Hi Forum,

I just experienced an issue.  

I fly the drone straight up and in a reasonable time it reached the height limit at 400 ft.  But when I tried to descending the aircraft from there, even with the left jog stick all the way down, it descended very very slow.  Perhaps it took 2 second to drop just 1 foot, according to the DJI GO 4 App camera view display of the H value at the bottom of the screen.

At the ground level and from looking at the nearby very high palm tree top, did not seem to be a windy day.   When this happen, I have 20% battery left.  It is a new battery.  I just got the P4p for a month.  When it came down so slow, I was worried that I might run out of battery before I could be landed.


Thanks
Sam.

Have you tried RTH with Land at Homepoint, to see what rate of descent that automatic function achieves?

No.  I did not try the RTH at that time, because there were trees closed by.  So, I did manual descending.  But does it matter to use RTH or manual descending?  Is it typical for descending slower than ascending, for whatever reason ?

Thanks
Sam.

Drone AV Posted at 10-17 12:55
No.  I did not try the RTH at that time, because there were trees closed by.  So, I did manual descending.  But does it matter to use RTH or manual descending?  Is it typical for descending slower than ascending, for whatever reason ?

Thanks

Aloha Sam,

     There are a number of reasons for a slower descent rate than an ascent rate.  One is Vortex Ring State (VRS).  VRS can create a loss of lift under power called "settling with power".  What that means is, as with all helicopters (including the V-22 Osprey - one crashed because of VRS), a downdraft is created that produces a localized condition in which the air rushes straight down in line with the descending aircraft.  If the aircraft remains in the descending column of air, it will crash no matter how much lift is applied to the main rotor.  The stealth H-60 involved in the Osama bin Laden raid also crashed due to VRS.

     For the most part, DJI changed the alignment of the four motors of their quads so that there is no full-blown down blast of air.  This started with the P2 V3.  But still, there are possible situations where your aircraft may get caught in its own downdraft due to unique wind conditions if it descends too fast.

     Hope this helps!

     Take care and be safe!

Aloha and Drone On!

Drone AV Posted at 10-17 12:55
No.  I did not try the RTH at that time, because there were trees closed by.  So, I did manual descending.  But does it matter to use RTH or manual descending?  Is it typical for descending slower than ascending, for whatever reason ?

Thanks

But does it matter to use RTH or manual descending?  
Probably not

Is it typical for descending slower than ascending, for whatever reason ?
Yes .. from the specs:
Max Ascent Speed  P-mode: 5 m/s
Max Descent Speed  P-mode: 3 m/s

But to properly comment on your situation it's necessary to see your flight data because it will show exactly what descent speed your drone is achieving and why.
Go to: https://www.phantomhelp.com/LogViewer/Upload/
... where you'll find instructions.
That will give a report you can post a link for the report here.
Or just post the .txt file

Great.  Will try soon.

But I think I noticed and forgot to mention earlier, as the P4P v2.0 descending, it was rotating somewhat, as the camera turns around slowly.  But could not remember if it rotated in full circle or not.

Thanks All.
Sam.

Is it possible that the joystick control calibration is off?

Anokadrone Posted at 10-18 07:02
Is it possible that the joystick control calibration is off?

That's probably not the issue.
I can think of one likely cause.
But until the OP takes a couple of minutes to post data, it's all just guessing

Thanks all.  Will go to the web site to learn how to upload the flight record.

Sam.

Drone AV Posted at 10-18 20:55
Thanks all.  Will go to the web site to learn how to upload the flight record.

Sam.

It takes 2 or 3 minutes max.
See post #5 for instructions.