Hi everyone,

I just got a brand new Air 3s, updated it to the latest available firmware (DJI Fly v1.15.4, drone: 01.00.0400, RC2: 04.01.0000) and tried it out.

I noticed in N mode, with Flight Assistance set to Brake that when the aircraft is moving forward it keeps braking shortly then moves again normally, without any error messages or warnings, without any obstacles in front of it, or anywhere near it and at an altitude of over 10m. This happens at any speed but it is more obvious at full speed forward.

I have not noticed this at all if the drone is moving sideways and it does this only ocasionally when moving backwards.

Initially I thought the controller had a problem, more specifically the joystick in forward position.

After checking this further, it looks like this does not happen at all when Obstacel Avoidance Action si set to Off. Bypass creates a similar issue as Brake, but instead of braking it looks like the drone is jumpig around trying to avoid something that is not there.

I tested it on a cloudy day, with no wind, visibility was great, no fog and plenty of light (no warnings from the sensors regarding the light).

My guess is the drone somehow sees something, maybe the proppelers and doesn't know there is no object in front of it or behind it.

Is this a known issue and is something being done about it?

Thank you in advance for any replies!

I have been using Bypass-Nifty for OA sensors since the Mavic 3 and do so with the Air 3S and it works better without the jerky movement.

Hi, thanks for the tip, I will give it a try tomorrow and come back with a result. I did try to set it to Bypass, but not to Nifty.

Still, this pretty much makes the Brake mode kind of unusable

Hi,

I was able to test it again today.

Conditions: No wind, sunny, flatland, no obstacles nearby, N mode for all tests

Case 1:

-  Flight Assistance set to Off: no issues at all, the drone accelerates normally and moves smoothly, at any altitude

Case 2:

- Flight Assistance set to Brake, altitude @10m: from 0km/h the drone inches forward for a bit on max speed (right joystick all the way forward) and then it suddenly accelerates to max speed. As it moves forward it brakes randomly, without any notices on the display

Case 3:

- Flight Assistance set to Brake, altitude @20m and above: the drone moves smoothly, very rare cases where it brakes suddenly

Case 4:

- Flight Assistance set to Bypass and Bypass + Nifty: especially under 10m and until the drone goes over 20m in altitude same thing as with Brake, the drone keeps trying to avoid something, it is more subtle on Nifty, but it still does it. At an altitude of over 20m this behavior seems to disappear.

It looks like the drone somehow sees the ground (or something) as an obstacle when it is pitched forward, but this is not shown on the display at all.

I had no such issues with the Air 2s, regardless of the altitude, speed or direction and light (dusk, daytime, it didn't mater).
The drone behaves the same way when it moves backwards. I was unable to reproduce these issues sideways.

Right now, if I want to film something while moving forward at an altitude of under 20m, where most obstacles are, I have to turn off Flight Assistance to avoid these jerky movements, which kind of defeats the purpose of having those sensors

DJI, any info about this?

Thanks!

Have you tried doing this in completely different places?

Hi, yes, 2km apart, same results. Regardless of the direction in which I pointed the drone (N, S, E, W).
Forgot to mention that I checked if the OA cameras work, they seem fine, if I move around the drone they detect me and display the warnings depending on which side I am and how close or how far. But when those glitches happen while flying there is no warning on the display.

Cosmin Posted at 12-1 03:55
Hi, yes, 2km apart, same results. Regardless of the direction in which I pointed the drone (N, S, E, W).
Forgot to mention that I checked if the OA cameras work, they seem fine, if I move around the drone they detect me and display the warnings depending on which side I am and how close or how far. But when those glitches happen while flying there is no warning on the display.

The OA system of the Air3s is a precise little high-tech masterpiece....

The development is a milestone in the consumer drone world. Of course there are certain "childhood illnesses"... you could compare it to occasional hiccups... But surely a later update will fix these and other small "bugs".  (I've flown a lot with my Air 3s over the last few days, even with OA switched on... but everything was perfect)

DroneZone Thailand Posted at 12-1 04:21
The OA system of the Air3s is a precise little high-tech masterpiece....

The development is a milestone in the consumer drone world. Of course there are certain "childhood illnesses"... you could compare it to occasional hiccups... But surely a later update will fix these and other small "bugs".  (I've flown a lot with my Air 3s over the last few days, even with OA switched on... but everything was perfect)

Hi, that's true, it is a very advanced piece of tech.

