https://www.phantomhelp.com/LogViewer/VO76RHFRQ01VQ7ZIBWOA

10m 50.9s        Sport        21.7ft        18.7mph last timeframe with CS input full down
10m 51.2s        Sport        18.0ft        16.7mph
10m 51.7s        Sport        14.4ft        9.3mph lowest reported altitude
10m 55s        Tripod        24.0ft        0.4mph highest reported altitude, by visual observiation this data or the previous data frame appear to mismatch with each other
10m 58.4s        Tripod        9.5ft                0.2mph uncommanded descent, first timeframe with CS input up
11m 0.2s        Tripod        7.5ft                0.9mph lowest point, the AC begins to regain elevation

I tried to replicate the incident with success. It happened again after a fast manual return towards the homepoint, from full stick down and full speed in Sport mode to a halt. Heigh discrepancy takes place after the AC has halted and the uncontrolled descent begins. Only full stick up can recover but quite slowly compared to how prompt the AC usually is.

12m 56.3s        Sport        32.2ft        22.3mph
12m 58.6s        Tripod        35.4ft        0mph
13m 10s        Tripod        19.7ft        0mph

A complete .dat log is available on request for DJI to further indagate the problem should they choose to do so.

Just taking the first entry, your coming straight down in sport mode 100% left stick down, you let go of stick at 10.50, did you think it would hold exactly at the height you stopped at without any room for breaking ?

Before you take a stance you should check the log file which from the way you answer it's clear you didn't check and probably didn't read my notes either.

Continually opposing everything that I report is becoming sport for you... bet also is not gaining you any more trust from other users despite your possibile intention of a constructive critique.

m80116 Posted at 1-25 14:14
Before you take a stance you should check the log file which from the way you answer it's clear you didn't check and probably didn't read my notes either.

Continually opposing everything that I report is becoming sport for you... bet also is not gaining you any more trust from other users despite your possibile intention of a constructive critique.

I’m not opposing anything and you shouldn’t be so defensive, but giving out information that may be wrong in the first place is not going to encourage anyone to look at your log, so basically I asked a question if you want to avoid answering it that’s fine .

I am not avoiding answering any questions. If you have a legitimate one come forward and I'll answer the best I could, but you should avoid making arbitrary statements like you're dealing with a dud.

The AC descended by itself and continued to descend after it was already stopped and regained perfect stationary attitude. Eventually the descent stops but very slowly, even full CS up stops the slow but steady descent very slowly compared to how quickly the AC usually responds. The timing and CS inputs are clearly recorded, what I don't believe is accurately stored is the height data which I reckon is what confuses the FC regardless of what is being reported by the IMU sensors.

I could make a video to better explain since this is a very replicable incident but... I think they should be already on it, and there's plenty of videos already. I think I've even spent too much time in this thread alone.

m80116 Posted at 1-25 14:29
I am not avoiding answering any questions. If you have a legitimate one come forward and I'll answer the best I could, but you should avoid making arbitrary statements like you're dealing with a dud.

The AC descended by itself and continued to descend after it was already stopped and regained perfect stationary attitude. Eventually the descent stops but very slowly, even full CS up stops the slow but steady descent very slowly compared to how quickly the AC usually responds. The timing and CS inputs are clearly recorded, what I don't believe is accurately stored is the height data which I reckon is what confuses the FC regardless of what is being reported by the IMU sensors.

look you posted the log, and again just on your first entry, from 10.45 to 10.50 approx, your log shows you full 100% down on throttle and 95% forward on elevator when you released sticks your craft lowered in its breaking as it should and that what it shows in your log.

m80116 Posted at 1-25 14:29
I am not avoiding answering any questions. If you have a legitimate one come forward and I'll answer the best I could, but you should avoid making arbitrary statements like you're dealing with a dud.

The AC descended by itself and continued to descend after it was already stopped and regained perfect stationary attitude. Eventually the descent stops but very slowly, even full CS up stops the slow but steady descent very slowly compared to how quickly the AC usually responds. The timing and CS inputs are clearly recorded, what I don't believe is accurately stored is the height data which I reckon is what confuses the FC regardless of what is being reported by the IMU sensors.

I doubt this is something DJI can fix with software. I think it is a pressure change inside the aircraft caused by the aircraft being operated very fast. When you stop, the pressure returns to normal, slowly, and this influences the barometer sensor causing the slow descent.

Interesting interpretation @Geebax

@hallmark007 you are remarking the obvious. AC was returning at high speed, Sport mode, full left CS down (Mode 2), it's one of the fundamental condition to replicate the problem.

From .50s the CSI down ceased, from 10m 55s  at 24.0ft  almost stationary in height dropped to 9.5ft by 10m 58.4s, from that point with full CSI up managed to stop at 7.5ft by 11m 0.2s.

