An air vehicle assembly and a corresponding method for launching an air vehicle assembly are provided, along with corresponding control systems and methods. The air vehicle assembly may include a plurality of air vehicles releasably joined to one another during a portion of the flight, such as during take-off and landing. By being releasably joined to one another, such as during take-off and landing, the air vehicles can rely upon and assist one another during the vertical take-off and landing while being designed to have a greater range and higher endurance following the transition to forward flight, either while remaining coupled to or following separation from the other air vehicles. By taking into account the states of the other air vehicles, the control system and method also permit the air vehicles of an air vehicle assembly to collaborate.