Height Restrictions

[JSM]

Hi All,
This may seem like a silly question however here it is ! the rules state we should not fly over 120 meters so, what happens if you are standing on the top of a hill which is already say 170 mtrs high ? does that mean you cant fly? and if the answer is yes ; when you take off, the ground will be sloping down very quickly which means unless you know the "real" altitude you are probably going to be over 120 Mtrs?
Cheers

 

[Meta4]

This may seem like a silly question however here it is ! the rules state we should not fly over 120 meters so, what happens if you are standing on the top of a hill which is already say 170 mtrs high ? does that mean you cant fly? and if the answer is yes ; when you take off, the ground will be sloping down very quickly which means unless you know the "real" altitude you are probably going to be over 120 Mtrs?

Yes .. it's a silly question.
You'll find drone altitude restrictions are all referring to height above the ground (and that's the ground below the drone).
Perhaps this fine artwork will make things clear for you:

 

[hactick]

Yes .. it's a silly question.
You'll find drone altitude restrictions are all referring to height above the ground (and that's the ground below the drone).
Perhaps this fine artwork will make things clear for you:

This art work is great. The FAA should make a pamphlet like this.

 

[JSM]

Thanks Guys however the Mavic cant measure / update the distance from the ground when the terrain changes; I have also had this noted from a CASA perspective as they then advise you need to adjust your height accordingly !!! good luck with that unless there is another App that can take care of this !!!

 

[Meta4]

Thanks Guys however the Mavic cant measure / update the distance from the ground when the terrain changes; I have also had this noted from a CASA perspective as they then advise you need to adjust your height accordingly !!! good luck with that unless there is another App that can take care of this !!!

No app is going to take care of that since the drone has no sensors that can measure it for you.
But you don't need to have the actual number showing on a screen.
You can always do what real pilots of light aircraft do and estimate.
When you see a small Cessna flying over, chances are that it doesn't have a radar altimeter, just an altimeter showing height above sea level.
The pilot uses little mental arithmetic to calculate from maps and knows what it looks like when he's 500 ft etc above the ground.

You have an altimeter that shows the height above launch point.
It's not hard to estimate how much higher or lower the ground below the drone is than where you are.

 

[JSM]

No app is going to take care of that since the drone has no sensors that can measure it for you.
But you don't need to have the actual number showing on a screen.
You can always do what real pilots of light aircraft do and estimate.
When you see a small Cessna flying over, chances are that it doesn't have a radar altimeter, just an altimeter showing height above sea level.
The pilot uses little mental arithmetic to calculate from maps and knows what it looks like when he's 500 ft etc above the ground.

You have an altimeter that shows the height above launch point.
It's not hard to estimate how much higher or lower the ground below the drone is than where you are.

M, not sure what your referring to re "altimeter"???? if its take off, push left stick up for height then yes, we all know what happens here re height from launch point however................if the terrain changes and lets say significantly, either up or down slope then as Pilots we actually have no accurate idea of how high / low we are in relationship to the ground; CASA in Australia have acknowledged this as a challenge for RPA Pilots to "somehow" work out where we are in this context !!! All I can say is DJI need to update the software to deal with this !!!.................

 

[Meta4]

M, not sure what your referring to re "altimeter"????

If you aren't sure look down at the bottom of your screen and you'll see a display of your height above the launch point.
That's your altimeter readout.

if the terrain changes and lets say significantly, either up or down slope then as Pilots we actually have no accurate idea of how high / low we are in relationship to the ground.

Read my post above again and think about how you would estimate.
It's not rocket surgery.

CASA in Australia have acknowledged this as a challenge for RPA Pilots to "somehow" work out where we are in this context !!!

Can you point to somewhere I can see what they said?
I can't see how it's such a big issue.

All I can say is DJI need to update the software to deal with this !!!.................

That's not going to happen.
Software won't make up for not having a sensor that can measure what you want.

 

[JSM]

Hey M, where are you located???, depending on which Country, will depend on our interpretations of Local / State and Federal regulations, I am I Melbourne ; Australia and have been corresponding with our Federal governing body CASA regards the inability of Drones to detect and adjust their height relative to the terrain, nothing to do with launching from a given location and measuring from this point as distinct from flying up terrain changes (or down) and knowing how high you actually are...............................

 

[BigAl07]

M, not sure what your referring to re "altimeter"???? if its take off, push left stick up for height then yes, we all know what happens here re height from launch point however................if the terrain changes and lets say significantly, either up or down slope then as Pilots we actually have no accurate idea of how high / low we are in relationship to the ground; CASA in Australia have acknowledged this as a challenge for RPA Pilots to "somehow" work out where we are in this context !!! All I can say is DJI need to update the software to deal with this !!!.................

