why 1400 ft max altitude?

[Zbip57]

An example is landing; [...] you go as low as needed to ensure a safe landing.

Of course, during landing/takeoff or in an emergency you can do whatever is necessary.

A tree is not a person, vessel, vehicle, or structure. Nor is a natural rock pile.

Yes, that's the way it's worded in your regulations. But why?

If I'm flying low in my manned aircraft and I spot a pile of rocks in my path, I'm not going to waste time trying to decide whether it's a "natural rock pile" or a man-made rock pile. I'm going to manoeuvre to avoid any rock pile, regardless of whether it's natural or a man-made "structure".

Even if the regs only require you to avoid man-made rock piles (structures), it's still not a good idea to buzz natural rock piles at low altitude.

Besides, your argument only increases my confusion.

There is no minimum altitude AGL for manned aircraft operating over water or sparsely populated areas, and yet drones are permitted to fly up to 400' in those areas. Where's the airspace separation in this? Unmanned aircraft are simply trusted to get the **** outta the way whenever there's a chance of conflict.

Okay, so what about built up areas? There, manned aircraft are required to stay 500' away from structures. So doesn't that mean this vacant space over and around structures is even more safely empty and available to drones, compared to sparsely populated areas or over water?

If I'm standing on the rooftop patio of our 400+' tall apartment building, with unobstructed sightlines in all directions, confident in the knowledge that no manned aircraft is allowed to come within 500' of me (helicopters excepted), why can't I launch my recreational drone from here? Because the requlations say you can't ever fly higher than 400' AGL, measured from the ground.

That's what it says, but it makes no sense. No recreational pilots, only Part 107 pilots can launch from that rooftop.

 

[Rich QR]

There is no minimum altitude AGL for manned aircraft operating over water or sparsely populated areas, and yet drones are permitted to fly up to 400' in those areas. Where's the airspace separation in this? Unmanned aircraft are simply trusted to get the **** outta the way whenever there's a chance of conflict.

Correct. Even when everyone is staying in the airspace they're supposed to be in, there are no guarantees of conflict-free operations. Furthermore, helicopters, powered parachutes, and weight-shift-control aircraft may be lower than the usual limits for fixed-wing aircraft. Drones are always required to see and avoid human-carrying aircraft, without regard to whether those aircraft are in their allotted airspace. That's a large part of the reason for the VLOS requirement.

Okay, so what about built up areas? There, manned aircraft are required to stay 500' away from structures. So doesn't that mean this vacant space over and around structures is even more safely empty and available to drones, compared to sparsely populated areas or over water?

The rules don't talk about "built up areas". 97.119 has rules for "anywhere", "over congested areas", and "over other than congested areas". A further subcategory of the "other than congested areas" is "open water or sparsely populated areas". Notice that the "500 feet from any person, vessel, vehicle, or structure" rule ONLY applies to open water or sparsely populated areas. In an area that is neither congested nor sparsely populated, the limit is 500' AGL. This could, at least in theory, place the aircraft closer than 400' from a structure, if the structure were taller than 100' AGL.

If I'm standing on the rooftop patio of our 400+' tall apartment building, with unobstructed sightlines in all directions, confident in the knowledge that no manned aircraft is allowed to come within 500' of me (helicopters excepted), why can't I launch my recreational drone from here? Because the requlations say you can't ever fly higher than 400' AGL, measured from the ground.

That's what it says, but it makes no sense. No recreational pilots, only Part 107 pilots can launch from that rooftop.

I'm guessing that the rooftop of the tall apartment building is probably in a congested area. There, the altitude limit for human-carrying aircraft other than helicopters, powered parachutes, or weight-shift-control aircraft is 1000 ft above the highest obstacle within a horizontal radius of 2000 feet of the aircraft. So yes, fixed-wing aircraft shouldn't be so close. But on the other hand, it's a congested area, and the consequences of a mid-air collision could be worse for people on the ground. And the likelihood of helicopters in particular is probably higher than in many sparsely populated areas.


