Demonstration of why Altitude Limits should be removed

[skyeboysteve]

Newbie Q. How does the drone keep track of it's changing altitude AGL? if it can't, how does it limit you to 400' AGL when flying towards downhill terrain. wouldn't it have to tie GPS to an accurate map database with terrain altitudes? or does it have a radar altimeter I don't know about? I'm getting a headache.

Depending on the model, it only keeps track of AGL between 10 to 30 feet using sonar, and in the later models, binocular "vision" from it's two downward facing cameras--which can estimate up to 30 feet--which is about the same distance the average human can determine depth with two perfectly good eyes.

The point of this thread is that the drones don't limit you to 400 feet AGL; but instead limit you based on where it took off from.

 

[Meta4]

Newbie Q. How does the drone keep track of it's changing altitude AGL? if it can't, how does it limit you to 400' AGL when flying towards downhill terrain. wouldn't it have to tie GPS to an accurate map database with terrain altitudes? or does it have a radar altimeter I don't know about? I'm getting a headache.

Your Phantom is much simpler than you imagine.
It doesn't have any way of telling how far below the ground it (except for the VPS which has a range of 10 metres as mentioned above)
It only knows where it was launched and all heights are relative to the launch point. Home = zero.
Your Phantom doesn't limit you to 400' AGL.
Any limit (up to 1640 ft) is configurable and relates to the launch point, not the terrain under your Phantom.
Just like the pilot of a single engine plane, the drone flyer has to do any mental arithmetic if he's concerned about AGL height.

 

[sar104]

Newbie Q. How does the drone keep track of it's changing altitude AGL? if it can't, how does it limit you to 400' AGL when flying towards downhill terrain. wouldn't it have to tie GPS to an accurate map database with terrain altitudes? or does it have a radar altimeter I don't know about? I'm getting a headache.

That's the issue - it doesn't keep track of altitude AGL - all it knows is altitude relative to takeoff point. The actual hardware restriction is up to 1640 ft, user selectable, but if you were to launch and then fly out over a valley then you could end up as high AGL as the valley is deep, plus 1640 ft.

 

[John Locke]

Newbie Q. How does the drone keep track of it's changing altitude AGL? if it can't, how does it limit you to 400' AGL when flying towards downhill terrain. wouldn't it have to tie GPS to an accurate map database with terrain altitudes? or does it have a radar altimeter I don't know about? I'm getting a headache.

It doesn't limit you. You can go 1640' above your take off point, but you'd need to climbing a mountain to stay within 400' AGL. You are responsible to maintain 400' AGL and there really isn't a way to do that, other than gestimating AGL by looking through the iPad display. That takes some experience to master, but with time you'll get fairly good at being able to tell the difference between 100' AGL, and 400' AGL, through the display. The AGL goal is to stay below 400 of course, but if the terrain isn't level, you'll need to be tuned into the view from the display to "estimate" AGL to the best of your ability, which is the reason for this AGL discussion.

The GO4 elevation is solely based on takeoff point, not the land below where the drone is, which could vary greatly. So if you're in the hills, or flying over a valley below, you need to be aware of your AGL and do your best. Where I have the most trouble is flying over a valley, taking off from the top of a hill, way above. It's really easy to exceed 400' AGL in that situation if you're not diligent at flying down into the valley. Your elevation will be -150ft or -300ft in the GO4 app sometimes when flying down in a valley at the proper AGL.

 

[skyeboysteve]

I can't believe I'm reading this from a former pilot. Altimeters are set to barometric pressure, not zero. This gives you an altitude readout above sea level.

FWIW, British pilots like to do this--or at least their military does. Their civilian flights within patterns usually do too. Acrobatic pilots like to use QFE as well, to save them from having to do EXTRA math and inverted spins at the same time. Sailplane pilots who plan to just fly locally, sometimes use QFE too.

 

[SoundByte]

FWIW, British pilots like to do this--or at least their military does. Their ciivilian flights within patterns usually do too. Acrobatic pilots like to use QFE as well, to save them from having to do EXTRA math and inverted spins at the same time. Sailplane pilots who plan to just fly locally, sometimes use QFE too.

All pilots do this!

 

[skyeboysteve]

All pilots do this!

I myself have never used QFE. I've always used QNH and I believe most pilots use pressure adjusted for sea level for their altimeter setting... I was just defending Nick whom I assume may have been in the British Army.

 

[SoundByte]

I myself have never used QFE. I've always used QNH and I believe most pilots use pressure adjusted for sea level for their altimeter setting... I was just defending Nick whom I assume may have been in the British Army.

