I was just curious about this.

If you start on a level field, then fly your drone to 400 ft. Then start flying toward a hill, that, let's say is 500 ft tall, you are allowed to then fly to 900 ft as you approach the top of the hill, is that correct?

But if that's correct, is the only way to know the elevations around you is by looking on a sectional map? Is there any other way?

Any thoughts appreciated.

Thanks.

Depends which way you are looking at it ... as per DJI FW limit or FAA / CAA limits :

If you are referencing to Take Off point ... then you cannot exceed maximum limit set in FW based on that Take Off points elevation. Therefore it means that if you take off from a hill or mountain - then you will actually fly higher than the guy who takes off in the valley. DJI FW will add the 500m to the zero it regards as the Take Off point.

But if you mean according to FAA / CAA / whatever Aviation Body rules your Countries skies ... then that is a highly debatable point - I'm sure someone will claim to know the exact answer - but in fact its not exact. Each Country has a max limit flyable by such as a drone / model aircraft. That limit is stated as xxx feet / metres altitude ... but does not actually specify the reference point. Is it based on Mean Sea Level as land heights are .. or on altitude above take-off point ? This point has been argued over by many bodies trying to define.
For us there is only one way to fly - and that is via the altitude reading on the display. This references to take off point.

We with our Drones do not set Altimeter as a full size pilot does. He has a reading he inputs based on locations elevation above Mean Sea Level. That then means that his Altimeter stays reasonably accurate over contoured land - subject of course to climatic change en route. But we have no way to do that - so our 'Altimeter' sets to zero when we power up.
If you are arrested or questioned by official body .. your Flight Log will give the altitude according to DJI FW ... which will then indicate to them that this is the only way you have to determine altitude during flight. Unless they are 'out to make example' - I would expect them to accept and let you alone.

Nigel

Thanks for that response. I know there is a provision that for the purposes of flying over buildings, you can go 400 feet above the height of the building, but I was just wondering about it as I was approaching a hill that is higher than 5oo feet and I was in the valley, so to speak.  Thanks again. I appreciate the comment.

If you increase height until you can see from the live video that you are level with the top of the hill then you can use that altitude reading as your base and go 400 beyond that.   Also a good way to ensure you don't hit any trees - look around for the highest and go up to find how high it is/they are, then keep above that height.

However if you do as you suggest then when you reach the top of the hill you will have no way of knowing what is about to fly over the top of it and it will be very difficult for you to give way to manned helicopters or planes that may be passing, therefore it is not a safe thing to do, much better to fly from the top of the hill where you have good all-round visibility.

As Nigel explains it really depends upon the country's flight limits; Here in France for example, the maximum altitude allowed for our drones is 150 meters (492 feet) above ground level (not take off point). In mountainous terrain this follows the slope. This also means that when flying from a mountaintop towards the valley, you are quickly out of the limit if you maintain your altitude.
Have fun & good flying!

solentlife Posted at 2017-10-28 01:11
Depends which way you are looking at it ... as per DJI FW limit or FAA / CAA limits :

If you are referencing to Take Off point ... then you cannot exceed maximum limit set in FW based on that Take Off points elevation. Therefore it means that if you take off from a hill or mountain - then you will actually fly higher than the guy who takes off in the valley. DJI FW will add the 500m to the zero it regards as the Take Off point.

That limit is stated as xxx feet / metres altitude ... but does not actually specify the reference point. Is it based on Mean Sea Level as land heights are .. or on altitude above take-off point ?

There is no debate and no mystery.  The answer is simple and well known.
All regulation heights are above ground level - that's above the ground directly below the aircraft.
And that's the same, no matter what country you are in.

Nothing else would make any sense at all.
You couldn't have regulations based on heights ASL.  People on the coast could fly high but those libing in the mountains couldn't even take off!
Limits based on launch point would be ridiculous.
Imagine two flyers, one on top of a hill and one down in the valley, both flying their drones side by side and one being legal and the other not because of their launch points?
Ridiculous.

Labroides Posted at 2017-10-28 01:41
That limit is stated as xxx feet / metres altitude ... but does not actually specify the reference point. Is it based on Mean Sea Level as land heights are .. or on altitude above take-off point ?

There is no debate and no mystery.  The answer is simple and well known.

Here we go ...

