Is there information available about estimated / calculated "terminal velocity" (free fall with air resistance) for DJI drones? I am specifically interested in Mavic 2 Pro / Zoom, Air 2S and Phantom 4 Pro v2.

I will need to get onto a different computer but I can look up a P3adv's if you like? (from the onboard DAT) There is also an either Mavic Mini or Mini 2 deliberate mid air CSC thread over on Mavicpilots but you'd have to do some searching for that, I think it was from quite high. The pilot didn't follow the instructions he was given and the drone was wrecked. I can't remember anyone worked out, and posted, the average fall speed which would be near enough terminal, I think the camera's view was recorded and posted on youtube etc. so the video might still exist.
There are/is deliberate CSC mid air stop and starts on you tube for something like a Mavic Pro but the pilot restarted quite quickly and I don't remember there being telemetry.

Sean-bumble-bee Posted at 6-30 03:32
I will need to get onto a different computer but I can look up a P3adv's if you like?

Thanks, yes please, I would appreciate that. Suppose the figures would be same / very similar for Phantom 4 Pro v2 ...

Probably, that was my thinking, I have edited my previous post, you may like to reread it.

Sean-bumble-bee Posted at 6-30 03:49
Probably, that was my thinking, I have edited my previous post, you may like to reread it.

Thanks! I read the mavicpilot thread and believe that the conclusion was that the Mavic 2 Pro terminal velocity was about 20 m/s.

Just incase you are thinking of it with an expensive Mavic xyz, be wary.
With the arrangement of props/centre-of-drag and C.o.G the P3 fell in a fairly flat spin, I think the same thing would apply to the P4. But there is, I think, a risk a Mavic will tumble and if so the drone may refuse to restart its motors if the angle of tilt is excessive when the restart is attempted.  It would probably be sensible to hold the restart (see next sentence) CSC position until motors restart or the drone crashes.
Also it is necessary to RELEASE the joysticks after the motors have stopped BEFORE trying a restart CSC, this was the mistake made by the Mini pilot, they held the CSC position all the way down with no joystick release 'in between'.
Note also that it may be necessary to give the drone throttle after the restart in order to halt the fall, the P3's motor restarted at idle. A Go4/Fly drone may throttle up automatically but be prepared for it not to.

Sean-bumble-bee Posted at 6-30 04:06
Just incase you are thinking of it with an expensive Mavic xyz, be wary.
With the arrangement of props/centre-of-drag and C.o.G the P3 fell in a fairly flat spin, I think the same thing would apply to the P4. But there is, I think, a risk a Mavic will tumble and if so the drone may refuse to restart its motors if the angle of tilt is excessive when the restart is attempted.  It would probably be sensible to hold the restart (see next sentence) CSC position until motors restart or the drone crashes.
Also it is necessary to RELEASE the joysticks after the motors have stopped BEFORE trying a restart CSC, this was the mistake made by the Mini pilot, they held the CSC position all the way down with no joystick release 'in between'.

Thanks. I have no intention to do any CSC tests. Just trying to figure out what the terminal velocity might be "theoretically". I need to calculate the kinetic energy for a SORA application. It surprises me that terminal velocity isn't part of the specs for each drone model actually as it is vital for the energy calculation and risk classification.

Henrik Carlsson Posted at 6-30 04:12
Thanks. I have no intention to do any CSC tests. Just trying to figure out what the terminal velocity might be "theoretically". I need to calculate the kinetic energy for a SORA application. It surprises me that terminal velocity isn't part of the specs for each drone model actually as it is vital for the energy calculation and risk classification.

Just trying to figure out what the terminal velocity might be "theoretically".
No need to calculate what it is theoretically and you'd have trouble getting a figure for the significant drag caused by the props..
The terminal velocity is similar for the models you listed.
Data from incidents shows that the resistance caused by the props is more than most would guess.
Terminal velocity is reached fairly quickly and oscillates between 15-19 metres/sec as the drone wobbles as it falls.

15.53m/s, that's from readings when it wasn't accelerating. Acceleration to terminal velocity was pretty quick.

It might be worth noting that as I understand the indicated motor speeds (negative during the free fall) it appears the P3's props were driven backwards in freefall, I am not sure what would happen with Mavic motors with stiffish blade pivots.
There are a couple of people over on Mavic Pilots who might have values, emperical or theoretical, it might be worth posting the question there.

Labroides Posted at 6-30 04:53
Just .......................

Labroides could you take a look at
https://forum.dji.com/forum.php? ... 4&page=1#pid2785976
which is entitled
"Lost Drone Overseas - DJI Care Refresh+"
please?