An axiomatic aerodynamic model is formulated for the attached flow past a wing and tailplane, based on a vortex lattice representation, with the wing wake fully relaxed at each instant of time. Conventional derivatives are estimated based on this model.

Predicted responses, using the above derivatives, are compared with ‘exact’ responses, using the axiomatic model for various elevator inputs and for both non-swept and swept aircraft configurations.

Surprisingly, even in these simpler cases, differences appear between prediction and ‘exact’ responses.