Sorry for the misunderstanding, to me it sounded like you were saying only certain pilots set their altimeters before flight. But you were referring only to field elevation, my mistake.

 

[ProFlightCamera]

has anyone noticed the ambiguity of the survey at the top of this thread? the only way it can be answered os with Yes, I do agree or disagree.

 

[sar104]

has anyone noticed the ambiguity of the survey at the top of this thread? the only way it can be answered os with Yes, I do agree or disagree.

It's not just badly posed, it is also a seriously loaded question. The discussions are far more valuable than the survey.

 

[blueh32006@gmail]

At play is the "deep pockets" aspect in any situation where there is damage or injury. If there was to be an aircraft incident and someone died their family's attorneys would sue everyone they could think of and this includes a $250 million company like DJI who would be at the top of the list. When a lawsuit is filed most companies have to set aside funds for legal costs and also a portion of what might need to be paid out in a settlement and that in effect freezes those funds which are not available for other uses.

DJI is understandably trying to minimize its future liability and the amount of manpower and funds it would take to manage a flood of lawsuits that could put the company out of business. Think about the Takata airbags problems and their impact on that company and the others that used their product.

My understanding is that the DJI 400 foot ceiling is AGL or above ground level which is not a new concept in aviation airspace management. My only problem with the 400 foot ceiling is that over wildlife areas there are federal requirements to fly no lower than 1000 feet or it is presumed that you are harassing the wildlife and subject to the penalties for doing so. Studies have shown that aircraft at low altitude, including drones, greatly stress animals on the ground and they have spikes in adrenaline that is easily measured.

The problem with selling guns to the general public is the wide range of people that encompasses. Same issue with 50 MPH drones sold by DJI and others. It is probably for the best that DJI has made it difficult for stupid people to do stupid things with the company's drones. I wish the cell phone manufacturers would make an effort to do likewise and keep people from texting while driving.

Your the kind of person who enables DJI to set restrictions on the drones they sell note I didn't NOT say DJI drones because once I purchased the phantom 4 I own, it doesn't belong to DJI any more yet they continue to modify the drone that belongs to me bought and paid for. Other than computer software which clearly states you don't own the software you are licensed to use it I can't think of any other company that believe they have the right to drastically alter a product they no longer own.

The Phantom 4 I bought has completely different characteristics than when I bought it and DJI basically requires software and firmware updates had I known DJI was going to radically alter the flight abilities I never would have updated software or firmware and quite possibly I might have purchased another companies drone.

I don't have a problem with DJI fixing bugs or improving the products, but they crippled some of the functionality my drone had when I bought it and DJI no longer lists the software and firmware for me to put my drone back to it's original configuration. The drone is my property not DJI's.

DJI should at the very least repost all the older software and firmware so I can choose to put my drone back to the configuration it had when I bought it. Can you imagine buying a new car and having it serviced at the dealership and when you pick it up you find out your car will no longer go faster than 35 miles an hour and they removed the back seat because if you get into an accident you will only POSSIBLY hurt two people instead of four?

 

[sar104]

Your the kind of person who enables DJI to set restrictions on the drones they sell note I didn't NOT say DJI drones because once I purchased the phantom 4 I own, it doesn't belong to DJI any more yet they continue to modify the drone that belongs to me bought and paid for. Other than computer software which clearly states you don't own the software you are licensed to use it I can't think of any other company that believe they have the right to drastically alter a product they no longer own.

The Phantom 4 I bought has completely different characteristics than when I bought it and DJI basically requires software and firmware updates had I known DJI was going to radically alter the flight abilities I never would have updated software or firmware and quite possibly I might have purchased another companies drone.

I don't have a problem with DJI fixing bugs or improving the products, but they crippled some of the functionality my drone had when I bought it and DJI no longer lists the software and firmware for me to put my drone back to it's original configuration. The drone is my property not DJI's.

DJI should at the very least repost all the older software and firmware so I can choose to put my drone back to the configuration it had when I bought it. Can you imagine buying a new car and having it serviced at the dealership and when you pick it up you find out your car will no longer go faster than 35 miles an hour and they removed the back seat because if you get into an accident you will only POSSIBLY hurt two people instead of four?

Whether your P4 behaves differently now or not is irrelevant. DJI did not force you to upgrade your firmware or software. They offered updates. You accepted them. You altered your P4, not DJI.

