Mechanically, how high can I go?

[Pharm]

Sorry, so far in this thread everyone was "flying off a cliff" so I started at the high side. Goes to show how simple one detail can change everything...

Yeah, I forgot to label the takeoff point before I posted it. Sorry about that!

 

[jwmcgrath]

Yeah, I forgot to label the takeoff point before I posted it. Sorry about that!

LOL I thought I was losing my mind, so before I replied I did the math about 9 times, but didn't think to do it from right to left!!

It IS a great diagram though!

It's also a great diagram to illustrate why estimating and setting the RTH height is so important... thinking your display says 200' but you're really only 30' off the ground.

 

[Pharm]

That's an awesome diagram...

But... are you sure?

Either I'm wrong or the the "Alt" reading, which you have defined as the "altitude the Phantom tells you" is off...

At point 1, reading left to right, you show the Phantom at 30' off the ground but the Alt reading as 200'... shouldn't the Alt (the altitude the phantom tells you) be 30'?

Or is it the way I'm reading it?

EDIT: Never mind, your edit came through as I was typing, and I had the takeoff point at the left, reading left to right!

I reuploaded it. Ignore the AGLMSL attachment.

 

[jwmcgrath]

May I?

I only added that to help everyone understand the difference between the altitude the Phantom thinks it's at, and what it's actually at, to complete the math of how it finds that calculation.

 

[Pharm]

Ha. I just did the same thing.

 

[Pharm]

May I?

I only added that to help everyone understand the difference between the altitude the Phantom thinks it's at, and what it's actually at, to complete the math of how it finds that calculation.

you may.

 

[jwmcgrath]

you may.

Ya but mine is red! [emoji1]

 

[Pharm]

Ya but mine is red! [emoji1]

Show off!

 

[jwmcgrath]

I just took a second look and we actually highlighted different dimensions;

In red is shown the distance between take off point, and ground level at the AC's new hover point, to show JUST the difference in ground elevation. So we're all good!

 

[Loz]

Good stuff shared in this thread, thanks to all that contributed, think we all gained something, including how others constructively word & draw to explain concepts so all may understand. Thank-you.

 

[DanMan32]

If I am high enough, I use the distant horizon to judge if I will clear going over an obstacle. Assuming my camera is set at horizontal, If tip of object shows below horizon, I'm good. If above, definitely a problem.
Probably won't work at very high AMSL unless horizon is also high AMSL.

 

[danny lewis]

I sure don't what to be responsible for bringing down an aircraft

 

[Roamer105]

I take it from your comment that where you live is fairly flat?
Where I live, if I didn't temporarily go over 400 feet then I would crash into a cliff face!
E.G. _O7A0938

AGL - of course you can climb legally well above 400 feet when the ground increases in elevation (above ground level).

 

[wolf~928]

[emoji106]

 

[jwmcgrath]

After further consideration, and 8 pages of answers, and because I need to distract myself from the new Canadian regulations, there actually is one, simple, black and while, yes or no answer to this question and it's printed right in the specs:

Mechanically, how high can you go?

6,000m in optimal conditions, with a starting point at sea level.

The math:

Maximum service ceiling, the point at which there is insufficient air for the propellers to to provide lift, 6,000m.
Battery life: 25min.
Maximum ascension rate: 5m/s
Maximum achievable altitude in 25min @ 5m/s: 7,500m

But since lift is lost at 6,000m, then 6,000m is the maximum limit.

Unfortunately it would take 20 minutes to achieve 6,000 at 5m/s and another 33 minutes to descend at a maximum descent rate of 3m/s so the battery would expire long before a safe landing.

I understand the argument has been made that maybe you could do a CSC to stop the motors and maybe restart in time to regain control for a landing, but that wasn't the question.

This is all assuming there is a way to override the firmware limit of 500m, but again the question was "mechanically".

Most of these answers are in here but I had a moment of boredom and stuck it all together.

 

[wolf~928]

Lol, that's fantastic info,great mAth ,,I like the way you think,,maybe you could deploy a parachute?

 

[neven]

After further consideration, and 8 pages of answers, and because I need to distract myself from the new Canadian regulations, there actually is one, simple, black and while, yes or no answer to this question and it's printed right in the specs:

Mechanically, how high can you go?

6,000m in optimal conditions, with a starting point at sea level.

The math:

Maximum service ceiling, the point at which there is insufficient air for the propellers to to provide lift, 6,000m.
Battery life: 25min.
Maximum ascension rate: 5m/s
Maximum achievable altitude in 25min @ 5m/s: 7,500m

But since lift is lost at 6,000m, then 6,000m is the maximum limit.

Unfortunately it would take 20 minutes to achieve 6,000 at 5m/s and another 33 minutes to descend at a maximum descent rate of 3m/s so the battery would expire long before a safe landing.

I understand the argument has been made that maybe you could do a CSC to stop the motors and maybe restart in time to regain control for a landing, but that wasn't the question.

This is all assuming there is a way to override the firmware limit of 500m, but again the question was "mechanically".

Most of these answers are in here but I had a moment of boredom and stuck it all together.

Here. Max altitude, no crash and not braking any rules.

 

[jwmcgrath]

Here. Max altitude, no crash and not braking any rules.

Perfect!!

(Unless you are in Canada and there is a bird or mountain goat within 75m) [emoji848]

 

[jwmcgrath]

Here. Max altitude, no crash and not braking any rules.

And I especially like your drawing program. Is that in the App Store?!

 

[neven]

And I especially like your drawing program. Is that in the App Store?!

It was on App store but sold out. Obviously why.