F-16 Fighting Falcon (Ukrainian: "Fighting Falcon")[comment. 1] is a single-engine light multirole fighter developed by General Dynamics for the US Air Force. Designed as a day fighter for air superiority, it evolved into an all-weather multi-role aircraft. Since production began in 1976, more than 4,600 aircraft have been built. Although the US Air Force no longer purchases this aircraft, improved versions are being produced for export customers. In 1993, General Dynamics sold its aircraft construction business to Lockheed Corporation (now Lockheed Martin). Due to its versatility and relatively low cost, the F-16 is successful in the international arms market, being in service with 24 countries. The F-16 is the most massive fighter of the fourth generation: as of 2009, more than 4,400 machines were built, in 2016, more than 2,500 were in service. The main features of the "Battle Falcon" are a frameless cockpit light for good visibility, a side joystick for easier control during maneuvering, an ejection seat that can be tilted 30 degrees from the vertical to reduce the impact of overloads on the pilot, and a fly-by- wire that helps stabilize flight control. For the first time, this system was installed on this particular aircraft.