Retrofit Reconfigurable Flight Control System and the F/A-18C

The United States Navy has completed the initial flight test of a Reconfigurable Control Law System (RCLAWS) on the F/A-18C. The purpose of reconfigurable control is to allow for the safe operation of an aircraft that has experienced a sudden change in aircraft dynamics resulting from aircraft damage or flight control effector damage. The RCLAWS utilized during this flight test are novel in that they are designed to augment the production flight control system instead of replacing it. In order to reduce verification and certification requirements, this retrofit reconfigurable methodology supplements pilot commands to compensate for undesirable aircraft dynamics instead of manipulating control surfaces directly. Through comparison of the aircraft’s actual response to model data of the aircraft’s desired response, the RCLAWS determines what commands need to be applied to produce the desired aircraft response.

Flight test data have been collected to determine the viability of the in-line retrofit reconfigurable control method. Although flight data indicate a modest improvement within the limited flight test envelope, simulation analysis has indicated that the retrofit RCLAWS provide substantial improvements for more aggressive failures. Simulation shows RCLAWS has proven to reduce the aircrew workload in a recent catastrophic failure present in the F/A-18 community and provide predictable aircraft dynamics for a safe recovery.