It's on the Operator/Pilot to do whatever is needed to stay within the regulations. If you can't accurately (within reason of course) judge the difference between 120 meters and 200 meters then you might need to take up a different hobby. If you happen to fly at 125 meters on accident it's not a big deal. If you happen to fly 250 meters "by accident" then you're being grossly negligent in your duties as a sUAS operator.

It's ultimately up to you to guestimate your distance above the ground (directly under your sUAS) and adjust to stay within the regulations.

It's not a "Software" modification. It's very much a significant HARDWARE modification and I doubt you would want to pay for the new hardware... in money or decreased performance on the Mavic aircraft. Not gonna happen.

 

[Meta4]

Depending on which Country, will depend on our interpretations of Local / State and Federal regulations,

Most or all countries have similar regulations, where you are makes no real difference.

have been corresponding with our Federal governing body CASA regards the inability of Drones to detect and adjust their height relative to the terrain, nothing to do with launching from a given location and measuring from this point as distinct from flying up terrain changes (or down) and knowing how high you actually are.

Like just about everyone on this forum, I understand that the ground is not pancake-flat.
I can't imagine a scenario where it's just too difficult to be able to estimate how high your drone is, or why CASA would see this as a serious issue.

It's really no big deal to estimate the height of your drone while flying.
You have a fairly accurate readout of its height relative to your launch point to start you off.
You should be able to look at the terrain under the drone and guess how its elevation differs from the launch point.
That's all you need to estimate the AGL height of your drone.
If you are going somewhere with complicated topography, you can do a little planning with maps or Google Earth to check heights.

 

[JSM]

Most or all countries have similar regulations, where you are makes no real difference.

Like just about everyone on this forum, I understand that the ground is not pancake-flat.
I can't imagine a scenario where it's just too difficult to be able to estimate how high your drone is, or why CASA would see this as a serious issue.

It's really no big deal to estimate the height of your drone while flying.
You have a fairly accurate readout of its height relative to your launch point to start you off.
You should be able to look at the terrain under the drone and guess how its elevation differs from the launch point.
That's all you need to estimate the AGL height of your drone.
If you are going somewhere with complicated topography, you can do a little planning with maps or Google Earth to check heights.

If you are going somewhere with complicated topography, you can do a little planning with maps or Google Earth to check heights. M, I have started to do this as we are all different when it comes to perception of height, speed etc..................

It's on the Operator/Pilot to do whatever is needed to stay within the regulations. If you can't accurately (within reason of course) judge the difference between 120 meters and 200 meters then you might need to take up a different hobby. If you happen to fly at 125 meters on accident it's not a big deal. If you happen to fly 250 meters "by accident" then you're being grossly negligent in your duties as a sUAS operator.

It's ultimately up to you to guestimate your distance above the ground (directly under your sUAS) and adjust to stay within the regulations.

It's not a "Software" modification. It's very much a significant HARDWARE modification and I doubt you would want to pay for the new hardware... in money or decreased performance on the Mavic aircraft. Not gonna happen.

If you can't accurately (within reason of course) judge the difference between 120 meters and 200 meters then you might need to take up a different hobby. If you happen to fly at 125 meters on accident it's not a big deal. Big A, hmmmm, beg to differ and wouldnt like to put this aspect of flying on an actual measured test might be a tad embarrassing !

 

[Meta4]

If you can't accurately (within reason of course) judge the difference between 120 meters and 200 meters then you might need to take up a different hobby. If you happen to fly at 125 meters on accident it's not a big deal. Big A, hmmmm, beg to differ and wouldnt like to put this aspect of flying on an actual measured test might be a tad embarrassing !

An actual measured test?
What's that look like?
A CASA inspector who just happens to be right where you are flying, when you are flying, with a very long ladder and a very long tape measure?
You are overthinking the whole thing.
The difference between 120 metres/125 metres is not anything anyone is ever going to worry about or know about.
It doesn't matter at all.
If it concerns you, then fly a little lower.
There's no rule that says you must fly at 120 metres.
Put your efforts into flying safely rather than silly efforts to stay at 120 +/- 1.00 metres over varying terrain.

 

[BigAl07]

Big A, hmmmm, beg to differ and wouldnt like to put this aspect of flying on an actual measured test might be a tad embarrassing !

Huh? Exactly what is it you're calling into question?

 

[JSM]

An actual measured test?
What's that look like?
A CASA inspector who just happens to be right where you are flying, when you are flying, with a very long ladder and a very long tape measure?
You are overthinking the whole thing.
The difference between 120 metres/125 metres is not anything anyone is ever going to worry about or know about.
It doesn't matter at all.
If it concerns you, then fly a little lower.
There's no rule that says you must fly at 120 metres.
Put your efforts into flying safely rather than silly efforts to stay at 120 +/- 1.00 metres over varying terrain.

M4, not a concern and just putting on record a personal comment / question for some help and guidance from the more experienced members on the Forum, not sure why you referenced " silly efforts" as I made no mention of any other flight scenarios other than clarification !!