Hi all,

Drone noob here. Just bought my first mavic pro for a trip. I know it's rated for 27 min flight time, just wondered if anyone had experience of flying at higher altitudes around 3000-3500m. How was the flight time affected if at all?

Thanks!

At that altitude you are looking at around 5 minutes less than at sea level, the air is of course thinner at that altitude so the motors spin a little faster to compensate....

MP can fly up to 6,000m ASL but yeah, thinner air means greater RPM on the motor output and you'll see a much shorter flight time. The flight time at normal altitudes is around 21-23 minutes depending on wind speeds and flight modes so at that altitude you'll be looking at around 15-18 minutes.
Drone police: before getting twitchy - this is about the highest take off altitudes above sea level - not flying 2 miles above the ground...

Don't do it, you will be in Class A airspace, remember if for some reason the AC failed and came crashing down to earth the authorities could learn all about you and your flight with the onboard black box data.

Hi. Thank you for purchasing a DJI Mavic Pro. I understand that you are interested to know how long will the battery last on a high altitude flight. Normally the max flight time of the Mavic Pro is 27 minutes (no wind at a consistent 15.5 mph ), the max hovering time is 24 minutes (no wind) and the overall flight time is 21 minutes ( In normal flight, 15% remaining battery level ). The higher the altitude the lesser the time you can use the Mavic Pro because of the thin air so the motors of the drone will work double and will consume a bigger amount of battery life.

Ive flown at 2500m a fair bit and cant say ive noticed any real difference in flight time or performance at all provided its not windy.
Yes the air is less dense but im not sure it makes any real world difference at that pressure altitude.

QuadKid Posted at 2018-6-19 05:01
Don't do it, you will be in Class A airspace, remember if for some reason the AC failed and came crashing down to earth the authorities could learn all about you and your flight with the onboard black box data.

??????????????????????????????????  Say what ?????????????????

A CW Posted at 2018-6-19 04:58
MP can fly up to 6,000m ASL but yeah, thinner air means greater RPM on the motor output and you'll see a much shorter flight time. The flight time at normal altitudes is around 21-23 minutes depending on wind speeds and flight modes so at that altitude you'll be looking at around 15-18 minutes.
Drone police: before getting twitchy - this is about the highest take off altitudes above sea level - not flying 2 miles above the ground...

My very first thought when I saw the title was "what the heck??  DON'T DO IT"

Then I read the actual question.  Realized OP was talking about taking off from that altitude and asking about the difference in the air.  Glad I didn't just pop off an answer!!  

Also really glad to know that it will make that big of a difference.  

Is it the same difference when flying in the winter vs flying in the summer?

3-D Posted at 2018-6-19 09:35
My very first thought when I saw the title was "what the heck??  DON'T DO IT"

Then I read the actual question.  Realized OP was talking about taking off from that altitude and asking about the difference in the air.  Glad I didn't just pop off an answer!!  

Kind of - it is all to do with the motor RPM in thinner atmospheres whereas temperature conditions affect the battery more.

Elevation vs Altitude            

AG0N-Gary Posted at 2018-6-19 09:49
Elevation vs Altitude

big difference in words

Griffith Posted at 2018-6-19 08:59
??????????????????????????????????  Say what ?????????????????

Ok, misunderstood the OP Post, thought he was talking about flying to, not flying from.

Triggered! lol I think the main consideration is that wind increases with altitude, and wind-shear especially around mountain ridges.

Thanks for replies. And sorry for confusion on wording! Yes I meant elevation not altitude. As I said I'm a noob!! If I can get 20 min per battery I'll be happy. 15 min still usable. Fingers crossed.

Temperature also make different. Higher temperature the air is thinner like high ground. It’s also possible over heat if you fly longer. My MA battery get close to 60 degrees C after 12 minuets flight. Temperature will go higher if flight longer.

At 3500m the temperature can be lower. You need to keep battery warm if too cold at there.

If I’m going to guess tempature has a biggest impact on flight time and performance.   

Alt/Elv defiantly plays a role in impacting things however I don’t think you will notice much difference in performance up at 3000m vs sea level.   Maybe 5% I heard it’s really not as bad as it’s been made out to be I live in the mounts, albeit I’m only up between 1200 feet and 1600 feet and 1600 feet is like just under 500meters, but I notice no difference between that and at the beach off the coastline.. and you would think you would notice some change at 500m up vs 0.


But on a day that is like 40c or 104F you will notice a drop in battery life compared to a crisp day at 18C or like 65F.

HereForTheBeer Posted at 2018-6-19 19:22
If I’m going to guess tempature has a biggest impact on flight time and performance.   

Alt/Elv defiantly plays a role in impacting things however I don’t think you will notice much difference in performance up at 3000m vs sea level.   Maybe 5% I heard it’s really not as bad as it’s been made out to be I live in the mounts, albeit I’m only up between 1200 feet and 1600 feet and 1600 feet is like just under 500meters, but I notice no difference between that and at the beach off the coastline.. and you would think you would notice some change at 500m up vs 0.

