Why does my electric RC plane have a downward angle on the prop?

by admin on January 21, 2010

When viewed from the side "wings level" the prop is about 20 degrees down faceing. It flys just fine [wings level] and the manual says that the down angel is correct (I guess I’m not the first person to think it was damaged in shipment ), but it doesn’t give any reason why.

Just wondering.
Thanks
Shawn
It flys level (or almost level) the angle of attack is no where near as steep as the down thrusting prop angle.

Thumbs up to Marvin! Model aircraft have the engine mounted with negative angle to help control the angle of attack. Almost all RC aircraft are WAY overpowered compared to a real aircraft of that type. It would be almost impossible to keep the plane from climbing, even with full down elevator, if the engine mount wasn’t pitched down during installation.
You would need to re-rig your elevator to compensate for the thrust angle, and doing that would increase drag and slow your plane down.

If you don’t believe me, reinstall the engine mount so that the propeller is vertical and try to fly it.

Also, RC engines are often mounted at an angle to the right, to help overcome torque and ‘p’ factor, which I won’t go into…

Here’s a link: http://www.rcaerobats.net/thrust_angles.htm

Cessna 182 Large Scale Electric Rc Plane

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  • Myshuno383

    probably to make the wind flow correctly over the wings to give it lift.
    References :

  • Mike M

    Sounds like it’s just the particular design of the prop.
    References :

  • Marvin: aka "The Man"

    Because the tail hangs low during flight and this gives the wings an upward tilt. The prop is aligned to this flying angle. 20 degrees seems a bit excessive. It’s probably not that steep.
    References :

  • threesheave

    Thumbs up to Marvin! Model aircraft have the engine mounted with negative angle to help control the angle of attack. Almost all RC aircraft are WAY overpowered compared to a real aircraft of that type. It would be almost impossible to keep the plane from climbing, even with full down elevator, if the engine mount wasn’t pitched down during installation.
    You would need to re-rig your elevator to compensate for the thrust angle, and doing that would increase drag and slow your plane down.

    If you don’t believe me, reinstall the engine mount so that the propeller is vertical and try to fly it.

    Also, RC engines are often mounted at an angle to the right, to help overcome torque and ‘p’ factor, which I won’t go into…

    Here’s a link: http://www.rcaerobats.net/thrust_angles.htm
    References :

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