Let's say I am at the Grand Canyon and launch @ 0 feet above the ground then fly out and over the canyon edge and suddenly I am now 1,500 feet off the ground.  What does the P4P pro do with regard to altitude limitations?  I can see many different senerios where I might be in similar situations.

The altitude limitations are based on the altitude that is currently displayed at the bottom of DJI GO. Flying over the edge of a canyon doesn't change the altitude of the aircraft. You need to ascend or descend to change the altitude.

See more details here.

The o point of altitude is determined from your home point.  You could fly down into the canyon and get minus readings.

If you fly off from the top of the mountain, and are above the national park below.

It seems that you are still theoretically flying safe.


RedHotPoker

Not a good example since the Grand Canyon is a National Park and is a so-called "No Drone Zone" which means no flying drones.  But otherwise, read post #2.

And BTW, who would give that post #2 a Downvote???  Are you serious?  I can only think of one person.  

Note that the OP's query was in regards to altitude LIMITATIONS, which of course, remain unchanged relative to the launch point.  

Mark The Droner Posted at 12-3 17:18
Not a good example since the Grand Canyon is a National Park and is a so-called "No Drone Zone" which means no flying drones.  But otherwise, read post #2.

And BTW, who would give that post #2 a Downvote???  Are you serious?  I can only think of one person.  

The down vote is probably from the same one wo generally does it a lot.   I believe I know who it is also.

That's pretty scary if you are serious???

Hi DennisM, the take-off point will be recorded as 0, and the maximum altitude is 500 meters if it is allowed by the local regulations. For GEO, you may visit this link: https://www.dji.com/flysafe/geo-map

Mark The Droner Posted at 12-3 17:18
Not a good example since the Grand Canyon is a National Park and is a so-called "No Drone Zone" which means no flying drones.  But otherwise, read post #2.

And BTW, who would give that post #2 a Downvote???  Are you serious?  I can only think of one person.  

FYI....Parts of the Grand Canyon lay outside of the Park's boundaries.

Since we are limited to flying below 400 feet AGL or 400ft above obstacles wouldn't it be correct to descend to that elevation after leaving the canyon edge?
And wouldn't it be a handy feature that the drone would tell us its elevation from the ground not from the launch point?
Just curious........

1Eagle Posted at 12-4 09:55
Since we are limited to flying below 400 feet AGL or 400ft above obstacles wouldn't it be correct to descend to that elevation after leaving the canyon edge?
And wouldn't it be a handy feature that the drone would tell us its elevation from the ground not from the launch point?
Just curious........

How will the AC determine height above ground ?  The sensors if fitted - only accurate with SOLID contrast  surface at about 3m and less.

Nigel

ALABAMA Posted at 12-3 17:51
The down vote is probably from the same one wo generally does it a lot.   I believe I know who it is also.

Well come on then - who ??

Nigel

msinger Posted at 12-3 12:47
The altitude limitations are based on the altitude that is currently displayed at the bottom of DJI GO. Flying over the edge of a canyon doesn't change the altitude of the aircraft. You need to ascend or descend to change the altitude.

See more details here.

Altitude LImitations ...

I get impression OP may be asking if the Altitude LIMITS such as 500m DJI, 400ft FAA still apply ? Which as we all know - the AC takes launch point as ZERO and then reports altitude referenced to that ..

As another says - fly down into the valley / canyon - altitude then reads -ve.

I've read so many versions of what applies and what doesn't ... interpretations of official documents and still its not iron-clad ... it also depends on which country / state as to what applies.

Cheers
Nigel

PS - Not me who Downvoted !! I reserve that 'click' to only one specific member of the forum !!

solentlife Posted at 12-4 22:34
Well come on then - who ??

Nigel

Well Cinderella, try the shoe on.

ALABAMA Posted at 12-5 04:49
Well Cinderella, try the shoe on.

I had an idea you were branding me. Well you are totally wrong.
I most likely use the Downvote a lot less than you do - as I said its reserved for one only. But I do use the Upvote a lot.

Nigel

The guy who downvotes me is Rodger8.  He's been doing it for about six or eight months or so - on every post he sees regardless of the content.  He does it to a number of other people too - members he deems to be his enemies.  I thought he'd get tired of it after a few months, but I was wrong.  I'm not sure what's wrong with him, but I'm pretty certain it has a name and I'd be willing to bet it's been mentioned in the American Journal of Medicine at some point.  

When talking about altitudes there are two different types. MSL (Mean sea level) altitude is based on your elevation at takeoff as well as barometric pressure. AGL (Above ground level) altitude is your absolute direct height from the ground. Hypothetically if you were to take off from the edge of the canyon and ascend to 100 ft and then fly out over the canyon your MSL would still be 100' while your AGL could be 1500'. When it comes to FAA regulations, aka the 400' rule, it does not specify MSL or AGL. At that point it would become the responsibility of the operator to operate in a safely manner. Keep in mind that your main goal, and purpose of the 400' rule, it to deconflict with other aircraft. Being the Grand Canyon I do know there are a lot of small helicopters that operate in and around the canyon so altitude is very important with safe operation. Also all other aircraft usually use MSL and the primary altitude source and only use AGL as a reference.


Edit: After posting this I looked up the actual 107 rules and it states the following:

§107.51   Operating limitations for small unmanned aircraft.

A remote pilot in command and the person manipulating the flight controls of the small unmanned aircraft system must comply with all of the following operating limitations when operating a small unmanned aircraft system:

(a) The groundspeed of the small unmanned aircraft may not exceed 87 knots (100 miles per hour).