Suggest go back and read it properly. All you've done is word it differently ... but of course because its 'solentlife' - its game on !!

For DJI purposes - it is Take Off point taken as ZERO.

For full size aviation as explained - Altimeter is set to elevation of the starting location ...

https://www.skybrary.aero/index.php/Altimeter_Setting_Procedures

https://www.ivao.aero/training/d ... timeter_Setting.pdf

On descent to an airfield Pilot can set to local settings to give him reference to airfields elevation, using ATC info provided on approach.

It does not change the fact the elevation of any point on land is referenced to mean sea level.

My point is that when FAA / CAA etc. tells MODEL community that you can only fly to xxx height - its a figure that can be misinterpreted. This is why I mentioned the difference of models and Full Size.

For practical purposes with DJI gear - we take altitude to be as per displayed - that is above Take Off point.

Even if you change Home Point during flight - the barometric reading will still be set as taken at original Take Off point. It has no way to change it. Except land and restart at a new location.

Nigel

DNR 1 Posted at 2017-10-28 01:17
Thanks for that response. I know there is a provision that for the purposes of flying over buildings, you can go 400 feet above the height of the building, but I was just wondering about it as I was approaching a hill that is higher than 5oo feet and I was in the valley, so to speak.  Thanks again. I appreciate the comment.

Aloha DNR,

     Where I live in the United States and fly, this question you raised is part of my flight zone.  I live next to cliffs (Pali) that tower more than 2000 feet above the jungle where my house is.  These cliffs have ridges that come down into the jungle and my house is on the lower part of one of those ridges.

     I regularly fly up to the "Needle" which is about 1600 feet above my house (launch area).  Our Phantoms are computer limited to 500 meters altitude, or 1640 feet.  The FAA Pt. 107 regulations require us to remain below 400 feet altitude wherever we fly but these regulations also say that we are allowed to fly within 400 feet of a structure and that manned aircraft must stay beyond 500 feet of a structure.  

     As you noted, a building, tower or bridge is considered a structure, but the FAA regulations also say that a geographic formation (like a mountain or hill) or natural formation (like a tree) is also considered a structure for the purposes of the regulations.  So, as long as I stay within 400 feet of the Pali and ridges, I am flying legal.  

     Now the manned "tourist" helicopters like to fly along the Pali to give a "good tour" and that can mean get close which is a violation if they get closer than 500 feet to the mountain - and they do, regularly.  Fortunately, the light planes and helicopters that pass by are loud enough that they can be heard far enough away that I can take evasive action if needed.  Nothing like hiding behind a thin ridge to liven things up, but fortunately I have only had to think about it, not actually do it - yet.

     So, to answer your question, yes, you can legally fly 900 feet higher than your launch point if your Phantom is above your 500 foot hill.  But, you will be flying blind for the other half of the flight zone around the hill.  That could be dangerous because there are pilots flying around who illegally cut required distances, just like there are drone operators out there who do stupid things.  And no matter what happens, if they hit your Phantom, you are held responsible.

     Finally, there is an interesting problem that pops up in our case.  If we go into a "Return to Home" scenario due to something like a software crash when we are flying high up in the mountains, or hills, the flight path of the Phantom takes it horizontally straight to home.  The Phantom will quickly fly more than 400 feet away from the structure or above the ground in that scenario.  Then you are illegal, even though your system is operating autonomously.  So, yiou have only seconds to get control over your Phantom before you are flying illegally and / or are endangering a manned aircraft.

     So, there is a little bit more freedom up in them thar hills, but there is also more responsibility.  Plan accordingly.

Aloha and Drone On!

DNR 1 Posted at 2017-10-28 01:17
Thanks for that response. I know there is a provision that for the purposes of flying over buildings, you can go 400 feet above the height of the building, but I was just wondering about it as I was approaching a hill that is higher than 5oo feet and I was in the valley, so to speak.  Thanks again. I appreciate the comment.

Sorry - think you misunderstood ...

There is no provision for adding building height - How ?

Basically because of the way your DJI determines altitude - you are set to Take Off point height as zero for reference to display height in GO / Litchi etc.

If you took of from the roof of the building - DJI doesn't know that, it just assumes that you are at 'ground zero'. Same as if you took of from a hill or mountain.