Anyway, one reason to explain why non-licensed pilots have a hard 400' AGL limit in uncontrolled airspace, regardless of nearby structures, is that Congress wrote it that way. I don't know exactly what they were thinking, but I believe simplicity was more important to them than maximizing flying opportunities. (I would NEVER claim that Congress always makes sensible choices.) Anyone who doesn't like the decision of Congress on that point is free to get a license and follow the FAA regulations.

 

[muabg]

I am a 107 certified operator and been flying drones commercially for over 20 years and now two years in the aerospace industry.

I do not understand why DJI would impose any limitations on a certified pilot, it is the responsibility of the PIC to fly legally.

IMO DJI should not impose any limitations on how a certified commercial pilot operates an aircraft, it would be like buying a car that will not drive faster than 65MPH and would not operate on private property. No one would buy it.

It is the clueless and careless Best Buy pilots that are causing all the problems, please leave me alone. I guess this is why Autel exists

 

[svenf]

It's my understanding that FAA allows my our drones to be 400AGL. If there is a hill ahead I can fly 400 above it legally. Why, then, if there is a 1400foot hill next to me, can't I fly above it? I can see my drone over 1500 ft away but if I recall from a flight some time ago in this exact situation, my drone will not get above something like 1400feet. I realize the drone does not know AGL from WTF but it seems odd for DJI to play nanny. Am I missing something?

To me the bizarre aspect of the reg is that you can stand on top of a hill, and fly your drone legally 400' above, but the moment your drone moves laterally you need to lower its altitude as it hovers over the surrounding valleys - in that scenario the drone can even be below you and you are in violation.

 

[FLDave]

To me the bizarre aspect of the reg is that you can stand on top of a hill, and fly your drone legally 400' above, but the moment your drone moves laterally you need to lower its altitude as it hovers over the surrounding valleys - in that scenario the drone can even be below you and you are in violation.

What is so bizarre about a rule that simply states that you cannot fly more than 400 above ground level?

 

[Zbip57]

What is so bizarre about a rule that simply states that you cannot fly more than 400 above ground level?

I posted these images before in a previous thread, but here's my issue with this nonsense...

Let's say we have a pyramid-shaped man-made "structure" that's taller than 400'. FAA regulations say that recreational flyers are never permitted to fly over any such structure as that would exceed their 400' AGL restriction.


If you do need to fly over such a structure you must first be a full Part 107 pilot, as they are allowed to overfly structures taller then 400', as long they remain within 400' vertically and 400' horizontally of the structure.


Then we have the third scenario, where everyone (Recreational & Part 107) is allowed to fly their drone above any natural terrain feature, even above any earthen hillside or mountain of this exact same shape, even if it's taller than 400' tall, as long as they stay within 400' AGL.


Congress told the FAA to do this, even though it makes no sense. An earthen hillside, or a man-made stone pyramid, each present the same obstacle to aviation. Why not have one consistent rule? Simple. Always stay within 400' vertically and 400' horizontally of any obstacle.

Which leads to the other commonly asked question, concerning cliff faces...

Everyone, both Recreational & Part 107, is allowed to fly up any gently sloped hillside of any height as long as they always stay within 400' AGL measured vertically from the ground's surface. Imagine a 400' long string dangling straight down from your drone. The string must always be able to touch ground.


But, as the slope becomes steeper, nearing vertical, it gets more and more difficult to follow this rule. The drone must be flown almost touching the cliff-face in order to remain within the 400' AGL vertical measurement.


Finally, if the cliff-face actually is vertical and taller than 400', you're no longer allowed to fly from the valley floor to the top of the cliff, nor fly out from the cliff top and down to the valley. You can only fly within 400' of the valley floor, or you can fly 400' above the plateau at the top of the cliff. You just can't go off the edge from one to the other.

And, get this, Part 107 pilots also cannot fly off this cliff!


Wouldn't it make a lot more sense if the extra 400' height within a 400' radius applied to everyone for every "obstacle", like this:

Part 107 pilots are permitted to fly within that vertical space only if this is a "structure"!
See: § 107.51 (b)

Part 107 pilots can fly up this vertical "cliff-face" only if it's a "structure" like an apartment building, office tower, or radio mast. If it's a similarly shaped vertical face made of natural earth or stone that allowance doesn't apply, as that's merely an obstacle, not a "structure".

