Density Altitude and Flight Times

[GregD]

Very good discussion so far. My point is asking the original question was not to understand the concepts that are involved in determining the DA. But more to understand if changing locations/altitude would really have that much bearing on battery life.

For instance, when I fly at home my RTH point altitude is approx. 2,600 MSL and at times I fly where the RTH is 885 MSL and just above MSL on the coast. I am curious if those changes will need to be considered when planning missions. My thought is that the change may not be enough to worry about.

I have also been using an iOS app “AutoDens” that has shown over the last two weeks how much can change at a given location.

 

[Weaponized]

Very good discussion so far. My point is asking the original question was not to understand the concepts that are involved in determining the DA. But more to understand if changing locations/altitude would really have that much bearing on battery life.

For instance, when I fly at home my RTH point altitude is approx. 2,600 MSL and at times I fly where the RTH is 885 MSL and just above MSL on the coast. I am curious if those changes will need to be considered when planning missions. My thought is that the change may not be enough to worry about.

I have also been using an iOS app “AutoDens” that has shown over the last two weeks how much can change at a given location.

I would think the difference would be marginal. If you were 2 of you average flight time between a bird flown at sea level in one let's say flown in Denver I doubt you'd see more than a minute or 2 of difference in battery life.

 

[747P4]

I would think the difference would be marginal. If you were 2 of you average flight time between a bird flown at sea level in one let's say flown in Denver I doubt you'd see more than a minute or 2 of difference in battery life.

I would agree with you on your comments. DJI probably did some analysis of altitudes to come up with an "average" battery life. I think OAT (outside air temperature) probably affects battery operations (as we already know) more so than altitude changes (not Flight levels).

 

[tcope]

I usually fly around 3000 - 4500' ASL. I've also flown at 9000 - 9500' ASL and there is not much difference in flight time. I'd say, perhaps 30 seconds or so.

 

[747P4]

I usually fly around 3000 - 4500' ASL. I've also flown at 9000 - 9500' ASL and there is not much difference in flight time. I'd say, perhaps 30 seconds or so.

Interesting

 

[sdold]

I'm interested in this because my drones sometimes carry payloads, and since the props need to spin faster at higher D/A I assume the "service ceiling" will be reduced at some maximum rpm, probably with some control issues.

I also wonder about the battery life. At high D/A the props need to turn faster, so frictional losses would be higher, but that might not be enough to matter. Looking forward to some data. I'll be taking mine close to 10,000 feet next week, I'll try to do some flying.