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This X-plane is meant to fly soon. enter image description here It's a modified Tecnam. The propeller direct wash over the wings, increasing lift. This allows the use of a smaller, high-aspect ratio, low drag wing. But this isn't quite clear to me. Here's what I know about this.

  • Light aircraft have oversized wings for cruise, needed due to a mandatory minimum 61 knots stall speed, and the lack of cabin pressurization generally prevents them flying high enough to make good use of the extra wing area at higher cruise speeds.
  • The propwash from the Maxwell would act like a blown flap at low speeds, achieving the above requirement without a large wing but presumably sufficient redundancy to not matter.
  • At cruise however, the propwash would increase friction drag by causing faster airflow over the wings, and possibly interfering with any laminar flow.
  • The giant propellers at the tips are somehow meant to reduce induced drag - but how?
  • This is a glorified blown flap.

What am I missing?

EDIT: I just discovered/remembered that at cruise the inner propellers fold to reduce drag. But the point remains: what is so special about this glorified blown flap?

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    $\begingroup$ Besides that it has electric propulsion? $\endgroup$
    – JZYL
    Jun 26, 2020 at 17:37
  • $\begingroup$ @zymhan Yes yes thank you. I think it does. OK, dupe this. $\endgroup$ Jun 26, 2020 at 18:41

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