First flights with the prototype of the commercial version of “our” JS-3!

Chocofly will be producing “our” JS-3 in a fully moulded version. Wing profile and layout are identical. The fuselage is newly made on the basis of the original CAD data. On Friday Chocofly’s Daniel Aeberli maidened the prototype. This afternoon he did some further tests at our club’s airfield. The prototype has a stiff middle wing that’s based on the “alpine version” specs. The outer wings of the 5.14m version of the prototype are in the GPS light version. The full plane, with JETEC 70 and 5S 5200 battery weighs only 6.3kg.

This plane is simply awesome, even better than our scratch-built versions. The first few production versions will be going to members of our building team, including a very lucky yours truly. I’ll be taking mine in the GPS light version, most probably also with a JETEC70 impeller.

The waiting list for this plane is unfortunately already extremely long, but it’s worth the wait. In the meanwhile, enjoy this “quick and dirty” video of this afternoon’s flights.

Chocofly JS3 – Prototype Test Flights from Jürgen L. on Vimeo.

4 thoughts on “First flights with the prototype of the commercial version of “our” JS-3!

  1. GPS light version. How will that handle the slopes?
    Still trying to figure out which version I ought to order next year…

    Douglas


    • The middle wing (alpine version) of the prototype is very stiff. If you compare videos of “our” JS3 and Dani’s Prototype, you will see that the prototype doesn’t bend its middle wing at all, even at high G turns and loopings, whereas ours are much more flexible and “hang” in the air much more like the original. The 2nd prototype that’s currently in production will have a “heavy slope” layout (HG Edition), and should be virtually indestructible. After that Dani will produce a lighter version, including for our building team. Once we’re able to compare the three versions, both in terms of wing flex and weight, Dani will also be able to make you a recommendation on which one to buy. In my experience, Dani’s planes that are produced by Karel K. (like the JS3) are extremely well built and very robust. The alpine version is for those who really want to push it hard in alpine slope conditions, whereas the lighter version will be more than fine for the vast majority of pilots. Note that even the lighter version will be stiffer than our scratch-built planes, which we also regularly fly on the slope. The only difference is that we don’t push the top speed too much (Georg has “only” clocked up to 250kmh on his JS3), I expect the Choco light version to be able to handle much more than that.
      What’s most important for me on the JS3 is its weight. I like mine to be light, flying weight under 6.5kg. I also love the wing flex of ours, as it makes tight curves just awesome (in tight thermals you can just about turn the plane on its wingtip and twist it up). The plane is such a good thermaller in light conditions, and I expect to be using it mostly for that. I’ve got enough other planes for heavy slope conditions, and it will be hard to beat my absolute favourite for such conditions, the 1:3.5 Diana2.


  2. So it will be entirely possible to buy a different wing setup for slope and thermalling? (Getting a lighter weight center section…as well as a very stiff one)
    We will not experience this…? “I also love the wing flex of ours, as it makes tight curves just awesome (in tight thermals you can just about turn the plane on its wingtip and twist it up).”


    • Best to check that with Dani. I’m not sure if two different center wing sections gives a large benefit over the costs. I’d probably go for a medium strength center section and flexible long outer sections as well as medium strength short outer sections. Unless of course you want to do 300kmh plus vertical drops and ridiculously high G turns.


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