Flight Control Design and Test of the Joint Unmanned Combat Air System (J-UCAS) X-45A

Abstract

The Joint Unmanned Combat Air System (J-UCAS) X-45A is an autonomous unmanned prototype aircraft under development by DARPA, United States Air Force, U.S. Navy, and Boeing, and is currently undergoing flight test at Edwards Air Force Base in California. This paper presents an overview of the flight control system used to autonomously control and stabilize the vehicle through taxi, takeoff, flight and landing. Also included are X-45A control system design challenges and how they were addressed, as well as a discussion of the advanced flight control system functionality included within the vehicle management system that was used during flight envelope expansion testing. Relevant flight test results are included throughout paper. I. Introduction The Unmanned Combat Air Vehicle (UCAV) Program was a joint effort between the Defense Advanced Research Projects Agency (DARPA) and the United States Air Force (USAF), and is now being managed as part of the Joint Unmanned Combat Air Systems (J-UCAS) program. Its purpose is to demonstrate the technical feasibility, military utility, and operational value of a J-UCAS system that can effectively and affordably prosecute 21st century Suppression of Enemy Air Defenses (SEAD)/Strike missions within the emerging global command and control architecture [1,2]. The J-UCAS system will exploit the design and operational freedoms of relocating the pilot outside of the vehicle to enable a new paradigm in aircraft affordability while maintaining the rationale, judgment, and moral qualities of the human operator. The weapon system will be capable of dynamic mission control while engaging multiple targets in a single mission under minimal human supervision. DoD’s vision of the 2010 battle space includes unmanned combat air systems as an integral part of the force structure. The initial operational role for the J-UCAS is as a “first day of the war” force enabler that will complement a strike package by performing the SEAD mission. In this role, J-UCAS would accomplish preemptive destruction of sophisticated enemy integrated air defense systems (IADS) in advance of the strike package and enable the attacking forces by providing reactive suppression against the remaining IADS. Throughout the rest of the campaign, J-UCAS would provide continuous vigilance with an immediate lethal strike capability to prosecute high value and time critical targets. The SEAD/Strike mission will be the first instantiation of the J-UCAS vision that will evolve to include a broader range of combat missions as the concept and technologies mature and the J-UCAS affordability potential is realized. This paper describes design and test of the J-UCAS X-45A Flight Control System.