I sometimes take off from my Balcony at back of my house. Powering up it takes that as zero. I have often then gone down to ground level and walked to my mooring area .. which has a drop of about 4m ground slope + balcony height of ~4m .... On landing I get a displayed figure of around the -8m approx.

I have even done the reverse. The point is reference is when powered up and take off ..

Nigel

Cetacean brings in the RTH item .... this is where another factor can be disaster !

Lets say you set RTH altitude as 30m .... and you go fly up the side of yon hill / mountain. You are above 30m but below the 500m limit referenced to Take Off point. The AC flies behind or at least does not have direct clear line back to Home Point ............. ZAP ! If it goes into RTH - it will hit the hill / mountain (we assume from this section of forum to be a P3A / P3P) ... because it will NOT climb to clear the obstruction and it will take direct route home.

Nigel

solentlife Posted at 2017-10-28 02:58
Cetacean brings in the RTH item .... this is where another factor can be disaster !

Lets say you set RTH altitude as 30m .... and you go fly up the side of yon hill / mountain. You are above 30m but below the 500m limit referenced to Take Off point. The AC flies behind or at least does not have direct clear line back to Home Point ............. ZAP ! If it goes into RTH - it will hit the hill / mountain (we assume from this section of forum to be a P3A / P3P) ... because it will NOT climb to clear the obstruction and it will take direct route home.

Aloha Nigel,

     Good point!  In that scenario, you really do not want to loose sight of your Phantom.  And I really like your "where another factor can be a disaster!"  Good line!

Aloha and Drone On!

solentlife Posted at 2017-10-28 02:25
Here we go ...

Suggest go back and read it properly. All you've done is word it differently ... but of course because its 'solentlife' - its game on !!

Because it's from Solentlife, there's a good chance it will be overly wordy, confusing and often wrong.

For practical purposes with DJI gear - we take altitude to be as per displayed - that is above Take Off point.
You might but it wouldn't be very practical unless you live on a pancake-flat prairie.
Anyone with a reasonable ability to handle basic mental arithmetic, knows that the app altitude is referring to height above launch point and can do a rough calculation if required to work out anything beyond that.

If you flew a small plane you'd have to do some mental arithmetic to work out clearance heights above terrain
It's not much different flying a drone.

Cetacean Posted at 2017-10-28 03:07
Aloha Nigel,

     Good point!  In that scenario, you really do not want to loose sight of your Phantom.  And I really like your "where another factor can be a disaster!"  Good line!

I would love to be at your place and watch the antics !!

Must get interesting.
I'd love to be up and video the Fire Fighter Heli's practicing at my place on the river, but safety first - I cannot.









They actually had to stop dropping the 'load' on the farm land across the river from me. The shock of so much water hitting 'killed' the grass !! Now they pick up and go back to Airport to drop on the runway ... and they repeat it all day for 2 - 3 days a time !

Means we get no flying near my place, but a free show !

I'm pals with Local Airport Management - so I get close up to the guys ..

Nigel

If you want to cut to the heart of it, and keep it simple then look at it this way, in the states under FAA requirements it's 400 feet AGL.  Unless you are trying to or actually operating in airspace other than Class G then all bets are off there.
Otherwise follow Cetacean's guidance he is correct there, the whole RTH thing not withstanding.  ...and you are required to give way to manned aircraft regardless of what altitude and airspace you are at.

You want to peel back the onion further go here and learn: https://www.faa.gov/uas/
Above all else have fun and be safe

Labroides Posted at 2017-10-28 03:11
Because it's from Solentlife, there's a good chance it will be overly wordy, confusing and often wrong.

For practical purposes with DJI gear - we take altitude to be as per displayed - that is above Take Off point.

As I said ... here we go.
Because the OP has his answers ... can you stop and not ruin another thread ?

Would be nice for all concerned.

Nigel

solentlife Posted at 2017-10-28 03:16
I would love to be at your place and watch the antics !!

Must get interesting.

Aloha Nigel,

     There are advantages and disadvantages to every location.  I live at the 5 mile mark for Marine Corps Air Station  - Hawaii, but they are not real friendly to visiters there unless it is an open house and you can forget about droning then.  But on Sundays the air field is closed so we can fly on Kaneohe Bay within the 5 mile mark.  Figure it out and work around the disadvantages.  At least you get intermittent entertainment there!

