Can Changing Landforms Cause Altitude Violation?

[Rich QR]

If you look at the FAA rules, it actually does not specify directly below, it says you have to be no more than 400' from ground. and a cliff face is "ground" according to the FAA.

I actually did look at the FAA rules, and they consistently specify drone altitude limits as Above Ground Level. Not to the side of ground, or diagonally distant from ground, but Above Ground Level.

I know you said someone at the FAA sent you that picture, but it refers to Article 94A, which is a UK rule for drones. That picture wasn't created by the FAA. You'd think that if it represented official published policy of the FAA, they could at least edit the text to refer to FAA regulations.

I make no claim about how the rules may be enforced. But I know what they say. With a few exceptions, they say you must go no higher than 400' Above Ground Level.

 

[MAvic_South_Oz]

I know you said someone at the FAA sent you that picture, but it refers to Article 94A, which is a UK rule for drones.

Good pick up.

A google image search doesn't find that post #32 diagram anywhere online.
Found one other diagram that support it, but again UK based . . . same text.

This looks like a notated official (2018 outdated ?) image, on Grey Arrows Drone Club forum post.

Article 94a only mentions this for special permissions 'above' 400', no mention of from a 'surface'.
I believe a few there in the UK may have brought their own interpretation into this using an old diagram.

 

[scro]

The current rules in Europe and the UK are nearly identical and both explicitly confirm that the 120m measurement is a distance from the closest point on the terrain and not a vertical altitude from a point directly below the drone (Drones (UAS) | EASA). Here's an up-to-date graphic from the EASA official site:



It doesn't clarify the situation for those under different jurisdictions though. Common sense would imply there's some leeway laterally but the exact wording of the regulations doesn't seem to make that explicit.

 

[smashse]

Well I am still going with what the FAA themselves sent. And like I said, it doesn't take into account perfectly vertical or inverted cliffs, but something off to the side at a 1 degree angle, you are definitely still above it. It no where says "directly above" it just says above in the rules. Read them, no where does it say directly.

Here's a screen shot, why doesn't anyone else take the time to email the FAA, and get an FAA answer? The FAA says so themselves if you take the 5 minutes to ask them? They aren't secretive, they literally have a "helpdesk" to answer questions like these.

Check who the email is from, it's highlighted so it is easy to find. The address is also highlighted so you can take the time to email them or use the contact form on the FAA.gov website like I did.



And as far as not finding the image on the internet, sorry but this took less than 2 minutes to find.. Reverse image search can only possibly work if the image is indexed, and it is possible this one isn't.

Let's talk about 400ft - Approved Drone Pilots

The internet loves an argument. I’m sure the CAA thought that putting out a notification that from 30th July 2018, the maximum legal height (NOT ALTITUDE) for a drone, hobby or PfCO (not withstanding separate OSC exemptions), was to be 400 of our imperial feet, would be accepted in a...

approveddronepilots.co.uk

Yes it is a UK drone site, but the email from the FAA themselves states that it is not from the FAA, and then answers the question that it applies to US regulations as well.

But I guess people here are smarter than the FAA, so I should listen to them instead. /s

 

[jaswalt]

Since the drone measure barometrically its altitude from the takeoff point (which is 0) if one were to fly to 390 ft and then fly on a level plane over a 100 ft deep wash or gully, would that be a violation?

Kevin

OK, so the image the FAA sent SMASHSE in post 44 shows that for 107 pilots the lateral distance of 400' does matter. Yet so many are saying it doesn't. Even the pilot institute post says that it doesn't matter. So what did we decide? I tend to go with the diagram sent from the FAA as it is almost identical to what was shown in the Part 107 training and there were similar questions on the part 107 test. But if a cliff does not count and diagram shows that a hillside does, does this mean that if the apparent cliff was not a perfect 90 degrees straight up from level but in fact the base was kicked out a single inch thereby making it a steep slope, is that considered a hillside and the 400' counts? If it still doesn't count but a hillside does, at what angle does the ground have to be at to qualify for the 400' from land being acceptable? I have to say, growing up out west and spending every spare moment in the mountains, I can only remember seeing a small handful of perfectly vertical cliffs. So what ended up being the verdict of all the discussion?

 

[Rich QR]

I have to say, growing up out west and spending every spare moment in the mountains, I can only remember seeing a small handful of perfectly vertical cliffs. So what ended up being the verdict of all the discussion?

I challenge anyone to find a vertical cliff of 400' or greater height in any place where the FAA has jurisdiction over drone flight.

In Yosemite, Half Dome and El Capitan are pretty extreme examples of topography, but my perusal of the USGS topo maps didn't reveal any portion where even 300 feet of contour lines got so close as to be indistinguishable. Tall? Absolutely! Steep? Very! But not vertical. Besides, these are in a national park where drone flight is prohibited for other reasons.

The idea of a 400' vertical cliff is a nice illustration to talk about what the literal meaning of the law is. But I doubt such a thing exists in the USA. I'd be happy to be proven wrong, though.

 

[pilotinstitute]

I believe there are cliffs in Moab in Class G airspace that have more than 400 foot vertical drops.

 

[smashse]

I challenge anyone to find a vertical cliff of 400' or greater height in any place where the FAA has jurisdiction over drone flight.

In Yosemite, Half Dome and El Capitan are pretty extreme examples of topography, but my perusal of the USGS topo maps didn't reveal any portion where even 300 feet of contour lines got so close as to be indistinguishable. Tall? Absolutely! Steep? Very! But not vertical. Besides, these are in a national park where drone flight is prohibited for other reasons.

