A positive aileron deflection is referred to as one which results in a positive rolling moment about the X-axis. That is, the deflection angle is positive for the left aileron with trailing edge DOWN and for right aileron with trailing edge UP.
Please note that sometimes the ailerons are used to create both lift (drooped ailerons) and rolling moment (original function of ailerons) at the same time. In such a data-rhwidget="HyperlinkPopover" href="Eqn_OpAileronDeflAngle.htm"> total aileron deflection angle is defined as:
where:
and
See Graphic