Abstract: A method of controlling a transition aircraft having actuators and which transitions between a first take-off/landing regime and a second horizontal flight regime, including: controlling a first actuator subset in the first regime and a second actuator subset in the second regime using the flight controller, by: a) providing measurements or estimates of flight parameters; b) depending on a current regime, checking whether a predefined set of conditions for that regime are fulfilled, by comparing flight parameters with threshold values; c) if conditions are fulfilled, signalling a decision-maker and awaiting confirmation regarding a transition to the other regime; d) instructing the flight controller to make the transition if approved; e) after transitioning in step d), commanding the aircraft according to the other regime; and f) returning to step a). Step e) includes gradually blending in a control law for the other regime over time while blending out the current regime.