Do you complain every time you upgrade your computer operating system that Microsoft/Apple/whoever inappropriately messed with your computer? On second thoughts, you probably do.

 

[blueh32006@gmail]

Whether your P4 behaves differently now or not is irrelevant. DJI did not force you to upgrade your firmware or software. They offered updates. You accepted them. You altered your P4, not DJI.

Do you complain every time you upgrade your computer operating system that Microsoft/Apple/whoever inappropriately messed with your computer? On second thoughts, you probably do.

The latest update said it was REQUIRED or your drone would be crippled to something like 30' height and 50' diameter and video would not work

I just think DJI should relist all firmware and software so customers can choose to revert back to an earlier version and as far as computer software goes you DO have the option to reinstall an older more stable version if you want or don't like the newer version

 

[SoundByte]

Your the kind of person who enables DJI to set restrictions on the drones they sell note I didn't NOT say DJI drones because once I purchased the phantom 4 I own, it doesn't belong to DJI any more yet they continue to modify the drone that belongs to me bought and paid for. Other than computer software which clearly states you don't own the software you are licensed to use it I can't think of any other company that believe they have the right to drastically alter a product they no longer own.

The Phantom 4 I bought has completely different characteristics than when I bought it and DJI basically requires software and firmware updates had I known DJI was going to radically alter the flight abilities I never would have updated software or firmware and quite possibly I might have purchased another companies drone.

I don't have a problem with DJI fixing bugs or improving the products, but they crippled some of the functionality my drone had when I bought it and DJI no longer lists the software and firmware for me to put my drone back to it's original configuration. The drone is my property not DJI's.

DJI should at the very least repost all the older software and firmware so I can choose to put my drone back to the configuration it had when I bought it. Can you imagine buying a new car and having it serviced at the dealership and when you pick it up you find out your car will no longer go faster than 35 miles an hour and they removed the back seat because if you get into an accident you will only POSSIBLY hurt two people instead of four?

For sure, you are absolutely correct. You do own the hardware outright. But not the firmware. DJI retains all rights concerning their intellectual property, and they merely grant you license to use it.

 

[Road King]

Good Grief, this has gotten completely crazy. The 400' is AGL ( above ground level ), yes it relates to the location you took off from but it also includes your flight path. According to mother FAA you are to remain below 400' AGL during your "FLIGHT", so if you fly over a mountain that is 10,000' you have to fly no higher than 10,399.99' ( i put the .99 in there for those that want to argue it's 400') while above the mountain, or the opposite if you fly into a valley. The height of your take off location is irrelevant except during take off and landing, unless of course you are in an area like the Bonneville salt flats.
I agree everyone should be responsible for their own actions but the actions of a few flying UA in the area of maned aircraft operations has prompted this action. It wouldn't surprise me a bit if in the future UA will have software that will not allow them to take off if within 5 miles of an airport.

 

[Shakemaker]

I can't talk about how I got to 2400 feet here, just know that I did. I'm one that believes in personal responsibility and believe this should be enforced by the justice system. Harsh judgements are the key, not manufacturer interference. As for car manufacturers, limiting speed based on tire capability does make sense - it will prevent a failure of the hardware when pushed past the maximum. Altitude restrictions don't prevent hardware failures. I do however respect your opinion.

Has any one rented a car dolly, or smal trailer driving 65 only to look in you rearview mirror and notice only for you to see a sign that says SPEED LIMIT 55? Did you slow down?

 

[sar104]

The latest update said it was REQUIRED or your drone would be crippled to something like 30' height and 50' diameter and video would not work

I just think DJI should relist all firmware and software so customers can choose to revert back to an earlier version and as far as computer software goes you DO have the option to reinstall an older more stable version if you want or don't like the newer version

There has never been a requirement to upgrade. Many of us are running older firmware. I've not seen the message that you referred to.

 

[John Locke]

There has never been a requirement to upgrade. Many of us are running older firmware. I've not seen the message that you referred to.

You will see this message on newer firmware. This is exactly why I refuse to upgrade from 1.3.509. I'm not one to embrace forced firmware upgrades.

 

[sar104]

You will see this message on newer firmware. This is exactly why I refuse to upgrade from 1.3.509. I'm not one to embrace forced firmware upgrades.

But is the message correct? Unless they are pushing backdoor changes to the existing software or firmware, how does the functionality change?

 

[Bakersfield Quad]

Did you see that all offending software, is removed from the software in the new version? You will be able to fly, completely anonymous.
I am no more worried about DJI than Microsoft, Android or the numerous software's that upgrade when they want.