This work presents a linear parameter varying (LPV) three-loop longitudinal autopilot that is derived using the dynamic inversion technique. The conventional three-loop autopilots are traditionally designed at various flight conditions using linearized models and are then scheduled as a function of several parameters such as Mach number, velocity, angle-of-attack, etc., which remains a challenging and time-consuming task till today. In contrast, the proposed three-loop autopilot embeds the parameterized gains, from which the parameterized gain-multipliers are directly obtained in the form of explicit formulae. Exploiting the utility of the proposed autopilot structure, a design methodology for LPV controller design is presented, in which, a linear three-loop autopilot designed at single flight condition can be transformed into an LPV autopilot using the derived parameterized gain-multipliers. Simulation results are also presented to demonstrate the performance of the proposed technique.