Starting flights at 5000ft ground level efficiency

[Manny D]

Does anyone know how much a starting altitude of 5000ft will do to the Typhoon H's battery efficiency. Have come mountain shoots coming up.

 

[Eagle's Eye Video]

I live at about 5000 feet here in ABQ... you do have thinner air that forces more work from the props to produce an equal amount of lift. I'm happy to get 10 - 14 minutes, but I have learned from the experts here to not bother chasing the time fairy.

Keep an eye on the ST-16 voltage... allow enough time to head back and land by 14.5V while in a hover. Allow more, if you will be going upwind on your return. It took 45 years, but I finally got something out of geometry... use the hypotenuse and decrease altitude at the same time you are heading back. For a longer shoot bring extra batteries.

 

[Steve Carr]

I finally got something out of geometry... use the hypotenuse and decrease altitude at the same time

Ha....perfect!!!!

 

[Manny D]

Thanks,
Now I just need the wind to stay away.

 

[PatR]

This thread makes me wonder if changes in flight efficiency due to altitude might roughly align, percentage wise, to the standard rate of change for oxygen density with increases/decreases in altitude.

If so it would make efficiency values relatively easy to factor using a pressure altitude reference model.

 

[mr_wes]

New guy here with a first post:
The flight characteristics (including duration) *should* track mostly with density altitude.
Here's a calculator:
Density Altitude Calculator - English/Metric

High, hot and high humidity all make flying harder.

I'm sure battery starting temperature will be a factor as well, but I'm not sure how much that will change things compared to the density altitude. I know density altitude has a direct and significant effect.

-Wes

 

[AH-1G]

don't forget about density altitude affecting your lift, requires more power

 

[WaterMainMan]

Thanks,
Now I just need the wind to stay away.

Yeah I hear that. I'm in Brighton, CO. We also have the high plains winds here. I've always flown in this environment so I don't guess that I would know what kind of performance one gets at or near sea level. I was in Alamogordo about ten days ago. The wind and dust reminded me of why we moved to CO about 50 years ago. Other than the wind, I do like NM however.

 

[FlushVision]

New guy here with a first post:
The flight characteristics (including duration) *should* track mostly with density altitude.
Here's a calculator:
Density Altitude Calculator - English/Metric

High, hot and high humidity all make flying harder.

I'm sure battery starting temperature will be a factor as well, but I'm not sure how much that will change things compared to the density altitude. I know density altitude has a direct and significant effect.

-Wes

Battery starting temperatures can be a significant factor. Progressively reducing flight times the colder the batteries are. It isn't uncommon for pilots to lose up to 10 minutes of lying time from that experienced in summer temperatures. A couple of pilots on this forum have even reported flight times measured in just seconds getting a low battery warning right after take-off!