Aloha and Drone On!

Cetacean Posted at 2017-10-28 03:52
Aloha Nigel,

     There are advantages and disadvantages to every location.  I live at the 5 mile mark for Marine Corps Air Station  - Hawaii, but they are not real friendly to visiters there unless it is an open house and you can forget about droning then.  But on Sundays the air field is closed so we can fly on Kaneohe Bay within the 5 mile mark.  Figure it out and work around the disadvantages.  At least you get intermittent entertainment there!

Interesting, do you have stated clearance via NOTAM or local agreement or FAA waiver for the allowance to incur on the airfield zone?
While the base may be closed, all that really means is the tower is closed, the field remains an operable airfield and simply goes from being a Class D to a Class E airfield (uncontrolled airfield) with the boundaries remaining as defined by FAA JO 7400.11B
AWP HI D  Kaneohe MCAS, HI Kaneohe Bay MCAS, HI   (lat. 21°27'02'' N., long. 157°46'05'' W.)
That airspace extending upward from the surface to and including 2,500 feet MSL within a 4.3mile (NM) radius of the Kaneohe Bay MCAS. This Class D airspace area is effective during the  specific dates and times established in advance by a Notice to Airmen. The effective date and  time will thereafter be continuously published in the Airport/Facility Directory, Pacific Chart Supplement.

Being that this is a military installation it is highly unlikely that any aircraft are going to operate there while the field is closed, however, because it is a military airfield it can be opened at anytime regardless of set dates and times.  They only have to put out an updated NOTAM.  Regardless, any available airfield is a viable option for emergency aircraft to use whether open or not.

Also per FAA https://www.faa.gov/uas/where_to_fly/airspace_restrictions/ :
Airports
Recreational operators are required to give notice for flights within five miles (SM) of an airport to both the airport operator and air traffic control tower, if the airport has a tower. However, recreational operations are not permitted in Class B airspace around most major airports without specific air traffic permission and coordination
Meaning, that while there is no tower ops, you must still notify the operator, in this case the Marine Corps.  If they are closed, I doubt they will care but this is what the FAA says you must do.

Cetacean Posted at 2017-10-28 03:52
Aloha Nigel,

     There are advantages and disadvantages to every location.  I live at the 5 mile mark for Marine Corps Air Station  - Hawaii, but they are not real friendly to visiters there unless it is an open house and you can forget about droning then.  But on Sundays the air field is closed so we can fly on Kaneohe Bay within the 5 mile mark.  Figure it out and work around the disadvantages.  At least you get intermittent entertainment there!

The Heli in the photo as you see is an Ex Soviet job that has been extensively rebuilt. There are a number of them left behind when Soviet era ended. Some have been revamped - others in process of.

The one here has some pretty good gear fitted and because of that - I was not allowed closer than 50m even though I'm friends with the guys.
It includes 'body search' gear ... they can fly over areas searching for 'buried' bodies as well as SAR.

They have latest military class gear on ...

They may look dated - but what they carry is not !!

Nigel

Labroides Posted at 2017-10-28 03:11
Because it's from Solentlife, there's a good chance it will be overly wordy, confusing and often wrong.

For practical purposes with DJI gear - we take altitude to be as per displayed - that is above Take Off point.

Amen, Labroides!  I fully concur with your reply.  Some people think they're the only ones right on here, and sadly, their often wrong.

solentlife Posted at 2017-10-28 06:27
The 'girls' are out from kindergarten I see ...

Oh, put down those Goggles.  I don't think that's a productive use of your drone and it's liable to get you into trouble.

Irate Retro Posted at 2017-10-28 08:34
Oh, put down those Goggles.  I don't think that's a productive use of your drone and it's liable to get you into trouble.

Funny you say that ... just stripping my P3S for motors etc and putting together a 450 FPV quad with the bits that still work after the 'swim'. (Anyone interested in the build ... PM me ... )

Goggles ... mind blowing the selection out there. Trouble - I'm too far away to see the girls patting each other on the back !!  

Life's never dull !!

Nigel

Just a quickie to show the 'swap over' P3S gear to SK450 ...







