August 15, 2019 | International, Aerospace
DARPA Invites Proposals For Active-Flow-Control X-Plane
By Graham Warwick DARPA has formally launched a program to build and fly an X-plane designed around active flow control (AFC), potentially eliminating the need for moving control surfaces. Designing from the ground up around AFC, rather than modifying an existing aircraft, is expected to yield performance and operational benefits. A broad agency announcement (BAA) was released on Aug. 12 for the first two of four planned phases of the Control of Revolutionary Aircraft with Novel Effectors (Crane) program. A proposers' day is scheduled for Aug. 26 and proposals are due to be submitted by Nov. 8. A budget of $21 million is available for multiple awards under the 12-month Phase 0, which will focus on the aircraft design process and understanding the trade space. DARPA expects performers to enter this phase with multiple candidate configurations and flow-control approaches. Each Phase 0 contract will end with a conceptual design review for one or more configurations. Phase 1 will continue to mature up to two concepts and is expected to involve component-level testing and demonstrations to inform a system requirements review. This nine-month phase is planned to culminate in a preliminary design review for the proposed X-plane. DARPA plans to downselect to one performer at the end of Phase 1 in second-quarter fiscal 2022 and award a contract for Phase 2 detailed design. This is planned to conclude in a critical design review and lead to a go/no-go decision in the second quarter fiscal of 2023 for Phase 3 building and flying of the X-plane. First flight is planned for the third quarter of fiscal 2024. DARPA wants a “tactically relevant scale aircraft,” the BAA says. This may include a “clean-sheet design or modification of an existing aircraft.” The agency expects substantial use of off-the-shelf components for the flight demonstrator so that program resources can be focused on AFC development and testing. AFC modifies the flow field around the aircraft using mechanical or fluidic actuators. The BAA specifically excludes using large external moving surfaces, mechanical vectoring of engine exhaust or other traditional moving aerodynamic control surfaces. AFC applications identified in the BAA include eliminating moving control surfaces for stability and control and improving takeoff and landing performance, high-lift flight, thick-airfoil efficiency and high-altitude flight. Proposers may identify additional applications and benefits. A NATO technical study involving Lockheed Martin, BAE Systems and academic institutes in the U.S. and UK identified that an unmanned combat aircraft with AFC could have stealth and other potential performance benefits during the ingress and egress phases of a strike mission. https://aviationweek.com/defense/darpa-invites-proposals-active-flow-control-x-plane