DJI Mavic, Air and Mini Drones
Friendly, Helpful & Knowledgeable Community
Join Us Now

Descent automatically slows to less than 1 mph

No I meant 1,000 ft agl and actual flight not more than 200 ft actual ground level. i.e. mountains go very high, even above 400 ft. MA2 tops out at 1640 ft agl.
You can't be 1,000' AND 200' above ground level (AGL) simultaneously. If you're 200' above a hill, then you're 200' AGL. I assume you started your flight 800' or so below the top of the hill/mountain, so you may have been 1,000' above your takeoff point, but your AGL is always in reference to where the drone is, not where it was.
 
  • Like
Reactions: eEridani
I've done all that... control is in max descent position and the descent rate just slows up for no reason.
Have you tried to calibrate the IMU?
I've calibrated the IMU. Here is a flight log of today's flight. I took the drone up to max altitude (1640') briefly to show you guys the issue. Watch the rate of descent slow up dramatically around 500 ft up. I toggled between all three modes at this point to no avail. Even took off the obstacle avoidance... doesn't help. Then it started a leading sequence at around 300' and after that, the issue disappeared.
 

Attachments

  • DJIFlightRecord_2022-03-24_[14-07-35].txt
    2 MB · Views: 11
Last edited:
I bought a new Mavic air 2 and it's acting strangely: It's rate of descent slows to less than 1 mph between certain altitudes. I can't control its descent rate no matter what I do with the controller in any mode. Just between certain altitudes. Any guesses as to what that's about?
I have had this same problem many times. Especially in the cold.
 
...Here is a flight log of today's flight...
Either you have something attached to your drone that goes into the view of the VPS sensor & makes it believe that you're approaching something & by that takes down the decent speed ... or it's something wrong with the VPS sensor.

It's clearly seen in the log ... there where I've placed the chart marker at 533sec into the flight the barometric sensor reports a height above your HP on 391ft ... but there the VPS sensor reports that it sees something only 2,6ft below the drone, you have the throttle stick on max for descend but the vertical speed is only 0,5mph.

It's also really odd that the VPS sensor, when it stops reporting at barometric height 180ft on the way up (operating range for the VPS is up to 60m/196ft) says it sees something there 41ft below the drone. The same thing repeats on the way down ... the VPS starts to report at a barometric height of 1073ft (odd, as the operating range is 60m/196ft) but the VPS height is there 30ft.

Red = Barometric height above the HP
Green = VPS sensor height ... height from something straight under the drone
Blue = Vertical speed ... positive value=descend, negative value=ascend
Purple dashed = Throttle stick input ... neutral stick have value 1024
(The different background colors in the chart is different flight modes)

If nothing is interfering with the VPS sensor on the belly of the drone ... or it isn't really foggy, I think this is a case for DJI to look at.

(Click on the chart to make it larger)
1648151213226.png
 
Last edited:
Thanks Slup... confirms what I've known all along... this thing has a bug in it... nothing is interfering with the sensor and it's not foggy... and my other drone has no problem in the same space at the same time... not interference.
 
An initial guess is that your downward vision system was getting confused and thought you were close to the ground; so it slowed the descent. Also may explain the forced landing mode around 400 feet.

1648153000223.png


ps: That said, hope you don't fly like this very often; it is these type of flights that make it tough on everyone. And yes, there are systems that track consumer DJI drones within 50km of the installations, systems sold by DJI to civil agencies around the US. Aeroscope - DJI

pps: oops - Slup already replied. So this is duplicate info.
 

Attachments

  • 1648152915000.png
    1648152915000.png
    23.7 KB · Views: 1
Last edited:
You might check for fingerprints on the lenses of the two downward facing cameras. I know it's pretty easy to grab the drone and touch places that shouldn't be touched.
 
Thanks Slup... confirms what I've known all along... this thing has a bug in it... nothing is interfering with the sensor and it's not foggy... and my other drone has no problem in the same space at the same time... not interference.
It may be a bug in all the models because several others including myself have experienced it.
 
It may be a bug in all the models because several others including myself have experienced it.
I've seen horizontal slow downs when flying into the sun, but never anything vertical.
 
Something makes the VPS think that the drone is near the ground. Strange!
You're lucky this didn't happen to you:
The guy in the video put a mavic 3 on the bottom of the matrice, also made the sensors think it is close to the ground and landing protection didn't work on RTH... If your drone has problems with VPS then be careful, I would send it to DJI!
 
  • Wow
Reactions: eEridani
Thanks all for your help, especially SLUP!! I'm returning the drone to the seller because I tried everything to address the issue to no avail. Very strange problem, but I'm guessing the issue is one of the things Slup points to. Thanks again everyone.
 
Recalibrate all, reinstall the app and try again.
Reluctant to file the text file? Why so, if you need further help do it.
 
  • Like
Reactions: Yaros
there was an interesting thread about this back in Jan of 2021.
Highest rate of descent - Mavic Air 2
I'm guessing that the air 2 might be vulnerable to losing lift when descending down into it's own prop wash, and that DJI built in a prevention to slow it down. so it has a much greater descent speed (according to this thread) when flying forward at 20+ mph than straight down. Again, I'm guessing.
 
  • Like
Reactions: Lob's Falcon
If you go to drone hacks and download their software , it free for you to adjust the parameters and you can increase the descent rate.. without paying for it!!
 
Had the same problem… It was descending at around 0.3m/s after going straight down with 3m/s. The cause of this was that I had fitted Air2s props on and not the ones from Air2. Maybe a coincidence but now it’s working fine. It might be because of turbulence
 

DJI Drone Deals

New Threads

Forum statistics

Threads
130,587
Messages
1,554,120
Members
159,591
Latest member
Albrecht0803