Slide 24 of 58
In the past, tailless aircraft directional control has been provided by spoilers or drag rudders. This was done to decouple the control system as much as possible. Unfortunately, spoilers and drag rudders have high attendant actuator requirements (a result of large hinge moments) and provide inadequate control power at high AOA.
With quantum advances in throughput capabilities of digital processors, it is now possible to take advantage of advanced integrated/adaptive flight control techniques that make a decoupled control effector a requirement. As a result, more efficient aerodynamic controls, like the all-moving wing tip or spoiler-slot-deflector, can now be used for tailless aircraft lateral-directional control. Integration of these effectors reduces control suite weight fraction 5%, reduces hydraulic power requirements 45% (because hinge moments are much less than those of conventional surfaces), and vastly improves high-AOA flying qualities. All of these factors contribute to improved agility.
Advanced flight control technologies that enable these unconventional effectors also reduce FCS complexity and cost and will reduce loss-of-control related accidents and mission-critical vulnerability.