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Correct signs for moment coefficient/pitching moment?

Correct signs for moment coefficient/pitching moment?

Correct signs for moment coefficient/pitching moment?

Reading "Mechanics of Flight" now. I'm confused about sign usage:

1. For the pitching moment about the wing aerodynamic center, is positive clockwise or counterclockwise? Is the coefficient the same sign as the moment itself?
2. For the pitching moment induced by a change in angle of attack, is positive up or down?

Thank you for all help!

RE: Correct signs for moment coefficient/pitching moment?

1) i think CCW ... i think the convention is a stbd wing , X-aft, Y-outbd, Z-up, MY is CCW (ie nose up).

yes the sign of the co-eff is the sign of the moment, so long as your sign convention is the same ... if you axes are different you have to account for that !?

2) +ve is +ve .... i believe the overall effect of pitch up is moment nose down ... careful reading this, i didn't say the wing moment is nose down, i said the overall effect of pitching the nose up is a "correcting" nose down moment.

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