Scenario: standing on a hill that is 600 feet above a valley below.

• record home-point
• take off
• fly up to 400ft (120M)
• fly over the valley below
  

You are now 1,000ft above the valley below, which is 600ft over the US FAA limit.

Q: Are we in trouble? Are we not supposed to do this?

Have a few areas near here like that but not 600' though.

as a recreational flyer no!
above recommendations and suggestions,  yes,  but in trouble legally, no.

possibly, if you are a 333 cert holder, you may since commercial ops are held to higher level than rec users.

with that in mind , I do think the 400 ceiling is PROPOSED vs current.

have fun and send the video

As i understand the reference is from your take off point, who knows, maybe some idiot will change that at some point and if i am wrong (not about the idiot, the reference point)  then i stand to be corrected.
Who in the hell is going to measure undulations in the earth to tell you that you were "x" feet higher than you should have been based on the fact that the earth "IS NOT FLAT"!

kirk2579@aol.co Posted at 2016-2-24 18:51
Have a few areas near here like that but not 600' though.

as a recreational flyer no!

Kirk2579, I hesitate to send video because it could get me in trouble. I don't have a 333 cert.

Let's just say that the Space Needle in Seattle is 605ft high (more than 200ft above the FAA limit were I to take off from the base of it). But within the range of a P3P, there's a hill with an elevation of about 450ft. So it is possible to get equal to or even above the height of the saucer at the top.

But I've been in other situations outside of an urban environment with the same question. I've flown from the top of Mt. Erie in Washington state which is over 1,200ft above sea-level. From there, I can fly up to another 400ft higher (so 1,600ft above sea-level), then fly over land below that is close to sea-level AND it is not uncommon to see small aircraft fly by at lower altitudes. In this situation, common sense kicks in and I just watch and listen for planes ... and just pretty much don't go so far out. But I'm certainly over the FAA recommended limit.

I started at the top of a mountain and went downhill and realized my height indicator was in the negative numbers. Since the phantoms go by the home point as ground zero, you really don't know how high it is over uneven terrain.

Northofthe49th Posted at 2016-2-24 19:08
As i understand the reference is from your take off point, who knows, maybe some idiot will change t ...

"Who in the hell is going to measure undulations in the earth to tell you that you were "x" feet higher than you should have been based on the fact that the earth "IS NOT FLAT"!"

Not this again. The very fact that the earth isn't flat is why there WILL in the future be controls to make sure you don't fly from a safe location to an unsafe location (how they might do that doesn't sound difficult to me). Unsafe meaning that you flew from area A that as under 400ft to area B that is well over 400ft.

But let's just look at today's rules:

You can already fly from a safe location to a not-safe location on flat ground. All you have to do is fly into an FAA controlled airspace such as an airport.

Any amount of reasonable thought would show you that the same thing is possible where the earth is not flat.

From the example in my reply to Kirk: I take off at 1,200ft above sea-level from Mr. Erie. I can fly to 1,600ft above sea-level above me (400ft above my reference home-point). If I then fly out over the valley below me, which is near sea-level, I could be 1,200ft or more above manned aircraft.

Does that sound safe to you? Do you actually believe that it should be allowed simply because you're still not flying over 400' above your reference home-point?

topleader Posted at 2016-2-24 19:43
I started at the top of a mountain and went downhill and realized my height indicator was in the neg ...

Which begs another question: if I'm in a valley and I want to fly to the top of a hill next to me, that is 600ft higher than home-point, is it okay for me to disable the 400ft (120M) limit set in my RC?

Not A Speck Of  Posted at 2016-2-25 14:56
Which begs another question: if I'm in a valley and I want to fly to the top of a hill next to me, ...

Of course it is.  The 400 ft limit you have configured is just for your convenience - not legal compliance.
You have to use common sense and do some thinking for yourself.
The limit you are wanting to comply with is that you fly at or below 400 feet above ground level.
That's not 400 feet above home point, or above sea level or above grandma's house or anything else.
It's 400 feet above the ground that is below your Phantom.

Not A Speck Of  Posted at 2016-2-24 22:38
Kirk2579, I hesitate to send video because it could get me in trouble. I don't have a 333 cert.

L ...

enjoy and just do what is common sense and reasonable to you, I feel myself if I stay LOS the altitude isn't so critical.
Having said that I have nor been above 400 as in Ohio not much need in my area.

I do have an area over the local  valley I intend to travers when I get a bit more gutsy that will involve that altitude  but the range is more my issue than the 400'.


been around for 60 + yrs,  pretty much found that discretion allows me to most anything without hassle.

fly where you want and just use that thing called common sense, pay attention, and seldom will you find issues.  
Enough idiots ,all over, attracting attention elsewhere usually....

ok don't post them,  but do take them!
it has to be too nice not too!

Not A Speck Of  Posted at 2016-2-24 20:56
Which begs another question: if I'm in a valley and I want to fly to the top of a hill next to me, ...

I did not have a choice but to turn off the 400ft limit or I would just crash into the side of the mountain. The mountains here in Utah go above 11,000ft above sea level. I use all 500m limit height when I am at a ski resort to reach the peak of the mountain.

"But let's just look at today's rules:"

recommendations,    not rules at this time,

not arguing but trying to be correct. They MAY be in the future, but I may not see  the future.....

under /over 400feet is not an automatic safe vs unsafe

situation and circumstances are more the overriding factor in my thoughts.

I am willing to bet YOU know what is safe
I would go with that......

sometimes overthinking can paralyze folks,
I don't mean don't think , but at some point one must jump!
or  fly in our case.


have fun flying.

I agree, I've flown over pastures at low altitude thought I was 20 ft up according to the display but I was really 5ft and heading to the bushes.

instudiozero Posted at 2016-2-25 00:45
I agree, I've flown over pastures at low altitude thought I was 20 ft up according to the display bu ...

low alt flying is very difficult like that .

also hard as hec to tell what it is doing without horizon to judge.

I think you have to use your own judgement & common sense.

Ask yourself, "am I likely to be in an area where I might collide with another aircraft?"  If I fly off a 1000ft cliff from the top of the mountain, but stay within say 100 meters of it, I wouldn't expect to see another aircraft at that altitude so close to the mountain.  There may be search & rescue helicopters there, but that can happen at any altitude, hence keeping visual line of sight of your aircraft.  There may also be military fighter jets training in the area at low altitude close to or between the mountains, but if you've checked NOTAM's you will be covered as far as practically possible.

Remember, most aircraft don't know exactly how high they are above ground level, so they have to work with worst case scenario's, i.e. if there's a mountain in the area, they need to be 500ft above that regardless of the surroundings.

Just do a risk assessment (in your head) & you shouldn't have any problems.  If you're really concerned, do a written risk assessment to show you're acting responsibly.

Just to keep things clear (for newbies and others) and in agreement with labroides comment. We are flying in the bottom layer of G (uncontrolled) airspace, under VFR (visual flight rules). This airspace is defined with respect to local ground level (usually up to 1200 feet AGL), and as such it follows the local sloping terrain. There is a risk of encountering aircraft above 150 meters is this space (hence the 120 m or 400 ft AGL safe limit). Flying over the slope is a transition region where some common sense is needed (be aware however that paragliders for example can fly very close to “ground” level in this terrain) , but as you move out over the valley… you will become a risk for manned aircraft.

kirk2579@aol.co Posted at 2016-2-24 23:03
enjoy and just do what is common sense and reasonable to you, I feel myself if I stay LOS the alti ...

Common sense is like a flower! It doesn't grow in everyone's garden!