Flying in higher elevations

Steve Brame · Oct 18, 2016

I'm about to head to NM, and the area I'll be flying my P4 is 6500' elevation. Are there any precautions to be had when flying at higher elevations? I know from my fixed wing days that higher elevations means thinner air, which adds a new dynamic.

Meta4 · Oct 18, 2016

Steve Brame said:
I'm about to head to NM, and the area I'll be flying my P4 is 6500' elevation. Are there any precautions to be had when flying at higher elevations? I know from my fixed wing days that higher elevations means thinner air, which adds a new dynamic.

6500 ft isn't a problem for a Phantom ... they can go to 6000 metres.

ftttu · Oct 18, 2016

I flew in New Mexico recently at over 8,000' with no problems.

Sky Pirate · Oct 18, 2016

Basically (without going to deep) fixed wing flying in thinner air (higher altitude above sea level) needs more speed of the air passing over the aerofoil for the fixed wing to effectively create similar amount lift to that at a lower altitude (more dense air). However with rotary wings its is simply overcome by the fact that the "wings" to create the lift are spinning (rotors/propellers) to create that lift, they just rotate a bit faster when required (controlled by the brains of the P4).

techmyjustin · Oct 18, 2016

This flight was over 10,000'

tcope · Oct 18, 2016

Only issue would be 1) slightly shorter flight times and 2) need to monitor the temps of the batteries this time of year.

I've flown at 8500' many times with only minimal reduction in flight time (I'd say 18 minutes down to 16). Only at 10,500' do I notice a significant decrease (I'd guess at 18 minutes down to 14 or 13).

At 8000' or even 10,500 feet I did not notice any difference in the handling of the Phantom.

I'd recommend planning on getting back to home point around 40% instead of 30%.

Thinking about your location, it should still be pretty warm at 6000'.

Patrick · Oct 18, 2016

Steve Brame said:
I'm about to head to NM, and the area I'll be flying my P4 is 6500' elevation. Are there any precautions to be had when flying at higher elevations? I know from my fixed wing days that higher elevations means thinner air, which adds a new dynamic.

Here in albuquerque, I personally havent noticed any difference if im flying at my typical launch point @ 5,237 ft or if im up in the mountains @ ~10,000 ft

Steve Brame · Oct 18, 2016

Sky Pirate said:
Basically (without going to deep) fixed wing flying in thinner air (higher altitude above sea level) needs more speed of the air passing over the aerofoil for the fixed wing to effectively create similar amount lift to that at a lower altitude (more dense air). However with rotary wings its is simply overcome by the fact that the "wings" to create the lift are spinning (rotors/propellers) to create that lift, they just rotate a bit faster when required (controlled by the brains of the P4).

You'd think having been a pilot that I could have figured that out.
Thanks!!

Steve Brame · Oct 18, 2016

tcope said:
Only issue would be 1) slightly shorter flight times and 2) need to monitor the temps of the batteries this time of year.

I've flown at 8500' many times with only minimal reduction in flight time (I'd say 18 minutes down to 16). Only at 10,500' do I notice a significant decrease (I'd guess at 18 minutes down to 14 or 13).

At 8000' or even 10,500 feet I did not notice any difference in the handling of the Phantom.

I'd recommend planning on getting back to home point around 40% instead of 30%.

Thinking about your location, it should still be pretty warm at 6000'.

Yeah, daytime highs should be in the low 70's, so temps hopefully won't be an issue. Thanks!

jlrsn · Oct 18, 2016

I just arrived to the SF Bay Area and I've never flown my P4 or P3P at less than 8,000 ASL and regularly fly up though 12,000 ASL. I live most of the year up in the North Central NM San Juan Range of the Rocky Mountains right up against the Colorado/NM Border. Battery times are a little shorter averaging about 16 minutes for my P3P and about 20 minutes for my P4. Right now the Aspen Trees up in the Cumbres Pass are bight yellow and the Steam Train carrying tourists from Chama, NM to Antonito, CO through the 12,000' ASL Cumbres Pass puffing black smoke makes great videos. I can't wait to see how my Phantoms fly at Sea Level.

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John Locke · Oct 20, 2016

Yesterday I flew Colorado's independence pass at 12,095', climbed up a neighboring mountain up to 12,800 with gusts beyond 40mph. She flew amazingly well, considering the wind. However it did warn me a couple times that maximum rpm was reached. I had never seen that before, even at loveland pass @ 12,000' last year. Although loveland was also windy last year, independence pass was worse yesterday, likely the reason for the high rpm warming. It happened two times, both while ascending in the thin air.

Guys if you ever get a chance to drive from Aspen, Colorado , driving East on Hwy 82 over Independence pass in the late September to early October timeframe, DO IT!. Oh man, the Aspen tree color is crazy beautiful. The road is narrow, but not too bad. Nothing over 35' long allowed.
View attachment 67470

QuadBart · Oct 20, 2016

40 mph winds?!?!?!

