Auto landed into a tree today

[Maui19]

Well heck. I'm new at this, and have only been able to take my MA2 out a couple times in the few days I've had it due to winds & rain. Today I was practicing near my house, which is nested in a pine forest with trees that are 100+ feet high. In past flights, I have been cautiously maneuvering down the driveway and street, and also taking it to 150'+ to take some pics and vids. So far, so good. Today I took the MA2 straight up to 150' to shot some vids. I decided to bring it back down using auto land to see how well it did. Well in previous ALs the drone had been a little twitchy, but I figured that's the state of the technology. Then it looked like it was coming down kinda close to some trees, but I figured it was ok. Before I knew it, the props were pruning pine needles. Crap!! I took it back up into the air, then brought it down without AL. Fortunately, there was no damage. I was surprised at how far off the MA2 drifted during AL, and further surprised it was willing to AL in the trees (there was plenty of battery left). There was zero wind, even in the tree tops. There was also plenty of light for the avoidance systems.

This all sent me back to the MA2 manual, which for me only serves to create more questions than it answers. But I am left with th thought that something is not right. Do I need to recalibrate some things?

 

[InvisibleName]

Did you have a good satellite lock before you flew off? Did it report that the home point had been recorded? What were the light levels like?

 

[Maui19]

I think I had 10 satellites locked on at launch. Plenty of light.

 

[DanMan32]

Auto land, as in go straight down at current position, or Return to Home (RTH) which first goes to home point (usually where it took off) an then lands?

RTH can be as far off as 5 feet from HP unless equipped with precision landing (PL) and TO allowed for PL. That's just the nature of GPS.

If you really did select auto land and wasn't accurately positioned over where you wanted to land, then what did you expect?

 

[Bop]

I have e M2Z but I imagine MA2 is the same. IF you initiate a RTH that is close to the home point, it will land where it is (immediately) and NOT go the home point. How far away were you from your home point when you hit RTH? I cant remember how far away you need to be from the home point BERFORE it goes to that exact spot. Your going to have to check your manual.
Hope this helps.

 

[boblui]

... bring it back down using auto land .... Before I knew it, the props were pruning pine needles. Crap!! ...surprised it was willing to AL in the trees

Not sure why it was any surprise. The drone was commanded to land so it landed. It treated the tree top as the ground. Obstacle avoidance is irrelevant in such situation.

I was surprised at how far off the MA2 drifted during AL

It should not have happened even if there was some wind and the battery was low. Can you post the flight log or uploading it to DJI Flight Log Viewer | Phantom Help ? The how-to instructions are at the bottom of the webpage.

Do I need to recalibrate some things?

I can't imagine what need be calibrated. It's more relevant to look into the flight log and check what has actually happened.

 

[DanMan32]

I have e M2Z but I imagine MA2 is the same. IF you initiate a RTH that is close to the home point, it will land where it is (immediately) and NOT go the home point. How far away were you from your home point when you hit RTH? I cant remember how far away you need to be from the home point BERFORE it goes to that exact spot. Your going to have to check your manual.
Hope this helps.

I forgot about that. Yes, if RTH is initiated within 60ft of HP, it will land.

 

[Angel new MA2]

Well heck. I'm new at this, and have only been able to take my MA2 out a couple times in the few days I've had it due to winds & rain. Today I was practicing near my house, which is nested in a pine forest with trees that are 100+ feet high. In past flights, I have been cautiously maneuvering down the driveway and street, and also taking it to 150'+ to take some pics and vids. So far, so good. Today I took the MA2 straight up to 150' to shot some vids. I decided to bring it back down using auto land to see how well it did. Well in previous ALs the drone had been a little twitchy, but I figured that's the state of the technology. Then it looked like it was coming down kinda close to some trees, but I figured it was ok. Before I knew it, the props were pruning pine needles. Crap!! I took it back up into the air, then brought it down without AL. Fortunately, there was no damage. I was surprised at how far off the MA2 drifted during AL, and further surprised it was willing to AL in the trees (there was plenty of battery left). There was zero wind, even in the tree tops. There was also plenty of light for the avoidance systems.

This all sent me back to the MA2 manual, which for me only serves to create more questions than it answers. But I am left with th thought that something is not right. Do I need to recalibrate some things?

Did you enable sensors? Have you been using Sport mode? Without sensors MA2 will not avoid obstacles. See the Safe tab

 

[Maui19]

Logs show that home point was off by about 30ft--which happened to be under a giant pine.

