if iplane == 1,
  % Boeing 747 data

  stype = 'Boeing 747';

  Cyb = -0.960;
  Cyp =  0;
  Cyr =  0;
  Clb = -0.221;
  Clp = -0.450;
  Clr =  0.101;
  Cnb =  0.150;
  Cnp = -0.121;
  Cnr = -0.300;
  
  S    = 5500; % sq. ft
  b    = 195.68; % ft
  rho0 = 2.3769e-3; % slug/ft^3
  a0   = 1116.45; % ft/s
  M0   = 0.25; % flight Mach number
  W    = 636600; % pounds
  Ix   = 18.2e6; % slug ft^2
  Iz   = 49.7e6; % slug ft^2
  Ixz  = 0.97e6; % slug ft^2

elseif iplane == 2,
  % F-104A data

  stype = 'F-104';
  
  Cyb = -1.170;
  Cyp =  0;
  Cyr =  0;
  Clb = -0.175;
  Clp = -0.285;
  Clr =  0.265;
  Cnb =  0.500;
  Cnp = -0.140;
  Cnr = -0.750;
  
  S    = 196.1; % sq. ft
  b    = 21.94; % ft
  rho0 = 2.3769e-3; % slug/ft^3
  a0   = 1116.45; % ft/s
  M0   = 0.257; % flight Mach number
  W    = 16300; % pounds
  Ix   = 3549; % slug ft^2
  Iz   = 59669; % slug ft^2
  Ixz  = 0; % slug ft^2

end

g  = 32.2; % ft/s
m  = W/g; % mass of aircraft
u0 = M0*a0; % flight speed
Q  = 0.5*rho0*u0^2; % dynamic pressure

Yb = Q*S*Cyb;
Yp = Q*S*b/(2*u0)*Cyp;
Yr = Q*S*b/(2*u0)*Cyr;

Nb = Q*S*b*Cnb;
Np = Q*S*b^2/(2*u0)*Cnp;
Nr = Q*S*b^2/(2*u0)*Cnr;

Lb = Q*S*b*Clb;
Lp = Q*S*b^2/(2*u0)*Clp;
Lr = Q*S*b^2/(2*u0)*Clr;