How can I calculate the moment coefficient around the center of gravity? Hi guys I was wondering if you could help me with the following problem:


Wing surface area= 260m2 (sw)
MAC= 6.608m (cw)
horizontal stabilizer surface area=69.5m2 (st)
distance from the cog till the aerodynamic center of the horizontal
stabilizer=30m (lt)
change in downwash angle vs angle of attack de/da=0.5
distance from wing til aerodynamic center (hacw) = 26% of mac angle (hacw)
of the wing is 0.12 per degree (aw)
angle of the stabilizer = 0.07 per degree (at)
downwash stabilizer at an angle of attack of 0 is e0=0
moment coefficient of the wing in the aerodynamic center is
Cmacw=-0.04 
CoG=31%


Calculate the moment coefficient around the CoG(Cmcg) of the entire airplane when the angle of attack is 3 degrees and the angle of the stabilizer is 1.5 degrees aircraft nose up.

I know the answer which should be Cmcg=-0.022 but I have no idea how it is calculated.

I am sorry, what i did was the following: I calculated the tail volume coficiency which is 1.213564, the position of the neutral point being it 0.61396. I am trying to use the following formula:

$C_{mcg}=C_{macw} + a_w  a_w (h-h_{acw}-{a_t\over a_w} V_h (1-{\Delta e\over\Delta a})) + a_t V_h (i_t+e_0)$

when filling in I do the following

$-0.04+a_w A_w (0.31-0.26-{a_t\over a_w} 1.213564 (1-0.5) + a_t × 1.213564(i_t+e_0)$

for aw and at I am not sure to use the 0.12 and 0.07 or do it times 3 and 1.5 for the degrees. it seems to be angle of the stabilizer but I am not sure. e0 I think is 0 but again not sure.
$-0.04+0.12*3 (0.31-0.26-{0.07\over 0.12} 1.213564 (1-0.5) + 0.07 × 1.213564(1.5+0)=-0.022$

note that aw=the slope of the liftcurve and Aw=the absolute angle of attack.