How does that make any sense?

 

[sar104]

I posted these images before in a previous thread, but here's my issue with this nonsense...

Let's say we have a pyramid-shaped man-made "structure" that's taller than 400'. FAA regulations say that recreational flyers are never permitted to fly over any such structure as that would exceed their 400' AGL restriction.
View attachment 146491

If you do need to fly over such a structure you must first be a full Part 107 pilot, as they are allowed to overfly structures taller then 400', as long they remain within 400' vertically and 400' horizontally of the structure.
View attachment 146492

Then we have the third scenario, where everyone (Recreational & Part 107) is allowed to fly their drone above any natural terrain feature, even above any earthen hillside or mountain of this exact same shape, even if it's taller than 400' tall, as long as they stay within 400' AGL.
View attachment 146493

Congress told the FAA to do this, even though it makes no sense. An earthen hillside, or a man-made stone pyramid, each present the same obstacle to aviation. Why not have one consistent rule? Simple. Always stay within 400' vertically and 400' horizontally of any obstacle.

Which leads to the other commonly asked question, concerning cliff faces...

Everyone, both Recreational & Part 107, is allowed to fly up any gently sloped hillside of any height as long as they always stay within 400' AGL measured vertically from the ground's surface. Imagine a 400' long string dangling straight down from your drone. The string must always be able to touch ground.
View attachment 146496

But, as the slope becomes steeper, nearing vertical, it gets more and more difficult to follow this rule. The drone must be flown almost touching the cliff-face in order to remain within the 400' AGL vertical measurement.
View attachment 146497

Finally, if the cliff-face actually is vertical and taller than 400', you're no longer allowed to fly from the valley floor to the top of the cliff, nor fly out from the cliff top and down to the valley. You can only fly within 400' of the valley floor, or you can fly 400' above the plateau at the top of the cliff. You just can't go off the edge from one to the other.

And, get this, Part 107 pilots also cannot fly off this cliff!
View attachment 146498

Wouldn't it make a lot more sense if the extra 400' height within a 400' radius applied to everyone for every "obstacle", like this:
View attachment 146499
Part 107 pilots are permitted to fly within that vertical space only if this is a "structure"!
See: § 107.51 (b)

Part 107 pilots can fly up this vertical "cliff-face" only if it's a "structure" like an apartment building, office tower, or radio mast. If it's a similarly shaped vertical face made of natural earth or stone that allowance doesn't apply, as that's merely an obstacle, not a "structure".

How does that make any sense?

The reason is very simple, and it makes complete sense. Manned aircraft are required to stay at least 500 ft from any structure (91.119). They are not required to remain 500 ft from terrain, such as a hill.

 

[Zbip57]

The reason is very simple, and it makes complete sense. Manned aircraft are required to stay at least 500 ft from any structure (91.119). They are not required to remain 500 ft from terrain, such as a hill.

That makes no sense at all. You are, in effect, saying the rules make perfect sense because, very simply, those are the rules.

I do understand that if the rules say manned aircraft are allowed in there, then drones are not allowed to share that same airspace.

But, it makes no sense that manned aircraft must stay 500' away from "structures", yet are not similarly required to stay away from equally dangerous terrain.

If it's a concrete vertical bridge piling ("structure") planes must stay at least 500' away. This one I understand.


But if it's a vertical cliff face of solid rock, then planes are allowed to brush their wingtips along the rock face? How does that make any sense?


Both are solid obstacles (structure or terrain), and they should equally be given a wide berth by manned aircraft.

 

[Rich QR]

The reason is very simple, and it makes complete sense. Manned aircraft are required to stay at least 500 ft from any structure (91.119). They are not required to remain 500 ft from terrain, such as a hill.

Actually, if you read 91.119 carefully, you'll notice that the "500 feet to any person, vessel, vehicle, or structure." language ONLY applies over open water or sparsely populated areas. If you're in an area that is not congested, and not open water or sparsely populated, the only rule is to maintain at least 500' above the surface. If there's a tall structure in such an area, there's no limit to how closely you may approach, as long as you maintain at least 500' above the surface.

Of course I'm not saying it's a good idea to buzz radio towers! There's always that prohibition against careless and reckless operation.

