function dalpha_dt = RHS(t,alpha,C)
dalpha_dt = zeros(2,1);


[th U]= IncFlow(t);

r = C.lt*[-cos(alpha(1)) -sin(alpha(1)) 0];

IncX = -U*cos(th);
IncY = -U*sin(th);

AngX = -C.lt*alpha(2)*sin(alpha(1));
AngY = C.lt*alpha(2)*cos(alpha(1));


th_prime = atan2(-(IncY+AngY),-(IncX+AngX));

AOAbeta = (alpha(1)+C.it)-th_prime;





[cl cd cm]=Coef0015(AOAbeta);


qinf = .5*C.rho*U.^2;
M0 = C.Lt*qinf*C.ct^2;
F0 = C.Lt*qinf*C.ct;



F(1,:) = F0*(cl.*cos((pi/2+th))+cd.*cos((pi+th)));
F(2,:) = F0*(cl.*sin((pi/2+th))+cd.*sin((pi+th)));
F(3,:) = 0; %M0*cm;


M = cross(r,F);



SumM = M(3)-0*alpha(2);


dalpha_dt(1) = alpha(2);
dalpha_dt(2) = (SumM/C.I);