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Old Jun 20, 2012, 10:24 AM
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Blacksburg, VA 24060 USA
Joined Feb 2000
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There is also the situation of the pylon-mounted motor located in front of the wing. I have such an airplane with such a motor, the Sea Cub II, which is based on somebody else's design.

Note that the motor has up thrust, which does two things: It provides a small thrust vector up to counter-act the nose-down tendency at low speed, and it provides some down wash on the horizontal tail. This seems to work well enough in flight, though ground take off is a long time coming. In flight, trim change is needed from low throttle to high, and vice versa.

To reduce scraping damage to the underside of the nose, when taking off from pavement, I added a small cheater nose wheel, in case I apply too much throttle on take off.

Then there is the case of the motor pylon mounted behind the wing in a pusher arrangement, like the Dynam Hawk Sky. This set-up seems to have neither up nor down thrust. So there isn't much corrective wash over the horizontal tail. When hand-launching, it needs less than full power, otherwise it will dive into the ground. Once it's up to speed, full power can be applied. I forget whether a trim change is needed from high to low throttle and vice versa.

Jim R.
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