Aurora Flights Sciences has received an award from the Defense Advanced Research Projects Agency (DARPA) to take its experimental X-plane through the next phases of the agency’s Control of Revolutionary Aircraft with Novel Effectors (CRANE) program. Aurora’s uncrewed X-plane concept uses an active flow control (AFC) system designed to supply “pressurized air to AFC effectors embedded in all flying surfaces” for effects such as “flight control at tactical speeds and performance enhancement across the flight envelope.” During phases 0 and 1 of the CRANE program, the company developed AFC-related tools and technologies, developed two X-plane concepts, completed preliminary design work on the chosen concept and conducted wind tunnel testing.
“Given all that we have learned about AFC and its application to tactical aircraft in prior phases of CRANE, the next step is to prove out these learnings in flight,” said Graham Drozeski, Aurora vice president of government programs. “The CRANE X-plane is designed specifically to explore the effectiveness of AFC technologies at mission relevant scale and Mach numbers.”
CRANE’s phase 2 calls for a detailed engineering design of a full-scale demonstrator aircraft, which will have a 30-foot wingspan and gross weight of 7000 pounds. During the third phase, currently an executable option on the award, Aurora would build the X-plane with an eye toward beginning AFC validation and demonstration flight testing in 2025. Featuring a modular design with replaceable outboard wings and swappable AFC effectors, Aurora’s CRANE X-plane is expected to be capable of speeds up to Mach 0.7.
And again in English, please?
Although the pictures show small conventional control surfaces in the wing trailing edges, the stated intent is for the craft to primarily be controlled by smoothly altering the airflow over the top of the wing surface through compressed air blown out of nozzles or slots in the wing top surface. I suppose conceptually you could think of it as altering the wing geometry in flight without any mechanical means.
Is there a reason to have added drag and added surface flutter on a new aircraft design?