Mechanically, how high can I go?

[jwmcgrath]

All the confusion comes from mixing terms. The phantom has a service ceiling of 6000 m. That's how high the bird can physically (or mechanically in the terms the OP used) fly. It doesn't matter if that height is over the ocean or in the mountains of Nepal. Firmware limits the height to 500 m above the point of take off, again regardless of the altitude of the takeoff point. Legally, proper authorities can legally limit the maximum height (referenced to the ground below the aircraft) such as the 400 agl limit for Part 107 pilots. All of the above are correct, you have to decide which question you are asking.

I'm not so sure about that. I think you are quoting statistical limitations without considering the physics.

I find myself wondering if the hardware itself is capable of flying 6000M above the peak of Everest...

At some point there won't be enough air for the propellers to displace in order to compensate for the weight of the craft, and the battery function at that temperature may either be so dramatically reduced as to be non-functional, or at the very least incapable of sustaining a 6000M climb.

 

[Meta4]

One thing that bothers me where I fly (east coast of Florida now), I often see manned aircraft flying the coast at well below our 400' max. This really bothers me and I am quite reluctant to take it over 100' or even less. I use AirMap and I am well outside of any no fly zone. Am I wrong in my understanding of the manned aircraft minimum height restriction?

'A lot of people are.
It's a popular misconception that aircraft must stay above 500 feet.
There are many situations where they can legally fly lower.
Here are the actual FAA minimum altitude rules for real planes, note c & d particularly

§ 91.119 Minimum safe altitudes: General.
Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:
(a) Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.
(b) Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.
(c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.
(d) Helicopters, powered parachutes, and weight-shift-control aircraft. If the operation is conducted without hazard to persons or property on the surface—
(1) A helicopter may be operated at less than the minimums prescribed in paragraph (b) or (c) of this section, provided each person operating the helicopter complies with any routes or altitudes specifically prescribed for helicopters by the FAA

 

[jwmcgrath]

Read post #18 again - it's in the ballpark.

Fair enough.

The frame of reference changes constantly as you delve through this or any thread. I got caught up in thinking about the variables...

 

[jwmcgrath]

Read post #18 again - it's in the ballpark.

I guess what I'm saying is this:

I get asked all the time, "wow, that's cool, how high can it go?"

I can't start just answering that question with a number, drop the mic and walk away. Because even then, I'd have to choose between 6900M, and 2550M.

My current answer is usually "theoretically, 6000M". I suppose I could always start asking, "theoretically, or mathematically?"... but then all the other physics come into play, of which there is no shortage.

 

[Meta4]

I guess what I'm saying is this:
I get asked all the time, "wow, that's cool, how high can it go?".... Because even then, I'd have to choose between 6000M, and 2550M.

If people in the park are asking you how high it can fly, they aren't asking about max service ceiling or how high it would go if not firmware limited.
The answer for those folks is 500m or 1640 feet. That's how high it can go.

 

[jwmcgrath]

If people in the park are asking you how high it can fly, they aren't asking about max service ceiling or how high it would go if not firmware limited.
The answer for those folks is 500m or 1640 feet. That's how high it can go.

Yep... and that's exactly what they get.

I usually say "the box says it's capable of 6000M but the programming limits it to 1640'."

(I use "programming" because "firmware" isn't a convo I want to get into either).

 

[Richard R]

I'm not so sure about that. I think you are quoting statistical limitations without considering the physics.

I find myself wondering if the hardware itself is capable of flying 6000M above the peak of Everest...

At some point there won't be enough air for the propellers to displace in order to compensate for the weight of the craft, and the battery function at that temperature may either be so dramatically reduced as to be non-functional, or at the very least incapable of sustaining a 6000M climb.

Making my point again, 6000m service ceiling is altitude in MSL. that is height above mean sea level not the height above ground. So no, you can take off from Everest and climb another 6000 me, you can't even take off from Everest because the ground level there (height =0) is above the service ceiling (altitude at the summit is about 8800 meters).

 

[Meta4]

I find myself wondering if the hardware itself is capable of flying 6000M above the peak of Everest...

At some point there won't be enough air for the propellers to displace in order to compensate for the weight of the craft, and the battery function at that temperature may either be so dramatically reduced as to be non-functional, or at the very least incapable of sustaining a 6000M climb.

No-one's suggested a Phantom can fly above Everest (which is 8,848 m).
Your Phantom has a service ceiling (max altitude at which it is capable of flying) of 6000 metres above sea level.
If you were to attempt to climb to 6000 metres, before you get halfway, you have passed the point of no return and your Phantom is not coming back in one piece.