I am not sure however if DJI is aware of this "issue", since it is repeatable under the same conditions I mentioned before. It is not just braking once, it's braking every 2-3 meters, random intervals and how hard it brakes is also random, sometimes it almost comes to a full stop.

Cosmin Posted at 12-1 04:34
It is not just braking once, it's braking every 2-3 meters, random intervals and how hard it brakes is also random, sometimes it almost comes to a full stop.

That sounds a bit strange though... Ask DJI if you should send the bird in for a check...
And take a close look at the flight log to see if the braking maneuvers are displayed there.

DroneZone Thailand Posted at 12-1 05:06
That sounds a bit strange though... Ask DJI if you should send the bird in for a check...
And take a close look at the flight log to see if the braking maneuvers are displayed there.

I just gave it a try, 3 flights forward, 2 at a low altitude, 0.5m and 2m, on both the drone would not accelerate at full speed (max speed is @5.5m/s) and the third at 2.9m and the brakes are visible in the flight record, normal speed is @8.5m/s and it drops to 5-6 and picks up again. Same thing in reverse.

If you want to fly so close to ground, there is a setting in the menu that allows that, just need to toggle that on.

Suren Posted at 12-1 08:28
If you want to fly so close to ground, there is a setting in the menu that allows that, just need to toggle that on.

Thanks, this happens up to an altitude of 20m, but is more frequent lower than 10m. Above 20m there are rare cases where it does this and when it does it, it's almost like a full stop, like you would just take the finger off the right joystick at full speed.

I don't plan on flying that low to the ground, but I did it to check how it behaves at different altitude values.

I am not sure what the drone sees or what triggers these braking actions or bypass actions, depending on the mode it is in. It doesn't feel normal for it to suddenly brake when there is nothing in front of it and it is well above the ground, 10m+. The terrain is even, no tall grass or anything to confuse it (bushes, plants).

For example yesterday I had it at over 20m altitude and it would not accelerate faster than @5m/s and then, randomly, it just sprinted to @8m/s and then a series of brakes followed, in N.

For now, the only solution for a smooth flight is to turn the OA cameras off.

Drone.Hunter Posted at 12-1 08:49
https://youtu.be/rOpf7Ce6mJw

Luckily it is not as bad as the one in the YouTube video and from what I have read about that case, it seems related to motion 2 and goggles 2.

Did you check the calibration of the sensors? And/or re-calibrate, just to be sure?

AgentSmith Posted at 12-2 11:41
Did you check the calibration of the sensors? And/or re-calibrate, just to be sure?

Hi, I forgot to mention, but yes, I did that twice before the tests, no improvement.

Did you check with a flashlight to see if the 'window' for the lidar is fogged up/damaged on the inside? It seems to me, one or more sensors are fooling the flight processor. Did you open a case with DJI support?

AgentSmith Posted at 12-2 11:54
Did you check with a flashlight to see if the 'window' for the lidar is fogged up/damaged on the inside? It seems to me, one or more sensors are fooling the flight processor. Did you open a case with DJI support?

No visible issues with the 4 OA cameras or with the lidar cover. I will open a case and let's see.

Hope they can fix it! Please, keep us posted.

Hi, just a small update, I reached out to DJI Support, I was advised to do a Firmware refresh, which I did. Unfortunately it did not help at all.

I gave it another try today, with the following settings and conditions: N mode, 15m altitude, OA Action set to Brake, full throttle, almost no wind (1-2m/s), 6 degrees celsius

The drone barely moves forward when the throttele is all the way forward, @5m/s and when it jumps to full speed it starts to brake constantly as if it would detect something in front of it. I also have  a video of this and I will reach out to support on Monday.

Here's a picture of the terrain. It is cloudy today, but the behavior is the same when it is sunny. I got no warnings of low light or obstacles.

So, just another update.

After checking this further with support, it looks like there are some possible issues with this drone. The behavior is not normal and the remote check indicates a problem (I don't have details at this point). A case has been opened and the drone will go in for repair/replacement.

Cosmin Posted at 12-17 09:25
So, just another update.

After checking this further with support, it looks like there are some possible issues with this drone. The behavior is not normal and the remote check indicates a problem (I don't have details at this point). A case has been opened and the drone will go in for repair/replacement.

Hi there,
thank you for reaching out.

As you have completed all the troubleshooting steps and the issue persists, the appropriate course of action is to send the product back for further inspection. We appreciate the update and are pleased that your issue is being addressed. Please keep us updated with the progress.

Hello, so here is another update regarding this case.

