Got a question about filming in a mountain area. I've read that the maximum height from the starting point is 150m (in Europe at least). So theoretically, if you start on top of a 1500m mountain, you could go as high as 1650m. But how low can you theoratically descent? Also 150m so you can't go lower than 1350m, or is the descent distance only limited by the maximum reach of either the controller or the battery?

I don't know what the limit is, but I live on the top of a hill and have flown my MA2 about 150 feet, or 50 meters or so below the launch point.  

I have flown down -800ft.

JohnLietzke Posted at 3-7 17:34
I have flown down -800ft.

The laws are different in every country. In the US it is 400ft above ground level. If you are flying near a structure/mountain, it is 400ft above it. You don't have to be directly on the mountain to be able to fly it's height plus 400ft.

There's no limit for negative altitude.

I've read that the maximum height from the starting point is 150m (in Europe at least).
There are no regulations about the height above the launch point.
Altitude regulations relate to the height of the drone above the ground and that can be very different to height above launch point.
The height above launch point is only going to be similar to height above ground if you fly in a very flat area.

Ok, thanks for the clarification, I see I also made a mistake, it is 120m over here, not 150m (my bad).

Armando80 Posted at 3-7 22:29
Ok, thanks for the clarification, I see I also made a mistake, it is 120m over here, not 150m (my bad).

Most of the drones have a 500m limit built in, so if you were mountain surfing this could be quite legal.

You can imagine that there is a 120 meter long cord hanging from the drone and that it always has to touch the ground. So you can fly down a steep slope from the summit to a valley, which is e.g. 300 meters lower. Or the other way, from the valley to the summit. But that also means that theoretically you shouldn't fly an inch over a vertical cliff that is 121 meters high. If you stick to the rules, then of course everything within sight of the drone. It would be interesting whether the Flyapp also brings a message "Max. Depth reached" ;-)
What is clearly missing in the app is the height above ground and not just the height from the starting point. In the example above, it would show 300 meters when it might only be 50.

jonny007 Posted at 3-8 03:48
You can imagine that there is a 120 meter long cord hanging from the drone and that it always has to touch the ground. So you can fly down a steep slope from the summit to a valley, which is e.g. 300 meters lower. Or the other way, from the valley to the summit. But that also means that theoretically you shouldn't fly an inch over a vertical cliff that is 121 meters high. If you stick to the rules, then of course everything within sight of the drone. It would be interesting whether the Flyapp also brings a message "Max. Depth reached" ;-)
What is clearly missing in the app is the height above ground and not just the height from the starting point. In the example above, it would show 300 meters when it might only be 50.

What is clearly missing in the app is the height above ground
What's actually missing is a sensor that could measure that, and is affordable and small enough to fit on the drone.
Until that's available, do what the pilots of light aircraft do and make an educated estimate.

jonny007 Posted at 3-8 03:48
You can imagine that there is a 120 meter long cord hanging from the drone and that it always has to touch the ground. So you can fly down a steep slope from the summit to a valley, which is e.g. 300 meters lower. Or the other way, from the valley to the summit. But that also means that theoretically you shouldn't fly an inch over a vertical cliff that is 121 meters high. If you stick to the rules, then of course everything within sight of the drone. It would be interesting whether the Flyapp also brings a message "Max. Depth reached" ;-)
What is clearly missing in the app is the height above ground and not just the height from the starting point. In the example above, it would show 300 meters when it might only be 50.

In the UK the rules state "Your drone or model aircraft must never be more than 120m (400ft) from the closest point of the earth’s surface!". So technically if you are flying over a 45 degree slope you can fly at 169m vertical height, because on a slope the closest point of the earth won't be directly below you, but at an angle towards the slope.
In your example above, your 120m cord is a stick and it doesn't have to go straight down , as long as it touches the surface.

The steeper the slope, the higher your vertical elevation can be while still keeping 120m from "the closest point from the earth's surface".
In theory, if a vertical cliff face is considered "the earth's surface", you can fly at any height as long as you keep within 120m of the cliff face.

delf67 Posted at 3-9 18:06
In the UK the rules state "Your drone or model aircraft must never be more than 120m (400ft) from the closest point of the earth’s surface!". So technically if you are flying over a 45 degree slope you can fly at 169m vertical height, because on a slope the closest point of the earth won't be directly below you, but at an angle towards the slope.
In your example above, your 120m cord is a stick and it doesn't have to go straight down , as long as it touches the surface.

haha good thinking - I dont think thats the intention of the regualtion but you are correct.
It would mean if you fly next to an infinte deep cliff the closest point would be the wall next to you while hovering in midair at 1000000000000000000000km ... or more ;)

LeChuck71 Posted at 3-9 22:50
haha good thinking - I dont think thats the intention of the regualtion but you are correct.
It would mean if you fly next to an infinte deep cliff the closest point would be the wall next to you while hovering in midair at 1000000000000000000000km ... or more ;)

Yep, if there is a rule or regulation, the first thing some people do is look for a way to circumvent them!