Not Impressed With This Feature

[Grizzo]

.
The user manual has this caution about RTH;

"If you move the throttle stick (left joystick) after the aircraft rises above 65 ft but below the preset Failsafe RTH altitude, the aircraft will stop ascending and immediately return to the home point."






I never liked this feature and had a feeling it would get me into trouble one day. Today it almost caused a crash.

I was flying in a park with tall trees all around the Mavic. My return to home set altitude is high enough to easily clear these. As I was descending between the trees, the video screen went blank and my RC signal started going in and out continuously.

The first thing you think about is to get some height and get signal back. So I held the left stick up not really knowing if it was actually going up but hoping for the best.. After about 8 seconds, video returns and I can see the Mavic returning to home and just barely clearing the height of the trees. Obviously I lost total signal and the Mavic was RTH. The signal likely returned a few moments before I saw the video clearly and I had no time to react to the near miss.

My left stick input stopped the Mavic from first going to its total RTH set altitude and proceeded to horizontally return. I got lucky that it was just high enough not to crash.

I know I should watch the screen more carefully and be aware when it disconnects to not react, but its something easily forgotten if you don't fly for a while and keep up with continuous manual studies.

In my situation the signal was at first, coming and going. You get nervous about losing your aircraft. You are thinking "maybe I still have a little bit of signal there". The natural reaction is to gain height and try to get signal back.

If the Mavic returns to home after signal loss that's great, but it should continue to go to the full set RTH height even if the controls are moved. Only cancel should stop it.

Not a fan of the feature at all.

 

[Alasas]

Agreed, never understood why they implemented this feature.

 

[jaysrmc]

.
The user manual has this caution about RTH;

"If you move the throttle stick (left joystick) after the aircraft rises above 65 ft but below the preset Failsafe RTH altitude, the aircraft will stop ascending and immediately return to the home point."






I never liked this feature and had a feeling it would get me into trouble one day. Today it almost caused a crash.

I was flying in a park with tall trees all around the Mavic. My return to home set altitude is high enough to easily clear these. As I was descending between the trees, the video screen went blank and my RC signal started going in and out continuously.

The first thing you think about is to get some height and get signal back. So I held the left stick up not really knowing if it was actually going up but hoping for the best.. After about 8 seconds, video returns and I can see the Mavic returning to home and just barely clearing the height of the trees. Obviously I lost total signal and the Mavic was RTH. The signal likely returned a few moments before I saw the video clearly and I had no time to react to the near miss.

My left stick input stopped the Mavic from first going to its total RTH set altitude and proceeded to horizontally return. I got lucky that it was just high enough not to crash.

I know I should watch the screen more carefully and be aware when it disconnects to not react, but its something easily forgotten if you don't fly for a while and keep up with continuous manual studies.

In my situation the signal was at first, coming and going. You get nervous about losing your aircraft. You are thinking "maybe I still have a little bit of signal there". The natural reaction is to gain height and try to get signal back.

If the Mavic returns to home after signal loss that's great, but it should continue to go to the full set RTH height even if the controls are moved. Only cancel should stop it.

Not a fan of the feature at all.

I did not know about this feature and it kinda sucks if you ask me. I can't even think why I would use this feature.

 

[Qoncussion]

I can see *part* of the usefulness behind this feature, say if you hit RTH due to a low flying aircraft or high winds in the area. But, I can also see how this can also be a serious issue, as this particular feature is never mentioned out here, and I had forgotten that it even existed. I don't use RTH, so I have not experienced this myself. Good to know.

 

[Grizzo]

I can see *part* of the usefulness behind this feature, say if you hit RTH due to a low flying aircraft or high winds in the area. But, I can also see how this can also be a serious issue, as this particular feature is never mentioned out here, and I had forgotten that it even existed. I don't use RTH, so I have not experienced this myself. Good to know.

At least in that situation you are aware of what you have done because you have the information still on the screen. The main issue is when it happens after you lose signal and have no idea what is happening.

I can't see a problem with making it so that during RTH you can move the aircraft any way you like, but as soon as the sticks are neutral, RTH AND its total set height resumes. Once full height is reached only then can it move horizontally. When auto landing during RTH it's like that. You can override and move the aircraft with the sticks, but as soon as they are neutral it continues to come down. RTH can always be cancelled if there is a problem with height.

 

[cfoxtrot]

Wow I never knew this either, glad you posted about this feature...yuk!

 

[tcope]

It's the lesser of two evils. First, the only way your left stick is going to do anything is if you are still connected to the Mavic. So now the question is, how should DJI program RTH if you move the left stick up and/or down? I'd say most of the time you are attempted to avoid hitting something. For example, your Mavic is flying toward a tree. Would you rather not have any control. You'd then blame DJI for not allowing you to fly higher or lower in order to avoid hitting the tree.

I'd say perhaps the best response would be the RTH set up to stop RTH all together if the left stick is used. But this has it's issues as well.

What you should have done.... switched to Sport mode or cancelled RTH when you noticed this problem. You can see the Mavic and see that your moving the left stick is causing it to rise and/or you can see the Mavic and see that it's not going to clear the trees.

 

[RayOZ]

this would be handy when RTH was triggered and the Mavic is under a tree. maybe it was programmed as a response to people complaining about crashing their drone that way. i guess you can't win either way.

 

[joejaxvic123]

Trees+RTH+Mavic=crash x 3.

 

[MiniPalourde]

Agreed, never understood why they implemented this feature.

For efficiency I guess. If you hit RTH in a place with no trees you might not want to wait for the Mavic to get high altitude.

 

[Grizzo]

It's the lesser of two evils. First, the only way your left stick is going to do anything is if you are still connected to the Mavic. So now the question is, how should DJI program RTH if you move the left stick up and/or down? I'd say most of the time you are attempted to avoid hitting something. For example, your Mavic is flying toward a tree. Would you rather not have any control. You'd then blame DJI for not allowing you to fly higher or lower in order to avoid hitting the tree.

I'd say perhaps the best response would be the RTH set up to stop RTH all together if the left stick is used. But this has it's issues as well.

What you should have done.... switched to Sport mode or cancelled RTH when you noticed this problem. You can see the Mavic and see that your moving the left stick is causing it to rise and/or you can see the Mavic and see that it's not going to clear the trees.

The way I explained earlier for how it should be programmed is that when it's doing the ERTH and you reconnect, you CAN move the drone up or down but when you let go of the left stick it still continues up to the set altitude. That way you can avoid something if you want to, and if you move the left stick without realising you have reconnected, it's will still go to the set RTH height. Kind of the opposite to how its programmed when auto landing on a low battery.

Also as I explained earlier, the controller reconnected before the video. The drone was well on it's way back to home before I had a chance to see it was not going to clear the trees.

 

[Grizzo]

For efficiency I guess. If you hit RTH in a place with no trees you might not want to wait for the Mavic to get high altitude.

You can press cancel and fly back yourself if you don't want to wait. Don't forget, the issue is during auto RTH not normal RTH.

In my opinion, the point of the set RTH altitude is for safety.I rely on it to get the drone back above any obstacles. Its all to easy to press the left stick and unknowingly stop the process functioning properly.