I sent the drone in for repair and this was the information I got:

"DJI Air 3S Gimbal Roll Motor Module was malfunctioned,which caused gimbal shake"

I received another drone, brand new, as a replacement.

I tested it, it behaved the same way as the first one, braking when it should not, without any obstacles in front of it even at an altitude of 26m.

A few days later I got a call from DJI Germany and had a longer conversation with the person from support, he said that indeed the first drone had a gimbal issue (I never noticed it), we discussed the second one and since then we have been investigating this (from the beginning of January). Shoutout to DJI Germany, really nice people!

After sending in more videos under various conditions, flight logs and recordings of the RC2 screen, I got an email that there might be a problem with the sensors and the behavior is not normal.

The conditions in which the drone had issues were the following:

- latest Aircraft Firmware and RC2 firmware
- latest Fly App
- temperature 12-14 degrees Celsius
- no wind
- mostly sunny, no light warnings
- the controller with the default settings
- OA on
- OA Action Brake
- N Mode
- Altitude 26m
- full speed forward or full speed backwards
- not pointed at the sun
- no obstacles for at least 500m
- no hills in the background, just an open field

The drone will not accelerate faster than 11m/s and the speed varies between 5 and 11m/s, depending on how hard it brakes. It does the same thing backwards.

At an altitude of 54m the drone did not brake, it worked fine. It also works fine if OA Action is set to OFF, at any altitude, or if the drone is in S mode. So, as long as OA Actions are turned off the drone moves smoothly.

Has anyone else seen this, or can anyone else test it under the same conditions please?

Cosmin Posted at 1-30 09:18
Hello, so here is another update regarding this case.

I sent the drone in for repair and this was the information I got:

Hello Cosmin,

FWIW, I've been experiencing a similar issue with my Air 3S with the OA set to nifty. The drone behavior is similar to the Mini 4 video posted above, where I noticed oscillation during the footage. After the update to the latest firmware, I also had on one occasion a "gimbal stuck" message and the gimbal went limp. Will try to fly with the OA set to off and see what happens. Will revert as soon as I test.

Hi Roberto, thanks for the info.

For me it happens randomly, at the begining of the flight it might brake a few times, then it will go fine for 100m maybe and then it starts braking again, there are no warnings on the RC2 display.

This is more obvious in N mode with OA turned on and Action set to Brake. It also tries to avoid something that is not there when set to Bypass, but it is not as obvious as on Brake, since the drone just tried to go around something or fly over, I can see it moving around in the air for no actual reason.

If you could give it a try, in an open field with OA on and action set to Brake, full throttle and watch the speed, it would be great to know, this might be a sw glitch, I doubt 2 new drones have the same identical HW defect, thanks again!

Cosmin Posted at 1-30 12:13
Hi Roberto, thanks for the info.

For me it happens randomly, at the begining of the flight it might brake a few times, then it will go fine for 100m maybe and then it starts braking again, there are no warnings on the RC2 display.

The Air 3s has a steeper attack angle than older models when  full stick forward have you tried half stick reducing the angle at which sensors are viewing terrain?  I have also encountered this kind of behaviour where in bypass the drone will randomly climb where no obstacle is present suggesting variance in terrain triggers the action.  In my case I was in open ground with only subtle changes in ground height across ploughed fields.

BaynhamPhoto Posted at 1-31 13:32
The Air 3s has a steeper attack angle than older models when  full stick forward have you tried half stick reducing the angle at which sensors are viewing terrain?  I have also encountered this kind of behaviour where in bypass the drone will randomly climb where no obstacle is present suggesting variance in terrain triggers the action.  In my case I was in open ground with only subtle changes in ground height across ploughed fields.

Hi, I did try it over a ploughed field and thought the same thing, it might be the terrain, but when I moved it over a plain field, with just grass it still did the same thing.

I did try to move forward slowly, but sometimes this happens as soon as I move the stick forward, the drone will not accelerate, right from the beginning, it just crawls forward, so it doesn't seem to be the angle as it never reaches a steep angle, until it just jumps to @11m/s for a few seconds and then brakes again, and it brakes hard sometimes, almost stops. I never had issues like this with 2S, it never braked unless there was an obstacle in front of it and it would have colided with it.

Cosmin Posted at 1-31 13:40
Hi, I did try it over a ploughed field and thought the same thing, it might be the terrain, but when I moved it over a plain field, with just grass it still did the same thing.