Nigel

Genghis9 Posted at 2017-10-28 04:37
Interesting, do you have stated clearance via NOTAM or local agreement or FAA waiver for the allowance to incur on the airfield zone?
While the base may be closed, all that really means is the tower is closed, the field remains an operable airfield and simply goes from being a Class D to a Class E airfield (uncontrolled airfield) with the boundaries remaining as defined by FAA JO 7400.11B
AWP HI D  Kaneohe MCAS, HI Kaneohe Bay MCAS, HI   (lat. 21°27'02'' N., long. 157°46'05'' W.)

Aloha Genghis,

     Good, you found the page and information.  Interesting yeah!  The Public Relations officer for the base comes to our meetings and she is the one that reminded me that the field is closed on Sundays.  Of course if you want to stay out of trouble you get tower clearance prior to their closure, just in case.  But, there are so many violations, even on open days.

     BTW, on the secional, at the horizontal midline, between the last "u" in Kahaluu and the closest dash of the 5 mile circle is where I live and launch.  Between the 2570 (altitude in feet ASL indication), the dash and the Kahaluu word are my flying grounds, as to be differentiated from the coffee grounds.  (Hey, it is morning in Hawai'i!)

Aloha and Drone On!

solentlife Posted at 2017-10-28 05:00
The Heli in the photo as you see is an Ex Soviet job that has been extensively rebuilt. There are a number of them left behind when Soviet era ended. Some have been revamped - others in process of.

The one here has some pretty good gear fitted and because of that - I was not allowed closer than 50m even though I'm friends with the guys.

Aloha Nigel,

     The helicopter in the photos looks like an Mi-8.  As for being rebuilt from the ground up, that is SOP fo the militaries around the world.  Look at the American B-52 bomber.  The 52 is its age in years!

Aliha and Drone On!

Cetacean Posted at 2017-10-28 12:33
Aloha Genghis,

     Good, you found the page and information.  Interesting yeah!  The Public Relations officer for the base comes to our meetings and she is the one that reminded me that the field is closed on Sundays.  Of course if you want to stay out of trouble you get tower clearance prior to their closure, just in case.  But, there are so many violations, even on open days.

Very nice, what a great place to fly and play
I ever get back that way I'll know where to hunt you down...

If the base PR person is tied in with you all then I'd say you are getting, at least, unofficial official clearance to operate inside the zone.  As long as the field remains closed you should be good to go, just keep an ear and eye out as there is never a guarantee they will always be closed like clockwork either.

Enjoy your day

Cetacean Posted at 2017-10-28 12:43
Aloha Nigel,

     The helicopter in the photos looks like an Mi-8.  As for being rebuilt from the ground up, that is SOP fo the militaries around the world.  Look at the American B-52 bomber.  The 52 is its age in years!

...and then some
The BUFF design was actually started in the post twilight years of WWII...memories

Genghis9 Posted at 2017-10-28 13:02
Very nice, what a great place to fly and play
I ever get back that way I'll know where to hunt you down...

Aloha Genghis,

     The fact that they are never closed like clockwork is noted on the opening page of their newsletter.  It pays to pay attention!

Aloha and Drone On!

Cetacean Posted at 2017-10-28 13:09
Aloha Genghis,

     The fact that they are never closed like clockwork is noted on the opening page of their newsletter.  It pays to pay attention!

I'm just a bit more curious...
You say you have a PR person come to your meetings, nothing wrong with that, however, do you ever hear from one of their flight safety officers?
In another life, that was a responsibility we had, it was to go out and visit local airfields, crop duster sites, helo pads, flying clubs, etc....we tried to do it once a year if possible.

Genghis9 Posted at 2017-10-28 13:18
I'm just a bit more curious...
You say you have a PR person come to your meetings, nothing wrong with that, however, do you ever hear from one of their flight safety officers?
In another life, that was a responsibility we had, it was to go out and visit local airfields, crop duster sites, helo pads, flying clubs, etc....we tried to do it once a year if possible.

Aloha Genghis,

     Not really.  The MCAS Kaneohe has had a bit of a problem over the years with flying over our neighborhoods and making a lot of noise.  The complaints have managed to get new rules that require all MCAS air field use aircraft to stay over water, or hear about it in a proceeding.  And to their credit, they have managed to do so.  (About the only exception we grant is to the Blue Angels for their rehersals and shows.)  But in recent years there is a detente of sorts.  The military now seems to use the MCAS airfield as a training for STOL in large aircraft and for support of FA-18 in exercises.