(b) The altitude of the small unmanned aircraft cannot be higher than 400 feet above ground level, unless the small unmanned aircraft:

(1) Is flown within a 400-foot radius of a structure; and

(2) Does not fly higher than 400 feet above the structure's immediate uppermost limit.

So it does reference the 400 feet as AGL, however it also says not higher than 400 feet from a structure's uppermost limit. So you would be authorized to fly up to 400' above the highest point of the canyon.

dont slow down Posted at 12-5 11:03
When talking about altitudes there are two different types. MSL (Mean sea level) altitude is based on your elevation at takeoff as well as barometric pressure. AGL (Above ground level) altitude is your absolute direct height from the ground. Hypothetically if you were to take off from the edge of the canyon and ascend to 100 ft and then fly out over the canyon your MSL would still be 100' while your AGL could be 1500'. When it comes to FAA regulations, aka the 400' rule, it does not specify MSL or AGL. At that point it would become the responsibility of the operator to operate in a safely manner. Keep in mind that your main goal, and purpose of the 400' rule, it to deconflict with other aircraft. Being the Grand Canyon I do know there are a lot of small helicopters that operate in and around the canyon so altitude is very important with safe operation. Also all other aircraft usually use MSL and the primary altitude source and only use AGL as a reference.

If the rule states "cannot be higher than 400 feet above ground level" and "within a 400 foot radius of a structure; and" "not higher than 400 feet above the structure".
Would the canyon wall be considered a structure?
Knowing that the Grand Canyon and the canyon wall are hypothetical, what if we were talking about a water tower or tall building? As soon as you got 400 feet away from the tower or building you would need to descend to 400 feet AGL. Partly to fly safe and avoid air traffic conflict and partly to operate within the parameters of the rule.

solentlife Posted at 12-4 22:32
How will the AC determine height above ground ?  The sensors if fitted - only accurate with SOLID contrast  surface at about 3m and less.

Nigel

I'm really just trying to say that the altitude above the home point or take off point is not really useful in some situations. Like the question at hand. However, IF the AC could tell us the altitude AGL it would be more useful in a situation like this. How to accomplish this is a different question.

1Eagle Posted at 12-5 11:27
I'm really just trying to say that the altitude above the home point or take off point is not really useful in some situations. Like the question at hand. However, IF the AC could tell us the altitude AGL it would be more useful in a situation like this. How to accomplish this is a different question.

Understood and I was not trying to 'provoke'.

The only way to derive height would be Radar Altimeter at the heights we often fly. But imagine the size, power need, weight addition ! Ultrasonics are not enough ... Laser not enough ...

So we are left with the change of Barometric pressure from Home spot to the elevation we are flying at to determine altitude ...

Cheers
Nigel

The 400ft from a structure and 400ft above .... makes me smile. Its a nice get out but what about the rule - which I am sure is in another section - where you are not allowed to fly near designated stuctures ?

There are many ... radar relay stations ... fire towers ..... TV towers ..... are examples in many countries rules - so I am sure I would find in USA rules similar ...

Nigel

1Eagle Posted at 12-5 11:24
If the rule states "cannot be higher than 400 feet above ground level" and "within a 400 foot radius of a structure; and" "not higher than 400 feet above the structure".
Would the canyon wall be considered a structure?
Knowing that the Grand Canyon and the canyon wall are hypothetical, what if we were talking about a water tower or tall building? As soon as you got 400 feet away from the tower or building you would need to descend to 400 feet AGL. Partly to fly safe and avoid air traffic conflict and partly to operate within the parameters of the rule.

The canyon walls would definitely be considered a structure, a natural structure. The only way to get AGL is like solentlife said, a radio altimeter, but even those only work up to a certain altitude. MSL works everywhere and at any altitude.

I didn't see where it says you must be 400 ft from a structure. It says if you are operating WITHIN 400 ft of a structure then you must be below 400 ft from the tallest point of that structure. It may be a different section but it is not in the 107 section. Of course there are structures you should avoid like those you mentioned, however if we are talking about the grand canyon here, then as long as you are outside the national park boundaries, and below 400 ft of the tallest point, then fly as much as you want.

In reality the 400 ft rule is very conservative. Unless an aircraft is on a VFR flight plan ATC would NEVER clear you closer than 400 ft to an obstacle. Even if you were on a VFR flight plan I'm sure the pilot would already know the risk associated with flying that close to a structure already, even with no drone present. 400 ft is nothing to an aircraft, even 1000 ft is too close for comfort, its not as much room as you think.

In my opinion the 400ft rule allows for a very large buffer to protect from even the most ignorant operator. Even if they flew up to 1000 ft most aircraft don't get that low until making an approach to an airfield. That gives at least a 600ft cushion for errors. If you are flying high enough to interfere with an aircraft you are talking about a whole other issue.

There are helicopter rental/rides around the major canyon...

You should be able to record one, while flying your drone there. Grin

RedHotPoker

dont slow down Posted at 12-6 09:09
In my opinion the 400ft rule allows for a very large buffer to protect from even the most ignorant operator. Even if they flew up to 1000 ft most aircraft don't get that low until making an approach to an airfield. That gives at least a 600ft cushion for errors. If you are flying high enough to interfere with an aircraft you are talking about a whole other issue.

I see.......
So the 400 ft rule is more of a guideline really.... haha
Kinda like the pirates code, aarrrrrr   Lol