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Hypothetical RTH scenario: What would the Mavic do?

Marko9219

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#1
Let’s say I launch with a RTH altitude set to 300 ft. I ascend to 400 ft and fly to a mountain side. I start climbing the mountain face to an altitude above launch point of say 800 ft.. However, I’m actually only 400 ft above the rising terrain. Say then I suffer a disconnect and the drone self initiates a RTH. Would it just turn towards the home point and start flying to the home point while descending to the set RTH altitude, or would it first descend straight down to the set RTH altitude (200 ft) thereby meeting the terrain before it can get down to 200 ft.? I was hovering over a mountain face today wondering exactly this.
 

msinger

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#5
Would it just turn towards the home point and start flying to the home point while descending to the set RTH altitude, or would it first descend straight down to the set RTH altitude (200 ft) thereby meeting the terrain before it can get down to 200 ft.?
Neither. The Mavic would fly back to the home point at the current altitude and then start descending straight down once it reaches the home point.
 

Marko9219

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#6
Neither. The Mavic would fly back to the home point at the current altitude and then start descending straight down once it reaches the home point.
That's what I thought I remembered reading, but when I was staring straight down at that mountain face, with my RTH altitude hundreds of feet under the surface, I started to question my memory! I just couldn't remember if it started its descent to RTH altitude during the return or once it reaches the homepoint. The thought of it descending to RTH altitude first is what freaked me out thinking about. Thanks
 

Dariof

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#7
Good question which required some thinking from me.

I get my drone today, So I have no stick time. But I’ve done tons of reading and according to the manual it will stay at the last altitude until it’s overhead.

But it got me thinking about it, so thank you for your post.
 

Xtreme Drone Pilot

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#8
That's what I thought I remembered reading, but when I was staring straight down at that mountain face, with my RTH altitude hundreds of feet under the surface, I started to question my memory! I just couldn't remember if it started its descent to RTH altitude during the return or once it reaches the homepoint. The thought of it descending to RTH altitude first is what freaked me out thinking about. Thanks
Whenever I invoke any autonomous function, I move my left thumb to Cancel button, ready to press it the moment I detect unexpected behavior. In half a second it takes me to react, Mavic won't move far. In this case, even if I forgot RTH 101 and feel nervous, I would do a safe experiment and see what Mavic does.
 

Mossiback

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#9
Let’s say I launch with a RTH altitude set to 300 ft. I ascend to 400 ft and fly to a mountain side. I start climbing the mountain face to an altitude above launch point of say 800 ft.. However, I’m actually only 400 ft above the rising terrain...
You got your RTH question answered above, but there is a problem with your scenario. Unless you change your max allowed height, you cannot rise above your initial 400 feet, even if you are flying uphill close to the ground. Your vertical position always starts at zero relative to your home point. That is why Go 4 refers to your vertical positioning as "height" as opposed to "altitude". It will display a negative number if you launch from a hilltop and go down the hill and the number will not increase if you fly over a valley.

So...if you want to get some shots climbing up a mountainside start at a high point, fly down, and then record going back up.
 

SunnyD

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#10
good question because for when RTH is set to 400 and you're at anything less, it goes straight up first, so I can see the logic behind your question.
 

Xtreme Drone Pilot

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#11
good question because for when RTH is set to 400 and you're at anything less, it goes straight up first, so I can see the logic behind your question.
No pilot, ever, should take off their Mavic without knowing all autonomous behaviors and other basics from the manual 1000%. Especially RTH.

This is why we see so many people crying rivers on these forums when their Mavic crashes and they didn't know RTH 101 or ever RTFM and that there's the Cancel button right under their retarded thumb! :D
 

okw

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#12
You got your RTH question answered above, but there is a problem with your scenario. Unless you change your max allowed height, you cannot rise above your initial 400 feet, even if you are flying uphill close to the ground. Your vertical position always starts at zero relative to your home point. That is why Go 4 refers to your vertical positioning as "height" as opposed to "altitude". It will display a negative number if you launch from a hilltop and go down the hill and the number will not increase if you fly over a valley.

So...if you want to get some shots climbing up a mountainside start at a high point, fly down, and then record going back up.
Or, change the maximum height setting and start at the bottom. This will work up to 500m above the take-off point. Much easier than climbing up the side of a mountain with the Mavic in your backpack. ;)
 

Mossiback

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#13
Or, change the maximum height setting and start at the bottom. This will work up to 500m above the take-off point. Much easier than climbing up the side of a mountain with the Mavic in your backpack. ;)
True, but I prefer mountains I can drive to the top of :).

If you do change your max height for this exercise, remember to change it back. The built-in limit is there to keep those that share the airspace safe.
 

Marko9219

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#15
You got your RTH question answered above, but there is a problem with your scenario. Unless you change your max allowed height, you cannot rise above your initial 400 feet, even if you are flying uphill close to the ground. Your vertical position always starts at zero relative to your home point. That is why Go 4 refers to your vertical positioning as "height" as opposed to "altitude". It will display a negative number if you launch from a hilltop and go down the hill and the number will not increase if you fly over a valley.

So...if you want to get some shots climbing up a mountainside start at a high point, fly down, and then record going back up.
I did in fact change my max altitude to accommodate the climb up the mountain face. That's how I was able to get to the 800 ft above my home point. Not all mountains I want to film have any access whatsoever from the top. Unless you are a mountain goat.
 

Mossiback

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#17
I did in fact change my max altitude to accommodate the climb up the mountain face. That's how I was able to get to the 800 ft above my home point. Not all mountains I want to film have any access whatsoever from the top. Unless you are a mountain goat.
Then you set it correctly to go up the mountainside. The way your OP was worded I thought it was a theoretical question. If the answer to your original question has been lost in all this chatter; the Mavic will fly at it's current height if it is already above the set RTH height until it is above the home point and then descend.
 

2X25MPG

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#18
Glad there are no mountains or even a hill anywhere near me because my brain hurts trying to keep up with this rth altitude stuff.
 
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