J5012

• J5012-PT (Fig. 12.52)

The J5012 is a 12% thick, symmetric section designed by Jef Raskin. The airfoil is intended for aerobatic slope soaring where inverted flying is as important as normal flight.

Beside this application, the airfoil is a candidate for use on tail surfaces. In this regard, however, the J5012, as well as some other symmetric airfoils (NACA.0009, NACA 64A010), has an undesirable characteristic if it is to be used as a full-flying surface, e. g. a stabilator. At Rn of 60k near zero angle of attack, the lift curve is nearly flat. Consequently a stabilator deflection around zero lift produces little response. This “deadband” is a common characteristic of symmetric airfoils, although it is not always present (compare the SD8020). As an aside, the aerodynamic characteristics are not quite symmetric about zero angle of attack because, as shown in Fig. 10.19, the airfoil profile itself is not symmetric.

Also see: SD8020, NACA 0009, NACA 64A010 Digitizer plot: Fig. 10.19 Polar plot: Fig. 12.52

Thickness: 12.00% Camber: 0.00%