function damping_confirmed()
H  = 1000; % m
V  = 38; % m/s
m  = 350; % kg
[success,opts, op_point] = get_trim_Lon(H,V,m);
if success
    [Glon,Glat] = linfdm(opts.fcn,op_point);
end
U0 = V;
A1 = Glat.A;
B1 = Glat.B;
c1 = Glat.C;
D1 = Glat.D;
% inputs: [da dr]
% states: [beta p r phi]
% outputs: [beta p r phi]
A2 = [A1(1,1) A1(1,2:end)./U0;A1(2,1)*U0 A1(2,2:end);A1(3,1)*U0 A1(3,2:end);A1(4,1)*U0 A1(4,2:end)]; % delta_beta = atan(delta_v/u0)
B2 = [B1(1,:)./U0;B1(2,:);B1(3,:);B1(4,:)];
C2 = eye(4);
D2 = zeros(4,2);
% inputs: [dr da]
% states: [beta r p phi]
% outputs: [r phi]
A = A2([1 3 2 4],[1 3 2 4]);
B = B2([1 3 2 4],[2 1]);
C = [0 1 0 0;0 0 0 1];
D = zeros(2,2);

sys = ss(A,B,C,D);
set(sys, 'inputname', {'rudder' 'aileron'},...
         'outputname', {'yaw rate' 'bank angle'},...
         'statename', {'beta' 'yaw' 'roll' 'phi'});
damp(sys)
figure(1)     
axis(gca,'normal')
h = pzplot(sys);
setoptions(h,'FreqUnits','rad/s','Grid','off');
figure(2)
impulseplot(sys,20)

figure(3)
sys11 = sys('yaw','rudder');    % select I/O pair
h = bodeplot(sys11);
setoptions(h, 'FreqUnits','rad/s','MagUnits','dB','PhaseUnits','deg');

figure(4)
h = rlocusplot(sys11);
setoptions(h,'FreqUnits','rad/s')

figure(5)
% need positive feedback
h = rlocusplot(-sys11);
setoptions(h,'FreqUnits','rad/s')
sgrid
% damping gain
k = 0.83;
cl11 = feedback(sys11,-k);

figure(6)
impulseplot(sys11,'b--',cl11,'r')
legend('open loop','closed loop','Location','SouthEast')
xlim([0 10]);

figure(7)
% see how the response for the aileron looks
cloop = feedback(sys,-k,1,1);
damp(cloop)   % closed-loop poles
impulseplot(sys,'b--',cloop,'r',20)           % MIMO impulse response
xlim([0 10]);

figure(8)
impulseplot(cloop('bank angle','aileron'),'r',18)

% Form the washout filter
s = tf('s');
H = tf([1 0],[1 1]);
figure(9)
oloop = H * (-sys11);          % open loop'
h = rlocusplot(oloop);
setoptions(h, 'FreqUnits','rad/s')
sgrid

figure(10)
k = 0.83;
wof = -k * H;            % washout compensator
cloop = feedback(sys,wof,1,1);
impulseplot(sys,'b--',cloop,'r',20)
end