planes, warning them by radio to leave their airspace. A photo taken by a JASDF pilot of one of the two Su-27s was released by the Japan Ministry of Defense. Russia denied the incursion, saying the jets were making routine flights near the disputed Kuril Islands. On 22 August 2013, two Russian Tupolev Tu-142 Bear-F maritime patrol aircraft entered Japanese airspace near the major southern island of Kyushu for less than two minutes. F-2 fighters were scrambled in response. Variants XF-2A: Single-seat prototypes. XF-2B: Two-seat prototypes. F-2A: Single-seat fighter version. F-2B: Two-seat training version. F-2A Super Kai: proposed variant with CFTs (conformal fuel tanks), based on the F-16C Block 60. It was intended to replace the F-4EJ Kai Phantom II. It was rejected when the F-35A Lightning II was chosen. Operators Japan Air Self-Defense Force As of March 2022, the JASDF operated 91 F-2. Air Defense Command Central Air Defense Force 7th Air Wing, Hyakuri Air Base 3rd Tactical Fighter Squadron (2001–present) Western Air Defense Force 8th Wing, Tsuiki Air Base 6th Tactical Fighter Squadron (2004–present) 8th Tactical Fighter Squadron (2008–present) Air Training Command 1st Technical School, Hamamatsu Air Base (2000–present) 4th Air Wing, Matsushima Air Base 21st Fighter Training Squadron (Reactivated) Air Development and Test Command Air Development and Test Wing, Gifu Air Base Accidents and incidents On 31 October 2007, an F-2B crashed during takeoff and subsequently caught fire at Nagoya Airfield in central Japan. The jet was being taken up on a test flight by Mitsubishi employees, after major maintenance and before being delivered to the JSDF. Both test pilots survived the incident with only minor injuries. It was eventually determined that improper wiring caused the crash. As a result of the 2011 Tōhoku earthquake and tsunami, 18 F-2Bs belonging to the 21st Fighter Squadron at Matsushima Air Base were damaged or destroyed. Of these 18, 5 were deemed beyond repair and have been scrapped. The remaining 13 F-2s are being repaired at the estimated cost of . In the meantime, training duties carried out by the 21st Fighter Squadron have been transferred to other air bases. Repair work was completed by 2016, when the 21st Squadron returned to Matsushima. On 20 February 2019, an F-2B crashed during a training flight over the Sea of Japan. Both the flight instructor and pilot survived the accident. In April 2021, two F-2 jets (an F-2A and an F-2B) reportedly