    One time a Russian Antonov AN124 used the field and I was at the south end of Kaneohe Bay.  That plane is so gigantic that it looked like it was flying over land but in fact it was on the normal flight path.  When I queried the MCAS PR person at the next meeting, they confirmed that it was an Antonov.

     The Marines now use V-22 Osprey and I must say that as much as the Osprey is fast at getting there, once it has arrived, it has to be the noisiest aircraft ever.  One flew over my house, and I knew I had to address that at one of our meetings.  But apparently it was a test and they have never flown over our neighborhood again.  The Marines have learned their public relations.

     BTW, when you served, were you a G9?

Aloha and Drone On!

Really great responses. I think I got it now.

Mahalo nui loa.

Cetacean Posted at 2017-10-28 19:56
Aloha Genghis,

     Not really.  The MCAS Kaneohe has had a bit of a problem over the years with flying over our neighborhoods and making a lot of noise.  The complaints have managed to get new rules that require all MCAS air field use aircraft to stay over water, or hear about it in a proceeding.  And to their credit, they have managed to do so.  (About the only exception we grant is to the Blue Angels for their rehersals and shows.)  But in recent years there is a detente of sorts.  The military now seems to use the MCAS airfield as a training for STOL in large aircraft and for support of FA-18 in exercises.

Uh?  So these meetings you refer to are community meetings to keep the peace with the locals about the airfield's operations, correct?  If that's the case then I guess flight safety showing up would be a bit redundant under those circumstances and not really that necessary.  It also explains why the PR person is there...

YUP - the V22 is can be noisy, that's what you get when you mix an aircraft with a twin rotor helo
Beating the air in to submission is never a smooth process, unlike taming the air by more refined measures

Over the last many years it has been harder and more difficult for military airfields to operate while attempting to keep the peace at home with the less and less tolerant public.  I've dealt with my share of noise complaints over the years, and I assure you everything that is possible to do to reduce the noise factor does get pushed, but at some point the Sound of Freedom just can't be fully contained!

DNR 1 Posted at 2017-10-28 21:01
Really great responses. I think I got it now.

Mahalo nui loa.

Aloha DNR,

     Good, you filtered some information out of this community discussion.  We may wander over yander but we do have fun doing it.  Not as much fun as flying, but fun none-the-less.

Aloha and Drone On!

Genghis9 Posted at 2017-10-28 21:03
Uh?  So these meetings you refer to are community meetings to keep the peace with the locals about the airfield's operations, correct?  If that's the case then I guess flight safety showing up would be a bit redundant under those circumstances and not really that necessary.  It also explains why the PR person is there...

YUP - the V22 is can be noisy, that's what you get when you mix an aircraft with a twin rotor helo

Aloha Genghis,

     The meetings are neighborhood board meetings and the MCAS PR representative provides us with the latest from MCAS.  But the MCAS part is only 3 to ten minutes of a three hour proceeding unless there are more serious issues regarding the base.  We also have a standing committee for military affairs.

     But, as you have noted, the military has realized that they need the support of the population they are tasked to protect.  No better way to do that than to listen to them and do what you can to meet their concerns.  In my decades of involvement, I am proud to say that the MCAS has vastly improved their relationship with the community.

Aloha and Drone On!

I have a FAA 48,000ft AGL Waiver!  Now What? I need to only go to 12,000ft from a starting point of about 9,000ft.

Can DJI lift the restrictions with proof of a FAA waiver and a FAA notam?

http://www.traphx.com/launch-information/launch-sites/

Dave

drmoore60 Posted at 2017-10-29 18:33
I have a FAA 48,000ft AGL Waiver!  Now What? I need to only go to 12,000ft from a starting point of about 9,000ft.

Can DJI lift the restrictions with proof of a FAA waiver and a FAA notam?

No, it is built into all DJI aircraft and cannot be switched off, altered or disabled by agreement.

drmoore60 Posted at 2017-10-29 18:33
I have a FAA 48,000ft AGL Waiver!  Now What? I need to only go to 12,000ft from a starting point of about 9,000ft.

Can DJI lift the restrictions with proof of a FAA waiver and a FAA notam?

Your only way would be to turn against solutions not recommended unless you still have old firmwares installed, then you can do some investigation on Parameter settings.