400 Foot Altitude Quiz

[yawnalot29]

I think we are saying the same thing, but to me there are two different viewpoints. Here's how I interpret it.

To keep it simple, Figure 1, below (not to scale) is how the DJI app measures your altitude. It measures it from the point where you launched the drone. If it were up to them, you wouldn't be able to fly above the dotted line. Now, if you take off from a different spot, like halfway up the mountains, then your 400ft ceiling would be raised. To reiterate, that's how the DJI GO APP measures your altitude. Everything is measured from where you take-off and the measurement doesn't change as you fly over higher or lower ground.

Figure 1:

The FAA guideline, however, can be interpreted such that you can maintain a 400ft max elevation above ground level.... period. This means the dotted line rises as the ground elevation rises, or lowers. DJI imposed a 1,640ft (500 meter) limit overall as they feel this is a reasonable ceiling to prevent people from getting into trouble with their drones. In short, that means you can go up to 1,640ft high (from your take-off point), as long as you don't go over 400' AGL altitude at any given time (to remain within FAA regulations/guidelines). See Figure 2 below.

Figure 2:

But, what about if you take-off from the top of the mountain and fly straight across the valley? According to the FAA guidelines, you would be flying too high (more than 400' AGL in many spots), yet your flight logs would show that you were never above 400' altitude. This is where I think things could get 'sticky', especially since the DJI app limits you to flying no lower than 200ft below your take-off elevation. See figure 3.

Figure 3:

The bottom line is there's some work to be done if the FAA expects to be able to enforce their 'guidelines'.

Does all this make sense, or am I delusional?

It's my opinion that FAA meant "figure 2".

In "figure 1" and "figure 3", I think of California coast (Palos Verde Estate, Santa Monica Beach, Corona Del Mar, Crystal Cove State Beach) or Grand Canyon or any kind of Canyon where you might get helicopter sight seeing tourist operation.

In those cases, figure 1 and 3 you are going to be easily co-existing with manned air craft flying passengers.

 

[Gary M]

I'm glad I found this thread because I was trying to ask this exact question. But another part of my question was,,,If you have a Phantom 3 flying on auto, and have altitude set at 400', will the drone compensate for fluctuations in ground level automatically?

 

[m0j0]

It seems you have trouble delineating what is legal and what the UAS is capable of.
Most of us know the difference.

Nope.. I read the question and answered the question. The answer reamins 500 meters above where he luanched it. ... The elevation is hard wired from DJI.

In reading your weak attempt to insult me. It becomes apparent that you yourself have a problem delineating what a "Law" is... I will illuminate... A law is not a recommendation... It is a policy or rule that is not negotiable. E.G. It is a law to drive faster than the posted limit. If you do you are subject to citation. It is not against the law to fly your UAV more than 400 feet above ground level. It is not recommended it is reckless and possible could result in interfering with air traffic carrying real people... It is therefore not recommended it is not... repeat... it is not a law to fly above 400 ft..

 

[m0j0]

The other simple answer is he is in compliance with the FAA RECOMMENDATIONS on safe flight if he is within '400 of the ground. I would say he can fly '400 feet above the bridge whatever that number is.. No slide rule, abacus, supercomputer, MIT Grad needed to come up with the answer here. Just a little common sense

Just sayin

 

[Meta4]

I'm glad I found this thread because I was trying to ask this exact question. But another part of my question was,,,If you have a Phantom 3 flying on auto, and have altitude set at 400', will the drone compensate for fluctuations in ground level automatically?

Since your Phantom has no way of knowing ground level, No.
The only level your Phantom knows is that home = zero.

 

[m0j0]

I'm glad I found this thread because I was trying to ask this exact question. But another part of my question was,,,If you have a Phantom 3 flying on auto, and have altitude set at 400', will the drone compensate for fluctuations in ground level automatically?

No it will not. As a matter of fact your Phantom measures height relative to take off point.. Today while flying here I was flying up the face of a mountain. I took off climbed to about 30 meters to avoid the huge lights etc.. started flying toward the mountain. Was pretty apparent that I was truly only about 10 meters above the ground at some points during the flight.. No change in the telemetry readings... Which is why LOS is so important.

 

[yawnalot29]

No it will not. As a matter of fact your Phantom measures height relative to take off point.. Today while flying here I was flying up the face of a mountain. I took off climbed to about 30 meters to avoid the huge lights etc.. started flying toward the mountain. Was pretty apparent that I was truly only about 10 meters above the ground at some points during the flight.. No change in the telemetry readings... Which is why VLOS is so important.

corrected it for you.

If it's just LOS... I can do FPV all day long 3 miles out which I will add, LOS, is a MUST on these long distance to get any decent signal receptions.

 

[Gary M]

No it will not. As a matter of fact your Phantom measures height relative to take off point.. Today while flying here I was flying up the face of a mountain. I took off climbed to about 30 meters to avoid the huge lights etc.. started flying toward the mountain. Was pretty apparent that I was truly only about 10 meters above the ground at some points during the flight.. No change in the telemetry readings... Which is why LOS is so important.