I did try to move forward slowly, but sometimes this happens as soon as I move the stick forward, the drone will not accelerate, right from the beginning, it just crawls forward, so it doesn't seem to be the angle as it never reaches a steep angle, until it just jumps to @11m/s for a few seconds and then brakes again, and it brakes hard sometimes, almost stops. I never had issues like this with 2S, it never braked unless there was an obstacle in front of it and it would have colided with it.

My Air 2 would occasionally brake if the sun was low if you didn’t encounter that on the 2s I’d say you were quite fortunate.  It definitely appears to be some kind of sensor calibration we could do with something similar to expo settings for this feature.

BaynhamPhoto Posted at 1-31 13:51
My Air 2 would occasionally brake if the sun was low if you didn’t encounter that on the 2s I’d say you were quite fortunate.  It definitely appears to be some kind of sensor calibration we could do with something similar to expo settings for this feature.

As I mentioned in my previous comments, there was plenty of light, I also tested it on sunny days, with the same results and it was not flying towards the sun, I specifically avoided this, as it sometimes confuses the sensors, but that would show a warning on the display from what I have noticed. The random braking does not display any warnings. On the Air 2S I only had issues when there was not enough light for the sensors to work, which showed a warning, not the case on the Air 3S.

Cosmin Posted at 1-30 12:13
Hi Roberto, thanks for the info.

For me it happens randomly, at the begining of the flight it might brake a few times, then it will go fine for 100m maybe and then it starts braking again, there are no warnings on the RC2 display.

Hello Cosmim,

Just to let you know that I could make some flight tests with my Air 3S and can confirm that the drone is changing altitude in a kind of zig-zag motion up and down in normal mode and with the sensors set to nifty.  With sensor off, the drone flies smoothly without any jerky movements. This behavior was also confirmed by a friend who also has a DJI Air 3S and already had turned off the sensors to avoid the annoyance. Also, in some instances flying exclusively with the 70mm lens, I also noticed a quick autofocus lost from the subject, which is a bug that still persists even after the last update. Finally, I discovered a weird bug, like what you described: during a flight, I cancelled the RTH to manually bring back the drone and the right stick was completely unresponsive. The drone refused to fly forward no matter what. The only way to bring my Air 3S back home was to invoke RTH again. Looks like DJI still has work to do with future firmware development.  Sorry, but I forgot to set the sensor to brake mode as you asked me. Hope this helps.

ROBERTO SMERA Posted at 2-3 03:48
Hello Cosmim,

Just to let you know that I could make some flight tests with my Air 3S and can confirm that the drone is changing altitude in a kind of zig-zag motion up and down in normal mode and with the sensors set to nifty.  With sensor off, the drone flies smoothly without any jerky movements. This behavior was also confirmed by a friend who also has a DJI Air 3S and already had turned off the sensors to avoid the annoyance. Also, in some instances flying exclusively with the 70mm lens, I also noticed a quick autofocus lost from the subject, which is a bug that still persists even after the last update. Finally, I discovered a weird bug, like what you described: during a flight, I cancelled the RTH to manually bring back the drone and the right stick was completely unresponsive. The drone refused to fly forward no matter what. The only way to bring my Air 3S back home was to invoke RTH again. Looks like DJI still has work to do with firmware.  Sorry, but I forgot to set the sensor to brake mode as you asked me. Hope this helps.

Hi,

Thank you Roberto, had the same issue with Bypass, it flies around trying to avoid something, it is not as obvious as on Brake, that's why I mostly tested it on Brake. I am beginning to think this is a firmware glitch and not a HW problem. I asked DJI this a few times, but got no answer at all for this question.

My drone is on its way back to DJI service, to be checked further.

My guess is, somehow what the vision sensors see is not interpreted correctly by the software under some circumstances, but I can't confirm this. I was advised by DJI to not turn off the sensors as that is not a solution and they also insisted that this behavior is not normal and the drone should not behave like it did in the videos and how they saw in the flight logs.

I never encountered the problem you mentioned, luckily, where the drone would not move at all, in my case it would just not accelerate properly as if something would be in its way and it would just crawl forward cautiously until it was sure there was nothing and then it suddenly accelerated properly, without any warnings on the display. But RTH was a disaster for me, with obstacle avoidance, in an open plain field and the RTH took some turns and brakes and changed the direction suddenly multiple times as if it was flying through a maze, I cancelled RTH as some of the moves the drone made were too strong, also the path shown on the display was constantly changing, but there was nothing between the home point and the drone. Normal RTH without obstacle avoidance at a fixed altitude worked fine.

I will update this post again once I know more from DJI.