 

[jwmcgrath]

Making my point again, 6000m service ceiling is altitude in MSL. that is height above mean sea level not the height above ground. So no, you can take off from Everest and climb another 6000 me, you can't even take off from Everest because the ground level there (height =0) is above the service ceiling (altitude at the summit is about 8800 meters).

I think you said "can" when you meant "can't"... and THAT'S where confusion happens! [emoji6]

But you're right, I misread your point regarding service ceiling. But I think we are now in agreement that no, it's NOT possible to fly 6000M above Everest.

 

[Latitude 65 Testing]

My understanding was that for rec pilots up to 500 meters(1620 something feet) above take off altitude was acceptable as long as it was no more than 400 feet AGL. So when I fly over my property out of town I take off from a 740 foot ASL river valley and follow a section line up the side of a 1350 foot ASL hill. If hovering above the peak I should be good to like 1020 feet above me, that being 400 feet above the hilltop. I'd be interested in any official info to the contrary.
Having said that I admit that my first attempt caught me flying too close to the crest, getting an aircraft disconnect message 4300 feet out and 744 feet above me. It did its job and came back at that altitude; as it was my first automatic RTH I let it come all the way back at 744 ft and neglected to keep it at the proper altitude on the way down the hill. From now on I will give more consideration to the fact that at those kinds of altitudes the RTH sequence can leave you with a bird way up in traffic and the descent taking almost three minutes.

 

[jwmcgrath]

No-one's suggested a Phantom can fly above Everest (which is 8,848 m).
Your Phantom has a service ceiling (max altitude at which it is capable of flying) of 6000 metres above sea level.
If you were to attempt to climb to 6000 metres, before you get halfway, you have passed the point of no return and your Phantom is not coming back in one piece.

You're right, my fault. I misunderstood Richard's post at the point he said "service ceiling".

 

[4Krusin]

LOL you do?! I've read the whole thread and I'm not sure I know the "real" answer yet!

I know the box says 6000M on it but I also know the software limits it to (I think) 1625', but I think the OP is wondering what max height is with electronic and legal restrictions removed... which would then become dependent on battery capability, air pressure, temperature, etc.

And THAT then becomes dependent on atmospheric pressure, starting point relative to sea level, model of phantom...

So no, I don't know the answer yet and I am quite certain that there is no one answer.

I see you are from Ontario. I am too and fly in the Lake Simcoe area in the summer. Thanks for your input. I know there is no exact answer and don't really care. My answer in the future will be more accurate however. My main concern with my comment is the apparent disregard of the minimum height that manned aircraft are supposed to follow. Is the 500' a legal restriction and if so, why is it not being enforced by the appropriate authority? There is no doubt in my mind that a drone is going to get hit in the future at less than 400' in a non restricted area and the drone pilot will receive full blame. Hopefully the aircraft will survive. We tend to assume that there is a safety buffer of 100', but in many places that doesn't really exist.

 

[Meta4]

My main concern with my comment is the apparent disregard of the minimum height that manned aircraft are supposed to follow. Is the 500' a legal restriction and if so, why is it not being enforced by the appropriate authority? ... We tend to assume that there is a safety buffer of 100', but in many places that doesn't really exist.

Read post #62 above (Canadian rules are similar to FAA rules)

 

[jwmcgrath]

I see you are from Ontario. I am too and fly in the Lake Simcoe area in the summer. Thanks for your input. I know there is no exact answer and don't really care. My answer in the future will be more accurate however. My main concern with my comment is the apparent disregard of the minimum height that manned aircraft are supposed to follow. Is the 500' a legal restriction and if so, why is it not being enforced by the appropriate authority? There is no doubt in my mind that a drone is going to get hit in the future at less than 400' in a non restricted area and the drone pilot will receive full blame. Hopefully the aircraft will survive. We tend to assume that there is a safety buffer of 100', but in many places that doesn't really exist.

Gorgeous area, Simcoe! I'm in Ottawa, and I have a seasonal trailer in a campground on White Lake. That campground is owned by an amateur pilot with whom I have become good friends and fly with in his two seater.

I suspect I will become much more educated this summer as it will be my first summer there with this Phantom. I have already warned him I will have a ton of questions for him; he currently has his license for the smaller, lighter aircraft and is working toward full licensing for the Cessna he just bought.