I was up at Boreas Pass on Saturday, 11,455 ASL with gusting winds in the 20s. And I have to say I didn't let it go downwind very far given the high altitude and high winds. Watching mine fly back to me against the wind it was barely moving (not in sport mode).

But agree, this thing flew really well. You could definitely hear the motors working hard!

John Locke said:
Yesterday I flew Colorado's independence pass at 12,095', climbed up a neighboring mountain up to 12,800 with gusts beyond 40mph. She flew amazingly well, considering the wind. However it did warn me a couple times that maximum rpm was reached. I had never seen that before, even at loveland pass @ 12,000' last year. Although loveland was also windy last year, independence pass was worse yesterday, likely the reason for the high rpm warming. It happened two times, both while ascending in the thin air.

Guys if you ever get a chance to drive from Aspen, Colorado , East to independence pass in the late September to early October timeframe, DO IT!. Oh man, the Aspen tree color is crazy beautiful. The road is narrow, but not too bad. Nothing over 35' long allowed.
View attachment 67470

Erised · Oct 20, 2016

Patrick said:
Here in albuquerque, I personally havent noticed any difference if im flying at my typical launch point @ 5,237 ft or if im up in the mountains @ ~10,000 ft

Your right Pat, the props will have to turn faster but the the energy needed to generate lift is almost the same, gravity is constant. The loses will be minimal. As for rpm the bearings can take more than the max rpm of the birds props. You will not be able to bank as hard in thinner air. (I wish I could go fly at higher elevations, where I live we have hill and no mountains)

John Locke · Oct 20, 2016

QuadBart said:
40 mph winds?!?!?!
I was up at Boreas Pass on Saturday, 11,455 ASL with gusting winds in the 20s. And I have to say I didn't let it go downwind very far given the high altitude and high winds. Watching mine fly back to me against the wind it was barely moving (not in sport mode).
But agree, this thing flew really well. You could definitely hear the motors working hard!

Hey, you were only about 60miles from Independence pass, as a Phantom flies. Yeah my winds measured about 25mph, but my meter showed gusts of 44 for brief moments on the ground. When I got up a few hundred feet atti mode measured 28mph, but that was a momentary measurement, as I didn't want it to go down wind very far. I was blown away (pun intended) how well she flew.

KB_Colorado · Oct 23, 2016

It sounds like the P4 has better high altitude performance over the P3. I flew my P3 pro a few weeks back neat Guanella pass (Colorado), I was at about 9,000 feet. The motors were definitely working harder, but I also received a message in the DGI App. That stated something like "The P3 performance would be limited" due to,..... it referred to the conditions, there was not a specific error message. I didn't capture the message, wish I had.

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John Locke · Oct 23, 2016

On a P3P that message will appear when the lowest battery cell is 3.6V. This is a reminder your battery is around half gone and it implements a governor to prevent large loads on the battery that could potentially cause problems. P4 doesn't have that because of a more robust battery.

Yesterday I flew the flatirons at Boulder. Man was it windy. I flew anyway and barely made it to the top where climbers were celebrating their climb. My second battery wasn't so lucky, the wind was so strong I couldn't make it to the top again, 1600' higher than launch point, about 6500' away from home, outside the park.

The reason? With no stick input I was doing 19mph and the motors were maxed out at top RPM, over 8000. I decided it was time to come home.

ftttu · Oct 23, 2016

KB_Colorado said:
It sounds like the P4 has better high altitude performance over the P3. I flew my P3 pro a few weeks back neat Guanella pass (Colorado), I was at about 9,000 feet. The motors were definitely working harder, but I also received a message in the DGI App. That stated something like "The P3 performance would be limited" due to,..... it referred to the conditions, there was not a specific error message. I didn't capture the message, wish I had.

Sent from my iPhone using PhantomPilots

All messages should have been recorded in your flight list's flight footage. When I used to get messages during flight, I'd see what they were later while watching the footage.

CactusJackSlade · Oct 23, 2016

12,000 feet at Loveland Pass, Colorado - no problem.... except the wind was howling...

John Locke · Oct 23, 2016

CactusJackSlade said:
12,000 feet at Loveland Pass, Colorado - no problem.... except the wind was howling...

Correct, it's usually blowing pretty good at Loveland pass. However I was there Friday and it's wasn't bad, about 15 to 20mph. I climbed another 1100 ft to the top of another mountain, over 13,000' ASL. My P4 performed amazingly. Then yesterday when I flew the FlatIrons in Boulder, CO it was unusually windy, much more than the other two times I've flown there in the last year. It was howling big-time when I got up around 1000' high while climbing the mountain. With no stick input it was being pushed 19mph and the motors were "red lined" at maximum RPM just trying to stay in a fixed position. I couldn't believe my eyes, I had never seen that happen before so I chickened out and turned around to come home. I did get some decent video though, I'll publish it later.