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Need advice for a tricky flight

Blacksmith

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This may sound like a guaranteed calamity, but I am serious about trying a tricky flight. My current photography project is to collect and exhibit images of sites of local interest. One of these is a stone viaduct carrying the old three-track Erie mainline (now NJTransit) over a small creek. The 130-year-old structure is beautifully fitted stone and virtually hidden from view since the brook it bridges runs through a steep gorge, heavily wooded. There are no unobstructed views. Very few people in the area even know it exists, never mind having seen it, even though it’s forty feet high and carries a roadbed that’s about 100 feet wide. The ravine isn’t more than 40 feet deep but the walls are too steep to negotiate (especially at my age—don’t ask) so climbing down for a shot isn’t an option. I might be able to buttslide down but the fire department would have to get me out.

Since trees overhang the water, the plan is to drop the Mavic down close to the bridge to about five feet above the water and then down the brook below the overhanging branches, spin it, take a few bursts, then bring it back the way it went in. One, I’m worried about losing GPS; two, there is a monster cell tower only about 100 feet away; and three, I’m nervous about trying to hover stably close the brook. Needless to say, I’d like to do this before the trees leaf out.

Got any advice (which may include fuggedaboutit)?
 
Other than possible GPS interference, you should be able to "war game" the entire maneuver in a less forbidding environment until your comfortable/competent. I spend a fair amount of time in my backyard with all sensors off flying slowly in and around trees, deck posts and rock walls in preparation for the coming back country hiking season.

Practice, practice, practice.

Lee
 
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This also would be a good candidate for Litchi or Autopilot. I don't use Litchi, but in Autopilot, you can map out the entire shoot including aircraft yaw, speed and altitude and gimbal tilt. It's very powerful and would let you map out the entire mission before executing it.
 
You'll lose GPS, plus you'll have to turn off downward visual positioning over the water. That equals ATTI mode, which means you're on your own trying to FPV fly it with a narrow field of view and the Mavic's not-renowned-for-sanity ATTI implementation.

Good luck, and I hope I'm being too pessimistic, but I think this is going to be a real tough one to pull off.

On a technical basis, RTH set to hover seems a good idea but it does rely on you being able to reestablish connection if you lose it due to the cellphone tower, but it's got to be better than it climbing straight into the trees then falling in the brook.
 
Other than possible GPS interference, you should be able to "war game" the entire maneuver in a less forbidding environment until your comfortable/competent. I spend a fair amount of time in my backyard with all sensors off flying slowly in and around trees, deck posts and rock walls in preparation for the coming back country hiking season.

Practice, practice, practice.

Lee

That's a great idea.
 
My recommendations in no particular order.

Survey the site and make sure you will have line of site in terms of any solid blockages that might cut out the signal.

Turn off VPS

I would use Tripod mode if this is such a tight area.

In case you lose signal make sure that the RTH is set to an altitude that will not send you into the trees and then into the water. Keep in mind the RTH altitude is above your take off point and your going down. If in doubt just have it hover instead of returning. You should be able to re position yourself to get back the signal.

Buy a getterback and attach it to the drone in case of the worst case scenario. Also get DJI refresh if you don't have it.

Do it in multiple safe flights if possible. By that I mean fly and film what you can and then land and reposition yourself to get another flight from a location that is better suited for that spot in terms of signal.

Attach a sticker to the Remote saying RECORD. I find that the complicated flights are the ones that I forget to press record on. Too much going on to remember.

Anyway that's all I can think of.

Good luck
Rob
 
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This may sound like a guaranteed calamity, but I am serious about trying a tricky flight. My current photography project is to collect and exhibit images of sites of local interest. One of these is a stone viaduct carrying the old three-track Erie mainline (now NJTransit) over a small creek. The 130-year-old structure is beautifully fitted stone and virtually hidden from view since the brook it bridges runs through a steep gorge, heavily wooded. There are no unobstructed views. Very few people in the area even know it exists, never mind having seen it, even though it’s forty feet high and carries a roadbed that’s about 100 feet wide. The ravine isn’t more than 40 feet deep but the walls are too steep to negotiate (especially at my age—don’t ask) so climbing down for a shot isn’t an option. I might be able to buttslide down but the fire department would have to get me out.

Since trees overhang the water, the plan is to drop the Mavic down close to the bridge to about five feet above the water and then down the brook below the overhanging branches, spin it, take a few bursts, then bring it back the way it went in. One, I’m worried about losing GPS; two, there is a monster cell tower only about 100 feet away; and three, I’m nervous about trying to hover stably close the brook. Needless to say, I’d like to do this before the trees leaf out.

Got any advice (which may include fuggedaboutit)?

Do it now before the trees leaf out. It will help prevent signal loss. You have me curious as to the location. I cross that line every day on 208 during my daily commute. That whole area, specially north from there looks like some neat track to explore.
 
Do it now before the trees leaf out. It will help prevent signal loss. You have me curious as to the location. I cross that line every day on 208 during my daily commute. That whole area, specially north from there looks like some neat track to explore.

About 50 meters south of the Hollywood Avenue level crossing in Ho-Ho-Kus.
 
About that cell tower, I've been reading critical warnings from fellow pilots since my first flight. Being quite a rebel, I tend to push my limits on most things, just to see where that **** line lays.
I've totally wrecked one phantom, and had many minor crashes (none with mavic) but one thing I am not by any means worried about today, are those celltowers that erects all around my home. I've flought beside, over, around them and even hovered within 0.5 meters distance from ceveral towers. Not once have I as much as dropped 1 sat or lost connection with anything. Mavic simply acts like a shy lady around an erection..... :)

My only concern about them is if I'd accidentally bumped into them as any other obstacle.

This was a totally different story with my phantom. He couldn't handle those fuckers at all. (Compass errors and force atti.)

This is my experience, I'm not saying it would necessarily be yours also....

On the subject of your flight, it's mad. If you're part of the wealthy 1% and $1000 can be burned for fun, by all means do it. But if you'll have to (once more) start a heavy debate with your lady about why you are going to spend your savings on a new quadcopter, please consider your options . [emoji23]

I can see how you would like to fly that mission (and to be honest I'd personally probably go for it my self)
But check your options, could you buy (even build) some cheaper bird. There are some rather cheap toys on sale with at least 720 cameras equipped.

If the only option is putting your mavic on the line : YOLO
I bought mine to use it, even if it's raining / snowing a little. I could've just put my $1300 in my drawer if that's where my mav is going to be put.
 
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