Here's What You Need to Know: The CRANE project is in the very early stages of research.

The United States’ X-planes were a series of experimental airplanes that were designed to push the boundaries of flight. Born in the aftermath of the Second World War, American X-planes set a number of first and world records, including the first supersonic flight, first flight to reach Mach 2, and the first Mach 3 flight. Indeed, the entire list of achievements is extensive. With a few exceptions, the planes themselves were not expected to enter serial production, but instead to glean valuable flight information.

Though groundbreaking, the flights themselves weren’t always a cakewalk. Some test pilots who survived the flights, like Chuck Yeager, became etched into the American consciousness. Others, however, did not. The test flights proved to be dangerous, and several pilots lost their lives in crashes.

The latest American X-plane is once again pushing the envelope—and is spearheaded by one of the United States’ more secretive research and development agencies.

DARPA at the Helm

Defense Advanced Research Projects Agency (DARPA) calls its new X-plane project CRANE program, which stands for Control of Revolutionary Aircraft with Novel Effectors. The project will attempt to “demonstrate an aircraft design based on active flow control (AFC), an area not fully explored compared to traditional flight controls. The goal is to demonstrate significant efficiency benefits of AFC, as well as improvements in aircraft cost, weight, performance, and reliability.”

According to a company press release, AFC is defined as “the on-demand addition of energy into a boundary layer for maintaining, recovering, or improving vehicle aerodynamic performance. CRANE is excluding already proven techniques that use large external moving surfaces, mechanical vectoring of engine jet exhaust, or other traditional moving aerodynamic control devices.” The company is in essence trying to find alternative flight control methods.

The CRANE program’s manager outlined what this means practically, stating that although initial research has been done into AFC, the technology remains conceptual and has not been integrated into an airframe before:

“The performers are looking at using active flow control very early in the design scope. That’s the differentiating piece that hasn’t been done before…AFC has been explored at a component level, but not as an integral piece of aircraft design. By altering the design approach, CRANE seeks to maximize the chance of a successful X-plane development while also integrating AFC into the aircraft’s stability and control.”

So far, the CRANE project is in the very early stages of research. Three groups have been given awards to develop test AFC components, Aurora Flight Sciences, Lockheed Martin, and Georgia Tech Research Corporation.

Postscript

CRANE’s project manager stated that “active flow control technology has matured at the component level to the point where a potential leap forward in aircraft technology is possible.”

“We see an opportunity with CRANE to open up the future design space for both defense and civilian applications.” Stay tuned for further future developments.

Caleb Larson is a Defense Writer with The National Interest. He holds a Master of Public Policy and covers U.S. and Russian security, European defense issues, and German politics and culture.

This article first appeared in November 2020.

Image: Wikimedia Commons / NASA