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Posts posted by coticj

  1. @mdrejhon You keep mentioning massive fuel cost savings. A typical caravan has (the ones we operated) had a fuel burn of 60-70L of Jet A1 per load. Current fuel price my country is 0.41€ per L. This comes to 1.85€ of fuel per person. Sure, the electricity is 4 or more times cheaper. But saving 1.4€ per ticket in a ticket that costs 30€ doesn't seem much.

    And for the fast charging that you are mentioning. The power consumption would be the same as for a wind tunnel, meaning huge infrastructure investments and massive electricity bills (I don't know if it is the same in US, but in my country the power company charges you for the power you use and the "available power" - for example household 7kw supply costs 5€ monthly and 21kw costs 25€).

    I don't think conversions are the way to go. Most (non Tesla) car manufacturers tried with converting existing models, but all of them found that it is just better to start from scratch.

    Lastly you keep mentioning the batteries that would be needed for a load + 30min reserve. What kind of battery do you think this would need?



  2. Well the longest flight they did was 3min. And for passenger service you don't need constant full power, like you do for skydiving.

    You can check the data avaliable for Pipistrel Alpha Electro:

    And then get a sense of what they are getting - but basically they have a 22 kWh battery pack + a 60kW motor and mentioning up to 1h endurance. Then when you read into it, they say up to 45min minutes with cruise at 18kW power.

    And the same is with the Beaver.

  3. 7 hours ago, aonsquared said:

    I would very much like to know where you get fuel that weighs that would be a bigger game-changer than electric :P

    In any case, here are the official weights from the Cessna website for the Turbo Stationair HD Cargo:

    Maximum Ramp Weight     3,806 lb (1,726 kg)
    Maximum Takeoff Weight     3,789 lb (1,719 kg)
    Maximum Landing Weight     3,600 lb (1,633 kg)
    Usable Fuel Weight     522 lb (237 kg)
    Usable Fuel Volume     87 gal (329 l)
    Basic Empty Weight     2,212 lb (1,003 kg)
    Useful Load     1,594 lb (723 kg)
    Maximum Payload     1,388 lb (630 kg)
    Full Fuel Payload     1,072 lb (486 kg)

    You won't really lose that much payload with electric, and they're just getting started :)

    Why does the fuel weight really matter? Based on the data you gave the numbers aren't that much different.

    Empty plane 1003kg, max landing weight 1633. You then have 630kg available. When you calculate the engine weight saving you have extra 148kg available. This means total 778kg.

    Batteries weigh 600kg, so that gives you 178kg available for passengers and pilot.

    "NASA batteries" isn't really a thing yet and it is not going to be for a few decades, and when it comes it is going to be super expensive.

    Even if they are not using standard production batteries they are not getting much better energy density the Tesla packs have.


  4. It is still useless for skydiving and it is going to remain such for a long time. As previously mentioned, you would need a 100kWh battery pack to get a load with a 206 up. The most advanced battery pack on the market currently (the one found in Tesla M3) weighs 168 Wh/kg. So a 100kWh battery pack weighs about 600kg. The one that would be made specifically for a plane wouldn't have such density, but lets ignore that.

    A C206 has a max payload of around 650kg.

    You will get some weight saving with the engine which is only 72kg as opposed to the 220kg of the IO520.

    So with the engine weight saving you would get around 200kg of usable payload. So a pilot and 2 very light skydivers.

    The Caravan would get you slightly better results, but still unusable for a real operation. The are mentioning 105 miles of range - yeah, but at a very low power setting, in cruise.


  5. 15 hours ago, gowlerk said:

    UPSA licenses are internationally recognized FAI documents. FAI does not issue licenses itself except sporting licenses for competition. Some National Associations are touchy about USPA or other foreign credentials when they are issued to their own Nationals. They should recognize your USPA issued FAI credentials if you are a US resident. But they may still require you to purchase a membership. If you look at you USPA license you should see some mention of the FAI printed on it. 

    They will recognize USPA for everybody, except for Austrian nationals. Austrian nationals need to have national licenses. It is probably the same in all EU countries - if you are a national, you need to have the national license.

    However FAI does indeed issue normal licenses (and not just sporting licenses). You can get the documents here:

  6. I jumped it the last couple of days. At first I was sceptical if I would actually hear or understand what it is telling me, but it is super clear. I still had an audible in my helmet, but with Vog telling me altitudes every 100 ft I didn't really need it.

  7. Does it only use 2g network? I think 2g switch-off is in plan over the whole world in a couple of years. Otherwise in Europe it should be fine...I can't remeber a dropzone that would have bad reception, even the ones in the middle of nowhere and in mountain valleys.

    How about using your own sim? There ares services available that offer 1mb of data per month free. For example this:

  8. peek

    Goodness, the things you learn about your fellow jumpers on!

    I too, have skysurfed. 12 jumps, with 2 different boards (and their release systems) designed by me. I might have the distinction of having been the first/only person to have skysurfed from an AN-2. Anyone else done that?

    I gave it up because it was such a hassle. No one likes a big guy with a large board strapped to him hopping around in a plane and stepping on people's feet while they get out.

    I did all these jumps with a double wing sit-suit and Spandex pants for low drag on my legs. I'm not sure I could have done it otherwise. I'm not that balanced or athletic or flexible.

    Just imagine me in something that looks like yoga pants. ... or perhaps not.

    There was a guy in Slovenia, that did skysurf jumps from An-2 in the early 90s and I'm sure he wasn't the only one.

  9. Anyone have some mounting suggestions for X3000? I currently have it mounted with the waterproof case on a flat top helmet and don't really want to drill holes for cables. Some sort of skeleton housing would be nice, possibly something that shields the power/rec buttons.