$4)$ A fighter aircraft has an accelerometer mounted at body$-$fixed coordinates rx$,$ry$,$rz$.$ At a particular instant while maneuvering, the accelerometer measures inertial accelerations in the body$-$axis system with components gx$,$gy$,$gz$.$ Gyroscopes mounted at the center of gravity measure a rotational angular velocity of p$,$ q$,$ r $($in body$-$axes$)$ and rotational angular acceleration of p $,$ q $,$ r $($in body$-$axes$).$ Write an expression for the inertial acceleration of the aircraft at its center of gravity, expressed in body$-$axes.