Flying up a river.

[NetDep]

LOS doesn't mean what many here think it does.
Line of Sight is a radio term that's been around since long before drones.
You have to have a clear, unobstructed LoS between your controller and the drone to fly it.
That's due to the laws of physics.
Your drone could be 10 miles away and have a clear LoS.
Being visible isn't part of LoS.

People get confused because some regulatory authorities use the clumsy expression Visual Line of Sight (VLOS) when they mean you should keep your drone in visual range.

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Well, it looks to me like and the FAA, that "line of sight," means exactly what is says - keeping it in visual range. (This applies if you are flying in the USA and under the jurisdiction of the FAA).

Fact Sheet – Small Unmanned Aircraft Regulations (Part 107)

From, "Operating Requirements:" "You must keep your drone within sight."

You are quite right that the drone could be ten miles away and you could have clear line of sight by your definition but you would be in violation of FAA rules if it could not be seen with the unaided eye (with brief periods of the aid of a vision enhancing device).

 

[JMF]

I fly the same terrain all the time, make sure your RTH altitude is high enough to clear trees, and when you start losing signal just increase your altitude.

 

[Meta4]

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Well, it looks to me like and the FAA, that "line of sight," means exactly what is says - keeping it in visual range. (This applies if you are flying in the USA and under the jurisdiction of the FAA).

You are quite right that the drone could be ten miles away and you could have clear line of sight by your definition but you would be in violation of FAA rules if it could not be seen with the unaided eye (with brief periods of the aid of a vision enhancing device).

The FAA invented the clumsy term Visual Line of Sight.
You'll find it here: Recreational Fliers & Modeler Community-Based Organizations
Fly within visual line-of-sight, meaning you as the drone operator use your own eyes and needed contacts or glasses (without binoculars), to ensure you can see your drone at all times.
The FAA never mentions LoS in drone regulations but forum folks have confused the two terms and say LoS when what they mean is VLoS

But Line of Sight is very important too.
Lose LoS by flying behind an obstacle and you lose connection.
You cannot control your drone if you don't have LoS.

 

[MAvic_South_Oz]

With RTH height set, you’d also have to consider that is height above TOP (take off point) ?
If the OP is “Flying up a river” they will have to consider they may increase altitude along the way, say 50m (metres on the setting as it is here in Australia).
So 30m standard RTH altitude might not cut it, it may need to be raised to say 70m or 80m to be safe.
That is hard to estimate, even with a topo map and contour intervals to help, you could be guessing a little.
If you go that high for RTH, you also need to be cautious of higher wind speeds if it is anything but perfectly still.
Always things to think about.

 

[Gecko10]

The FAA invented the clumsy term Visual Line of Sight.
You'll find it here: Recreational Fliers & Modeler Community-Based Organizations
Fly within visual line-of-sight, meaning you as the drone operator use your own eyes and needed contacts or glasses (without binoculars), to ensure you can see your drone at all times.
The FAA never mentions LoS in drone regulations but forum folks have confused the two terms and say LoS when what they mean is VLoS

But Line of Sight is very important too.
Lose LoS by flying behind an obstacle and you lose connection.
You cannot control your drone if you don't have LoS.

Yes, and that is exactly what I did, confuse the terms. I ment VLOS. Sorry about that.

 

[Marko9219]

Be sure that your RTH height is adequate, and more importantly, be aware of your signal strength, be sure to recalibrate your compass before your flight

Why on Earth do you want to recalibrate a compass that is already calibrated? If it isn't broken, quit trying to fix it. There's no justification for constantly recalibrating a compass. I've not recalibrated my Mavic in over a year of flying.