This paper describes a method for determining an optimal control allocation function for aircraft with an unconventional control surface setup (i.e., that does not consist of a conventional elevator, rudder, and ailerons). A typical application of this control mixing would be to impart RLconventional handling qualities to an unconventional unmanned aerial vehicle, which will enable a pilot to fly the unmanned vehicle manually during flight testing. The mixing can also be used as a backup mode to recover the unmanned aerial vehicle manually, should any sensor failures occur during flight testing. Furthermore, the allocation can be used to simplify the inner control loops of an unmanned aerial vehicle autopilot or stability augmentation system. The control allocation design process was formulated as a multi-objective optimization problem. A methodology was proposed to define the constraints, which can be customized for a particular aircraft or application.