''I don’t think you will notice much difference in performance up at 3000m''

I think I can confirm that from my last hike in the alps. Also with a takeoff at more than 3000m I did not notice any difference to my other flights (I live at an altitude of about 100m above sea level). I think there is a difference because it would be logical, but it is so small that it is not noticeable if you do not pay attention to it or really test it out. On the summit of Mt. Everest it would probably be something else.

HereForTheBeer Posted at 2018-6-19 19:22
If I’m going to guess tempature has a biggest impact on flight time and performance.   

Alt/Elv defiantly plays a role in impacting things however I don’t think you will notice much difference in performance up at 3000m vs sea level.   Maybe 5% I heard it’s really not as bad as it’s been made out to be I live in the mounts, albeit I’m only up between 1200 feet and 1600 feet and 1600 feet is like just under 500meters, but I notice no difference between that and at the beach off the coastline.. and you would think you would notice some change at

This is how it works.https://translate.google.is/translate?hl=is&sl=en&tl=is&u=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FAtmospheric_pressure&anno=2

G_Sig Posted at 2018-6-19 20:08
[view_image]This is how it works.https://translate.google.is/translate?hl=is&sl=en&tl=is&u=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FAtmospheric_pressure&anno=2

This is what it should have looked.

G_Sig Posted at 2018-6-19 20:25
This is what it should have looked.
[view_image]

i could be wrong, but i do know the drones are more like helicopters not so much like airplanes... but drones have props on each corner so probably even more effective at generating lift than a helicopter.  and airplanes are differant and this pressure stuff matters more when it comes to lift and stability with airplanes vs copters..

QuadKid Posted at 2018-6-19 10:00
Ok, misunderstood the OP Post, thought he was talking about flying to, not flying from.

I think everyone who read the subject header at first glance had a mixed understanding. This thread has taken a high level discussion and I would say it's helpful for everyone to conceptualize the difference of the Mavic Pro flying in higher altitude versus near ground level. As I said very useful thread developing here.

HereForTheBeer Posted at 2018-6-19 21:00
i could be wrong, but i do know the drones are more like helicopters not so much like airplanes... but drones have props on each corner so probably even more effective at generating lift than a helicopter.  and airplanes are differant and this pressure stuff matters more when it comes to lift and stability with airplanes vs copters..

"pressure stuff" is no different fixed wing to rotary wing.
A helicopter/quad rotor blade is nothing more than a wing that spins round.
Given the mavic probably produces near zero lift from aerodynamics at all the spinning wing is everything.

Note also in any flight duration calculations that higher altitude = cooler, thinner air = less drag on blades  (but also airframe too).  
Similarly, sea-level flight on a hot day in humid air will also have some aerodynamic effect on the aircraft, and hence flight duration.

I suspect all the manufacturer's duration benchmarks were set at sea-level, 30 degree's C, and 80% humidity. Shanghai or Shenzen on a summer's day.

I believe the standard flight time is based on Shenzhen weather where DJI located.

sanuk Posted at 2018-6-20 02:11
Note also in any flight duration calculations that higher altitude = cooler, thinner air = less drag on blades  (but also airframe too).  
Similarly, sea-level flight on a hot day in humid air will also have some aerodynamic effect on the aircraft, and hence flight duration.

"Note also in any flight duration calculations that higher altitude = cooler, thinner air = less drag on blades"

I believe you just said (or implied) that cooler air is thinner than warmer air. This is a common misunderstanding. Actually cold air is heavier and denser than warm air. http://www.weatherdudes.com/facts_display.php?fact_id=51.

It's true that drones must work harder in less dense air than in more dense air, and therefore less dense air will cause reduced battery time. In fact, drone's can't even fly in a vacuum (the ultimate version of "less dense" air), as you can see here:
There are three factors which affect air density:

1. Altitude
2. Temperature
3. Humidity

Increasing altitude decreases density, but also decreases temperature which *increases* density. That is, cooler air is more dense than warmer air. In addition, drier air is *more* dense than humid air (contrary to common sense). I think you must take all three factors in to account when modeling battery life based on air density.

So you will get your maximum flight time at sea level in cold, dry conditions. You will get minimum flight time at higher altitudes, with warmer, humid conditions (although that combination is not very common).

All that said, ambient temperature also directly affects how much charge a battery can hold. For example, at 40°C (104°F), you can get a loss of 40% of available charge. Batteries are affected even more by lower temperatures. At –20°C (–4°F), most batteries are at a 50% performance level. You'll get your optimum life at around 20°C (68°F) .

So, if you're 3 kilometers up a mountain and the temperature is really cold, possibly the direct affect of the temperature on the battery will be more significant than the decreased air density due to elevation and also more significant than the increased air density due to the lower temperature, and the effect of humidity would be insignificant by comparison. Or not. It depends on the details.

Danger Lampost Posted at 2018-6-20 10:49
It's true that drones must work harder in less dense air than in more dense air, and therefore less dense air will cause reduced battery time. There are three factors which affect air density:

1. Altitude

Great reply. Thanks for correcting my assumptions.

Good information and logic. A LOT of parameters clearly need to go into the mix when assessing likely flight-times at any altitude.

Forget about 3500m, how about 8,400m! Wow, that seems amazing. Is this really true? https://dronedj.com/2018/07/16/d ... or-27600-feet-high/