Thanks for that info. I am very new to this and you guys seem to know what you're talking about. So another question. Speaking of mountains, how well does Phantom 3 handle in those environments? Are there funny air currents up there that effect flight in any extreme way?

 

[Dirty Bird]

No it will NOT compensate for terrain changes. The Phantom calculates altitude based on your altitude above point of launch. It doesn't know anything about ground level or AGL so you have to make sure you do this calculation when setting RTH altitude.

I'm glad I found this thread because I was trying to ask this exact question. But another part of my question was,,,If you have a Phantom 3 flying on auto, and have altitude set at 400', will the drone compensate for fluctuations in ground level automatically?

 

[Meta4]

Thanks for that info. I am very new to this and you guys seem to know what you're talking about. So another question. Speaking of mountains, how well does Phantom 3 handle in those environments? Are there funny air currents up there that effect flight in any extreme way?

The Phantom 3 will position hold in 20+ knots of (horizontal) wind
It can climb at 5 metres/sec and descend at 3 m/s. Updrafts/downdrafts greater than that will cause it to be a but shaky in the vertical axis.

 

[yawnalot29]

Some of you might find this tip-bit interesting, especially for those "401ft!? What are you thinking" crowd.

From AMA Government and Regulatory Affairs:

Your questions answered-The 400 foot limit for model aircraft. | AMA Government Relations Blog

Mr. McGraw’s mention of a 400’ ceiling is somewhat of a carryover from the guidelines established in AC 91-57 and has been FAA’s premise in terms of separating small UAS from the manned aircraft environment. During the crafting of the language in the MA amendment to the reauthorization bill the inclusion of a 400’ criteria was considered. However, AMA resisted this limitation with the belief that it is overreaching, unnecessary and potentially detrimental to the hobby. Ultimately the congressional leadership agreed with the AMA and elected not to include this restriction as part of the minimum safety criteria stated in the Bill.

AMA’s 75 years of experience tells us that MA operations above 400’ pose little to no risk to the manned aircraft community. The only time this activity is of concern is when model aircraft are operated in close proximity to airports. As such, AMA stands by its 3mi/400’ safety criteria established in the AMA National Safety Code. Though there are other mitigation measures that may need to be considered, AMA will continue to advocate to maintain the aeromodeling community’s access to the national airspace.

 

[yawnalot29]

Maybe AMA members can chime in on this, but it does NOT look like AMA has a guideline for blanket under 400 feet AGL ceiling.

Per AMA National model Aircraft Safety Code (and this may not be the most updated, but it is as of 2014).

http://www.modelaircraft.org/files/105.PDF

The only place I see 400 feet ceiling mentioned is:

(c) Not fly higher than approximately 400 feet above ground level within three (3) miles of an airport without notifying the airport operator.

Seems to me if you are OUTSIDE of that 3 miles range OR have notified the airport operator.......

Any AMA members can chime in on this? Obviously, AMA is NOT FAA, but I am curious what exactly is AMA's stand on this.


ps. No hand catching either (B.7)
Under no circumstances may a pilot or other person touch an outdoor model aircraft in flight while it is still under power, except to divert it from striking an individual.

 

[yawnalot29]

Here's another article I dig up by Gigaom Research (not sure how crediable they are, but they seem to be legit organization)

Gigaom About

So you want to fly drones? Here's what the law says
So you want to fly drones? Here’s what the law says

Specifically on height:

Drone fans, pay attention to Class G: an unregulated space from the ground to 700 or 1,200 feet, where the drones can fly below the airport tiers.
The 700 to 1,200 feet rule is distance from the ground, not sea level — so if you’re in Denver or another high altitude city, you can fly higher.
While the FAA suggested in 1981 that model aircraft operators fly below 400 feet, the document was just an advisory, and two aviation lawyers contacted by Gigaom said the agency has no authority below 700 feet — for now.

But according to article found on Lexis Nexis (you lawyers will be familiar with this tool) indicate this:
Are Drones Legal as "Hobby" Aircraft?

Don't assume that these guidelines mean that flying a drone under 400 feet means the FAA will consider such usage legal. The FAA recently called this belief a "misperception" of the law, stating: "The FAA is responsible for the safety of U.S. airspace from the ground up. This misperception [that the FAA has no control under 400 feet] may originate with the idea that manned aircraft generally must stay at least 500 feet above the ground. Read: Busting Myths About the FAA and Unmanned Aircraft. - See more at: Are Drones Legal as "Hobby" Aircraft?


So, what does this mean? It means anyone that says they know what the "LEGAL" ceiling is BULLSHXX!! I mean, come on, FAA and aviation lawyers (2 of them) says opposite things. Who's right?

 

[Rumbaar]

Drones are NOE crafts, and do not have that capabilities. There can't be a legal expectation of such, within that 400' guideline.