 

[sar104]

That makes no sense at all. You are, in effect, saying the rules make perfect sense because, very simply, those are the rules.

I do understand that if the rules say manned aircraft are allowed in there, then drones are not allowed to share that same airspace.

But, it makes no sense that manned aircraft must stay 500' away from "structures", yet are not similarly required to stay away from equally dangerous terrain.

If it's a concrete vertical bridge piling ("structure") planes must stay at least 500' away. This one I understand.
View attachment 146535

But if it's a vertical cliff face of solid rock, then planes are allowed to brush their wingtips along the rock face? How does that make any sense?
View attachment 146537

Both are solid obstacles (structure or terrain), and they should equally be given a wide berth by manned aircraft.

This has been explained many times. If you are unable or unwilling to understand that very simple explanation then I'm not going to waste any more of my time or yours on it.

 

[sar104]

Actually, if you read 91.119 carefully, you'll notice that the "500 feet to any person, vessel, vehicle, or structure." language ONLY applies over open water or sparsely populated areas. If you're in an area that is not congested, and not open water or sparsely populated, the only rule is to maintain at least 500' above the surface. If there's a tall structure in such an area, there's no limit to how closely you may approach, as long as you maintain at least 500' above the surface.

Of course I'm not saying it's a good idea to buzz radio towers! There's always that prohibition against careless and reckless operation.

That's correct. Over congested areas it's 1000 ft vertical and 2000 ft horizontal.

 

[Zbip57]

This has been explained many times. If you are unable or unwilling to understand that very simple explanation then I'm not going to waste any more of my time or yours on it.

It always comes down to that. You claim the answer is very simple, but not worth your time to explain it. So let me explain how I understand it.

Originally the rules were very simple. Model Airplanes must not be flown in a manner that puts manned aircraft or persons on the ground at risk. That was very simple and easy to understand.

Now we have ever more complex rules, some of which make no sense.

The altitude restriction for remotely piloted aircraft was set at 400', based on providing sufficient separation from manned aircraft who (for the most part) should not be operating below 500'. Yes, there are plenty of exceptions to the 500' minimum requirement for manned aircraft, but this rule mostly makes sense.

Then commercial drone pilots complained that the 400' ceiling prevented them from doing inspections on radio towers. Hence the provision for an extra 400' height above the tall tower as long as it's done within a 400' radius. Again, that allowance seems safe enough since manned aircraft are supposed to stay 500' away from such "structures". That also makes sense.

Then Congress gave in to pressure to give all sorts of concessions to Recreational flyers, forcing FAA to create the Recreational exemptions, which do not include this extra 400' over structures allowance.

That is the simple explanation for how we got to this point. That's the gist of your "very simple explanation". It is a reasonable explanation of why the rules ended up saying what they do. But it doesn't explain why those rules make sense in the drawings I illustrated in my previous posts (#66 & #68 above).

Why should it make any difference whether that pyramid-shaped obstruction is a natural terrain feature or a man-made "structure"? Why should they be treated any differently? What if that pyramid is a land-fill dump composed entirely of garbage? Is that a structure, or is it terrain? What if it's subsequently covered with dirt and grass and used as a ski-hill in winter? Why should any of that make any difference as to how this obstacle affects aviation?

How does it make any sense that manned aircraft are not prohibited from scraping their wingtips along terrain features like a vertical cliff-face? As illustrated in my diagrams above, all drones are prohibited from flying higher than 400' AGL alongside any vertical terrain feature, even within inches of a cliff-face, because the rules say that space is reserved solely for manned aircraft.

More than 400' AGL, the space in a 400' radius above and around any "structure" is considered safe for use by Part 107 pilots, yet similar space around any solid vertical terrain feature is entirely prohibited for all drones (including both Part 107 and Recreational).

I ask why terrain features are treated differently than "structures", and your "very simple explanation" always boils down to, "that's what the rules say."

But the rules, as currently worded, are nonsensical in their application to my examples. The rule generates obvious confusion, as evidenced by the many times the subject of flying off cliff-tops comes up over and over again in these forums. I'm certainly not the only one who thinks the rule, as written, makes no sense.