 

[A.O.]

If the AC is farther away than 20m from the HP the AC will rise to the RTH height and return

At less than 20m it will just fly at present altitude to RTH point and land

If less than 5 m from home point it will just land

Mavic_Air_2_User_Manual_v1.2_en.pdf (djicdn.com) (page 12)

 

[4wd]

I have e M2Z but I imagine MA2 is the same. IF you initiate a RTH that is close to the home point, it will land where it is (immediately) and NOT go the home point. How far away were you from your home point when you hit RTH? I cant remember how far away you need to be from the home point BERFORE it goes to that exact spot. Your going to have to check your manual.
Hope this helps.

This is why it did it, the RTH feature doesn't kick in if you are still close to the launch point - it just starts to descend where it is. Make sure you haven't inadvertently changed the RTH behaviour to land in place rather than return home.
You might want the other options if under trees or close to other obstructions.

 

[DanMan32]

You can't change RTH behavior.
You may be thinking of fail-safe (loss of signal) behavior where you can set it to RTH, hover or land.

 

[Maui19]

Well after viewing the log, it appears that the home point was set in the location of some large pine trees. It is unclear to me why this happened, since I checked the GPS strength while hovering after taking off and assumed the home p. I definitely need to pay full attention to where the home point is being set, because today my MA2 set the home point in the middle of a lagoon. In this case I know we didn't have a strong GPS signal when we took off so the home point was set after it was flying for a bit. The thing I don't understand about the pine tree landing is why the downward avoidance systems let it descend into a tree.

 

[Meta4]

Well after viewing the log, it appears that the home point was set in the location of some large pine trees. It is unclear to me why this happened, since I checked the GPS strength while hovering after taking off and assumed the home p. I definitely need to pay full attention to where the home point is being set, because today my MA2 set the home point in the middle of a lagoon. In this case I know we didn't have a strong GPS signal when we took off so the home point was set after it was flying for a bit. The thing I don't understand about the pine tree landing is why the downward avoidance systems let it descend into a tree.

There are a couple of possible explanations for why your home point is not where you've assumed it to be.
If you post your flight data someone will be able to analyse it and find the explanation.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.

Or just post the .txt file here.

 

[MA2 317]

The thing I don't understand about the pine tree landing is why the downward avoidance systems let it descend into a tree.

It doesn't know it's a tree.
All it knows it's a place to land, which happened to be a tree.

 

[Maui19]

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It doesn't know it's a tree.
All it knows it's a place to land, which happened to be a tree.

I would like to think it know is it an obstruction, given that it knows it's landing altitude is 65ft below.

 

[DavidT_ NZ]

Check your Fly app settings for height at RTH command. Make sure it is above any trees. Take off in a clear area and I would recommend that you use an “H” target pad, partly for ground identification (during landing). Hover at about 15 feet AGL and wait for the drone to “set” a landing image then fly away. Check GPS satellite numbers; best if over 12. If not, be prepared to land manually, as some satellites may be low, near the horizon, and you may lose them behind trees, as the drone descends. But if you are flying some distance away, try RTH, as it is great watching the tech do its thing! But be ready to go manual landing. And use the F/1 button, set for vertical camera, up/down, so that you can monitor the landing on to the pad (auto or manual). Setting F/2 to turn on the landing light is also advisable, if light is overcast or low. And always land in Tripod or Normal modes, to activate the sensors. Safe flying - and relax and enjoy!????????

 

[Meta4]

I would like to think it know is it an obstruction, given that it knows it's landing altitude is 65ft below.

Your drone doesn't know its "landing altitude".
You can land anywhere, lower or higher than the launch point.

If you want to find out what happened to help you avoid a similar situation in future ... check post #14.

 

[DanMan32]

Precision landing needs 20ft vertical ascent from TO with HP having been set.
No need to hover, just be sure you went high enough vertically.

He's got a point. Landing protection should have detected the tree as unsuitable to land on. However landing protection might only work on solid surfaces where IR can determine you're within a few feet of ground. Then it can use imaging to see if the ground is suitable. IR probably went right through the tree branches so it didn't think of the tree as ground.

 

[icecoldgin]

RTH is a good safety feature but I will only use this as a last resort, IMHO.

Since flying the MA2, I have not landed it using RTH. I always hand catch it when landing. This was the same with the Mini.

And, I only initiated RTH (or rather the MA2 initiates the RTH) when the signal to the controller is lost. But once I regain RC signal, I always cancel RTH and land manually.