But the fact is, he is currently flying his manned aircraft out of a hangar on the property, across a field and onto the water and takes off from there... so yes, there is a substantial amount of time he spends <500'. He also skims the water for extended periods of time, whether it be to practice, the view or just to have fun.

I plan on having extensive conversation with him in another month, not only out of curiosity but because we will be sharing the same airspace, and altitude, which will require intelligent coordination.

Part of my summer plan actually, is to capture some footage of him taking off and landing, with his support and permission (safely) of course.

 

[jwmcgrath]

But the fact is, he is currently flying his manned aircraft out of a hangar on the property, across a field and onto the water and takes off from there... so yes, there is a substantial amount of time he spends <500'. He also skims the water for extended periods of time, whether it be to practice, the view or just to have fun.

...in summary, as much as all the science in threads like this fascinate me, and awareness of the law is critically important, there is NO black and white to any of it.

Because if I'm flying at 200' and my friend slams his ultralight into my quadcopter, the intricacies of the argument over fault will be as unique as any perspective on this forum.

 

[sar104]

...in summary, as much as all the science in threads like this fascinate me, and awareness of the law is critically important, there is NO black and white to any of it.

Because if I'm flying at 200' and my friend slams his ultralight into my quadcopter, the intricacies of the argument over fault will be as unique as any perspective on this forum.

I'm not sure there would be much debate about fault in that case, because the FAA requires UAVs always to yield to manned aircraft, whether flying under the special rule or Part 107.

Getting Started

 

[jwmcgrath]

I'm not sure there would be much debate about fault in that case, because the FAA requires UAVs always to yield to manned aircraft, whether flying under the special rule or Part 107.

Getting Started

It can either become extremely complex, or default to ultra simplistic.

If I'm line of sight but 1000' feet away in a stationary hover at 200', and along comes an ultralight skimming over the treetops at 160MPH and smashes my craft, while I can understand the judge may very well decree that I didn't yield, the physical fact is I could never have foreseen the need to.

 

[sar104]

It can either become extremely complex, or default to ultra simplistic.

If I'm line of sight but 1000' feet away in a stationary hover at 200', and along comes an ultralight skimming over the treetops at 160MPH and smashes my craft, while I can understand the judge may very well decree that I didn't yield, the physical fact is I could never have foreseen the need to.

Those would be some tall trees. I don't disagree that it would be hard to be able to yield in that situation and I'm sure that the ensuing debate would be lively but, given the FAA guidelines and rules, I cannot see any cause for optimism on the liability issue.

 

[jwmcgrath]

Those would be some tall trees. I don't disagree that it would be hard to be able to yield in that situation and I'm sure that the ensuing debate would be lively but, given the FAA guidelines and rules, I cannot see any cause for optimism on the liability issue.

LOL I was going to go back and revise the numbers for that reason and thought nah... the point is made!

But the fact is he lands on the water 200' from shore so there is a point that he is at zero elevation before touchdown too. The trees could be 30' and I could be hovering at 40' and there is still the potential for impact.

None of this may matter because I like and respect him and at the end of the day I'm a tenant in his campground, and if he indicates that for any reason he is uncomfortable with me having my AC on his premises, then I won't bring it.

That's a distinct possibility as he won't want to ask or second guess whether I'm in the air before he takes off. I suspect he'll want to take off without the worry. He's very independent like that. He knows I have it and we've spoken of it, he appreciates the video I've shown him, but that may change when I show up with it in "his air space".

And then someone is going to get a great deal on a well cared for P3S.

 

[Bobby]

Look at the monster I have created...

Seems as though I was away too long, but if you would allow me to respond to a few previous posts:

First off, to anything relating to the intent of breaking the altitude laws or endangering other aircraft, you missed the ball. Like, a lot. I tried really hard to stress that this was strictly an educational discussion, that attempt failed. I don't believe I could have made that more clear though, so I guess it was doomed to those kinds of comments from the start. Frankly, I don't really care, but I feel the need to point one thing out; the original reason I made this thread.

You ready? I was bored.

Yup, that's it. I was looking at a charging P3A, and then looking at a forum and saying "hmm, what's something I wonder that others might wonder as well..."

So, just being ultra-super-crystal-clear that you all know about my malicious intentions. *evil laughter

Other than that? I mostly really like where this went. Talk about the service ceiling, the air pressures at those heights, how we get asked questions like "how high?" and how we're supposed to be able to answer that question when we can't find the actual answer. Good stuff, thanks for thinking with me guys. Even if I still don't have a 100% blanket answer, at least now I can explain to bystanders, if they understand it or not.