NASA isn't the only one with X-Planes. Japan is developing it's own experimental aircraft to test an airframe, engines, and other advanced systems and equipment for fifth-generation fighter aircraft for the country's self-defense forces. The project's primary contractor, Mitsubishi Heavy Industries, has conducted the successful maiden flight of the X-2 advanced technology demonstrator jet, the first Japanese-built warplane to incorporate stealth technology.

According to Mitsubishi, the X-2 prototype took off on April 22 from Nagoya Airport under the command of a company test pilot. After carrying out a series of basic flight maneuvers, such as climbing, descent, and circling, it landed at the Japan Air Self-Defense Force's Gifu Air Base, where the pilot described the flight as "extremely stable."

The X-2 project has been under development by a consortium of 220 Japanese companies under Japan's Acquisition, Technology & Logistics Agency (ATLA) for over 10 years, with Mitsubishi as the primary contractor developing the airframe since 2009.

According to the International Assessment and Strategy Center, the program is part of Japan's efforts to replace its aging military aircraft. Originally, the Japanese government wanted to buy US F-22s, but when Washington banned the export of the air supremacy fighter, Japan decided on a domestic replacement.

Janes says that the X-2 is a one-man aircraft with a length of 14.2 m (46.5 ft) and a wingspan of 9 m (30 ft). Powered by two IHI XF5-1 low-bypass turbofans punching 49.03 kN (11,023 lbf) of thrust, it has a maximum speed of Mach 2.25 (1,713 mph, 2,756 km/h), a range of 2,900 km (1,802 mi), and features advanced technology, such as a fly-by-light system that replaces wires with fiber optic cables.

"Control of the aircraft went exactly as in our simulated training sessions," says the test pilot. "And after piloting the aircraft, I'm 100 percent positive the X-2 is magnificent and will meet the Ministry of Defense's requirements."