Recent content by DonEstenan

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    "Micromaster"-- Centerline twin using small industrial engines

    I can't find it now, but I read an investigation report into the crash of G-CIMA (SD-1 with V-twin engine). The conclusion was: inadequate takeoff performance (good in January, but by May it progressively declined; combined with no headwind and inability to raise the tail quickly). Anyway, with...
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    "Micromaster"-- Centerline twin using small industrial engines

    Even as tiny aircraft as SD-1 is really struggling with just 25hp or so. Maybe if you are 60-70kg, but with 90-100kg pilot 25hp is simply not enough for safe takeoff/climb out. Yes, you can give it more wing, at the cost of flying _really_ slowly, but then the utility decreases quite a bit, and...
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    "Micromaster"-- Centerline twin using small industrial engines

    The problem is that engine prices go up very steeply as the power increases. Weight & fuel burn is also a problem. What about an industrial V-twin to modified to run @ say 4500rpm, and an electrical motor connected to the PSRU to help on take-off/initial climb and in case the engine dies?
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    "Micromaster"-- Centerline twin using small industrial engines

    Hmm, what about a generator at the back of the (mostly laminar) central pod, powering fixed cruise propeller (and hopefully reducing the pod's drag by sucking the boundary layer) + 2 electric motors (+ some batteries) on the wings powering simple (but foldable) climb propellers. This way all the...
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    Does such an airplane exist?

    - can carry 120kg (pilot+luggage)+some fuel for 2-3h (or more) flight - powered by Polini Thor 250DS (36hp) or something cheaper - can cruise at 100mph (or even better, knots) - reasonably safe Luciole seems to fit the bill, except for the carrying capacity ... but it is built using...
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    Boeing-backed startup to bring electric planes to market by 2020

    You probably don't want to do disconnection at 100knots, need to safely deal with rejected takeoffs ... ... better to disconnect at the beginning of the runway. And lugging electric motors into the air is also unnecessary ... wouldn't it be simpler and safer to just have a tug tug you to the...
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    Pound for pound.. electric vs gas

    C'mon, at least be serious. Many(most?) GA pilots use noise cancelling headphones for a reason. Road vehicles have silencing weight budgets way beyond what is feasible on an aircraft. Electric cars are still noticeably quiter anyway. YO-3 went to great lengths to contain engine noise, far...
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    Pound for pound.. electric vs gas

    Hmm, I think the point of an electric airplane is not whether pound per pound you can get deal better than the ICE one, but the whole package: 1. you get much simpler and hassle-free operation (& maintenance too) 2. quieter ride 3. (once the technology has matured a bit) greater reliability due...
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    Why battery-powered aircraft will never have significant range

    Umm, with fixed L/D, you spend the same amount of energy (kW) - but when flying higher, you are flying faster. Hence, if you are total-energy limited (batteries/but also fuel tanks), you spend the same time in the air (ignoring the energy needed to go higher - can be partially recovered when...
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    Low budget Ultralight Aircraft

    Hmm, what about VC460+ https://hobbyking.com/en_us/turnigy-rotomax-150cc-size-brushless-outrunner-motor.html +10min batteries for takeoff/climb boost and/or backup if/when VC460 fails... How would you connect that combo?
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    Fly by wire and control laws for EAB FBW

    The way I see it, if/once somebody develops and sells it, many may opt to use it. After all, "connect your stick to this electronic box, these servos to your control surfaces, now connect them by wires this way" is way simpler/faster than properly building the control linkages. It might help...
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    Fly by wire and control laws for EAB FBW

    Is it possible to use FBW to smooth the ride in turbulence? Doesn't Diamond do something like that? Still no EAB, but far from Lockheed/Sukhoi ...
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    Why battery-powered aircraft will never have significant range

    Marginally possible, not really practical yet. Some improvements (battery capacity & cost) are still needed to make it the preferable choice. For going distances ... get a hybrid using free-piston linear generator (if/when it finally becomes feasible/practical, hmmmm)
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    Why battery-powered aircraft will never have significant range

    Maybe the things will really move forward when several technologies synergestically combine: 1) somewhat increased energy density of batteries. 400wh/kg is not THAT far away from 250wh/kg 2) a configuration with large laminar flow fuselage - large for comfort, significantly increases the appeal...
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    Why battery-powered aircraft will never have significant range

    Uhmmm, that is true for 'standard' aircraft, designed around standard engines, operated in a standard way. Not so much the case for motorgliders which might want decent power for takeoff and climb, but can cruise on a very small fraction of that power. Hybrid has other potential advantages: -...
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