I was quite surprised to see a quadcopter flying that high! It was done by Денис Корякин as shown on his youtube channel.
Specs:
Receiver: TrueRC 5.8GHz X²-AIR Antenna RHCP
FPV glasses: Furious True-D V3.5 Diversity Receiver System
Video transmission: Antenna FOXEER Thor 60mm RHCP / SMA PA1331
RC link: TBS CROSSFIRE
Motors: Cobra CM2206 / 1400
ESC: T-Motor f30a PC: Matek: f405-AIO
Propellers: Gemfan 7038
Battery: Assembling Li-ion 4s3p
Weight: 1.06kg
Interestingly, we can estimate the amount of energy spent to go that high and compare it to battery use. A quick estimate is 1.1kg * 10000m * 9.8m/s/s = 110 000 J (gravity energy), and 14V * 6Ah = 300 000 J (electrical energy). This is just above 30% of the maximum theoretical efficiency if there was no aerodynamic losses. The flight up was 17 minutes. You have to balance how fast you go up. Too fast and the aerodynamic losses are high. Too slow and you spend too much time hovering. For rockets, the optimal speed is about the free fall terminal velocity. That would seem to indicate that he could go higher by going a bit faster.
Another potential problem is motor overheating. I don't have much experience with motors that high, but the low air density can make cooling difficult.
Although those records are fun, there is a regulatory challenge associated with them. 10 km is about the height of airplanes, so you need clearance from ATC.
Have you flown higher?
Comments
Ravi is not right. Propeller aircraft can go to 50000 feet. Google Grob G520 if you don't believe me.
They also will show a cruise quad with nuclear power plant and unlimited range.
Russians fake news...
Sorry, forgot link: https://www.youtube.com/watch?v=yi6tBl4AAiY
Here's a video with more build details. Ravi is correct, this is truly remarkable and defies all logic.
I've been to 4.1km with fixed wing FPV and I can tell you the props really lose bite up there. Also, most GPSes don't work over 3km altitude. Typical baros on FCs at very low pressures are almost useless.
propeller aircrafts have problem above 4000 meters because the air density decreases rapidly.
Thrust is proportional to air density. Air density is exponentially lower with altitude. This means that the propellers will spin faster at higher altitude. Consequently, the limit is probably how fast your propellers can spin. You need to find a motor that can support the low speed, high torque of low altitude, and high speed, low torque of high altitude. The propeller has to be very well balance and strong enough to support very high speeds. High speed propellers are much less efficient. There is quite a bit of optimization to do. I do not think there is a single limit, but many ceilings could be established based on energy density and material strength.
it is not that I do not believe it. but flying a small quad at 10000 meters defies all logics
1. The baro would fail (a correction has to be applied)
2. the gyros would fail (-48 (deg)
3. the batteries should fail (-48 deg)
4. The RC has a poor vertical polarization.
if this is true NASA would envy this quad.
by the way which FC are you using.
and CONGRATULATIONS! this is remarkable.
Does anyone know if there is a theoretical limit to how high a aircraft of this type can go (i.e. jet engine vs propeller)? The air gets thinner the higher you go, so there must be some point where the aircraft could not propel itself further up, no?