ALTA 8 At High Altitude

Discussion in 'ALTA 8' started by Tom Comet, Aug 28, 2019.

  1. Tom Comet

    Tom Comet Member

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    Hello All. I have a gig coming up where we need to fly really, REALLY high. Think 20,000' +. Obviously this won't be happening with a stock A8 as the performance tables stop at 10,000' and, even there we loose 10lbs of carrying capacity. I did a search and found some info on high altitude props but not much in the way of real world results. How high can I really operate an A8 with the HA props? Obviously minimal payloads, lightest batts possible and HA props. Are there any other mods that will make our chances of success better??
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Whoa! That is reallly high, Tom. Gotta ask where?

    I've not heard of anyone operating that high -- you'll be breathing oxygen at that level. I've flown the sailplane up I used to own up to 22 grand, but it is really cold up there too.

    Cheers
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  3. Jason Smoker

    Jason Smoker Active Member

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    you flying on Everest? thats crazy high? you be better off asking Freefly send them a email then post a reply on here to keep everybody on the loop!
     
  4. Tom Comet

    Tom Comet Member

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    We will be flying all around the Himalaya and the Everest area. We have reached out to Freefly and they had very little comment on flights above 10'000' and suggested I try the forums. Hoping I can get a hold of someone with some real world experience. That being said, we are flying Inspire2s up high as well. Not a Freefly thing but any word there would be appreciated also.
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Tom:
    Check out this table of atmospheric data: https://www.engineeringtoolbox.com/standard-atmosphere-d_604.html
    The air at 20,000 is considerably less dense and less viscous so the first thing I would be concerned about is whether the props will generate enough lift to carry the payload and/or the aircraft itself.

    You might be better off to contact some of the universities who teach aerodynamics or perhaps even NASA (there is on-going research for using multi-rotor copters on Mars which also has an extremely thin atmosphere.

    The FAA has also published data on helicopter performance: https://www.faa.gov/regulations_pol...helicopter_flying_handbook/media/hfh_ch07.pdf

    Hope this helps.
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Tom: Contact Larry Young at NASA Ames Research. He's leading the team creating a helicopter to fly on Mars.
    https://nari.arc.nasa.gov/young
    The article from I got his name is here: https://www.airspacemag.com/space/helicopter-dreams-of-mars-180971739/

    I've got to believe that either he knows some answers for you or can direct you to someone who does.
    Cheers
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  7. Tom Comet

    Tom Comet Member

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    If anyone would know that would probably be the guy...

    TC
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    One other problem you may have, Tom, is keeping the LiPos warm before you use them. When they get cold they tend not to give back as much charge as when they're warm. Of course, once you've flown a pair of them, then you can use them as Lipo Warmers® for the others.

    Cheers
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  9. Tom Comet

    Tom Comet Member

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    We are based in Canada so I have a lot of experience with COLD weather OPs. We have found that Batts charge very poorly in the cold as well. They appear full but that is not always the case. Planning on lots of warming strategies for sure.
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    In which case take two cases of beer: 1) Péché Mortel and 2) Lucky Lager. Keep the Lucky Lager very warm and surround the LiPos with it.

    The Péché Mortel? That should be kept cold. It's for drinking, eh?

    Cheers
    Andy
     

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