Not only the drop is not normal but it starts slow and gradually and accelerate with time. If let go it goes on, and gradually stops descending and stabilizes. Full CSI up causes a lethargic response because the AC is affected by some wrong logics or data. I hope this clarifies your concerns.

m80116 Posted at 1-25 14:14
Before you take a stance you should check the log file which from the way you answer it's clear you didn't check and probably didn't read my notes either.

Continually opposing everything that I report is becoming sport for you... bet also is not gaining you any more trust from other users despite your possibile intention of a constructive critique.

2nd that... this guy always has a way of putting down whatever you say and i'm sure people leave this forum because of it. I guess because he has the "Captain" title allows him to be condescending and rude.
I have no use for people like that. cya!

m80116 Posted at 1-25 15:26
Interesting interpretation @Geebax

@hallmark007 you are remarking the obvious. AC was returning at high speed, Sport mode, full left CS down (Mode 2), it's one of the fundamental condition to replicate the problem.

It’s difficult to know, you were flying within vps range over trees or rough ground , so maybe vps was reading from top of trees which we see often in all dji craft .

dutch937 Posted at 1-25 15:52
2nd that... this guy always has a way of putting down whatever you say and i'm sure people leave this forum because of it. I guess because he has the "Captain" title allows him to be condescending and rude.
I have no use for people like that. cya!

Maybe we should all be as helpful as you, obviously coming to the thread to cause trouble, not much help there.

hallmark007 Posted at 1-25 16:05
Maybe we should all be as helpful as you, obviously coming to the thread to cause trouble, not much help there.

Buddy, you were in one of my threads ripping it apart and quoting things that were never said... This is exactly why I will never post anything ever again..i'll read the threads where people have constructive things to say and completely ignore everything you say from now on. You're a joke.

dutch937 Posted at 1-25 16:33
Buddy, you were in one of my threads ripping it apart and quoting things that were never said... This is exactly why I will never post anything ever again..i'll read the threads where people have constructive things to say and completely ignore everything you say from now on. You're a joke.

Your really getting the hang of this, your starting to sound like a fish wife
Personally attacking people won’t get you anywhere

My apologies to the OP for my part in taking this off topic.

Hall,   this ->  My apologies to the OP for my part in taking this off topic.        HAPPENS ALL TOO OFTEN.

The OP has seemingly attempted to reasonably test and prove a theory.  It appears he has done so, and that DJI might have something to review and look at.  

So STFU.   Or do your own testing and provide YOUR results here on the forum.  HALLMARK007 Please,  you have some good insights but you NEED to stop and re-read your posts BEFORE posting.

Randy

rwynant V1 Posted at 1-25 18:43
Hall,   this ->  My apologies to the OP for my part in taking this off topic.        HAPPENS ALL TOO OFTEN.

The OP has seemingly attempted to reasonably test and prove a theory.  It appears he has done so, and that DJI might have something to review and look at.  

Might be worth checking before you put your foot in your mouth again.

https://forum.dji.com/forum.php?mod=viewthread&tid=207555

Hiya,

Just to make it easier to see; your point about loosing height of your MM,  see my chart  ( the first drop in height )

Just after the UP/DOWN and FWD/AFT sticks to zero ; drone pitches up (to brake the speed), increased in height first, dropped (to correct height change) and guess would have levelled out but your gave UP input. (logic ; flying low...)

Is this normal?  Well, for sure MM is not as height stable as a MA for instance, this with rapid stick movements.

Is this a problem? YES > if you want to fly low with rapid stick changes and do want that the MM is rock steady at its height performance.
NO > if a MM user fly more 'normal'.  And ofcourse for each MM owner 'normal' is how he/she like to fly a drone.

BTW red line in height line = > 0.1 m/s down with a delay of 0.5 second.

cheers
JJB

My post reported uncontrolled and unintentional drop in S mode after coming to an abrupt stop, yaw left slowly and descend slowly, stop, then the mini started dropping fast without stick input. That was done on 2200m highland and just above zero. My guess is the gust lowered pressure making the mini think it had an expected ascend so it dipped to correct it. DJI did check my log and concluded that a free repair is to be offered due to the suspected barometric sensor error. I won't if this is every unit's issue or just an isolated case of a fault. If it is isolated then it means my mini is due for replacement...

JJB* Posted at 1-26 04:08
Hiya,

Just to make it easier to see; your point about loosing height of your MM,  see my chart  ( the first drop in height )

I tested today 100% down and forward stop and mini drops almost 6ft then slowly rises to the point where you let go of the sticks .

I am not  sure we're dealing with the correct flight log data.

What I perceived on the field is the clear braking action, very normal and a regain in attitude after ceased full CS input after which the faulty logics takes place and start intentionally descending the drone before a stop and slight recover. I'd hastily quantify in 20:100 the ratio of regained heigh to the heigh loss without CS input (providing you have enough clearance).

Maybe I'll try again with a colleague... my intention (for other purposes) is to film a drone being a drone and doing drony things

Hallnark is a d|ck dont mind the snake in the grass....no one likes hims dont know why he is still here...