Posted 4 days ago
The U. S. Defense Advanced Research Projects Agency (DARPA) is moving forward with a program to develop an experimental aircraft that maneuvers in mid-air without using traditional flight controls, instead directing blasts of highly pressurized air to alter the aircraft’s flight path.
While traditional aircraft use ailerons, flaps and rudders as control surfaces, DARPA’s Control of Revolutionary Aircraft with Novel Effectors (CRANE) program is looking to just use bursts of air to alter the yaw, pitch and roll of an aircraft. This concept of using directed bursts of air is called Active Flow Control (AFC).
DARPA is seeking an aircraft with this AFC technology as a way to reduce the weight and mechanical complexity of aircraft that ailerons, flaps and rudders add to an aircraft.
“Active flow control could improve aircraft performance by removing jointed surfaces, which currently drive design configurations that increase weight and mechanical complexity,” DARPA’s CRANE program description reads. “Demonstrating AFC for stability and control in-flight would help open the design trade space for future military and commercial applications.”
AFC-based flight controls could be particularly advantageous for stealth aircraft. Traditional flight controls require space between the wings and the control surface so that the surface can articulate to redirect airflow. That space between the wing and control surface — be it an aileron, flap or rudder — can raise the aircraft’s radar cross section, making them easier for radars to detect. AFC technology could allow an aircraft to altogether eliminate gaps between its wings and its flight controls, to eliminate that potential increase of its radar cross signature.... (Read more)