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RTH Altitude Risk

Threshold

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I keep my RTH altitude at a max of 120M or 400'. I have heard stories of people crashing their mavic's using RTH, even with an altitude of 80M. If your Home point has an elevation of say 1,000' and you fly your drone over an elevation of 1,200', with tree height (~60-100') you would need minimum clearance of about 300' to return home without any issues.

So in layman's terms, I think the mavic pro sets a zero point where every you are standing and doesn't take in account other topographic elevations. This could be dangerous to those who fly around hilly areas with a RTH set low. So this is why I set my RTH to a max altitude of 400'.
 
I think the mavic pro sets a zero point where every you are standing and doesn't take in account other topographic elevations
That's correct.

When setting the RTH altitude, find the tallest obstacle above the takeoff point and add 50 feet. That will allow for some error in the estimated altitude.
 
That's correct.

When setting the RTH altitude, find the tallest obstacle above the takeoff point and add 50 feet. That will allow for some error in the estimated altitude.

Exactly. It's a relative height, not an MSL or even AGL height. You need to set RTH height with respect to the highest possible obstacle in the area relative to the home point.
 
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That is correct and some people understand that and some don't. Some people crash some don't.
 
Cool, thanks for confirming.

Though under your specific example it would return at the current altitude, not drop down to RTH. Only goes up to RTH. If already above designated RTH it stays there. In theory you would be fine. Again, with your specific example.


- Sport Mode addict, ride the wind!
 
How do you guys go about estimating the height of obstacles in your fly zone?
 
Only thing about setting it that high would be if the winds were really strong at that altitude. Could make the return flight longer than the battery.
 
How do you guys go about estimating the height of obstacles in your fly zone?

Well after some time of flying you get pretty good with guessing, but at first you want to manually fly up with the camera level and do an inspection via the camera and what the altitude reads on your phone or tablet. If your flying around within you range and see a taller tree or poll size it up and then make sure you RTH is higher then that.

Like i said later on you have an idea more or less that trees in your general area are no taller then XXX feet. You'll also know that no telephone poles are taller then XXX feet. Just error on the high side and you'll be good.
 
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Personally I'm usually correcting my RTH altitude during my flights. I always know the cap the Mavic will take in case of RTH and adjust the RTH altitude to be sure it will not encounter obstacle. Sometimes mountains, trees or electric lines need a high RTH altitude. Sometime not and I reduce it to not loose time and battery for climbing to an unnecessary high altitude in case of emergency.
Your RTH altitude is a moving number, DO NOT set it and forget.

Sent from my A0001 using MavicPilots mobile app
 
Does the mavic limit your alititude to 400ft? My phantom 3 advanced allows you to set it much higher (even though the legal limit is 400ft)
 
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You can set it to the max of the craft. A warning box pops up, but thats it.


Ok thanks, I thought i read on here people saying it limited them in the app to 400ft so I thought maybe something changed. Even though tis not legal, I sometimes go a little higher if it lets me fly much further to get certain shots, end of the day no one is goign to know the difference in altitutude of a plastic drone the size of a football between 400ft and 480ft.
 
When judging whether an obstacle will be cleared, it's necessary to see the horizon beyond, assuming a level camera, of course. If you see the horizon, note the altitude and add your safety factor.
 
When judging whether an obstacle will be cleared, it's necessary to see the horizon beyond, assuming a level camera, of course. If you see the horizon, note the altitude and add your safety factor.

Can you change RTH during flight


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