Longitudinal Stability (fixed stick) DWT automatically runs
multiple Cmarc analyses in order to calculate the stability
derivatives necessary for longitudinal analysis. Parameters are
automatically varied over a prescribed increment in order to use
first order differencing to calculate the derivatives. The
calculation of the necessary parameters requires two parameter
variations, elevator deflection and the angle of attack (alpha).
In order for the longitudinal calculation to be most accurate,
it is best to perform the differencing at the trimmed condition.
Once this point is established (elevator deflection and aircraft
angle of attack) at some given flight condition, alpha may be
varied in order to calculate the stability derivatives that are
a function of alpha and the elevator may be deflected in order
to calculate derivatives that are a function of delta. Although
DWT does calculate derivatives that are a function of elevator
deflection, at this time DWT is limited to calculating the short
and long term