 

[Solar Deity]

Just be safe. Watch for other air traffic. You are not the only one that likes to fly under high bridges. Blah Blah Blah

Wow. Must take a couple legs up to get down of that horse you're riding there?

Flying over the bridge at 400ft is a VIOLATION.

A violation? Of what? A guideline? A suggestion? An encouragement?????

Well IF you should have one of those battery failures and your aircraft drops like a rock onto a moving vehicle that then crashes into someone else and so on....... YOU HAVE A BETTER CHANCE OF WINNING THE POWERBALL.....

You're in greater risk driving to the bridge. Pretty sure the odds of that scenario are quite slim? If it does, play the Powerball. It's your week. Aren't we always responsible for our actions? Aren't they called accidents for a reason? What if he lost control driving over that bridge with his car and caused an accident? I'm sure we all know we are responsible for our actions. We're all big boys here.

Therein lies the problem.

You can fly as high as your craft will allow. It's been going on for decades. It will continue to go on and the FAA will amend their knee-jerk reaction. If you are in a safe place, it's safe to fly above 400'.

I am a pilot and I have not met one that thinks that way. It's just another way to fly. Like it or not, if you are operating an aircraft, you are a PILOT.

NO 400ft AGL of the aircraft from the ground it is directly flying over.

It seems you have trouble delineating what is legal and what the UAS is capable of.
Most of us know the difference.

You're the one who has a problem "delineating what is legal". The FAA's recommendation is just that, not a law by any means. Like I said, there are plenty of RC aircraft that fly above 400', and they all do it safely and will continue to?

I guess there is always someone somewhere. Newbe's are always treated different in the beginning. I have found the "pilot" community to be extremely welcoming. The airspace belongs to all of us.

You couldn't have stated it better. ALL of us. RC aircraft and GA aircraft. It's been going on safely at flying fields across the country for a very long time.

SD

 

[Dirty Bird]

If a Phantom battery fails & the quad drops on a car or a roof the inhabitant is going to hear a thud. The car will suffer a dent or a broken window. Only if one is directly struck in the head are they likely to suffer a fatal injury.

Aircraft fall from the sky too on occasion. When they do, they crush and/or incinerate EVERYTHING in the vicinity. Sometimes the path of destruction carries on for miles if a large jetliner breaks up at high-altitude or crashes with a tank full of fuel at a shallow angle.

The risk imposed by a Phantom falling vs. an airliner falling is hardly comparable.

Well IF you should have one of those battery failures and your aircraft drops like a rock onto a moving vehicle that then crashes into someone else and so on.......You will not be flying very much after that. I find it interesting how some put other peoples lives and well-being at stake with not another thought. Your "guideline" reference and disregard of others safety is why the FAA is involved. I am comforted by the knowledge that certificated pilots do not perceive the FAA rules & regulations as "guidelines". I am not comforted knowing people like you are out there doing what they please and disregard the rest of us. IF the above mentioned, completely plausible, scenario should occur. It would make us ALL look bad.

 

[Dirty Bird]

There is no RULE regarding a 400' hard limit. It is only a recommendation. Further the world isn't flat & the aircraft currently has no access to topographical data. Even so, if you are flying among mountainous terrain these things don't have terrain-following radar. One can't be expected to follow the topography at precisely 400' If you flew over the rim of the Grand Canyon you don't dive 6000' when you cross the rim.

The Phantom isn't aware of "ground level." It only knows the point at which it was launched is "0'". So if you took off from the point where the bridge contacts the hill, you can go 400' up. If you took off from the river bed you would be showing 400' before you were half way to the bottom of the 900' bridge.

This is where common sense has to come into play. Launching from the peak of the hill on either side one can abide by the recommendation & go 400' up. The bridge is a fixed object on the ground. It makes no sense that launching from the river bed you can't climb to the same 400' above the bridge deck as you could by launching from the peak.

Flying over the bridge at 400ft is a VIOLATION.

 

[Gary M]

corrected it for you.

If it's just LOS... I can do FPV all day long 3 miles out which I will add, LOS, is a MUST on these long distance to get any decent signal receptions.

 

[Gary M]

Now when you guys say LOS/Line Of Sight, you are meaning that the remote control has direct LOS to the drone, correct? Not necessarily meaning that you can SEE the drone? I'm sure it's not too far away when you're not able to actually see it anymore. And what is FPV?

 

[Gary M]

I hate to say this, but I actually know more about firearms and gun safety than I do about drones. I am taking what you guys say about the FAA's "Rules" could be likened to the "Rules of Gun Safety." Always treat a gun as if it is loaded. Never point a fun at something you don't want to shoot, keep finger out of trigger well, etc. Are there laws saying that you check your gun to see if it's loaded before you clean it? Not to my knowledge. So what your saying is FAA rules are like that I guess? You can't get locked up or lose your drone to the Feds if you fly over 400' or at night,they just don't like it?