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ALTA 6, EPIC, and 9000 ft...

Discussion in 'ALTA' started by Josh Lambeth, May 30, 2016.

  1. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Hey guys,
    I have a job request for a shoot which would require flying an epic at 9,000ft. Air temps will be about 25*C. Think the ALTA will do it even for a short amount of time? Anyone with experience at these higher altitudes, please comment. Thanks. Total takeoff weight will be right at 30lbs.

    Josh
     
  2. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Okay this won't be happening. Just calculated the density altitude with current weather conditions and it's almost 11,200ft! To big of a risk even with our X8... Thinking about trying to buy an Inpsire 1 x5R and see if they will go for that.

    Josh
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Yeah, Josh, up there is quite thin!

    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
     
  4. Thai Christen

    Thai Christen Member

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    You can do it with the right X8 setup.
    Last December I flew for CBS in the Mont Blanc French Alps at 3500m (11500 feet) AND minus 20 Degree Celsius. No problem for my X8 and Wookong FC. Important is to choose right motor (low Kv) / props combination (high pitch) and constantly watch out battery voltage of your lipo. Flight time is cut to 50% from flying at sea level. And keep your lipos in a lipo heater. Only take them out shortly before take off.

    Good luck!

    Thai
     
    #4 Thai Christen, May 30, 2016
    Last edited: May 31, 2016
  5. Thai Christen

    Thai Christen Member

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    Oh, one more thing.
    At 11500 feet, YOU will be fighting with the thin air too. Be prepared, some people get headache. Everything is kinda slomotion at this altitude. It helps if you have a good body condition.

    And gees, plus at minus 20 degree celsius, our SmallHD Monitors started flickering and wont work until we heated them up with our breath and heat pads. Your fingers will freeze within 2 minutes, velcro and tapes will detached on their own due to the extreme cold. It was quite an experience.
     
    #5 Thai Christen, May 30, 2016
    Last edited: May 31, 2016
    alex ryan likes this.
  6. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Our problem is it's going to be +25*C at 9000ft which puts our density altitude at 11,200ft. My x8 rig just won't fly that without issues.
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Where on earth (literally) does it get to be +25C at 9000 feet, Josh?

    Andy
     
  8. Gary Haynes

    Gary Haynes Administrator
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    Rocky Mountain national park, Pikes Peak, summer days when Denver is baking at the occasional 40c. I imagine AZ is worse in their mountains.
     
  9. Thai Christen

    Thai Christen Member

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    I am sure with the right setup, it is doable.
    I recall when we flew later the day at noon with full sun, temperature rose from -20C (early morning) to -7C, my X8 flew even better (same altitude 11500ft). So I assume, with warmer temperature (air less densed) at the same altitude it only gets easier. But I could be wrong.

    If you have a chance, go there for test first (or arrive at least 1-2 days earlier than shoot schedule).
    Lift your copter about 5m and see how it behaves. If it wobbles a lot, land and adjust your gain. Start again, same proceedure and slowly get to a point where you feel comfortable. Even if it wobbles, its ok. DONT panik. Land and adjust.

    Thai
     
  10. Ozkan Erden

    Ozkan Erden Distributor

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    It's the opposite. Warmer, it gets harder.
     
  11. alex ryan

    alex ryan Member

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    Maybe in -20c temps the batteries weren't working at full efficiency? Maybe that's why you felt it was doing better at -7c? It is strange that it was performing better in warmer conditions. That's the only reason I could think of. What do others think of my hypothesis? I've never flown in extreme low temps so am interested in how it effects performance.
     
  12. Ozkan Erden

    Ozkan Erden Distributor

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    You are right about the batteries. The flight tiime would reduce if batteries aren't kept warm. Even more, most of the electronics are not rated to work under -20C degrees. The batteries and hands should be kept warm as much as possible :)
     
  13. Thai Christen

    Thai Christen Member

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    I know that it is the opposite. However, this thesis might not apply to extreme cold condition below 0C. I dont know.
    But for sure, at -20C AND 11500ft everything is not ideal, lipos, electronics, monitors, gaffer tapes, velcro, your hands etc. I can go on with the list.
    If you ask me, I am less concerned flying at 11500 and 25C than flying at 11500 -25C.
    Even if you wear gloves - and believe me - I slipped heat pads under my gloves - still, after 3min I had to land. Couldnt do any longer. (Ok I admit that my gloves were just thick enough that I could still feel the sticks).

    I remember the DP of the show, he operated a Sony F55 and Fujinon Zoom lens - bare handed. You could hear him shouting screaming every once and then because his fingers froze.

    So later the day when temperature rose with the bright sun, it made a huge difference. More flight time and copter behaved similar like flying at sea level (still below 0C though).
    This might sound weird, but this is what I remember. Or maybe after this extreme cold everything seemed so easy suddently - still challenging, but less ;-)
     
    #13 Thai Christen, Jun 1, 2016
    Last edited: Jun 1, 2016
  14. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    The Inspire would struggle too.... I recently gave up a job in Bogota Colombia for those reasons they wanted Alta6 + Epic (9,350 feet, 2,850m) even at 17ºc the FF chart shows maximum AUW of 9.6Kg
    rig AUW is 12.5kg thats 3 big kilos
     
    #14 Jose Luis Ocejo, Jun 2, 2016
    Last edited: Jun 2, 2016
  15. Guillaume MARION

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    Flown 2month ago in Himalay up to 3900m with 20°/25°.

    Set up was ALTA 6 + M5 + A7S2 + METABONE + ZEISS 21.

    7"30 with 2x4500, total weight 10,1kg
     
  16. Thai Christen

    Thai Christen Member

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    Hey Guillaume

    Have you also flown at this altitude AND -20C with this setup? I am curious to know your experience.
    Just for comparison, with my custom X8 15/16 mix props and 2x4500 lipo I get at 3500m and -20C

    4" with M5, GH4, Metabone and Leica-R 24 cinemod lens (total weight approx. 9kg)
    3" with M5, Red Weapon with Jetpack and Leica-R 24 cinemod lens (total weight approx. 10.2kg)
    Safe, so basically I could have pushed for another 30-60s but didn't want to take the risk though.
    Lipos were kept in Pelicase with heat pads but were completely cold when it was our call time.

    If you plan and coordinate your shot carefully, 3-4" is still enough. And your fingers will freeze after 3" which will force you to land anyway.

    Thai
     
    #16 Thai Christen, Jun 13, 2016
    Last edited: Jun 13, 2016

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