Preliminary design of redundancy management for LSA -02 automatic flight control system

Abstract

The final objective of this paper is to make preliminary design concept of redundancy management, which applied for the automatic flight control system in LAPAN Surveillance Aircraft - 02 (LSA-02). The LSA-02 concept use a certified class I aircraft, which has a MTOW < 6000 pounds and use single reciprocating engine. Then, an automatic flight control system (AFCS) is installed in the aircraft, hence added the aircraft capability to fly autonomously. Although the pilot still onboard and act as safety pilot when the AFCS is going wrong, the design of AFCS shall be safe. The AFCS consist of components where some of them are critical and need redundancy. The identifications of component criticality are come from functional hazard analysis (FHA) where the result are list of critical and non-critical component in AFCS during the automated flight. The FHA is a systematic, comprehensive examination of basic aircraft system to identify potential minor, major, hazardous, and catastrophic conditions that may occur due to a malfunction or a function failure of AFCS. The FHA result shows the critical components of AFCS that may lead to the catastrophic conditions in case of failure are the actuator that connected to the elevator, flaperon, rudder and throttle stick, also the flight control computer. Therefore, they need redundancy and the design of redundancy explained in the redundancy management. The redundancy management suggest eight actuators needed for the critical control surface and the throttle stick. This critical actuator is configured as cold standby redundancy. For non-critical control surface (flap and air break), two actuators are needed and configured with no redundancy. The flight control computer is also a critical component and built in dual modular redundancy (DMR) configuration and one independent communication channel for each flight control computer.