A Pragmatic Approach to DO-178C-Inclined Software Development for Lift-to-Cruise Aircraft Nonlinear Flight Control

Systems whose failure or defective behavior can lead to either the loss of human life, serious injury, environmental harm, or significant equipment or property damage are referred to as safety-critical systems. Considering the impact that these systems have on human safety, it is necessary to thoroughly verify their behavior and rigorously test them before exposing them to the public. In aviation, the development of such safety-critical software, such as a flight controller or a battery controller, requires adherence to stringent methodologies to formally certify the software according to standards like DO-178C/DO-331. One such safety-critical flight controller software, based on the incremental nonlinear dynamic inversion (INDI) approach, is being developed for an electric vertical take-off and landing (eVTOL) aircraft. This aircraft features a fixed-wing configuration with a wingspan of 2.1 meters and is equipped with an electric propulsion system consisting of two propellers and one impeller. The complete software development toolchain used for this flight controller development is presented, along with the necessary requirements-based verification results. The research showcases the model-based software development and static model and code verification results.