I changed the props to constant speed and increased HP to 300.
    It will now hover in helicopter mode at 12000 feet. But in that mode
    it's still difficult to get it out of the zero airspeed mode with the
    existing controls. Reducing power it goes into the upside down deep
    stall. Your gimbal on the thrust vector or some shift in cg or more
    authority on the elevator might be required.

    Perry

    Figure on a thrust vector of 10 degrees down if that is possible
    in the simulation. I am in the process of writing a program
    that will calculate the rate of pitch during take off. It fist
    considers the
    wing area as a flat plate drag on forward velocity. The trust  vector
    is broken down into horizontal thrust and vertical thrust.
    As the wing angle of attack passes through the stall angle the
    the lift on the wing is then calculated.

    There are two distinct modes. Up to wing stall and then beyond
    wing stall into horizontal flight. The downtrust angle is
    adjusted to always supply a vertical force equal to the weight
    of the airplane until the wing reaches its lifting angle.


    --
    Paul Lamar ...No rotor no motor.

Perry,

Does your model include collective control?  If so, pitching forward
should allow you to fly away from the hover...  Or, starting out from a
hover at low altitude (where the excess thrust is high), and
accelerating vertically should allow you to gain enough airspeed to fly
away.  Having collective would allow much improved flexibility, control
margin, and flexibility.


Regards,

Matt-

Matt, I think we are better off using the Air Scooter trick of changing
the trust vector. Much cheaper and lower technical risk than a
fully articulated counter rotating rotor head with collective pitch
change.

Here is a preliminary force vector diagram.
At 10 degrees down thrust we have a horizontal force of 17.63% of 2000
pounds or 353 pounds pitching around the center of lift on the main wing.

For more back ground on this I have updated the web site.
http://www.rotaryeng.net/STOL.html

Paul Lamar ...No rotor no motor.

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