Lost Mavic Mini
- Thread starter Chetrari
- Start date
Yepp ... but flyCState doesn't tell the whole truth, looking at the flightAction signal reveals that it was in failsafe mode ... which was Hover.
It's obvious that it wasn't hovering and looks like OSD.flycState = GoHome was accurate.
It's a difference here & you don't spot it until looking at the signal flightAction together with the signal failSafeAction ...
Here below the signal state from one log with GoHome initiated due to loss of signal... & another log where GoHome was initiated by means of using the RC button or app button. Note that both have flyCState=GoHome ... but they differ in the flightAction signal.
The craft can behave in the same way in both these cases ... but only if the failSafeAction is set to RTH. Set to Hover or Descend the behavior will differ.
So in this thread's incident we see this from the log just before it cuts out for the last time ...
This tells us that we are dealing with a loss of connection which have initiated the failsafe action Hover ... Hover will not ascend to set RTH height nor will it go back to HP. Instead it will try to hold position both horizontally & vertically. But being blown away at the same time here, will make the craft pitching full down according to P-mode specs trying to resist ... & at the same time aligning the yaw in the direction to the position where it got the failsafe command Hover.
So with this said ... it's interesting that the craft have gained height between the points where it was connected to the RC ... either the OP held the throttle stick activated & the uplink returned shortly or the wind took it up. But in the end of the day this doesn't matter, the Mini is gone & the possibility to estimate a acceptable accurate touchdown spot is slim to none ... but I seriously doubt that it ended up at 434m height.
In 50 seconds of lost signal, it has already gained 51 metres of altitude and it continues to climb as the data records.
For this to be a result of wind would require the kind of wind no-one has ever seen.
When signal is restored at 2:34.5, the flight mode is showing as Go Home and GoHomeStatus is showing as Ascending to RTH altitude and what do we see but the drone gaining height.
It's pretty clear that the drone is actually (attempting to) RTH and is on its way to 300 metres.
There's a lot more evidence that it gained height because it was attempting to RTH and would have continued to.
Well ... the Mini have a maximum descend speed in P-mode of 1,8m/s ... in order to be pushed up to higher altitudes with 1m/s it would require an upwind of 2,8m/s, is it that you call "kind of wind no-one has ever seen" ?
And at the same time the same log shows failsafe action Hover ... that's why I earlier wrote "a thing for thoughts ..." We clearly see discrepancies & contradictory facts from this log ... & the only fact we have is that we don't know why. All after that is speculation ...
Yeah, feel free to be certain ... I prefer to just look at the log & what I see don't make it pretty clear ... instead it leaves it open for other course of events.
How many times have you seen a wind that blows a drone upwards?
I have just once but it was the result of a strong wind coming off the sea and hitting a cliff.
And it was only a localised thing that quickly dissipated away from the cliff.
You just don't get strong uplifting winds out in the open.
.. and there was no sign of it before signal was lost.
And just because it's important ... the flight mode is showing as Go Home and GoHomeStatus is showing as Ascending to RTH altitude when the drone was "mysteriously" ascending.
There's one odd thing with the Failsafe showing Hover.Yeah ...you have made up your mind, that's pretty clear, fully respect that. And as I can read logs pretty well also, I say I'm still open minded about what happened.
And there are several not-at-all-odd things with all the other data matching the drone's recorded performance that shows the drone in RTH, climbing to 300 metres.
The only way to deny what is obvious, is to come up with a very unlikely explanation.
I'd rather go with what obviously happened and is believable.
Well ... in this case all will stay at just theorizing, the AC very likely drifted a fairly long distance considering the remaining battery percentage & the present height above the house roofs and the log gives to little to interpolate any touch down with accuracy.
Another plausible outcome here would also be that the Mini never reached any obscene heights if it really was in RTH (considering the RTH height setting) Instead it went down in a much shorter distance from the HP compered to drifting on until the battery was depleted. Base of course this on the bad pitch there in the end which could have been the first signs of under performing rear props making rear motors rev maximum, maybe that developed later to an uncommanded descent. Access to the mobile DAT log could confirm or rule that out ...
... in this case all will stay at just theorizing, the AC very likely drifted a fairly long distance considering the remaining battery percentage & the present height above the house roofs and the log gives to little to interpolate any touch down with accuracy.Another plausible outcome here would also be that the Mini never reached any obscene heights if it really was in RTH (considering the RTH height setting) Instead it went down in a much shorter distance from the HP compered to drifting on until the battery was depleted. Base of course this on the bad pitch there in the end which could have been the first signs of under performing rear props making rear motors rev maximum, maybe that developed later to an uncommanded descent. Access to the mobile DAT log could confirm or rule that out ...
Similar threads
