!
Bevore updating I had NO PROBLEMS at all now I have......like many other pilots
they all are wrong ou think???

Adding to my post #5 all updates have been done with I Pad mini 4 and not with the assistant. I also did not do any calibrations other than the compass when told to do so by the go4 app.

here answer out of problems with firmware update..

"Update: DJI send me a new drone. So definitely something not right with latest firmware."
       

# 1 Wachtberger
What date of production is your Air?

Wachtberger Posted at 2018-5-27 22:26
My strong advice would be not to try downgrading. The fact that the .400 firmware does not allow downgrading indicates that very serious issues have been fixed with it.

I don't want to downgrade.  But I do want to fly.  And I'm still looking to try to find what was so severe in .300 that I shouldn't run it.

What was so major that DJI would risk soiling the Mavic brand?  

HedgeTrimmer Posted at 2018-5-28 09:16
I agree it is important to take time to track down the root cause.

But when several people report different problems after upgrading to .400 firmware, there is something related to either upgrade process or firmware itself.

I can fully agree to that. This is also why I tested all three take off modes because my initial suspicion has been that just one or two of them might show the symptoms, while I, normally taking off manually,  had not experienced any problems. Now I have had no problems in all three modes and have reported that (like others did as well).
I want to put one thing straight here once and forever: It is not at all my intention to play anything down or to protect DJI. If I find a problem I report it frankly and have done so many times before. When I do such tests it is my goal to help identify the root causes of problems that users are experiencing because the same could happen to me any time too and I would depend on the help of other pilots to get it solved.
Here we have a case where the root cause was perceived to be the firmware update, but some doubts must be allowed too. If there was a general issue, this forum would be flooded by relating reports and complaints. This is clearly not the case. Thus what remains is to try isolating the possible cause to the extent possible and identify which particular user settings or other factors might lead to it. If we are lucky it can be found quickly, but it also can be a long and painful search.
It is obvious that some are experiencing problems and that warrants a solution. Thus let's all join our efforts to find it, ok?

HedgeTrimmer Posted at 2018-5-28 09:16
I agree it is important to take time to track down the root cause.

But when several people report different problems after upgrading to .400 firmware, there is something related to either upgrade process or firmware itself.

"Code that accesses wrong memory location. "   YES.
And this is why doing a factory reset and then refresh the firmware could make a difference in some.  If DJI starts with a greenfield Mavic Air, it could not take into consideration the affect of upgrading the code.
Any customizations or settings that were changed, could affect how the fimrware is applied.

Also, for 20+ years I have done trouble shooting this way:

what has changed since it worked properly?  oh, you upgraded?  well let's look at what changed, to see what the problem is.  

That is why people are blaming the firmware.  My mavic was damn near flawless prior to the firmware update.  then after the update, it was not.  What else am I supposed to blame the new failures on?

It's not pilot error.  It's not a bad location.  It's a change in the firmware.  my biggest problem here is the radio silence from DJI.  We as pilots should not have the burden of figuring out what the manufacturer did to disable our crafts.  

A CW Posted at 2018-5-28 10:07
Yep - RC, IMU, gimbal then finally the compass before take off at my flight location.
Before the calibrations I refreshed the firmware on both the AC and RC via GO4 on my iPhone 7+ only.

You are the very experienced pilot that I mentioned in my OP and therefore I wanted to test myself possible scenarios. Thanks to you we now know that at least one of the possible calibrations or a firmware refresh can fix the issue. Hopefully other pilots who experience the same problem can help to narrow the search down. On the other side I have by now seen two users blaming the firmware update to cause drifting at take off, while their flightrecords clearly showed insufficient satellite link to be the most probable cause.

3-D Posted at 2018-5-28 12:28
I don't want to downgrade.  But I do want to fly.  And I'm still looking to try to find what was so severe in .300 that I shouldn't run it.

What was so major that DJI would risk soiling the Mavic brand?

I fear we shall never learn about that. But I have seen similar firmware updates before that did not allow downgrading. They only do it if important security relevant issues are fixed with an update, this is all I know and can say.

Heavenone Posted at 2018-5-28 10:23
#1 Wachtberger

Nice to hear that  YOUR Mavic Air has no problems..

Please list the "hundreds" here, then we can continue your argument. And as said before in other posts, my only intention is to help track down the root cause of the issue for those experiencing it. You appear to be mainly driven by emotions...

Wachtberger Posted at 2018-5-28 12:42
You are the very experienced pilot that I mentioned in my OP and therefore I wanted to test myself possible scenarios. Thanks to you we now know that at least one of the possible calibrations or a firmware refresh can fix the issue. Hopefully other pilots who experience the same problem can help to narrow the search down. On the other side I have by now seen two users blaming the firmware update to cause drifting at take off, while their flightrecords clearly showed insufficient satellite link to be the most probable cause.

Thank you but only been flying a couple of years
I think it was the RC and IMU calibrations causing the yaw issue in my case. So relieved all was OK today.
I totally appreciate that the motive of this thread is to help others trouble shoot the issues they are facing rather than to undermine their issue. In my case, there was a minor yaw glitch and thanks to this thread and your efforts I can see it is not a universal problem which I found encouraging.
So I went through the whole FW refresh and calibration procedures and did four flights afterward with NO glitches at all - not one! Reached 0.8 miles in a CE area, 43MPH in Sport mode, tested every intelligent flight mode and RTH. My Mavic Air performed perfectly during the one-hour, eight minutes it was in the air today. All my footage, panos and stills show no issues too with no drift or yaw issues. All I can suggest is for others to do the same and if their problems persist then raise a ticket with DJI support or wait for another FW update and hope that sorts it.  

Heavenone Posted at 2018-5-28 10:34
here answer out of problems with firmware update..

"Update: DJI send me a new drone. So definitely something not right with latest firmware."

Is that yours and did DJI inform you that the latest firmware update has destroyed your Mavic Air and that is why they replace it? If not, you better provide good evidence about the true facts would be my advice.