Maximum flight altitude limit in mountain terrain?

[Lady Rover]

Hi,

over here we have a maximum flight altitude of 100m above ground.
That makes me wonder what happens on a sloping hill if I start a bit up on the hillside.

If I go to 100m at my start position and then fly level from my starting point away from the hill I gain altitude without actually raising the bird further.
Do I need to follow the terrain?
Do I need to bother?

It's highly unlikely here that someone will fly in the valley with a manned aircraft. Above the hilltop surely, but below pretty surely not.

Still how do you interpret the max flight altitude?

MavicAir shows the max altitude above start level.
If I fly horizontally above a 200m ravine, I am instantly 100m to high?!

Thanks for your thoughts,

Franziska

 

[DanMan32]

Height is based on launch point, not ground level directly below aircraft. After all, unless you are within VPS range, how can it tell how far the ground is below it?

 

[Bigbird48]

I would say as long as your below 100meters AGL you should be ok

 

[Simmo]

To be legal, think about a 100mtr string hanging off the aircraft. The string must always touch the ground.

 

[Lady Rover]

Simmo, that's what I thought, described in a good simple way.

So it's terrain tracing we ought to do.

So ideally the drone should display height over ground at its current location. Without that flying at a legal height seems guesswork unless you are on a large level plane.

 

[Level]

Think of it this way, most lawmakers have very flat heads, it originates from being square to begin with.

 

[tcope]

Posting no information about where this applies or the actual rule/law makes it next to impossible to put any answer into the correct context.

 

[Lady Rover]

Europe, Germany. 100m Max flight altitude above ground.
I think the analogy of the 100m string tangling from the drone pretty much nails it. Still we are shown only the flight altitude in relation to the lift off point on the controllers.
Not good for keeping the 100m above ground limit, no?

 

[ac0j]

Europe, Germany. 100m Max flight altitude above ground.
I think the analogy of the 100m string tangling from the drone pretty much nails it. Still we are shown only the flight altitude in relation to the lift off point on the controllers.
Not good for keeping the 100m above ground limit, no?

I think you are OK to approximate. I dont know of any way for someone to easily determine your exact altitude over the ground below your Mavic.

 

[Lady Rover]

Thats what I do.
Still I think DJI should introduce actual height above ground a.s.a.p.
Not as an automatism (what would happen if you pass a dramatic drop in altitude, like a cliff?!!!) but as an informational display at least.

 

[ac0j]

Thats what I do.
Still I think DJI should introduce actual height above ground a.s.a.p.
Not as an automatism (what would happen if you pass a dramatic drop in altitude, like a cliff?!!!) but as an informational display at least.

Or the rules could be changed to Maximum height above average terrain.

 

[Lady Rover]

Flight rules for manned aircraft are unlikely to be changed for drones....
At least in the medium term future that is.

 

[Level]

I agree with Lady Rover, the MA and newer UAVs should be enabled to display elevation AGL, at least to a minimum height of say, 3M, or 15 feet. I'm thinking it would be very useful to know how far the aircaft is above ground.....it is almost impossible to determine this from any reasonable distance, line-of-sight or otherwise. This would be very useful in avoiding undesired ground contact when low level flight is required.

 

[Duke846]

All to keep us out of controlled airspace.
Most of the us is surface to 1200 agl, around non controlled tower airports. Air traffic control owns it down to 500 agl around airports so aircraft can fly in the clouds and descend to land, So this 400 foot agl is very good to keep drones and manned aircraft separated.

 

[Simmo]

I agree with Lady Rover, the MA and newer UAVs should be enabled to display elevation AGL, at least to a minimum height of say, 3M, or 15 feet. I'm thinking it would be very useful to know how far the aircaft is above ground.....it is almost impossible to determine this from any reasonable distance, line-of-sight or otherwise. This would be very useful in avoiding undesired ground contact when low level flight is required.

It does that now for low level flight when the VPS can see the ground.....

 

[Level]

Great catch, can't believe that never really sunk in...probably too busy tensing on the sticks for those low level passes! Here's the scenario: You're flying a ridge with a steep drop off and want to barely clear the edge for maximum effect, essentially falling off the cliff. How accurate is the AGL readout if I fly this pattern from telemetry alone? I'll be testing this myself tomorrow.

 

[Simmo]

You can test the accuracy of VPS right in front of you in a safe environment!
I see your scenario well, dont forget to post the video!

 

[Lady Rover]

Hey guys,

actual height above ground at actual flight location should be available during all flight levels and all the time, but, only as an info display.

No need for another mandatory enforced limit then, because we can all more easily comply with rules.

I'm also not to fond on using it as an automatic flight control feature, as it would create real issues when passing a cliff.

 

[Keule]

actual height above ground at actual flight location should be available

While this would be a good idea firsthand, but who should supply this (elevation) data? And how is this data distributed to GO4 and/or the aircraft? This is a lot of data to handle worldwide. Of course you can download only a small dataset for a given area to save space.
There is this kind of data available, look at Google Earth or other mapping providers.
But non of these are giving data out for free for commercial use.

 

[Lady Rover]

No need for terrain data. A simple laser range finder pointing downwards should suffice.
Sure DJI have the technology to integrate something like this in a safe manner.