Two methods were developed for online control design as part of a flight test effort to examine the feasibility of the NASA Learn-to-Fly concept. The methods use an aerodynamic model of the aircraft that is being identified in real-time onboard the aircraft to adjust the control parameters. One method employs adaptive nonlinear dynamic inversion, whereas the other consists of a classical autopilot structure. Effects from the interaction between the realtime modeling and the developed control laws are discussed. The Learn-to-Fly concept has been deemed feasible based on successful flights of both a stable and unstable aircraft.= wing span c = wing mean aerodynamic chord C l , C m , C n = body-axis nondimensional aerodynamic moment coefficients g = acceleration due to gravity I x x , I y y , I z z , I x z = inertia tensor elements J = advance ratio K = control gain L = aerodynamic lift m = mass M = vector of aerodynamic moments M δ = vector of aerodynamic moments due to control surface deflection n c = number of modeling regressors N = number of data points p, q, r = body-axis roll, pitch, and yaw rates q = dynamic pressure R = propeller radius S = wing reference area T x , T z = body x-axis and body z-axis components of engine thrust T h = throttle V = true airspeed V C AS = calibrated airspeed X = matrix of modeling regressors Y = aerodynamic side force z = vector of observations α = angle of attack β = sideslip angle δ = surface deflection ε = vector of residuals * Research Engineer, Dynamic Systems and Controls Branch, MS 308