Su-27 fighter (Russian: ????????? - 27, English: Sukhoi Su-27, Chinese: Su-27; NATO code name: flanker, Chinese: flanker) is a single seat, dual engine, all-weather air superiority heavy fighter developed by Sukhoi Design Bureau of the Soviet Union, and its main tasks are land air defense, escort, maritime patrol, etc. This aircraft adopts wing body fusion technology, hanging wall type middle single wing, with smooth curved forward extended strake wings outside the wing root, normal layout of double vertical tails, wedge-shaped inlet is located in the front and lower part of wing body fusion body, which has good aerodynamic performance. There are grid type auxiliary doors at the bottom and side wall of the inlet to prevent foreign matters from being inhaled during takeoff and landing. All metal semi-rigid shell fuselage, nose slightly sagging, a large number of titanium alloy, traditional three beam wing, four redundant fly by wire control system, no mechanical backup, static instability design