Flight modes and protection envelopes based on inertial attitude estimates for radio-controlled airplanes

A flight control unit for a radio-controlled (RC) airplane comprising:

• a receiver configured to receive command data corresponding to one or more flight control commands from an RC controller containing a transmitter associated with the RC airplane;
• an attitude sensor array comprising one or more accelerometers and one more gyroscopes;
• and
• one or more processors configured to (i) estimate an inertial attitude of the RC airplane based on data received from the attitude sensor array, (ii) determine whether the estimated inertial attitude exceeds at least one of a first inertial pitch range or a first inertial roll range corresponding to a first flight envelope of a first flight mode, (iii) in response to determining that the estimated inertial attitude exceeds at least one of the first inertial pitch range or the first inertial roll range, generate at least one control signal for application to at least one of a plurality or servomotors to adjust one or more of the control surfaces, wherein the plurality of servomotor are configured to adjust one or more control surfaces of the RC airplane;
• and (iv) in response to receiving command data comprising at least one control stick input, adjusting at least one of a throttle and/or one or more control surfaces of the RC airplane based on an inertial attitude corresponding to the at least one control stick input, wherein the at least one control stick input corresponds to an inertial attitude of the RC airplane rather than a rate of rotation about a corresponding pitch, roll, or yaw axis of the RC airplane.