The objective of this paper is to illustrate that the standard form or Linear Fractional Transformation LFT framework is a unique and powerful framework to treat with nonlinear systems during control law synthesis and analysis. It is also shown that the expression linear in the acronym LFT is too restrictive as a nonlinear behaviour can be simulated by using the LFT framework. Within this paper, a precise and as small as possible LFT for a nonlinear 2-DOF aircraft with time varying parameters is derived. This LFT is validated both in a linear and nonlinear framework.