The idea of a 400' vertical cliff is a nice illustration to talk about what the literal meaning of the law is. But I doubt such a thing exists in the USA. I'd be happy to be proven wrong, though.

Well I disagree and believe it does matter, because even if there is a 1' kickout, you are going to be more than 1' away from the ledge, so the entire distance has to count since you would be 50-100' away from the cliff face, and how far of a drop is that? The argument is about is it counted "directly" below, or nearest ground? The FAA as @jaswalt says, has been saying it is the nearest ground point for a while. Some are saying it is ONLY directly below the drone.

Also, have you checked out Big Sur CA? Notch Peak, UT (might be in MOAB)? And if you are 100' horizontally off the top of El Capitan is it more than a 300' at that point?

It also comes into play when you are 350' up crossing over a 55' cliff, such as sunset cliffs in San Diego CA? Sunset Cliffs is listed as 200' at it's highest point and most of it from my memory is inverted slightly from the ocean beating on it.

 

[pilotinstitute]

Well I disagree and believe it does matter, because even if there is a 1' kickout, you are going to be more than 1' away from the ledge, so the entire distance has to count since you would be 50-100' away from the cliff face, and how far of a drop is that? The argument is about is it counted "directly" below, or nearest ground? The FAA as @jaswalt says, has been saying it is the nearest ground point for a while. Some are saying it is ONLY directly below the drone.

Also, have you checked out Big Sur CA? Notch Peak, UT (might be in MOAB)? And if you are 100' horizontally off the top of El Capitan is it more than a 300' at that point?

It also comes into play when you are 350' up crossing over a 55' cliff, such as sunset cliffs in San Diego CA? Sunset Cliffs is listed as 200' at it's highest point and most of it from my memory is inverted slightly from the ocean beating on it.

AGL is just that, Above ground level, so it means directly under the aircraft. The FAA doesn't have any language about "nearest". Just like flying over people, it's when any part of the aircraft is over any part of a human body.

 

[smashse]

AGL is just that, Above ground level, so it means directly under the aircraft. The FAA doesn't have any language about "nearest". Just like flying over people, it's when any part of the aircraft is over any part of a human body.

So just completely IGNORE what the FAA said? interesting. I'd suggest asking the FAA, they were very clear about it. Or. not, your choice because the rule does not say directly below in the elevation part. But let's ignore that as well. I mean it really strikes me that NO one else will ask the FAA, and instead go on their own assumptions. If you won't ask the authority, i.e. the FAA, then you really shouldn't be spreading misinformation. This isn't facebook.

 

[dronerdave]

Actually I do hope it is 400' from surface and FAA considers a rock face surface. I've always felt it would be a more logical rule. It's places like this that makes it difficult to fly within compliance if the rule is AGL (directly below the aircraft). But I always want to fly within regulations required at the time I fly.



Even 200' from a surface would make me happy. But I'd love to see the FAA's actual response.

 

[Meta4]

So just completely IGNORE what the FAA said? interesting. I'd suggest asking the FAA, they were very clear about it. Or. not, your choice because the rule does not say directly below in the elevation part. But let's ignore that as well. I mean it really strikes me that NO one else will ask the FAA, and instead go on their own assumptions. If you won't ask the authority, i.e. the FAA, then you really shouldn't be spreading misinformation. This isn't facebook.

I'm not wading into this silly hypothetical topic but I'll just point this out.

The problem with asking the FAA, is you get a response from an individual FAA employee.
Sometimes they give accurate information, sometimes they give their own (incorrect) interpretation.
That one FAA person said something, is no guarantee that what you've been told is true.
There have been numerous cases where it hasn't been.

 

[Rich QR]

So just completely IGNORE what the FAA said? interesting. I'd suggest asking the FAA, they were very clear about it. Or. not, your choice because the rule does not say directly below in the elevation part. But let's ignore that as well. I mean it really strikes me that NO one else will ask the FAA, and instead go on their own assumptions. If you won't ask the authority, i.e. the FAA, then you really shouldn't be spreading misinformation. This isn't facebook.

An email from an anonymous clerk at the FAA doesn't carry as much weight as the laws and regulations, in my book. If you get a signed memo from the General Counsel, or a court decision, or any other formally published ruling, I'll pay more attention. Until we have that, I'll trust the words that are in the carefully worded laws and regulations.

When they express altitude limits as "Above Ground Level", they don't use the term "distant from ground", or "beside ground".

If a Beechcraft is at an altitude of 10,000 ft MSL, and a Boeing is at an altitude of 12,000 ft MSL, how far above the Beechcraft is the Boeing? Most would say the Boeing is 2,000 feet above the Beech, whether the planes are separated by 10 feet horizontally or two miles horizontally.

Imagine a hilltop at 2500 feet MSL. If I'm flying at an altitude of 2499 feet MSL and 500 feet to the side of the peak, am I 500 feet above the peak? Or am I one foot below the peak and 500 feet to the side?

I contend that the word "Above" is measured in the vertical direction, and horizontal distance doesn't matter.

Congress is fully capable of writing what they mean, and they could have written 49 USC 44809 (a)(6) to say "the aircraft is flown within a distance of 400 feet or closer to the nearest ground". But they chose not to. They wrote "the aircraft is flown from the surface to not more than 400 feet above ground level".

Nobody at the FAA has the authority to override Congress.

I'll grant that there's a possibility they may have meant something different from what they wrote. And I'll surely grant that the actual people in charge of enforcement may not care so much about enforcement in such unusual topographical cases.

But I believe the law says what it says, until a court issues an opinion that says the law says something other than what it says.